The ACADEMY of NATURAL SCIENCES
of Philadelphia
FOUNDED 1812

Presented by

JOURNAL

OF

The Academy of Natural Sciences

PHILADELPHIA.

VOLUME IX. SECOND SERIES.

PHILADELPHIA:

PRINTED FOR THE ACADEMY.

1884-1895-

\

, A ^ ^

‘se'T,

CONTENTS.

PART I.

ART. I.—Urnatella gracilis, a Fresh-water Polyzoan. By Joseph Leidy, M. D. (Plate I) .

ART. II.— The Terrestrial Mollusca Inhabitieg the Society Islands. By Andrew J. Garrett.

(Plates II and III)‘' ^ f

ART. III. —The Tertiary Geology of the Eastern and Southern United States. y ro .

Angelo Heilprin. (Plate

PART II.

ART. IV. — On some New and Little Known Creodonts. By W. B. Scott. (Plates V, VI

and

art. V. — On the Structure and Classification of the Mesozoic Mammalia. By Henry Fair-
child Osborn. (Plates VIII and IX)**

155

186

PART III.

ART. V^I. — ^A Memoir Upon the Genus Palieosyops Liedy and Its Allies. By Charles Earle.

(Plates X, XI, XII, XIII and XI V)"

ART. VII. — A Study of the Fossil Avifauna of the Equus Beds of the Oregon Desert. By

R. W. Shufeldt, M.D. (Plates XV, XVI and XVII)’ 389

PART IV.

ART. VIII. — New and Little Known Palaeozoic and Mesozoic Fishes. By E. D. Cope. (Plates

XVIII, XIX and XX)** 427

ART. IX. — On Cyphornis, an Extinct Genus of Birds. By E. D. Cope.’* 449

ART. X. — Extinct Bovidre, Canidie and Felidae from Pleistocene of the Plains. By E. D.

Cope. (Plates XXI and XXII)”> 4511

ART. XI. — The Structure and Relationship of Ancodus. By W. B. Scott. ( Plates XXIII

and XXIV)” 461

ART. XII. — The Osteology of Hyienodon. By W. B. Scott.” 499

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JOURNAL .

OF

THE ACADEMY OF NATURAL SCIENCES

OF

PHILADELPHIA.

SECOND SERIES. VOL. IX.

PART 1.

PHILADELPHIA:

PRINTED FOR THE ACADEMY:

Kildare’s Printing House, 734 fc 736 Sarsoh St.

1884.

JOURNAL

OF THE

ACADEMY OF NATURAL SCIENCES

OF P H I L A D E P H I A.

URAATELLA GRACILIS, A FRESH -WATER POLYZOAN.

By Prof. Jo.sefii Leidy.

Upwards of thirty years ago, and on several snhsequent occasions, in the Pr«Kre<liiigs
of this Acadeniv (1851, 321; 1854, 191; 1858, 1; and 1870, 100), the writer has
briefly described or noticed an interesting fresh-water ciliated polyj., or pol>/<Nm, to
which the name of Urnatella gracilis was given. It was first chscovenal in the
Schuylkill River, under low-tide mark, below Fairmount dam, Philadelphia. It was
found in association with PhmateJla, PalndiceVa. and other animals common m such
positions. At the times of collecting it in 1854 and in 1870, it was in comparative
abundance in the locality, but lately appears to have become scarce, due to the
destnretive influence of the city scAvage which now flows ,so abundantly into the river
In similar places under flrvorablc circumstances, Urnntdhi is probably not ran-, though
incidentallv in the search of aquatic animals 1 have not found it elsi-when-. nor liaAc

of the drawings accompanying the present coramunication weie m. 1 Schuylkill

at the mouth of the neighboring canal. In the autumn of 18.6, ^ „r

River, below the city, by dredging, and I had the agreeable '‘"t'cip expectations for we hmiid Oie

together with other interesting animals. We were isapponi imbued with oil, derive*! from

sediment of the river, everywhere from the city to the mouth o the Schuylk U, imbued
the waste of the gas-works and oil refineries, so that no living thing could exist.

2 .JOUR. A. N. S. PHILA.,VOb. IX.

UUNA

tella gracilis, a fresh -water folyzoax.

I seen any published notice of its having been discovered by other observers.^ In o,u
instance, n.v friend Dr. Isaac Lea directed my attention to tlm shell ol a Ln^o, from
the Scioto River, Ohio, on whicli were several dried, but stdl charactenstic, specimens
of Urnatella. This fact not only indicates the existence of the polyp m the lallei eif
the Mississippi, but probably also a wide distribution of it throughout the country.

From the time I first saw Urnatella I felt it was of such interest as to be wortliy
of a thorough investigation, and this I resolved to undertake at a favorable oppor-
tunity. Otlier occupations, and the want of a ready supply of the neces.sary material,
liave prevented my intention, and I am now led to communicate what I have learned
of the animal, with the view that some of my younger countrymen and co-laborers,
under more fevorable circumstances, may be induced to do what I had liojied and
wished to do.

Urnatella is a most beautiful form, and quite peculiar among tlie known fresli-
wat3r polyzoa. In its relations it is most nearly allied to the marine genus Pedkellina,
typical of a small order of the polyzoa, and of the family Pedicellime.

Urnatella lives in positions and has habits similar to those of the iamiliar Pluma-
tella, species of which are found almost everywliere in fresh waters, from tlie little
rivulet to the largest lake. It is attached to fixed objects, commonly the under side
of stones, beneath which the water freely flows. In this manner it was rejieatedly
collected on stones, taken from the bed of the Schuylkill R,i\er, in association with
Plnmatella vexiev laris, Paludicella elmujata, Linmias sccialis. Hydra earnea, Sjxynyilla
fragilis, and several worms, such as Plauariu, Kmea ruhra, Clejisine, Manayiiid.-ia
sjieriosa, etc. In the same locality, in a few instances, I found it attached to shells ol’
Unin eonvplanatns and Melania viryinica ; and less frequentlv young spi'cimens were
observed on eel-grass, Vallisneria spiralis, and on Avater-star-grass, Scholhra yraminea.
Recently Mr. Edward Potts .submitted to me several specimens taken from a pu'ci'
of sunken wood from the c-anal at Fairmount.

As more commonly observed, Urnatella consists of a pair of stems pendant from
a common disk of attachment and terminating each in a single polyii-head or bell, or
in several little branches terminating in like manner, as seen in figures 1, 2, Plate 1.
The stems diverge, straight or in a gentle curve, are slightlv tapering, beaded in
appearance, alternately whitish or brownish Avhite and black. U.sually they are com-
posed of from two to a dozen segments, including the terminal polvp-bcdl and reach
from an oighth to „ sixth of an inoh in length. The largest s,,eein,ens oheerv,.d
consisted of eiglit™, .segments, ,vith a length of about the fonrtl, of an inch Tlie
Waded a,,, lean, nee of the ,,oly|.-ste,ns is due to the expansion with light coloring „f
the median portion of the segments, and the intermediate nariwing I'lnd hlack folor

ill rrrrT The stems may end alone in a single

po p-bell I, nt commonly in addition they have one or tivo pairs of lateral hninclu-s
rvith terminal bells, coming off fom the two segments of tl e main stem nex "o t

UKNATELLA GRACILIS, A FRESH-WATER FOLVZOAN.

7

terminal bell. Frequently also in like manner the primary brandies give oft s(‘condary
ones. See figures of Plats I, and also the accompanying woodcuts.

1. Young Urnatella, in which one stem con-
sists of a simple pedicel with a polyp-bell,
and the other stem is divided into two seg-
ments besides the polyp-bell.

\ '

'\ -
u

\

^

2. Young Urnatella, in which one stem
consists of two segments supimrting
the polyp-bell, and the other of three
segments with the polyp-bell. The
first segment of each stem has as-
sumed the uni-like form.

llarely, a branch, consisting of two or more segments, is given off, apparently witli
no regularity, from any other of the segments of the main stem tlian the usual ones,
as represented in figure 4, Plate T.

Sometimes the polyp-stock of UniateUa consists of a single stem arising from its
hast', and at others it may consist of a number up to half a dozen, starting from the

same disk of attachment. ,

The stems of Urnatella are highly flexible, but not contractile or capable of lieing
visibly shortened or narrowed, except perhaps in the case of the one or two segments
next the bell, which sometimes appear feebly contractile, especially in young s,H-«-imens.
In the usual condition the stems appear nearly straight, or slightly curxed, but after
intervals of ciuiescence they are observed spontaneously and rather abruptly to bi-nd
and twist, as if wearied from remaining so long in the same position. Not unfre-
quentlv the movement is quickly repeated before the polyps resume thmr tcm,H,rary
rest. Similar movements arc to be seen in the con.pnttively loi.R nn«.Bn,ento.l
petlioels of the .narine MiceHma. In UnmtM., the movement evteinis thro,.«ho..t
Ihe entire length of the segmentetl stem, and is by no means conhned to tl.c
terminal more flex, bio segn.cnts. ns n.igl.t be sn,, posed from „ view ol ‘ *

of Like the latter, Cemt* is exceedingly senstt.ve ; w.th > 'b

distnrbanec the tenta.les are qniekly .lonbled on themselves and .

mouth of the bell, which is then closed by contraction, and the »t, ,s s.ul, . nly
bowed outwardly, so that the heiul is brought to the ground, or when the stem long.

8

URNATELLA GRACILIS, A FRESH-WATER POLYZOAN.

as iu more mature specimens, it may become involute, as represented in figure 1

J ItlLL 1. 1 • 1 1 1

'I'he segments of the stem of Urnatella are chiefly urn-like in sliape and are nearly
uniform in size and other respects, except tire first one and the last two of the series
next tlie bell. The body of tlie urns forms the swollen, translucent, light-colored
portions of the segments,' and exhibits a more or less finely and transversely wrinkled
appearance, lined with brown in the same direction, and also spotted with bronn, or
often furnished with little tubercles of the same color. The neck and pedicels of the
urns conjoin one another in the different segments, and are black and opaque. The first
segment of the stem is likewise urn shaped, like those which usually .succeed it, but is
considerably larger, and its pedicel expands into a broad, circular or oval disk, which
tightly adheres to the stone on which tlie polyp is attached. Tlie two segnumts of the
stem of Urnatella, next the bell, are narrower, more cyiindroid, softer, more translucent
and more flexible than the others, and they are not abruptly contracted and blackened at
the extremities. The last segment, attached to the bell, is cylindrical or often clavate,
and colorless. The jireceding .segment is barrel-shaped, or intermediate in shape to
the former and the urns, and is colorless or slightly colored like the latter.

The ])olyp-stem of Urnatella is composed of an external homogeneous, tougli,
chitinous integument, transparent and colorless, or of a pale amber hue, except at the
constricted portions of the stem, where it appears black, and elsewhere, where it
api)ears lined and dotted with brown. It extends in a delicate layer uijon the terminal
.segments of the stem to the outside of the polyp-bell. The disk of attachment of th(‘
polyp-stems is mainly composed of an extension of the chitinous integunu-nt.

Within the more translucent portions of the .stems of Urnatella, a cylindrical cord
is seen extended throughout the axis, from the base of attachment to the polyp-hell.
It fills the narrower imrtions of the urn-like segments, and usually also the whole
of the .segment next the bell. In the wider portions of the stem a more transhicent
interval is occupied by indistinct and undetermined material. The axis cord of the
stem is superfic-ially finely striated in the length, and interiorly appears to be composed
of a granulated substance, as represented in figure 2, Plate I, where a portion is seen
extending from the end of the first segment of a stem.

Projecting usually from the opposite sides of the urn-like .segments of the stem of

bud'b., 171.7"°"' I ”i8i»nlly look,..! „p„n

matUT 1.1 P'O'i-g tl,e„. be e,.,p,y shell, of el.itin,,,.,

el,e,vl,e,e. sleti.ne, a 1 eatabl.si.ed ... the fon.,.lati„„ of ,-,>l„„ie,

and p,rely t,v„ 1 °°°“" °"‘»'

I apinar on „pix„.te side, of the san.e segment. Oeeasionallv

UKNATELLA GRACILIS, A FRESH-WATER I’OLY/OAN.

9

specimens are found in wliich, instead of one of the cups, a branch is givcm off, a«
represented in figure 4.

In the simplest condition Urnniella is observed as a ])olyp-hell attached to a simple
cylindrical pedicel, thus resembling the ordinary appearance of an individual P&Ueelliud.
Such a specimen is represented in figure 5, occurring in the usual way as a pair of
individuals springing from a common disk of attachment. Tlie simple pedicc'l is much
longer than the corresponding segment in the more divided stem of UnxifeJht, but is
otherwise of the same character. It appears as a solid column, translucent white, and
consists of an internal cord or axis, longitudinally striated and muscular in nature,
invested with a transparent chitinous integument. The pedicel is highly flexible,
spontaneously bends in all directions, but appears to bo feebly if at all contractile.

Other specimens of Urnatella were observed in which one or both pedicels, as in
those just described, were more or less distinctly divided each into two segments, as
rcpre.sented in woodcut 1, and in figarres 6, 7, of Plate I. The.se ('vid('ntly indicate
the origin of the segments of the stem of Urnatella through continued growth and
the process of successive division of the originally simple pedicel. Abundance of
specimens of Urnatella, occur rvith segments ranging from the smalk'st to the greatest
number, clearly indicating the successive production of the segments through the
process of division, very much in the same manner as in the production of the
proglottides of tape-worms from a scolex.

In the first r iew of Urnatella one might suppose that the st'gments of the stem
represented so many distinct polyps as in Pliimatelh(, but examination leads to tlie fact
that the terminal polyp is the only one of the series.

In the production and growth of the segmented stems of Urnatella, after the first
division of the original simple pedicel, which is a cylindrical column, the segments
distally from the latter and its polyp-bell, successively assume tlie char.icteristic urn-
like shape observed in the more matured specimens, and as repre.simted in figures 1.
2, 4, 8. In most matured specimens observed the stems rarely consisted of mon' than
a dozen segments, including the polyp-hell.

After the division of the simple pedicel of the young Urnatella into two or more
segments, the various specimens observed would appear to indicate that the one or
tw^o st'gments next the bell put forth buds in pairs laterally near the upper end or
base of the segments. These buds appearing as spheroidal or o>-oidal pro< es.ses then
develop and grow into branches, commonly consisting of a bell and pedicel like the
early parent. In like manner specimens go to show that secondary branches are
produced in a similar manner from the primary ones. AVoodcuts 3 and 4 repress nt
examples of such specimens just described.

From the usual mode of branching of Urnatella, that is to .sj.y. from the branches
coming off from the two segments of the stem next the polyp-hell, and from the nsnal
absence of branches from the succeeding urns, with the presenc.' ol the appanmt

10

UKNATELLA GRACILIS, A FRESH-WATER FOLYZOAN.

remains of brunches as empty cup-like processes, I Imve been led to suspect that the
brandies are spontaneously and habitually detached from the parent stem, to become
elsewhere attached, and thus form new colonies. The separation I have not actually
observed, nor have I had an opportunity of ascertaining if such is the fact, since the
suspicion occurred to me. The specimens which have come under observation, as
illustrated by the accompanying drawings, exhibit every step of the process, so as to
render the view at least probable. In further confirmation of it, I may add that in one
instance in which I placed a number of profusely branching specimens of Z^rnatella
in an aquarium, after a few days I noticed that they had been shorn of most of their
branches, but whether this was the natural healthy course in the life of the animal,
or due to unfavorable circumstances, I am not ready to decide.

y. Voung UrnntelUi, in which the two .segments
next the polyp-bell give off" buds and branches.

4. 1 oung Urnatella, giving off both primary and secondary
branches. Buds are also seen given from the latter.

llie ,,oIyp.|R..d, or |,olyp.boU, of UrmrieUa (see figure .3), which terminates tl.e
main stem im.l its bmnehes, when in active condition, appears as a hell-slmped laalv
with a widely expanded oval or nearly eireular month, directed obliquely to one side
m ven rally. The mouth of the hell is bordered by a broad waving band or colkr
i om the inside of which springs a eirole of tentacles. Of these there are iisuallv
sixteen though sometimes I have counted fourteen and twelve. They are cvlindiicai

musenlar in eharaeter, diverge on each side to ihe inner s^LI^f tlZumlmbi^;;;

speimn::":,^ ^

PP to be fuimshed with minute scattered tubercles.

rUNATELLA GRACILIS, A FRESH -WATER I’OLYZOAN.

11

'Ihe interior of the polyp-bell is mainly occupied by tlie alimentary apparatus,
riie mouth of the bell converges in a wide funnel-like manner to the pharyn.x, whicli
occupies the venti-al or shorter side of the bell. When the tentacles are retracted,
they are doubled on themselves and withdrawn into the funnel-like month of the hell,
and the collar marked with circular fibres contracts in a circular baud around them.
The mouth of the bell is lined with ciliated e])ithelium, and the cilia produce visible
currents convergent to the bottom of the funnel or pharynx. From the latter a
cylindrical tubular oesophagus is extended upwards along the shorter or ventral side
of the body, and turns dorsally to open into the stomach, 'fhe walls of the pharynx

Urnatella, with stem of four seg-
ments with polyp-head giving off a
branch, with a ]iair of secondary
branches.

0. PedicclUna, from NewiHtrt harlmr,
I?. I.

and irsoplinKUS nre formed of rhort columnar ciliated epithclinm. 'I hc inovcincnt-
of tlie cilia nre directed into the stomach. This is a capacious organ, rvliich nearly
occupies half the interior of the polyp-bell, arrd always appears more or less tilled
with liquid and solid materials, which are kept in incessant motion. The stomach n,
shape resembles a retort or still, with an alembic, and consists of a large oval tlnek-
walled receptacle with a conical prolongation or pylorus extended from the former
at its lower part downward on the dorsal or deeper side ol the body. lheu|qa.r
part of the stotnach is flattened, and is connected with the bottom of the po y,ebcl
L a sort of button, which ap,Kars to be a co.rtinnation of the nttenor
o? the sten, of the polvp. The lateral walls of the stomach are forme, I o tlnek
lu ttnar epithelium : the upper part and the sides of the pylorus of a much tlnnner

12 URNATKLLA eilACILIS. A PBESH-WATiill rOBYZOAN.

•Ai V flip vpntral wall is colored brown, and probably partakes

1" hepatic 3ion.‘'Tl,ro„gl.o..t, the stontach « furnished "'■‘'' ‘“S;
which keep the content, in incessant motion, whirling them from light
vo„, and then in the reverse course, and m.aintaiiiing the solid materials in the long
avis of the cavity. The contents of the stomacli, ordinarily seen, consist of an
elliptical mass occupying the pyloric cavity, with a tapering twisted prolongation
e.ytending into the main cavity. With this solid food, diaton.es, desn.ids, and other
vegetable organisms, may often be detected.

With the exception of the few specimens of Urnatella which were collected the
last antnmn, those of former collections were remarkable for being .almost invariably
infested with a ciliated infusorian, living in the stomach. Ihe infusorian, a species
of Anoplophrija, which I have described under the name of Leiicophri/s socialis, was
observed in variable numbers, sometimes few, at others in such a multitude as to fill
the main receptacle of the stomach. They congregate together in the central portion
of the latter, and together with the food are ke])t incessantly whirling around through
the ciliary action of the stomach, while they, at the same time, move spontaneously
among one anotlier in a swarming manner.

From the lower end of the pylorus, a short, tubular intestine descends, and turns
inwardly to ex])and in an elliptical pouch or colon. This occupies a position ohlicpiely
between the lower portion of the stomach, including the pylorus dorsally, and the
funnel of the polyp-bell ascending from the mouth to the pharynx. Its u])per
extremity is extended as a short tubular rectum, which terminates just 1k*1ow the
centre of the funnel converging to the pharynx.

I he walls of the intestine, including the colon and rectum, are composed of sliort
coluimiar cpitl.elium, and cxl.il.it no ciliary movements. The colon Is nsimllv oc. iii.icl
by an cll,pt.cal ,„..ss of excrement, which from time to time is snddcni;- expclh-d
tliiongh the short rectum and the month of the polyp-bell.

'fhe long, active cilia of the expanded tentacles of Urnafelh, give rise to a lively
crclar current the s,.r.o,.„di..g water, which brings particles of fed witl 1 ,hc
power of be po yp. The food, consisting mahtly of fegLblc matters is 1 cy„

Xn-ri't:.:: air-

ag'.s into the stomach. Here the acn.mi.Iat™ the u-sopl,.

maintained in position in tlio lonv axis of 1"* 1 '"T’

wi,™ the tentacles of

- of f„o.i i„ ,i,e

c.n.t.' of tl.e stomacli and in the i.harynx.

OS, and retracted
in the stoma

is still observable within the main

URNATELLA GRACILIS, A FRESH-WATER POLY/OAX.

13

In none of the specimens of Urnatella which have come under my observation,
have I been able to detect the slightest trace of organs of generation or ova. 1 ha\ e
further been unable to discover distinct elements of a nervous system. At times I
have thought I could obscurely distinguish the presence of a body in tlie interval
between the pharynx, stomach and colon, that I suspected to be a ganglion, but
obtained no definite view of it.

On the approach of winter, or under unfavorable circumstances, the polyp-bell of
Urnatella dies and disappears. During the winter the matured segmented stems
apparently continue alive and unchanged. It has occurred to me that the urn-like
segments of the stem serve as reproductive bodies, of the nature of tlie statoblasts of
Plumatella. Ordinarily they do not appear disposed to become isolated or separated
from one another ; at least I have never obser^'ed them in the latter condition.
Perhaps, as reproductive bodies, after the polyp-bells perish, they remain in conjunc-
tion securely anchored through the first of the scries, and are preserved during the
cold of winter, until under the favorable condition of spring, they put forth buds and
branches, which, by separation and settlement elsewhere, become the foundation of
new colonies. In apparent confirmation of this view, I have repeatedly met with
what appeared to be old stems and fragments of others, which had lo.st their poly{)-bells
and branches, and from some of the remaining segments had developed new polyi>-
bells. Such a specimen, collected late in September, 1882, is represented in figure 1).
Further, I have observed specimens of Urnatella, preserved in an acpiarium, after
losing their polj^p-bells in the autumn, remain in this condition all winter, and repro-
duce their polyp-bells the followhig spring.

Urnatella has the essential constitution of the marine ])olyzoan PedueUlna, and
clearly forms a genus of the same family. The polyp-bells an? alike in Ibrm and
constitution. The arrangement of the tentacles and the course and construction of
the alimentary canal, and the relative position of the oral and anal apertures, are
the same.

In Pedicellina, a creeping root-stock or stem is attached to fixed bodies and gives
off simple pedicels supporting each a polyp-bell. In Urnatella free seginenti'd steins
■suspended from a fixed point end in a polyp-bell, and give off branches corresimnding
with the polyp-bell and pedicel of Pedicellina.

In another genus of the family, recently described by the Rev. T. llincks under
the name of Barentsia, the polyp-bells are like those of Pedicellina, but are supported
on pedicels, which arise from an erect and undivided chitinous stem with a bullious
base.

The only known remaining genus of the family is Loxosoma, of which then* an*
a number of species, remarkable generally from their living as parasites on marine
worms. The species, too, are further remarkable I'rom their occurring as isolat<*d or
single individuals, corresponding with the polyp-bell and pedicel of the other genera.

3 JOUR. A. N. S. PHILA., VOL. IX.

14 UllNATELLA GRACILIS, A FRESH-WATER POLIZOAN.

In this genxxs the polyp-bells put forth buds which develop into polyps like the
parent; and the young polyps then spontaneously separate to attach themselves to
other objects, just as we have reason to suppose is the case with the young ot
Urnatella.

The polyzoa of the family of Pedicellince, thus far described, are as follows :
PEDICELLINA.

1. PEDICELLINA CERNUA. , tit •

Smitt: dfvers. Vetens. Akad. Fdrhand., Stockholm, 1811, 1132. Hineks : British Marine
Polyzoa, 1850, 505.

BracMonus cernuus. Pallas: Natiirges. merkw. Thiere, 1178, 57, Tab. It , fig. 10.

PedicelUna echinata. Sars : Beskr. og lagttag., 1835, 5, Tab. I, fig. 1. Hassall : An. Xat.
Hist., 1841, 365. Johnston : British ZooplyTes, 1847, 382, PI. LXX,fig. 5. Xitsche : Zeits.
wis. ZooL, 1870, 13, Taf. 2, 3. Barrois : Rech. sur PEmbryol. d. Bryozoaires, 1877, 27, PI. II.
Xoc«Z%.— Shores of Norway, Spitzbergen, Heligoland, White Sea, Great Britain,
France and Sicily.

2. PEDICELLINA GRACILIS.

Sars: Boskriv. og lagttag., 1835, 6, Tab. I, fig. 2. Smitt: Ofvers. t etens. Ak. Fdrli.,
Stockholm, 1850, 1133. Hineks : British Marine Polyzoa, 1850, 570, PI. LXXXI, figs. 4-C.
Ijocality. — Norway, Spitzbergen, White Sea, Roscoff, Great Britain.

3. PEDICELLINA BELGICA.

P. J. Van Beneden : Mem. Acad. d. Sc. de Bruxelles, 1845, 23, PI. I, II.

Locality. — O.stende, Belgium.

4. PEDICELLINA NUTANS.

Dalyell: Remarkable Animals of Scotland, ii, 1848, 63, PI. XX. Hineks: British Marine
Polyzoa, 1880, 507.

Locality. — Scotland ; Tenby.

5. PEDICELLINA AUSTRALIS.

Ridley: Proc. Zool. Soc., 1881, GO, PI. VI, fig. 8.
PedicelUna n. s.? Studer: Archiv f. Naturges., 1870, 124.
Probably not different from the succeeding species.
ZocaZi///.— Straits of Magellan; Kerguelen Land.

6. PEDICELLINA AMERICANA.

• Leidy: Jour. Acad. Nat. Sc., 1855, 11, PI. X, fig. 25. Verrill : Rep. of the Sea Fisheries of
1871, 2, Washington, 1873, 405, 707. Ryder : Rep. of Com. of Fish, of Maryland, 1881, 34.
Zoca%.— Point Judith, Rhode Island ; Chesapeake Bay, Md.

7. PEDICELLINA.

A„,o„g „,„c note I n„d tho following d„„riptio. and acoompanj-ing .ketch of a specie, of
M.cellwa, (.voodent C), apparently dWe.ent from the preceding. The specimen was obtained in

bewpoit harbor, Jr. I., from a depth of twenty fathoms, in .Tilly IS.hh Polvn atocl-

jointel root, sending off .tern, ...pportlng single polyp-bells, fro; one to thrive liny, sS

URXATELLA GRACILIS, A FRESII-WATER POLYZOAN.

15

Polyps exceecliiiglj' sensitive, on the slightest disturbance closing their hell and lK)wing the
highlj^ flexible muscular steins, which often become more or less revolute. The species nearly
resembles P. gracilis, and may be the same. It has no median dilatation to the stem, and this is
long and slender, and even becomes revolute when the animal is disturbed, while in P. gracilis it
appears simply to bend downward from the base.

BARENTSIA.

Barentsia bulbosa.

Hincks : An. Nat. Hist., 1880, 285, PI. XV, figs. 12-14. Urban : Ibidem, 27C.

Locality. — Barent’s Sea.

URNATELLA.

Urnatella gracilis.

Leidy : Proc. Ac. Nat. Sc., 1851, 321 ; 1854, 191 ; 1858, 1 ; 1810, 100. Allman : Fresh-water
Polyzoa, 1856, 117.

! Urnahella “ d’eau douce de PAustralie.” Salensky : An. Sc. Nat., 1877, 47.

Locality. — Scliuylkill River, Philadelphia ; Scioto River, Ohio.

LOXOSOMA.

Keferstein, 1863.

Strephenterus, 1861. Norman. Described by the author as an echinoderm, but as he subsc-
quentlj" (recognizing the true position of the animal on which the genus was founded), adopted
the later name, with other authors, I have followed him.

1. Loxosoma singularb.

Keferstein : Zeits. was. ZooL, 1863, 131, Taf. XI, fig. 20. Claparede : Beob. u. Anat. u. Entw.
wirb. Thiere Normandie, 1863, 105, Taf. II, figs. 6-10. Schmidt : Arch. mikr. Anat., 1876, 3.
Barrois : Embryol. d. Bryoz., 1877, 9, 10, PI. I, XVI, fig. 6. Hincks : British Marine Polyzoa,
1880, 573, PI. 81, fig. 78. Norman: An. Nat. Hist., 1879, 137. Urban: Ibid., 1880,270.

Locality. — St. Vaast-la-PIogue, Normandy ; Shetland Islands; Barent’s Sea.

2. Loxosoma neopolitanum.

Kowalewsky : Mem. Acad. Sciences, St. Petersbourg, 1866. Norman : An. Nat. Hist., 1879, 137.

Locality. — Bay of Naples.

3. Loxosoma kefersteinii.

Claparede : An. Sc. Nat., 1867, 28, PI. VI, figs. 1-3 ; Zeits. f. wis. Zook, 1870, 34, Taf. XI, fig. 4.
Nitsche: Ibid., 1875, 451; Supplem., 361, Taf. XXV, figs. 4-20, Taf. XXVI, figs. 7-13.
Norman : An. Nat. Hist., 1879, 137.

Locality. — Bay of Naples.

4. Loxosoma claviger.

Strephenterus claviger. Norman : An. Nat. Hist., 1861, 112, PI. IX, figs. 1-4.

Loxosoma phascolosomatum. Vogt: Arch. Zool. Exp., 1876, 305, PI. XI, XII. Barrois;
Embiyol. Bryozoaires, 1877, 8, PI. XVI, figs. 3, 4. Norman: An. Nat. Hist., 1879, 133,
137. Hincks: British Marine Polyzoa, 1880, 574.

Locality. — Roscoff; Bantry Bay, Ireland.

5. Loxosoma cochlear.

Schmidt: Arch. mikr. Anat., 1876, 3 ; Zeits. f. wis. Zool., 1878, 69. Norman: An. Nat. Hist.,
1879, 137.

Barrois views it as the same with L. neapolitanum.

Locality. — Bay of Naples.

IG

UIWATELLA GRACILIS, A FBESH-WATEK ROLVZOAX.

6. Loxosoma eaja.

Schmidt: Arch. mikr. Anat., 1876, 3, Taf. I,
An. Nat. Hist., 1879, 137.

fig. 1 ; Zeits. f. wis. Zool., 1878, 71.

Locality. — Naples.

Norman :

7. Loxosoma alata.

Barrois: Embryologie Bryozoaires, 1877,9.

L. pes = L. singulare. Schmidt : Zeits. wis. Zool., 1878, 69, 70.
1879, 137.

Locality. — N aples.

Norman: An. Nat. Hist.,

8. Loxosoma crassicauda. . x- »

Salensky : An. Sc. xNat., 1877. Schmidt : Zeits. f. wis. Zool., 1878, 71. Norman : An. Nat.

Hist., 1879, 137.

Locality. — Bay of Naples.

9. Loxosoma tethy^.

Salensky: An. Sc. Nat., 1877. Schmidt: Zeits. f. wis. Zool., 1878, 71. Norman : An. Nat.

Hist., 1879, 137.

Locality. — Bay of Naples.

10. Loxosoma claviforme.

Hincks: British Marine Polyzoa, 1880, 575, PI. 81, figs. 9-12.

Jjxality. — Guernsey Island, English Channel.

Plate I.

Fio. 3.
Fia. 4.

Fig. 5
Fig. 6

Fig. 7.

Fig. 8.
Fig. 9.

EXPLANATION OF THE FIGURES OF URNATELLA GRACILIS.

. Incurved appearance of the stem and closed condition of the polyip-bells, as the position
assumed by Urnatella when disturbed. The main stem represented consists of eleven
segments, including the polyp-bell. The other stem consisted of nine segments, including
the pol3'p-bell. 75 diameters.

!. Appear.ance of 17rna<eZ7a fully extended. The main stem of a dozen segments, including
the polyp-bell. The first segment of the second stem represented with the molecular
structure of the central cord projecting. 75 diameters.

Polyp-bell of Urnatella, with the succeeding segment. 166 diameters.

Specimen in which a brancli of six segments is given from the second segment of the
main stem, consisting of eleven segments. The other main stem, of ten segments, likewise
gave off a brancli which consisted of five segments. 40 diameters.

. '1 oung Urnatella ; each stem consisting of a polyp-bell and simple pedicel. 75 diameters.
. A oung Urnatella; m which one stem has a simple pedicel, and in the other it has under-
gone division into two segments. 75 diameters.

A'oung Urnatella, m which both stems are divided into two segments. One stem extended
with the polyp-bell expanded ; the succeeding segment with a bud. The other stem bowed
and tlie polyp-bell closed, the position assumed when the poly)i is disturbed. 75 diameters.

Lrnatella, with the two stems each of five segments, including the polyp-bell. Polyp at
rest, the stems bowed .and bells closed. 55 di.ameters.

,>oi'vXT‘ « „e,v brnnol,, con.Uting of a

polj ibbcll with Its pedicel. Prom the latter a hud has put forth. 60 diameters

[ n ]

THE TERRESTRIAL MOLLHSCA INHABITING THE SOCIETY ISLANDS.

By Andrew Garrett.

The Society Islands, which are the largest and most important group in southeastern
Polynesia, comprise eight islands of volcanic origin and two of coral formation.
Seven only, i. e., Tahiti, Moorea, Huaheine, Eaiatca, Tahaa, Borahora and Maupiti,
have each one or more species peculiar to it or not found elsewhcri'.

Tahiti, the largest island in the group, is about thirty-eight miles long and twenty-
three wide. It may be described as two islands of very imequal size connech'd by a
low narrow isthmus. Moorea, which is eight miles west of Tahiti, is about nine miles
long and six wide. Huaheine is seventy-two miles W. N. W. of Moorea and is about
the same size as the latter island. Raiatea is twenty miles west of Huaheine and is
about fourteen miles long and seven wide. Tahaa, which is about the siime size as
Huaheine, is two miles north of Raiatea and inclosed in the same encircling reef with
the latter island. Borabora is about half the size of Huaheine and situated nine miles
northwest of Tahaa. Maupiti, which is smaller than Borahora, is about twenty-three
miles west of that island.

The earliest recorded Society Island land .shells are Limax faha (= Partula /<tbn),
Martyn, and BiiUmus Otalieitanus (= Partula OlaJieitann), Brugnicre, which were
published nearly a century ago. These two species were discovered when the islands
were visited by Capt. Cook in his second or third voyage. From that early period up
to 1819, when Ferussac recorded IMix trochiformis in his “Prodrome,” no .s])ecics.
so far as I can learn, were published. In 1825, Dr. Gray added llelicuta Maugeri<r
to the list. In 1830, M. Lesson (Voy. Coquille) described Auncuhi viola, Partula
lutea, Helicina miniata and Partula lineata, all Borahora shells, except the last, which
inhabits Moorea, but was erroneously assigned to one of the Caroline Islands. In
1832, MM. Quoy and Gaimard oy. de I’Astrolabe) described an elongate dextral
variety of Partula Otaheitana under the name of IMix Yaniuoreuais, and wrongly
accredited it to Yanicoro in Melanesia.

The islands were next partially explored by that prince ol collectors, Mr. H.
Cuming, who discovered many new species which were described by Brodcrip, Ih’cvc
and Pfeitfer. But, unfortunately, he was so very careless in regard to the pn-cise
habitats of his shells that about two-thirds of the localities recorded on his authority

18

terrestiual molltjsca inhabiting society

ISLANDS.

.synonymous species. Several years axucx ^ number of new

States Exploring Expedition, commanded by Capt. Wilkes, collected a number ol ne

species, all of small size, wliicli were described by Dr. Gould in t le “
the lioston Society of Natural Hletory and subeoquoutly

and hgurod in tlio official work, “Mollusca and .Sliclls.” In 1864, MM. Ilomb.on .u d
Jacquinot (Voy. Pol Sud), described two new species and added a spronym to
Gould’s nelix CrMa, two to Pfeiffer’s Helix eoarctata, and one to Goidd^^s HeUx
hursatella. In 1867, Johann Zelebor, one of the naturalists of the “>ovara
expedition round the world in 1857 to 1859, described Piqm hyalina (= Vertigo
pediculns). Pupa Dunlceri (= Vertigo tantilla), and Hydrocena Scherzeri, all found on
Taliiti ; tlie last probably equals one of the extreme forms of the variable Omphalo-
tropis 8citula.

During the years 1860 to 1863, I made a much more thorough exploration than
any of my predecessors, and, by searching in nearly every valley in the group, dis-
covered over 50 new species. Most of these were described by the late Mr. . 11.
I’ease in the “ Proceedings of the Zoological Society,” and in the “American Journal
of Conchology.” The other species with his MS. names have been freely distributed,
and tlie majority recorded in catalogues. All of these are for the first time described
in the following pages. Since my residence in the group, from 1870 up to tlie present
time, I have continued my researches, and added 19 new species to the list, one of
which, Partula acuticosta, Mousson, MS., is recorded in “Museum. Godeffroy Catal., v,”
and one, Parhda Mooreana, Hartman, is described in the “ Proceedings of the
Academy of Natural Sciences of Philadelphia.”

Genus MICROCYSTIS, Beck.

I restrict this genus to a group of small Helices, Avhich are characterized by their
orbicular, more or less depressed form, rounded, angulate or subangulatc periphery,
and smooth, shining surface. The umbilicus, though usually closed, is occasionally
minutely perforated, llic peristome is straight and sharp, with remote margins.
The columella is simple, or callous, and frequently armed with a nodule or slightly
t\\ isted plait. In color they vary from whitish corneous, through all the intermediate
tints, to fulvous ; rarely ornamented with bands and spots. One species only exhibits
a sculptured surface.

They are widely diffused throughout Polynesia, ranging from the lowlands near
the seashore to several thousand feet above sea-level. A majority of the species are
strictly terrestrial, and delight in moist stations, hiding beneath decaying leaves, under
rotten ivood and among loose stones. Others are entirely arboreal, on the foliage of
shrubs and ferns. A number of the species are gregarious.

TERRESTRIAL MOLLUSC A INHABITING SOCIETY ISLANDS.

19

M. VERTiciLLATA, Pease. Plate II, figs. 31, 31 a, 31 h.

Nanina verticillata, Pease, Amer. Jour. Conch., 1867, p. 228.

Helix verticillata, Pfeiffer, Mon. Hel., vii, p. 66.

Helicopsis verticillata, Pease, Proc. Zool. Soc., 1871, p. 475.

Nanina cicercula, var. “ Mousson,” Schmeltz, Cat. Mus. Godeff., v, p. 91.

Helix brunnea, Carpenter (Anton?), Proc. Zool. Soc., 1864, p. 675.

I found this species very abundant beneath moist rotten wood and amongst
decaying leaves, on the north part of Moorea, and more rarely at Iluahcine.

It is about the size and shape of M. cicercAila, Gould, a Sandwich Island spc'cies.
but differs in liaving a rounded periphery and more convex whorls. I'lie Iluahcine
shells are a little larger and darker colored than Moorea specimens. The former
have the inner edge of the columella simply thickened with callus, and in the lattei
the callus is frequently developed into a slight tubercle or somewhat tu isted plait.
My largest examples are 7 mill, in diameter.

M. SIMILLTMA, Pease. Plate II, figs. 32, 32 a, 326.

Helix simillima, Pease, Proc. Zool. Soc., 1864, p. 669. Pfeiffer, Mon. Ilel., v, p. 50.
Helicopsis simillima, Pease, Proc. Zool. Soc., 1871, p. 475.

Nanina simillima, Schmeltz, Cat. Mus. Godeff., v, p. 207.

A somewhat rare species, peculiar to Eaiatea, where it occurs high up in the
mountain ravines, and is found beneath moist decaying leaves and under rotten wood.

]Mr. Pease, who received his type specimens from me, correctly labeled as regards
locality, gave the vague habitat “ Central Pacific,” and subsequently “Tahiti,” where
it does not occur. His brief diagnosis is not very satisfiictory. I add the following
description : —

Shell orbicular, depressed, thin, smooth, shining, pellucid, fiiintly striated, yellowish
corneous; spire slightly elevated, convex, apex obtuse; suture faintly inijiressed,
narrowly margined; whorls 3i-4, flatly convex, regularly and rather rapidly increasing,
the last one not descending in front, depressed, periphery rounded ; base flatly convex
and deeply indented at the axis; aperture ovately lunate, nearly vertical; peristome
thin, straight, regularly curved, with remote margins and simple columella.

Major diam. 10, height mill.

Its large size, depressed form, and rather rapidly increasing whorls, will readily
distinguish it from any other South Polynesian species.

M. NOBMALis, Pease. Plate II, tigs. 33, 33 a, 336.

Helix normalis. Pease, Proc. Zool. Soc., 1864, p. 669. Pfeiffer, IMon. Ilel., v, p. 59.
Helicopsis normalis, Pease, Proc. Zool. Soc., 1871, p. 475.

Nanina normalis, Schmeltz, Cat. Mus. Godeff., v, p. 91.

Very abundant beneath rotten tvood at Tahiti, Moorea and Iluahcine. I add the
following characters omitted by Mr. Pease in his short description .

It varies in the height of the spire, the apex is obtuse, and the suture is margined

20 'fERKESTlilAL MOLLUSOA INHABITING SOCIETY ISLANDS.

by tlic gno periphery-kecl. Tl.e beautiful oblique striiO are congnecl to tl.o upper surface,
tbe lower being smooth and more glossy. The axis is more or less dtstmctly punctate.
The sliL'htlv oblique aperture is angulate-lunate.

Tlie crmvded, regular, raised strife and delicate filiform keel will at once distin-
guish it.

M. DiscordIsE, Garrett. Plate II, figs. 35, 35 a, 35 b.

Microcystis Discordise, Garrett, Jour. Phil. Acad. Nat. Sci., 1881, p. 383.

Nanina subtilis, Schmeltz (not of Anton), Cat. Mus. Godeff., v, p. 91.

Abundant under damp rotten wood, and ranges throughout the group. It is
equally as common at the Cook’s or Harvey Islands. A few specimens were taken by
me at the Marquesas group.

A small, fragile species, about the size of normalis, with a more or less distinctly
aiigulate body-whorl, smooth upper surface and lighter colored than the latter.

M. CULTR.ATA, Goulcl.

Helix cultrata, Gould, Proc. Post. Soc. Nat. Hist., 1846, p. 172; Expl. Ex. Shells, p. 46, fig.

59. Pfeiffer, Mon. Hel., i, p. 37 ; {JErepta) Vers., p. 128.

Sagda cultrata (Gastrodon), H. and A. Adams, Gen. Moll., ii, p. 113.

Xanina cultrata, Gray, Cat. Pulm., p. 130. (Microcystis) Albers, Ilel., p. 49. Bland &
Binney, Anier. Jour. Conch., 1871, p. 189 (dentition).
llelicopsis cultrata, Pease, Proc. Zool. Soc., 1871, p. 475.

In 1862, I found examples of this species amongst decaying vegetation in Taliiti,
but cannot state the precise locality.

It is a depressed, orbicular, very shining species, 6 mill, in diameter, with five
whorls, the last one carinated and the columella dentated.

.AI. ANGUSTIVOLUTA, G.arrett. Plate II, figs. 34, 34 a, 84 b.

Sliell small, orbicular, depressed, imperforate, thin, smooth, shining, pale amber-
color, with or without small, irregular opaque-white spots ; spire convex, apex
depressed; suture laintly impressed, narrowly margined; tvhorls 5|-6, subplaniform,
narrow, slowly and regularly increasing, last one dej)ressed, not descending in front,
periphery subangulate ; base flatly convex, deeply indented at the axis ; aperture
nearly veitical, ver\ narrow, luniform, much wider than deep; peristome thin, simple,
witli very remote margins ; columella small, very oblique.

jSIajor diam. 4|, lesser diam. 4, height 2^ mill.

Hah. — Moorea Island.

A few examples were found under damp rotten wood on the northeast part of the
island.

Its most obvious characters are its depressed form, numerous, narrow whorls sub-
angulate periphery, narrow aperture and indented base.

TERRESTRIAL MOLLTTSCA INHABITING SOCIETY ISLANDS.

21

M. scALPTA, Garrett. Plate II, figs. 30, 30 a, 30 b.

Shell imperforate, orbicular, depressed, thin, smooth, subpellucid, very glossy;
fulvous, minutely dotted and irregularly lineated with whitish radiating lines ; spire
convex, moderately elevated ; suture rather faintly impressed ; whorls five, flatly
convex, moderately increasing, last one rounded, not deflected in front ; base convex,
indented at the axis ; aperture nearly vertical, orbicular-lunate ; peristome straight,
thin, regularly curved, margins remote ; columellar region thickened with callus.

Major diam'. 10, height 6 mill.

Hah. — Tahaa Island.

This fine species occurs plentifully in a small area in Ilaamene valley on the east
of Tahaa. They were gregarious beneath stones, rotten wood, and under heaps of
decaying leaves. Not a single example taken in any other part of the island or group.

It is the same size as simllliina, but may be distinguished by its more solid texture,
darker color, more elevated spire, deeper body-whorl, more rounded ap(uture, and the
whorls are flatter and more tightly coiled. The peculiar pale markings which
suggested the specific name appear very much like scratches on the surface of the
shell.

Genus TROCHONANINA, Mousson.

In 1869, Prof. Mousson established the genus or subgenus Trochonanina (Jour, de
Conch., p. 329), for the reception of the Polynesian trochiform or conical Nanime, the
type of which is N. ^JimeUziana. Mr. Pease injudiciously classed it witli Trocho-
morpha, and Helix conula, Pse., which is precisely the same type he places in the
genus Helicopsis = Microcystis.

I fully share Mousson’s views in regard to the propriety of eliminating this group
from the typical Microcystis. They differ from the latter genus in the more or less
elevated-conical or trochiform shape, angidated or filocarinate periphery, closed or
perforated base, and subrhomboidal luniform aperture. Like the preceding genus, the
columella is either simple, nodulous or spirally plaited. The base is always smooth
and shining; the superior surface is rougher, the strice more decided and regular,
sometimes rib-like, and frequently with fine spiral raised lines.

They possess the habits of Microcystis, and, except the Sandwich Islands, where
they appear to be absent, have nearly the same distidbutiou.

T. CONULA, Pease. Plate II, figs. 30, 36 o, 36 h.

Helix conula, Pease, Proc. Zool. Soc., 1861, p. 243. Pfeiffer, Mon. Hel., v, p. 62.

Helicopsis conula. Pease, Proc. Zool. Soc., 1871, p. 475.

Nanina Tongana, Schmeltz (not of Qiioj' and Gainiard), Cat. Mus. Godeff., v, p. 01 (“sec
Mousson

Microcystis conula, Garrett, Jour. Acad. Nat. Sci. Pliila., 1881, p. 383.

Rather plentiful ou the foliage of low bushes and common to all the islands. It
occurs, also, at Rarotonga, one of the Cook’s or Harvey Islands.

4

JOUE. A. N. S. PHILA.,VOL. IX.

22 tebrkstkial mollusca inhabiting society islands.

I„ trochifoon shape, acutely angular body, and conspicuous peculiar colmncllnr
plait, will determine it.

“Tii ITic.!’;" s;!!^!, p. CCS. Pfcnsr, Mo„. He,., v, p. 86.

Trochomorpha obconica, Pease, Proc. Zool. Soc., 1871, p. 475.

Nanina obconica, Schmeltz, Cat. Mus. Godeff., v, p. 207.

This species is peculiar to Raiatea, where it is very local and somewhat rare. It

occurs in the higher portions of two valleys, one on the east and the otlier on le

west side of the island. _ .

Its mo.st essential characters are its depressed-trochoid form, acute carination, sma
but pervious umbilicus, and fine crowded striae. My largest example is 8 mill, in
diameter.

T. CALCUI/O.SA, Gould.

Helix calculosa, Gould, Expl. Ex. Shells, p. 48, PI. V, fig. 63. Pfeiffer, Mon. Ilel., iii, p. 41.

Zonites (Conulus) calculosus, H. and A. Adam.s, Gen. Moll., ii, p. 116.

Nanina calculosa, Gray, Cat. Pulm., p. 126. Schmeltz, Cat. Mus. Godeff., v, p. 91.

Nanina {Trochomorpha) calculosa, Albers, Hel., p. 60.

Not uncommon on foliage and is diffused throughout the group, ranging from the
lowlands near the seashore to about 1 000 feet above sea-level. I also obtained many
examples on Dominique, one of the Marquesas Islands, and a few at INIalolo, one of the
Viti group. Its exi.stence in the latter location is the more remarkable as it has not
been observed on any of the intermediate islands.

My largest exam])les, wliich are 4| mill, in diam., and a trifle less in height, are
larger tlian Gould’s specimens. It may readily be distinguished by its globose-
pyramidal form, angulate body-whorl and oblique aperture. The umbilicus, though
generally clo.sed, is sometimes punctiform, and the columella reflexed.

It is not included in INIr. Pease’s List of Poljmesian Land Shells.

T. SUBRUGOSA, Garrett. Plate II, figs. 38, 38 a, 38 b, 38 c, 38 d.

Shell small, imperforate, globose-conic, thin, subpellucid, fulvous ; upper surface
with crowded, slightly oblique, plicate strise ; spire depressed-conic, apex planulate ;
suture linearly impressed ; base convex, smooth, glossy, indented at the axis ; whorls
4-4i, strongly convex, slowly and regularly increasing, last one narrow, rounded, not
descending in front, periphery with a thread-like keel; aperture slightlv oblique,
transversely ovate-luniform ; peristome thin, simple, regularly curved, with remote’
margins ; columella slightly thickened with callus.

Major^^diam. 2^, height 2 mill.

IlaJ). — Tahiti and Moorea.

Tim small Bcdptmcd siKcies is somewhat rare. It was fomd under stones on the
northwest side of lahiti, at an elevation of about 1000 feet. A few examples were

TERRESTRIAL MOLLUSCA IjSrHABITi:N'G SOCIETY ISLANDS.

23

taken in a large valley on the north side of Moorea, bnt at a much less elevation
above sea-level.

Its most important characters are its globose-conic form, rib-like striic, dark color,
smooth base and delicate periphery-keel. It cannot be confounded with any other
Polynesian species.

T. Tahitensts, Garrett. Plate II, figs. 39, 39 a, 39 h, 39 c.

Shell small, subperforated, depressed-turbinate, thin, subpellucid, above with tine,
sharp, crowded, oblique, elevated striae, fidvous corneous ; spire dome-shaped, smooth
and rounded at the apex; suture moderately impressed, margined above by the
continuation of the periphery-keel ; base depressly convex, smooth, glossy, perforation
punctiform, not deep ; whorls four and a half, flatly convex, regularlv increasing,
last one narrow, not deflected in front, periphery with a prominent thread-like keel ;
aperture slightly oblique, ovate-lunate ; peristome straight, acute, with distant margins ;
columella with a large, white, tubercular nodule.

Major diam. 2|, height 2 mill.

Hub. — Tahiti.

This, the smallest species inhabiting the group, was found adhering to the under
side of loose stones at an altitude of 2000 feet, on the northw'est side of Tahiti.

It is nearly the shape of suhrngosa, but is more rare, smaller, whorls flatti*r, spire
more regularly dome-shaped, striae much finer, and the conspicuous columellar nodule
will at once distinguish it.

Genus ZONITES, jMontfort.

Z. Mookeana, Garrett. Plate II, figs. 28, 28 a, 28 h.

Shell small, perforated, orbicular, depressed, thin, pellucid, shining, faintly striah'd,
whitish corneous ; spire convexly elevated ; suture faintly impressed, narrou ly mar-
gined; whorls four, slightly,^convex, regularly and moderately increasing, last one
somewhat depressed, not descending in front, rounded on the perii)liery ; bas('
depressly convex, deeply indented at the axis, which exhibits a small perforation ;
aperture subvertical, orbicnlar-luniform ; peristome acute, straiglit, roundly curved,
margins distant ; columella simple.

Major diam. 4, height 2| mill.

Of this small species I have five examples before me, all found associated with
M. verticillata at Moorea.

It can scarcely be ^distinguished from Vitiensis, except in being smaller, more
polished, paler and the strise smoother.

Genus TROCHOMORPHA, Albers.^

So far as I can ascertain, the Society Islands are the only group in Eastern Polynesia
inhabited by the above genus. Dr. Pfeiffer, on the authority of Anton, cites Opara
= Rapa as one of the localities of T. trcchiformis. If the genus occurs on that

24 terrestrial mollusca inhabiting society islands.

smnll island which I very much doubt, the species is distinct from the Society Island
she'll!. Mr.’ Gloyne, in his very valuable paper on the “ Geographical Distribution of
Terrestrial Mollusca ” (Quar. Jour. Conch., i, p. 315), erroneously assigns three species
of Tro,J.<ymorpha to the Cook’s Islands, where tlie genus does no occur He is also
wroim in referring the genera Palaina, Gychmorpha and djdophorns to that group.

In the Society Islands all the Trochomorplne are peculiar to the group, and occui
on all the islands except Borabora and Maiipiti. Having personally collected severa
thousand specimens at the five islands inhabited by the genus, and after a thorough
study and critical comparison with numerous species from the various islands in the
Western Pacific, I do not hesitate to assign five species to the group. One restricted
to Tahiti, one to Hiiaheine, two common to Raiatea and Tahaa, and one common to
Tahiti and Moorea.

T. TROciiiFORMis, Ferussac.

Helix trochiformis (Hellicella), Ferussac, Prod., p. 301. Pfeifler, Symb., ii, p. 40; Mon.
Hel., 1, p. 206. Chemnitz, ed. 2d, No. 68, p. 13, figs. 1, 8. Gould, Expl. Ex. Shells, p. 61
(part). Reeve, Conch. Icon., No. 606, PI. CYIII, fig. 606.

Trocliomorpha trochiformis, Albers, Die Ilel., p. 116. Pfeiffer, Yers., p. 133. Pease, Jour,
de Conch., 1811, p. 398; Proc. Zool. Soc., 1811, pp. 456, 414.

Zonites trochiformis {Trochomorpha), H. and A. Adams, Gen. Moll., ii, p. 115.

Nanina trochiformis ( Trocliomorpha), Albers, Die Hel., ed. 2d, p. 60. (Discus) Paetel, Cat.
Conch., p. 85.

This very variable species lives on the trunks of trees and is restricted to Raiatea
and 'I’ahaa. Dr. Pfeiffer, on the authority of Anton, erroneously cites Tahiti and
Opara = Rapa as its habitat. It is scarcely necessary to add that Fcrussac’s locality,
“ Isle de France,” is also erroneous.

It is subject to more variation than any other known species. The usual proportion
of height to the greatest diameter is 10 by 16, and the extreme variation 12 by 14
and 9 by 14 mill. The umbilicus is deep and narrow. M^horls six, convex, conspicu-
ously margined, last one with a compressed periphery-keel. Base rather strongly
convex, and Pfeiffer’s “ margine columellari recte descendente ” is a well-marked
feature in se])arating it from the nearest allied species. The color is yellowish brown,
honey-yellow, more rarely orange-yellow, with a dorsal and basal deep brown-black,
generally .sharply defined band. The dorsal band which occupies the lower half of
the wliorls is narrower than the basal one, which latter is submarginal. The acute
periphery-keel is pale straw-yellow. Occasionally the bands arc diffused OA’er the
whole width of the whorls, except the keel and sutural margination. A more rare
variety occurs of a pale greenish yellow, with the bands nearly or quite obsolete.
Uniform honey-yellow specimens are also very rare.

Hybrids between this species and Swamsomi are not infrequent, and arc more
depressed, the umbilicus more open and the columella more obliquely curved than in
the normal condition. Mr. Pease may have mistaken these hybrids for Gould’s

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

25

T. FALLENS, Pease. Plate III, fig. 43.

Helix trochiformis, Gould (not of Per.), Expl. Ex. Shells, p. 61 (part).

Helix Gressida, Schmeltz (not of Gould), Cat. Mus. Godeff., v, p. 95.

Trochomorpha trochiformis, var. pallens, Pease, Jour, de Conch., 1810, p. 399; Proc. Zool.

Soc., 1811, pp. 451, 414.

Common, but very local on the trunks of trees at Tahiti and ]\Ioorca. It has
usually been confounded with trochiformis, and was described by Mr. Pease as var.
imllens. After a critical comparison of a large number of specimens from the al)Ove.
mentioned localities with the Raiatea shells, I have separated it as a distinct, though
closely allied, species.

Shell umbilicated, rather solid, subtrochiform, obliquely and roughly striated,
scarcely shining, yellowish white, with two narrow, revolving, reddish chestnut bands,
the basal one the larger, and both submedian ; spire depressly conoid, witli nearly
planulate outlines and rounded apex; suture with a narrow, depressed margin ; whorls
six, slightly convex, slowly and regularly increasing, last one not deflected m front,
acutely and compressly keeled, keel whitish ; base flatly convex, umbilicus narrow,
about one-sixth the major diameter of the shell; aperture rhomboid-luniform ; peris-
tome, above the keel, acute, straight, beneath the keel, gently arched, receding;
incrassated at the base.

Major diam. 16, height 9 mill.

Hah. — Tahiti and Moorea.

Var. a. Bands median, wide, blackish chestnut. Common.

Var. h. Pale honey-yellow, with narrow reddish brown bands, which are frequently
marginal. Somewhat rare and local.

Var. c. Uniform whitish or yellowish white. Very rare.

Var. d. Excepting the white keel and sutural margin, blackish che.stnut. Rather rare.

As compared with the preceding species, it is more depressed, the whorls flatter,
the base more planulate, the strim rougher and the columella more oblique and arched.
The keel and sutural margin are white, and the aperture is more depressed.

Examples of these shells sent to three good conchologists were by one referred to
Gressida, Gld., by another to Apia, H. and J., and the third referred it to cxc7«va,
Fer. I sent at the same time specimens of trochiformis, which were coiTCCtly

determined.

arelL, Gould, Proa ^ Soc. Nat. Hist., 1846, p. 176; Expl. Ex. Shells, p. 57,
fig. 56. Pfeiffer, Mon. Hel., i, p. 123.

Zonites Gressida, H. and A. Adams, Gen. Moll., n, p. 114.

Nanina Gressida (Discus), Albers, Die Hel., ed. 2d, p. 62.

Helix FoMae, Hombron and Jacquinot, Toy. Pol. Slid, PI. YU, gs.

Helix exclusa, var., Pfeiffer (not of Fer.), Mon. Heb, iv, p. 115.

Helix Swainsoni, var., Pfeiffer, Mon. Hel., iii, p. I5t.

Much doubt and confusion exist in regard to Gould’s Helix Gressida, wind, he

26 TEKEESI'EIAL MOLLCSCA INIIABITIUa SOCIETY ISLANDS.

Bays inhabits Tahiti and Samoa; the lattef location is undoubtedly
S'lvs (Jour de Conch., 1870, p. 399) Creasida is a good species, and inhabits Raia . .
nLilg personally collected all Mr. Pease’s Baiatea si, ells, and havmg now before me
numerous .lupl.cates, I have failed to discover one which co.ne.des with Gouhl
description. Mr. Pease’s Helix Imte, MS. (= Swainwm, var.), is the nearest allied
form, but is much smaller, thinner and has a more convex base.

Dr. Gould’s original description is as follows :

“ T. variabilis, solida, depressa, lenticularis, acute carinata, nitida, dense et acute
striata, coloribus flavo-viridibus et castaneis coalescentibiis fasciata, infra subplanulata,
nmbilico magno et profundo perforata; anfr. 5 vix convexi; apertura triangularis;
labnim acutum ; faux lilacina. — Lat. yVs ult. J poll.” (Gould).

The only shell I can satisfactorily refer to the above diagnosis is a somewhat scarce
species inhabiting two large valleys on the northwest side of Tahiti. ’Fhe localities
are near the two principal harbors and probably were the first ones explored b} the
naturalists of Wilkes’ Expedition.

I have now before me five examples, the largest measuring 18 mill, in tlie major
diameter and 6 in height. It is a solid, shining, depressed shell, with crowded,
irregular, rather sharp, obliquely curved stria?, and 5-5^ subplanulate whorls. The
suture is margined by the continuation of the acute periphery-keel. The flatly conve.x
base exhibits a wide umbilicus in which may be easily enumerated all the volutions.
The color is light yellowish brown, with or without a dorsal and basal light chestnut
band wliich gradually fades into the ground color. Occasionally the basal band is
obsolete, and the dorsal one so faint as not to be seen except in certain lights. The
aperture is diagonal, depressed, securiform, with three angles rvhich suggested Gould’s
“ apertura triangularis.” The peristome, above the carination, is trenchant, rectilinear
and regularly curved from the keel to the columellar region, the inner margin
strengthened with callus.

T. SwAiNsoNi, Pfeiffer.

Helix Swaimoni, Pfeiffer, Proc. Zool. Soc., 1846, p. 28; Mon. Hel., i, p. 122; {Videna)
Vers., p. 132. Reeve, Conch. Icon., fig. 601. Carpenter, Proc. Zool. Soc., 1864, p. 675.
Schmeltz, Cat. Miis. Gocleff., v, p. 95.

Zonites Swaimoni {Rotula), H. and A. Adams, Gen. Moll., ii, p. 116.

Helix scuta, Pease, MS. Coll. Pease, 1863.

Helix lenta, Pease, MS. Coll. Pease, 1863.

Nanina Swainsoni {Rotula), Paetel, Cat. Conch., p. 85.

Trochomorpha Swainsoni, Pease, Proc. Zool. Soc., 1871, p. 474 (part).

This BiKcics, whM, inhabits Ibaiatea and Tahaa, ocenrs in nearly all the laiare
m It »» It is a ground species, and

^^cather, mat be seen creeping a short distance up the trunks of trees.

TERRESTRIAL MOLERSCA INHABITING SOCIETY ISLANDS.

27

Dr. Pfeiffer, on the authority of Mr. Tucker, cites “ Tahiti ” as its habitat. I am
confident it does not occur on that island.

It is a thin, depressed, acutely cariuated species, of a luteous or whitish horn-color,
with a dorsal and basal brownish red line ; the upper one traversing the middle of the
volutions, and the lower one submarginal. The whorls are depressed or slightly
convex and striated by rather rough lines of growth. The faint sutural line is
narrowly margined. The convex base is considerably excavated on the boundaries of
the umbilicus, which latter varies from moderate to large, conical and freely exposing
all the volutions. The very oblique aperture is depressed, subsecuriform. Peristome
thin and nearly straight, above the keel, beneath which it gently recedes, and presents
a slight curve to the axis of the shell. They vary some in the elevation of the spire,
and occasionally the lineations are obsolete. My largest examples are 1(5 mill, in the
greatest dianuker.

The animal, as seen through the thin shell, is maculated with dark slate and light
gray. The exposed parts are slender and of a light gray or slate-color with a grayi.sh
buff creeping-disk. The eye-peduncles are long and slender, darker generally than
the other parts. The tentacles are very small, and the foot, Avhich equals in length
the major diameter of the shell, is laterally grooved.

Pease’s Helix lenia, which gradually merges into the typical Sivainsonii, is brownish
horn-color, with or without a submedian obscure chestnut band, and usually has the
whorls more convex and the last one narrower than in the type. It is closely allied
to T. ahrochroa, Crosse, inhabiting the Viti Isles.

T. AssiMiLis, Garrett. Plate III, fig. 44.

Shell umbilicated, rather solid, .subpellucid, subtrochiform, strite fine and oblique;
greenish horn-color, with two brownish red revolving narrow bands, one above nearly
median, the other on the base and intermarginal ; spire variable, more or less depre.ssly
conoid, rounded above ; suture with a narrow pale margin ; whorls 5^-6, the up|K'r
ones convex, the three lower subplanulate, narrow, slowly and regularly increasing,
the last one acutely carinated, the carina compressed, rugose; base subplanulate,
umbilicus moderate, profound, with rounded margins ; aperture diagonal, depressed,
securiform ; peristome thin, straight, above rectilinear, beneath the keel gently arched ;
columella and base incrassated.

Major diam. 15, height 7 mill.

Hah. — Huaheine.

This species is restricted to the above island, where it is not infrc'qucnt on the
trunks of trees.

It has hitherto been confounded with trochifm'mis and Eurydice, the latter a Tonga
species. It is more nearly related to p<dlens than any other species ; but appears to
me sufficiently distinct to rank as a separate species. Tliey are very uniform in color

28

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

and fasciation ; they vary some in the elevation of the spire. The various species of
tliis genus are so closely allied that it is difficult to express in words the specific
differences.

Compared with pallens it is smaller, color different, the band always narrow, and
the umbilical region more excavated. The whorls are also a little more flattened.
The obliquely arched columella will at once separate it from trochiformis.

Oenus UATUnA, Ueld.

P. -MODiCELLA, Ferussac.

Helix modicella, Fer., Mus. Deshayes, in Ferussac’s Hist. Moll., i, p. 90, PI. LXXXVI,
fig. 3. Pfeiffer, Mon. Hel., iii, p. 92 ; vii, p. 149. (Pafula) Paetel, Cat. Conch., p. 92.
Nanina modicella^ Gray, Cat. Pulm., p. 129.

Pityg modicella, Pease, Proc. Zool. Soc., 1811, p. 414.

Patula modicella, Sclimeltz, Cat. Mus. Gocleff., v, p. 93. Moiisson, Jour, de Conch., 1813.
p. 104.

Pithyg Atiemis, Pease, Jour, de Conch., 1810, p. 394.

Pitys Atiensis, Pease, Proc. Zool. Soc., 1811, pp. 453, 414.

Patula Atiengia, Garrett, Jour. Acad. Nat. Sci. Phila., 1881, p. 386.

Helix Atiensig, Pfeiffer, Mon. Hel., vii, p. 165.

Patula vicaria, Mousson, Jour, de Conch., 1811, p. 11, PI. HI, fig. 2 ; 1813, p, 104. Schracltz
Cat. Mus. Godeff., v, p. 93. ’

Helix vicaria, Pfeiffer, Mon. Hel., vii, p. 181. {Patula) Paetel, Cat. Conch., p. 93.

This species, which is distributed throughout the group, is found adliering to tlie
under side of dead wood in the lowland forests. It appears to be more rare in tlie
Panmotus, and is widely diffused over the Harvey Islands. I also obtained it in the
onga, and Dr. Graffc gathered examples in the low coral islands of the Ellice -roup
winch gives it a wider range than any other Polvnesian species ^ ’

and this species, copies De.shaves’ description

mo":- as i,s habitat. He' describos’it ai

anfr" temiUsima striata, late umbilicata, corneo-fulva ■

— ---- —

are novot, boles, foe, aon.lv olaZ; d ^

tions. Tlio four and a half whorl. ^ ^ tessella-

apiro is sliffhtly ooavev or plam,l„to“%ZZs'' ^ “ ^““"*<1 s„,„r„I li„e. The
above the iioriphcry and thn ^ ‘Convex, last one moderately flattened

riblots. which arc very slightlv biaZaTr' The

of the major diameter of the' shell. ' P^i^Pectne umbilicus is nearly a third

TERRESTRIAL MOLLUSOA INHABITING SOCIETY ISLANDS.

29

^Ir. Pease’s Pitliys Atiensis, which I add to the synonymy, is thus described : —

“ T. orbicularis, tenniscula, late umbilicata, confertim costulata, havido et rufb
tessellato-strigata ; spira vix elevata, apice obtuso ; anfr. 5, convex!, nltimns ad peri-
pheriam rotundatus ; sutiira bene impressa ; apertura obliqua, subcircularis, lamellis
carens ; perist. simplex, rectum. Diam. 3, alt. If mUl.” (Pease).

The Plarvey Island shells, which attain a larger size than those found elsewhere,
differ none in shape and sculpture, and the coloration is the same as Society Island
specimens. The umbilicus varies from one-fourth to one-third the greater diameter
of the shell.

I also add to the synonymy Mousson’s Patula vicaria, described as follows : —

“ T. pai'vula, aperte umbilicata, orbiculato-depressa, regulariter et tenuiter costulato-
striata, striis squamulosis, faciis pallide corneis et fnseis radiatim picta. Spira planiuscula,
subarcte spirata ; suninio minuto, Isevigato, obtuso ; sutura perimpressa. Anfr. 4^,
lente accrescentes, convex! ; ultimus lente descendens, supra paulo ttimidulus, deinde
regidariter rotundatus. Apertura subverticalis (15° cum axi), cxacte lunato-
semicircularis, plicis destituta. Perist. rectum, acutum ; marginibus convergentibus ;
dcxtro et basali antrorsum leniter biarcuatis, columellari non reflexo, nec. protnicto.
Umbilicus f diametri sequans. Alt. 1-5, diam. 3 mill. Hat. anfr. 7:2. Rat. apert.
1 : 1” (Mousson).

With the exception of being a trifle smaller, is not dissimilar in any respect Irom
the Harvey Island shells.

The above author has described a variety of modiceUa from the Kcrmandec or
Sunday Island, as follows : —

“Anfractibus magis rotundatis, costulis, sed tenuibus; albescens, maculiset flamimdis
rufis transverse picta; diam. 3, alt. 1-2 mill.” (Mousson).

P. CONSIMILIS, Pease. Plate II, figs. 12, 12 a, 12 b.

Helix consimilis, Pease, Amer. Jour. Conch., 1861, p. 227. Pfeiffer, Mon. Hcl., vii, p. 262.

Helix radiella, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675.

Pitys consimilis, Pease, Proc. Zool. Soc., 1871, p. 474.

Patula societatus, “ Mousson,” Schmeltz, Cat. Mus. Godeff., iv, p. 73. P.aetel, Cat. Conch.,
p. 95. Pfeiffer, Mon. Hel., vii, p. 482.

Patula consimilis, Schmeltz, Cat. Mus. Godeff., v, p. 207.

Common and diffused throughout all the larger valleys of Haiatca, wlicre it is
peculiar. Mr. Pease’s habitat, “ Tahiti,” is wrong. I collected all his type examples
at the former island.

The spu'e is convex, the first and second whorls planulate and the suture cliannclcd.
The whorls are narrow, slowly and regularly increasing, turgid next to tlie suture and
the rib-like strim are very thin and closely set. The aperture is nearly vertical and
the parietal region with one or two larainte.

5 JOCK. A. N. s. PHILA., VOL. IX.

.PKUKESTKIAL MOI.LCSOA INHABITING SOCIKTY ISLANDS.

r.*C.I.oo.rA,Mo,...o»,MS. Pl.IC II, ligs. 13. 6

— -

“ «?;Tde.y nmWHcatod. depie^ed-orbiculav. coineous ivMi reddish
lions; radio, ely striated with thin, rather closely

flatly convex, apex plaiiulate; suture deeply impressed ; whorls fi^e, con >

and regularly increasing, turgid next to the suture, last one slightly ( ^

not descending in front, base convex; umbilicus large, perspective, exhibiting all the
uhorls, about one-third the major diameter of the shell; aperture nearly vertical,
irregularly orbicular-lunate; parietal region with one or two, very rarely three laminae;
peristome simple, straight, Avith remote margins.

Major diara. 4;|, height 2 mill.

A very rare variety occurs which is uniform whitish horn-color.

As compared with* consimiZis it is larger, more depressed, umbilicus larger and ribs

P. L.AMELLicosTA, GaiTett. Plate II, figs. 11, 11 a, 11 fc.

Sliell small, widely unibilicated, orbicular, depressed, thin, subiiellucid, brown or
liilvous-brown, nnicolored or tessellated with deeper brotvn ; radiately striated witli
rather distant, oblique, slightly tvaved lamelliforni riblets ; spire flat, not rising above
tlie ix'nnltimate whorl; suture deeply impressed; Avhorls four, convex, slowly and
regularly increasing, the last not descending in front, rounded on the ix'riphery,
obliquely depressed above ; umbilicus more than a third the greater diameter of the
shell ; aperture oblique, orbicular-lunate.

Major diam. 3, height I3 mill.

Appears to be a scarce species, living beneath rotten wood in damp stsitions at
Tahiti. It is more openly umbilicated than any other Society Island species. The
proportion of the umbilicus to the major diameter of the shell is the same as P.
gradaia, Gld., and the sculpture is similar to P. tenuicostata, Garr.

Genus PITYS, Beck.

As Stated in my paper on the “ Terrestrial Mollusca inhabiting the Cook’s or
Harvey Islands,” published in the Journal of the Academy of Natural Sciences of
I’hiladclphia, I restrict this genus to those species characterized by the existence of
laminae on both the parietal region and palate.

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

:n

P. Maupiensis, Garrett.

Pitys Maupiensis, Garrett, Proc. Cal. Acad. Sciences, 1812, p. 204; Proc. Acad. Nat. Sci.

Phil., 1873, p. 233, PL III, flg. 64.

Patula Maupitiensis, Schmeltz, Cat. Mus. Godeff., v, p. 93.

Helix Maiipitiensis, Pfeiffer, Mon. Hel., vii, p. 481.

Very common, and confined to the small island of Maupiti.

It may be distinguished from any other Polynesian species by its fine, crowdt'd,
elevated (not costidate) striae, convex spire, numerous very narrow rounded whorls,
numerous internal laminae and deep vertical umbilicus. The parietal lamimc an* three,
rarely two, and sometimes the one on the columellar region is obsolete. Besides the
usital four palatal laminae, there exist, sometimes, finer and shorter intermediate ones.

P. PAEViDENS, Pease. Plate II, figs. 14, 14 a, 14 6, 14 c.

Helix parvidens, Pease, Proc. Zool. Soc., 1861, p. 243. Pfeiffer, Mon. Hel., v, p. 220.

Pitys parvidens, Pease, Proc. Zool. Soc., 1871, p. 474.

Patula incerla, “ Mousson,” Schmeltz, Cat. Mus. Godeff., v, p. 93.

Helix incerta, Pfeiffer, Mon. Hel., vii, p. 481.

Very abundant and confined to Tahiti, Moorea and Iluaheine. Examph's from
the three different localities are precisely alike as regards the character of tlie fine,
rib-like stria;, size of the umbilicus and shape of the spire. There are generally two,
rarely three, parietal laminae, and usually four, sometimes fi\ e in the palate. Taliiti
and Moorea specimens are a little larger and darker-colored than those from Ilualieine,
which latter have a cinereous base.

P. CONSOBEINA, GaiTctt. Plate II, figs. 17, 17 a, 17 6, 17 c.

Shell umbilicated, thin, orbicular, depressed, radiately striated with very fim*,
crowded, nearly straight, membraneous riblets; yellowish horn-color, t<'ssellated and
striped with reddish brown ; spire planulate ; suture channeled ; wliorls six, very narrow,
convexly rounded, subangtdate next to the suture, slowly and regularly increasing, tlie
last one not deflected in front, much deeper than wide, obtusely rounded on the
periphery; base convex; umbilicus perspective, showing all the whorls, nearly a third
the greater diameter of the shell ; aperture vertical, narrow, irregidarly orbicular-
lunate ; parietal region with four (very rarely three), and tlie palate with from seven
to nine lamina' ; peristome thin, straight, simple with remote margins ; columella with
or without a lamelliform plait.

Major diam. 3, height 1| mill.

Hob. — Huaheine Island.

Rare and peculiar to one valley. The spire is more planulate and the body-whorl
deeper than parvidens. It also has one more whorl, and the lamime are much more
numerous than in the latter species.

P. suBTiLis, Garrett. Plate II, figs. 15, 15 a, 15 6, 15 c.

Shell umbilicated, orbicular, depressed, thin, yellowish corneous, tessellah'd and

* T T r^CA INHABITING SOCIETY ISLANDS.

32 terrestrial MOLLLSCA

*iSZaKKe<l 'vi* Tpex fiat, stturc channeled;

crowded, snbbiarcixate riblcts, p e suture, slowly ixud regularly

whorls five, narrow, • base convex; umbilicus moderate,

increasing, last one rounded P ^ aperture vertical, narrow, orbicular-

iml XwHnd the palate wiih four (rarely three or bve) lamium ;

peristome thin, straight, with remote margins.

Major diam. 3, height mill.

ftmewllar^re^^r^^^^^^ confined to a valley on the north end of Huaheine. It
differs ?;rU-ie«/in having the riblets ntneh fntthet apart, deeper channeled
suture and the whorls angulated next to the suture.

P.PUNCTiPKRFORATA, Garrett. Plate II, figs. 16,16 a, 16 &, 16 c.

Slicll siinall, perforated, orbicnlar, depressed, thin, corneous, tessellated ahoTC with
reddish brown, beneath corn-color, or radintely striped with the same hue; stine vert
closely set, thin, rib-like, subarcuated, smaller and more crowded beneath ; spne
convenorconvexlyroraidod; apex planulate ; suture deeply impressed; whorls six,
roiiiidod, narrow, regularly and slowly increasing, last one not descending in Iront,
gibbous above ; base convex ; umbilicus very small, puuctiform ; aperture vertical,
narrow luniform ; parietal region with two (rarely three), and the iialate witli from
four to five lainime, one of which is columellar ; besides the laminm there exist parallel
raised lines both on the wall of the aperture and in the palate ; peristome thin, simple,
with remote margins; columella thickened with callus.

Major diam. 3, height Ij mill.

JIab. — Moorea Island.

A few examples w'ere found at the above locality, but not obtained in any other
jiart of the group, liie minute umbilicus will at once distinguish it from any other
Soi icty Island species. One specimen is uniform pale horn-color.

P. Boraborensis, Garrett. Plate II, figs. 18, 18 a, 18 6.

iSliell orbicular, depressed, widely umbilicated, thin, corneous under a light brownish
epidermis ; above tessellated, beneath with or without undulating stripes of a dark
chestnut-brow'n ; sculpture consisting of small, thin, crowhed slightly waved riblets ;
spire but little elevated, apex fiat ; suture deeply impressed ; whorls seven, convex,
very slowly increasing, last one subangulate, base convexly rounded ; umbilicus large,
perspective, exhibiting all the whorls ; aperture subvertical, ovate-lunilbrm ; parietal
region with four and the palate with five or six laminae, peristome simple with remote
margins.

Major diam. 5, height mill.

Hah. — Borabora Island.

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

33

This, the largest species inhabiting the group, is comparatively rare, and is peculiar
to the above island, where it was found about 900 feet above sea-level.

Its most obvious characters are its large size, wide perspecti^-e umbilicus, depressed
form, numerous whorls, subangulate periphery and numerous lamina?.

Genus LIBERA, Garrett.

There exists a good deal of confusion in regard to the synonymy of the Society
Island species of Libera, caused, no doubt, by the intermixture of specimens collected
in different localities. Such, I am sure, was the case with the examples collected by
the naturalists of the United States Exploring Expedition, which were described by
Dr. Gonld under the name of Helix hursatella and varieties. The numerous specimens
collected by the writer at Tahiti and Moorea, in 1861, passed into Mr. Pease’s possi's-
sion, and, like Gould (with one exception), he regarded them as a single variable
species.

In my subsequent explorations of the above two islands I made a careful study of
the specimens gathered in the different valleys on each island, and am thoroughly
convinced that there are several valid species included in Goidd’s If. hursatella and
varieties. In fact the various species are as well defined and distinct from each other
as the majority of Helices, and, so far as I know, do not intergrade with each other.
It is particularly noteworthy that each species has its special habitat ; some restricted
to a single lalley, and others ranging throughout two or more valleys, but never
intrnding on each otlier’s localities. The Tahiti species are specifically distinct from
the Moorea shells, and both differ from those inhabiting the Cook’s group. It is a
noteworthy and remarkable fact that this genus, which in this group is restricted to
Tahiti and Moorea, is represented in all the leeward islands by the allied gtmus
Endodonta.

Dr. Pfeiffer appears to have been somewhat bewildered in his treatment of the
various species described by Gould, Reeve, Hombron and Jacquinot, and himself. In
the first volume of his “ Monographia Heliceorum,” he simply repeats Gotild’s de.scrip-
tion and varieties. In his third volume he restricts and redescribes Gould’s species,
and adds to its synonymy H. turricula, Homb. and Jacq., and removes Gould’s var. h,
together with H. excavata, Homb. and Jacq., to the synonymy of II. Jaxqninofi, Pfr.,
and cites Tahiti and Marquesas as habitats. On the same page he describes If.
cavermda, Homb. and Jacq., with H. coarctata, Pfr., as a synonym. In the fourtli
volume he eliminates H. turricida from the synonymy of II hursatella, and removes
II. excavata from H. Jacquinoti to Gould’s species. He also shifts II. cavernida,
Homb. and Jacq. (not of Pfr.), to the synonymy of H. Jacquinoti. His H. carcriiida
(not of Homb. and Jacq.) he refers to II. streptaxon, Rve., and quotes II. coarctata,
H. turricida and Gould’s H. hursatella, var. h and c, as synonyms of Reeve’s shell. In
the fifth I'olume he doubts H. cavernula, H. and J., being synonymous with II. Jacqui-

M teueesteial mollusca inhabiting society islands.

and desciBes a now speciea under the name of //. the eommm.eet

lortn inhabiting all the valley* near the principal harbors at Tahiti, and ™'^““Medly
included among Gould’s varieties of hursMa. In the seventh volun.e he
IL coarctata and H. turrkula being synonyms of H. sirepta;,^.

Mr. Pease, in his list of Polynesian land shells (P. Z. S., 1871), refers H coarctata,
II excamta, II. streptaxon and II turricula to the synonymy of II hursateUa, and adds
//. to the synonymy of II Jaa,>dnoti, Pfr. He also reeords II Heynernanm

Pfr., and H. Oceanica, Le GuilL, as distinct species, unknown to him. He doubts II
Jacquinoti, which Pfeiffer assigns to the Marquesas, being a Society Island species. 1
niPlincfl to believe it inhabits the Austral Islands, and not Marquesas.

L. BURSATELLA, Goukl.

Helix bursatella, Gould (part), Proc. Bost. Soc. Nat. Hist., 1846, p. 175 ; Expl. Ex. Shells, p.
51 (part). Pfeifler, Mon. Hel., i, p. 185 (part) ; Hi, p. 142 (as restricted). Chemnitz, ed. 2d,
PI. eXXV, figs. 23-25. (Endodonta) Albers, Die Ilel., p. 189. Reeve, Conch. Icon.,
PI. CXI, fig. 635. (Pitys) 11. and A. Adams, Gen. Moll., ii, p. 113. {Endodonta) Paetel,
Cat. Conch., p. 91.

Helix turricula, Ilombron and Jacquinot, Voy. Pol. Sud, Mol., PI. YI, figs. 21—24.

Pitys bursatella, Pease (part), Proc. Zool. Soc., pp. 452, 475. Prauenfeld, Verh. Zool. Rot.
Ges. AVien, 1869, p. 873.

In 1861, 1 gathered numerous examples of this species at Tahiti, but, as previously
mentioned, my specimens of Libera were more or less intermixed, so I cannot state the
precise locality where I took the specimens.

It may be di.stinguished by its serniglobosc form, rather elevated dome-like spire,
crowded, slightly arcuate riblets, flattened and rather smooth base, and the absence of
spiral striie. There are six to seven internal laminae.

Major diani. 7| mill.

L. COARCTATA, Pfcirt'cr, Plate II, fig. 10.

Helix bursatella, Gould (part), Proc. Bost. Soc. Nat. Hist., 1846, p. 175 ; Expl. Ex. Shells,
p. 51.

Helix coarctata, Pfeiffer, Proc. Zool. Soc., 1849, p. 128; Zeit. Malak., 1849, p. 74. {Endo-
donta) Albers, Die Hel., p. 89.

Helix cavernula, Hoinbron and Jacquinot, Yoy. Pol. Sud, Moll., PI. YI, figs. 33-36. Chem-
nitz, ed. 2d., No. 781, PI. CXXY, figs. 29-31. Pfeiffer, Mon. Hel., iii, p. 143. {Pitys)
H. and A. Adams, Gen. Moll., ii, p. 113.

Helix streptaxon, Reeve, Conch. Icon., PI. CXII, fig. 641. Pfeiffer, Mon. Hel., iv, p. 154.
{Endodonta) Paetel, Cat. Conch., p. 95.

Common and diffused throughout several valleys on the north and east .side of
Moorca. On the ground in forests.

The spiral, raised striie will readily distinguish it from Z. recedens and Z. gregaria,
inhabiting the same island. They vary some in the height of the spire, and some

TERRESTRIAL MOLLUSCA INHABITIXG SOCIETY ISLANDS.

35

have the riblets more distant than others. Examples with receding body-whorl are
not infrequent. A variety (local) occurs which is uniform whitish.

L. RETUNSA, Pease, Plate II, flg. 8.

Helix retunsa, Pease, Proc. Zool. Soc., 1864, p. 610. Pfeiffer, Mon. Hel., v, p. 220.

Pitijs retunsa, Pease, Proc. Zool. Soc., 1811, p. 415.

Mr. Pease’s type specimens Avere collected by me on the south side of Tahiti,
where it is not uncommon beneath rotten wood.

This remarkable shell differs from the preceding species in having rounded whorls,
the last one neither carinated nor angled, and in the absence of the lamina in the
palate. The spire, which is more or less elevated, is truncate, dome-shaped ; u horls
6-7, cancellated with fine, crotvded, revolving, raised lines, and radiating, distant,
delicate, obliquely curved riblets. Parietal region with a single, elongate lamina,
and a small one on the columella. Color whitish or yellowish horn-color, above
tessellated, and the base with waved, radiating stripes, reddish brown.

Diam. 4, height 2-3 mill.

L. Heynemanni, Pfeiffer, Plate II, fig. 9.

Helix Heynemanni, Pfeiffer, Mai. Blat., 1862, p. 151 ; Mon. Hel., v, p. 219.

Pitys Heynemanni, Pease, Proc. Zool. Soc., 1811, p. 415.

Patula Heynemanni, Schmeltz, Cat. Mus. Godeff., v, p. 93.

Helix bursatella, Gould (part), Proc. Bost. Soc. Nat. Hist., 1846, p. 115.

Very abundant in several valleys on the northwest part of Tahiti, where they live*
beneath loose stones and decaying wood.

There is not the slightest doubt in respect to this common species having been
collected by Wilkes’ naturalists, who carefully explored that part of Tahiti. Examples
sent to Mr. Pease tvere by him referred to hursatelJa, Gould. Some sent to one ol my
English correspondents were also referred to Gould’s species. On the other hand, a
lot forwarded to the Museum Godeffroy, were by Prof. IVIousson identified with
Pfeift’er’s Heynemanni.

Although Mr. Pease quotes Heynemanni as distinct, yet it is CAident from his
remarks on the Tahiti species that he did not identify the shells received from me as
being that species.

It may be characterized by its exceedingly fine transverse and revolving raised
stricC, Avhich are so closely .set as to impart a silky lustre to the shell. Pfeiffer, avIio
does not allude to the concentric lines, merely says “leviter striata.” Ihe spire, Avhich
varies slightly in height, is depressed dome-shaped, Avhorls 6-7, nearly planu-
late, submargined, the last one not descending and acutely carinated. '1 he convex
base is cancellated the same as above. There are two parietal lamiiuT, the lower one
the shorter, four in the palate, three conspicuous, deep-seated, beneath the keel, and
one above not so conspicuous and sometimes obsolete. A small one on the columella.
Color Avhitish or luteous, rarely uniform broAvnish, generally profusely spotted and

30 TKimESTBIAL MOLLUSCA INHAEITINfi SOCIETY ISLAEUS.

Sliipci, will, che.n„l-w,i. Tl.e ,evo.vi„, slri. lu-e sometime, „..a..y

obsolete.

Diam. o-5|, height 2i-3| mill.

L. OREUAKiA, Garrett, Plate II, figs. 6, 6 a, 6 &. v.' ' itr elrmelv and

Sholl small, umbilicatcd, solid, ™

ol,li,,„cly striated with smaU, regular, slightly b.arcuate, rough ^ restnut-

cwled on the base- whitish corneous, tesseUated and undulately rayed with the.stnut
brown; spire depressed dome-shaped, apex flattened; suture '

whorls seven, slightly convex, narrow, slowly and rcgularlj incieasi e .

earinated, sometimes descending a little below the penultnnate who 1 , base fla ly
convex, .-oncave on the boundaries of the umbilicus; umbilicus (m
exposing all the whorls, one-third the major diameter of the shell ; m adults stio „ y
eonstricLl by an acute expansion of the last whorl; aperture small, ohln.ue,
depressed, irregular rhomboid-luniform ; laniinte 0-6, two in the parieta repoli,
elongate, of equal length, one columellar, two in the palate beneath the keel,
short ronspicuons, one above the keel, inconspicuous and occasionally absent ; peris-
tome acute, straight, basal margin continuous with the acute umbilical constriction;
columella short, concave, receding.

Major diam. 7, licight 85 mill.

Hdh. — Moorca.

I discovered two colonies of this very distinct species in two valleys on the south-
west iiart of Moorea. They were congregating in immense numbers on the under side
of loose stones. 'I’liough carefully searched for, I failed to detect them in any other
part of the island. No other species of this genus occurs in the same location witli
tlie shells under consideration.

M’ith the exception of a slight difference in the elevation of the spire, they arc
very uniform in all their specific characters.

L. RECEDENS, Garrett. Plate II, fig. 7.

Shell small, umbilicated, not shining, rather solid, depressed, orbicular, with thin,
crowded, slightly oblique, rough, elevated striae, which are finer and more close!)’ set
on the base; dark chocolate-brown, with or without yellowish horn-colored tessellations
and undulated stripes ; spire depressly convex, apex flattened ; suture linearly
impressed ; whorls seven, very little convex, narrow, slowly and regularly increasing,
last one earinated, gradually descending below the periphery of the penultimate
wliorl ; base convex, concavely indented at the axis ; umbilicus (in adolescence) freely
exposing all the whorls, a little more than one-third the greater diameter of the
sliell ; in adults the umbilicus is constricted to about one-third that of adolescent
examples ; aperture small, depressed, oblique, irregularly rhomboid-luniform ; laminae
six, two on the parietal region, elongate, the lower one deeply seated, a stout one on

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

37

the columella, two short conspicuous ones in the palate between the keel and base,
and a less conspicuous one above ; peristome thin, straight, the lower margin contin-
uous with the umbilical constriction ; columella short, concave, receding.

Major diara. 51, height 21 mill.

Hah. — Moorea.

Very abundant beneath decaying vegetation, and restricted to the louder part of
one valley on the west side of Moorea, and the only species found in tliat location.

The deflection of the last whorl below the periphery of the penultimate wdiorl,
which is an accidental character in some of the species, is constant in this. The per-
sistence of this feature, together with the fine, crowded striae, dark color, absence of
concentric lines, as well as difference in the internal laminae, are its most essential
characters.

Genus ENDODONTA, Albers.

This genus was instituted by Dr. Albers for a peculiar group of small Helices
inhabiting the Sandwich Islands, the type of which is Helix lamellosa. For. Five
species are known to inhabit that group ; all of which are characterized by their len-
ticular form, acutely carinate periphery, large umbilicus, subrhomboid or securiform
aperture, which is garnished with two parietal, one columellar, and three or four
palatal laminae.

Some of the Society Islands species are very closely related to the Sandwdcli Islands
shells in shape, and the existence of one or more deeply seated lamina' in the palate ;
the latter character was overlooked by Pfeiffer, Pease, and the writer, when describing
the different species inhabiting the group.

They are all very widely umbilicated, the last whorl carinated or angulate, and all,
with one exception, have one or two parietal lamina? ; the low'er one, when two are
present, is always shorter, and owing to its being deeply seated has hitherto been o\ er-
looked. The aberrant species are Helix fabrefacta. Pease, which is without lamina', and
H. ololus, Gould, which has a single one on the parietal region ; otherwise the shaiK?
of the shells is quite similar to the others. The laminae are not so prominent as in
the typical species, and are distinctly represented in the different stages of growth,
but, excepting those on the last two whorls, are gradually absorbed by the animal.

They inhabit aU the Islands except Tahiti and Moorea, where they are represented
by a distinct group of Helices, the type of which is Helix Imrsatella, Gould. They
are all ground species, and are very numerous in certain favorable localities.

E. IltJAHEiNENsrs, Pfeiffer. Plate II, figs. 26, 26 a, 26 b, 26 c.

Helix Huaheinensis, Pfeiffer, Zeit. Mai., 18.53, p. 55 ; Mon. Hel., iii, 640.

Endodonta Huaheinensis.! Pfeiffer, Yers., p. 129. Albers, Die Hel.,ed. 2, p. 9. Pease, Proc.

"Zool. Soc., 1871, p. 474. Paetel, Cat. Conch., p. 91.

Patula HuaheinensiS! Schmeltz, Cat. Mus. Godeff., v, p. 93.

This species is abundant in all the large valleys on Huaheine. Though widely

6 JOUK. A. N. S. PHILA., VOL. IX.

T athtitTSCA inhabiting SOCIETY ISLANDS.

38 terrestrial mollusc a iiM

0.1 breaking away about one-fourth 'ftr'eo'’ tactile pJlate

Ltirh^ire;," o- «■-

n:»r:r r of .0

keel to the colnmellar region.

E. FiCTA, Pease. Plate II, figs. 25, 25 a, 25 &. at tt^.i v n 99'5

Helix ficta, Pease, Proc. Zool. Soc., 1864, p. 669. Pfeiffer, Mon. Hel., v, p. 223.

Hndodonta ficta, Pease, Proc. Zool. Soc., 1871, pp. 455, 474.

This species Is confined to Tahaa, not “ llaiatea,” as stated by Peoso, wi.ere it
occui's plentifully, associated with E. fahref<icta.

Bf'sides the constant single parietal lamina mentioned by Pease, there is a second
one deeply sealed in the palate between the keel and base of the shell.

As compared with the preceding species, which it closely resembles in texture,
color and markings, it is larger, has one more whorl, the umbilicus wider and its
margin mo’c acutely angulate, and the aperture more decidedly rhomboidal in outline.
The upper surface of the last whorl is more or less distinctly concave or sulcated next
to the suture, a character not observed in Huaheinensis.

E. FAIIRF.FACTA, PcaSC.

Helix fabrefacta, Pease, Proc. Zool. Soc., 1864, p. 669. Pfeiffer, Mon. Hel., v, p. 190;
vii, p. 210 ; Novit. Conch., fasc. xxxvi, p. 505, PI. CVIII, figs. 28-31.

Endodonla fabrefacta, Pease, Proc. Zool. Soc., 1871, p. 474.

J’alula fabrefacta, Schmellz, Cat. Mus. Godeff., v, p. 207.

Palula conicava, “ Mousson,” Schmeltz, Cat. Mus. Godeff, iv, p. 72. Paetel, Cat. Conch.,
p. 89.

Helix conicava, Pfeiffer, Mon. Hel., vii, p. 480 (name only).

A common species, confined to four large valleys on Raiatea, and one on the east
coast of Tahaa. On the ground in forests.

This is one of the aberrant species previously alluded to, which in the type is
entirely destitute of internal laminrn. In every other particular, it cannot be distin-
guished from the typical Endodonta.

Dr. Pfeiffer has given an accurate description and figures of this species in the
“ Novitates Conchologicaj.”

It attains a larger size than given by the above author. My largest examples are
nearly 9 mill, in the greatest diameter by 4 in height. They vary some in tlie eleva-
tion of the spire, and the brown spots are occasionally absent. The spire is always
more or less concave in outline, and the broad umbilicus is funnel-shaped, with planu-

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

39

late walls. In adults there are eight flat whorls, the last three subcoucave, and tlie
aperture is a nearly equally four-sided square.

Var. PiCEA, Garrett.

This variety, Avhich I have distributed to my correspondents under the name of
Pitys picea, differs none from the type, except in being smaller and the parietal wall
unilaminate. The aperture is also vertically narrower.

Not infrequent on the west side of Eaiatea.

E. OBOLTJS, Gould.

Helix obolus, Gould, Proc. Bost. Soc. Nat. Hist., 1846, p. 115 ; Expl. Ex. Shells, p. 53, fig. 50.
Pfeiffer, Mon. Hel., i, p. 187.

Endodonta obolus, Albers, Die Hel., ed. 2d, p. 90. Pease, Proc. Zool. Soc., 187 1 , p. 474.
Pitys obolus, H. and A. Adams, Gen. Moll., ii, p. 114.

Patula obolus, Schmeltz, Cat. Mus. Godeff., iv, p. 72. Paetel, Cat. Conch., p. 93.

Helix acetabulum, Pease, Proc. Zool. Soc., 1861, p. 242. Pfeiffer, Mon. Hel., v, p. 222.
Endodonta acetabulum, Pease, Proc. Zool. Soc., 1871, p. 474.

Pithys? celsa, Pease, Jour, de Conch., 1870, p. 396.

Endodonta celsa, Pease, Proc. Zool. Soc., 1871, pp. 455, 474.

Helix celsa, Pfeiffer, Mon. Hel., vii, p. 260.

Patula Barffi, Garrett, Schmeltz, Cat. Mus. Godeffr., v, p. 93.

Patula intermixta, “ Mousson,” Schmeltz, Cat. Mus. Godeff., v, p. 93.

This variable species, which is confined to Eaiatea and Iluaheine, is plentiful and
widely diffused over the two islands.

Dr. Gould’s habitat, “ Taheiti,” is undoubtedly wrong. Having personally explored
every valley on Tahiti and Moorea, I did not find a single example of this tyi>c of
Helices. His specimens were probably from Eaiatea. Dr. Gould describes it as

follows: — .

“ T. parva, discoidea, deorsum compressa, supra planulata, infra concava, radiatim
minutissima et iuEequaliter striata, fusco-ferruginea, piceo tessellata ; spira; anfr. 5^,
supra excavati, ultimus superne costato-carinatus ; apertura subrhomboidea, faucc
lamella unica semmdum anfractum penultimum volventi. Lat. i, alt. poU-

(Gould). .

The above description accords well with the shells under consideration, and tlie
“supra excavata” agrees better with the Eaiatea shells than those from Iluaheine.
But the above author’s reference to Planorhis vortex as similar in shape renders tlie
identification beyond doubt.

I am fully convmced that Pease’s acetabulum is specificaUy the same as Gould s
species.

Mr. Pease’s diagnosis, which is rather obscure, I reproduce ;

••T. par™, planorboidea, superne leviter convexa vel plana; umb.licus ainplus,
cyathiformis; utriuque subtililer radiato-striata, ad periphcriam et umbilici iiiargiucm

40 ™.UIKSTRIA,, MOL.USOA INHABITING SOCIKTY IBLANGS.

, 1 i. f„fo . onfr 6 carinato-rotvindati, seriebus

carinato costata, subtus siibo so e e cos ‘ . ’j Apcrtura subrlioraboidea,

™lia„m,„,|,ilon™b..ovium ‘Xr;— et fnlvo fusco les-

lamella nnioa in anfr. ponultimo munita. Testa satuiati castauco

scllata. Diam. 5, axis 2 mill.” (Pease). though he was well aware

I collected Mr. Pease’s type specimens at Huaheinc , o
of the fact, yet he gave the wrong habitat “Tahiti” to this and several

species obtained on the former island. ^ • .i _ TTi<!

The base is never “ carinato-costata.” It is rounded or faintly angulate-. His

“ pilorura-brevium ” exists in immature examples only. „ , . .1

Eight vears after receiving from me a lot of Raiatea specimens o t is species le
published his ceha ” (1. c.). His description is as follows

“ Testa discoidea, late umbilicata, radiatim tenuitcr, regulariter rugoso striata,
concentrici irregulariter sulcata aut tenuiter costata ; spira depresso elevata, convexa;
anfr. 7, rotundato-convexi, pleriimque angulati, ultimus ad peripheriam rotundatus;
umbilicus yV diametri occupans ; apertura vix.obliqiia subcircularis, lamella unica
volvcnte instructa ; perist. simplex rectum ; radiatim fusco et albido tessellata. Uiam.

6, alt. 3 mill.” (Pease).

The following year he redescribes it under the name of ^'•Endodonta ceha (1. c.),
without referring to his former diagnosis. I repeat his description : —

“T. orbicularis, solidiuscula, late umbilicata, tenuissime radiatim creberrime
striatula, rufo et albido pallide tessellata; spira elevata, apice obtusiusculo, nucleus
rufesrenti-fuscus, sutura bene impressa ; anfr. 7, convex!, interdum concentrice elevato-
striati, rarissime sulcati aut angulati, ultimus ad peripheriam obtuse angulatus, subtus
rotundatus ; apertura obliqua, fere circularis, lamella unica in anfr. peindtimo munita.
Diam. 7, alt. 3| mill.” (Pease).

lie gives the correct habitat “Raiatea.” It will be observed that there is some
discrepancy between the two descriptions of ceha, proving it to be a variable species,
llis measurement, 6 mill., is correct, but his last one, 7 milh, is larger than any
specimen known to me.

Having a second time gone over the same ground and collected hundreds of speci-
mens, both on Raiatea and Huaheine, I do not hesitate, after a careful study of the
numerous examples, to add both acetabulum and celsa to the synonymy of obolus.

I am not positive, but I think I am correct in referring Mousson’s interm>xta (which
I collected at Raiatea) to Gould’s species. My Barffi, MS , is the Huaheine shell.

riiis species, in the shape, and the absence of palatal laminae, is nearly intermediate
between Endodonta and those species of Patula with the single parietal lamina.

The height of the spire varies from a perfect plane to a depressed cone, hence a
deeper or shallower umbilicus. They also vary in the distinctness of the periphery-
keel, and some have that part of the sheU obtusely angular, without the slightest

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

41

indication of a keel. Rarely they exhibit slight traces of spiral riblets, but the sliallow
sulcation on the upper surface is not infrequent. Immature shells have usually radi-
ating, distant, thin, deciduous, lacerated or hirsute membraneous riblets both above
and beneath. The color is greenish corneous, with small spots and stripes of reddish
brown. Raiatea examples are more variable than Huaheine specimens. The w'horls,
6-7, are marked by fine, not smooth, striae of growth. The very wide umbilicus is
more than half the diameter of the shell. The base of the last whorl is either rounded
or slightly angulated, and the aperture is subcircular in full-grown shells or subrhom-
boidal in immature examples.

E. CRETACEA, Garrett. Plate II, figs. 21, 21 a, 21 b.

Pitysficta, Garr. (not of Pease). Schmeltz, Cat. Mus. Godelf., v, p. 223 (ex. Garr.).

%

Shell very broadly umbihcated, rather solid, depressed, lenticular, finely striated,
dull whitish, with small, irregular, scattered brown spots ; spire depressed convex, or
subplanulate, with flat outlines; apex subacute; suture linear; whorls 6^-7, planu-
late, narrow, slowly and regularly increasing, the last two slightly concave, acutely
carinate on the periphery, not descending in front ; beneath the keel oblique, planu-
late; base acutely angulate; umbilicus very large, funnel-shaped, with plamilatc
Avails ; aperture oblique, quadrate ; parietal region with a single revolving lamina, and
one in the throat between the keel and basal angle ; peristome simple, acute, straight ;
columella simple.

Major diam. 6, height 2 mill.

Hal. — Borabora Island.

Common, but very local and restricted to the above island, where they Ua o on the
ground in forests at an altitude of about 600 feet above sea-level.

It is shaped and colored nearly the same as fabrefacta, but is smaller, more
depressed, and the last whorl is not so deep, and the flattened space between the tAVO
angles is more oblique. They also dilfer in the outlines of the spire, and the tAvo
internal laminae are constant.

Many of the adult shells have the umbilicus covered Avith a thin broAvnish yelloAV
membrane, Avhich, in all I examined, was perforated. Probably the animal, as in
Lihera, oviposits into the umbdicus and covers the opening Avith the membrane, and
the perforations were made when the young escaped. 1 searched, in vain, for intact
membranes in hopes of discovering either the eggs or young shells. This jx^cuhar
feature has, so fiir, only been observed in the Borabora shells. I copy the following
from the Jour, de Conch., 1865, p. 395: —

“ L’Endodonta lamellosa, Per., depose ses oeufs dans I’ombihc, ainsi qu’une autre
espece dcs iles SandAvich communiquee par M. Harper Pease: dans cette dcrnicre
I’ombilic etait convert d’une sorte d’epiphragme” (O. A. Morch).

42

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

E. Tane.«, Garrett.

mys Taneee, Garr., Proc. Cal. Acad. Sciences, 1872, iv, p. 204. Proc. Acad. Nat. Sci. Phil.,
1873, p. 234, PI. HI, fig. 65.

I’atula Janeee, Schmeltz, Cat. Mus. Godefl^’., v, p. 93. (Typ. err.)

Helix Janese, Pfeifier, Mon. Hel., vii, p. 481. (Name only ex. Schmeltz.)

Helix Tanem, Pfeiffer, 1. c., p. 482. (Name only.)

Helix Boraborensis, Pease, MS., Mus. Pease, 1863.

^^ery abundant and restricted to Borabora and Maupiti, where they live on the
ground in forests.

AVhen I wrote my description of this species I had only half a dozen specimens of
Boraborensis named from Pease’s types. Plaving subsequently gathered several
hundred of the latter species at Borabora, I find the two species gradually intergrade.
Maupiti specimens are remarkably uniform in shape, sculpture and coloration. The
Borabora shells, on the contrary, are subject to considerable variation in all the above
characters. In order to incorporate the characters of .the latter, I rede.scribe it as
follows : —

Shell widely umbilicated ; depressed, lenticular, rather thin, corneous or brownish
bom-color, irregularly spotted and rayed with rufus-brown, rarely unicolored; sculpture
consisting of very small, rude, crowded, oblique, subarcuate, raised stri®, with remote
larger ones intermixed ; the latter sometimes absent in the Borabora shells, and in the
immature they are frequently membraneous and lacerated ; spire more or less con^•ex
sometimes nearly planulate, rarely depressly conoid; apex mucronated, generally,’
suture lightly impressed, occasionally margined by the continuation of the periphery-
keel. Whorls 5|-7l, convex or subplanulate, very narrow, slowly and re^mlariv
increasing, last one not deflected in front, rarely sulcate above, periphery Cutely
bj more or less dislinctly angulate, rarely rounded; umbilicus funnel-
drapr'd, a little more than a third the greater diameter of the shell. .Vpr.rturc oblinue

Major diam. 4|, height 11 mill.

Tl.e „„mb„ra

young are occasionally dark brownish with r i i f deyated. The

undulated, and the stri® yery uniform’ Ind' l conspicuously

whorls more tightly coiled the striation “ infrequent which have the

the body-whorl is deeper ^rd the keel morobtus^

frequent ^

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

43

Genus STENOGYRA, Shuttlewortli.

S. Tockeri, Pfeiffer.

Bulimus Tuckeri, Pfeiffer, Proc. Zool. Soc., 1846, p. 30; Moii. Hel., ii, p. 158; (Opean)
Vers., p. 156. Reeve, Conch. Icon., PL LXVIII, sp. 481 ; (Opeas) Cox, Moii. Aust. Land
Shells, p. 69, PI. XIII, fig. 9. Brazier, Quar. Jour. Conch., i, p. 272. Garrett, Jour. Acad.
Nat. Sci. Phila., 1881, p. 393.

Stenogyra Tuckeri (Opeas), Albers, 265. (Opeas) Frauenfeld, Verb. Zool. Bot. Wien., xix.
p. 873. Pease, Proc. Zool. Soc., 1871, p. 473.

Bulimus junceus, Gould, Proc. Bost. Soc. Nat. Hist., 1846, p. 191 ; Expl. Ex. Shells, p. 76,
fig. 87. Pfeiffer, Mon. Hel., ii, p. 220.

Stenogyra junoea, Mousson, Jour, de Conch., 1839, p. 340 ; 1870, p. 126 ; 1871, p. 15 ; 1873,
p. 106. Pease, Jour, de Conch., 1871, p. 93; Proc. Zool. Soc., 1871, p. 473. (Opeas)
Paetel, Cat. Conch., p. 104. Schmeltz, Cat. Mus. Godeflf., v, p. 90. Garrett, Proc.
Acad. Nat. Sci. Phila., 1879^ p. 19.

Bulimus Walli, Cox, Cat. Aust. Land Shells, p. 24. Pfeiffer, Mon. Hel., vi, p. 99.

Stenogyra Upolensis, Mousson, Jour, de Conch., 1865, p. 175. (Oheliscus) Paetel, Cat.
Conch., p. 104. Schmeltz, Cat. Mus. Godeff., iv, p. 29.

Bulimus Upolensis, Pfeiffer, Mon. Hel., vi, p. 100.

Stenogyra nouemp^rato, Mousson, Jour, de Conch., 1870, p. 126. (Suhulina) Paetel, Cat.
Conch., p. 104. Schmeltz, Cat. Mus. Godeff., v, p. 90.

Bulimus novemgyratus, Pfeiffer, Mon. Hel., viii, p. 138.

A very common species, distributed throitghout all the Polynesian islands, and
extends its range to the East Indies. They range from near high-water mark to over
2000 feet above the level of the sea.

For further remarks on this species, see my paper on the Cook’s Islands land shells,
published in the Journal of the Academy of Natural Sciences of Philadelphia.

Genus PARTULA, Ferussac.

The genus Partula, so far as known, is restricted to the Pacific islands, ranging
from the Marquesas throughout all the groups as far west as New Guinea ; but is not
found in New Zealand, nor New Caledonia, nor Australia. North of the equator,
they occur at the Caroline, Pelew and Marianne Islands, the latter being the northern
limit of the genus. They are entirely absent from the Sandwich group, where they
are represented by the closely allied genus Achatinella. Neither do they occur on any
of the low coral islands.

It is now a well-known fact that each group, with one exception, is inhabited by
peculiar or endemic species. The solitary exception is P. hyalina, whicli has its
metropolis in the Austral Islands; is also found on Mangaia, one of the Cook’s group,
as well as at Tahiti.

The Society Islands, which are inhabited by nearly one-balf of the known siiecics
of Partula, may be regarded as the central point of distribution of the genus. Out
of fifteen subgenera lately established hy Dr. Hartman, ten are found in the group,
and, besides the type, which is peculiar, seven of his subgenenc types are found
no\4ere else. It is also the only group possessing strictly ten-estrial or ground

44

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

species ; and nowhere else do we find so great a variety of forms in the shape of the
shells, which varies from the almost globose P. Hebe to the slender P. elongata. It is
no less noteworthy that nearly one-half of the species have a “ button-like ” tooth on
the parietal wall, and some have a tooth-like projection on the inner margin of the
peristome, which gives the aperture an auriculatc shape — a feature found in no other
group. The Society Islands shells are also the most variable in color, and more than
half of the species are more or less spirally banded — a character rarely found in the
cxtra-limital species. y

The distribution of the various species throughout the group presents many very
interesting features, which are, indeed, worthy of more attention than I am able to
give to the subject With three exceptions, each island is inhabited by distinct species,
and some possess peculiar types or subgenera. The specific centre or metropolis of
nearly all the species is clearly defined by the profusion or concentration of indi
vuluals m Imutcd areas. In some instances we find two, rarely three, species havinir
thcr centre, of distribution in a single valley, and in some eases one is entirely
restneted to tts he^quarters, whilst the others have spread into two or more valleys
n lahiti, die largest island m the group, we find eight species only, six of which
arc endemic. One (P. c/am), which has a limited range, appears to lie graduallv
lK.ommg extinct. Four species (P .;?/am, no./om, prolaotl Ld ./o/if/a) a^ h

fact that, notwithstandincr both soeciV. h islands. It is a noteworthy

Lave not deveioped a Stgk tXrfe^tlmTf

uniform in ail their specific characters One ’ u ’ a'”''™vy, are reinnrkiiWy

etcamples of P. ° routliem

"on (eferwed coral reef,), would have exhibit d temperature and different forma-
rroin the Tahitian specimer iy ng in

, ng in d higher temperature on a volcanic

conditions of life, jttTo^hTvVmT^^^^^^^ the island, and all subject to the same
typical forms, and the other, which is verv ^ to depart from the

"’™> '“O"' '"ioties. The above facts w hU Las developed

-ggest that physical conditions are no he

“ '•>0 operation of some unknown law ‘ but that it

Moorca, which is separated from Tahiti bv a cl , ,

bj a channel only eight miles wide, is

TERRESTRIAL MOLLUSC A INHABITING SOCIETY ISLANDS. tf)

inhabited by four species found nowhere else. One (P. Ut^niata), which lias its
metropolis in a large valley on the north coast, is, like P. OtalieiPnm, a very ^'ariable
species, and has spread round three-fourths of the island, and, like the latter species,
has developed local varieties which have received distinct names. P. llneata, which
inhabits that ])art of the island not occupied by tceniata, is nearly as variable as that
species. P. elongata, which is confined to the same portion of the island as Uneata,
is less variable, and where it comes in contact with tceniata we find liybrids between
the two so common as to suggest a certain degree of fertility in the intermediate forms.
P. Jlooreana, which is always reversed, is confined to a single valley and shows but
slight variation.

One peculiar feature in the Tahiti and Moorea shells is the profusion of sinistral
forms which are entirely absent from the leeward i.slands in the group.

Huaheine, like Moorea, possesses four endemic species, all of a dift'erent type from
those inhabiting the preceding two islands. Two (P. argata and annertens) are
restricted to two valleys, and the latter, like P. clara, appears to be gradually becoming
extinct. Both species are remarkably uniform in all their specific characters. On
the contrary, the other two species (P. rosea and varia) have spread nearly all over
the island, and are subject to considerable mutation. It is worthy of remark that
dentated species, which are so common at all the islands except Borabora, do not occur
on Huaheine.

Raiatea, though only fourteen miles long and nearly half as broad, is inhabifi'd by
twenty species of Part at a, being one-half of the number assigned to the whole grou]),
and eighteen are found nowhere else. These, according to Dr. Hartman’s divisions,
include not only the type, but fi^e out of his fifteen subgcncra, two ol‘ which are
peculiar to the island. Nearly all the species are remarkably prolific, and. with few
exceptions, are subject to greater or less variation. Ten of these varieties being local,
have usually be('n regarded as distinct species. Six species are strictly terrestrial.
The fine large typical P. fa^a, which has its metropolis at Utuloa on the north end of
the island, has spread into nearly all of the valleys, and is e(pially as variable in all
})arts of the island as in its headquarters. On the adjacent island of 'lahaa w^e find
the same species represented by distinct varieties. Two of the Eaiatea species {P.
targlda and P. attenaata), though having an extensive range, do not vary in a single
feature ; the former, like P. clara and annectens, seems to be dying out. Three s])ecies
(P. calli/era, citrina and aariculata) are restricted to single valleys, and the two former,
like iurgida and attenaata, are very uniform in color and shape. All the other sjiecies,
though having special headquarters, ha\e a greater or less range over two or more
v alleys, and ten species have produced local varieties.

Passing over the narrow lagoon to Tahaa, the latter about the size ot Huaheim*
Ave find four endemic species, and, as before stated, tAVO local A'arietics of P. faha ; one

JOUR. A. N. S. PHILA., VOL. IX.

46

TERRESTRIAL

MOLLUSCA INHABITING SOCIETY ISLANDS.

()ccui)yiiig tliat part of the island nearest to the metropolis of the t> pe, and the other,
which is fr(>qiiently deiitated, is distributed over the remainirig portion of the island.
The beautiful P. hiUneata is confined to a single valley on the eastern coast, and P.
planilahrum, which has its headquarters in the large Haamene valley, just to the
southward of the home of the former species, has established a colony in the valley
on the north side of the one occupied by P. bilineata. P. rnnhiUcatu, which shares
the metrojiolis of phinilahriim, has, like that species, avoided intruding in the home
of hilineota, but to the northward it occupies several valleys, slightly overlapping the
northern range of P. virginea, which latter has its metropolis on the west coast, and,
like P. tnnhilicida, ranges throughout several valleys north of its headquarters.

Borabora, the smallest island inhabited by Parfidn, possesses a single species of a
peculiar type, which has spread nearly all over the island without develo])ing a single
local variety.

Hybrids between P. elongata and P. tcenvda, and between P. (rarretfii and P.
Thalia, are so common where those species come in contact, that I am inclined to
believe they possess a certain degree of fertility. 1 have also detected several hybrids
bc'twcen P. faba, var. si/baugalata, and P. virginea ; one between the arboreal P.
imperforata and the terrestrial P. lagabris ; two between J\ Hne(da, var. strigosa, and
l\ taaiiata ; about a dozen between the arboreal ]\ faba and the terrestrial P. raduda ;
a number between P faba and P. fasca, and many between the latter and P. naidga-
foria, as well as many between the latter and P. faba. I failed to det(>ct hybrids
between the 'fahitian species, and found none at Iluaheine.

Ihe examination of the animals of the various species has convinced me that they
])ossess no reliable external leatures that will aid in their determination. The colora-
tion ill all the species varies from pale cinereous, through all the intermediate shades,
to black or dusky slate. The arboreal species arc generally lighter colored than the
ground spiTies, and have a more expanded creeping-disk. The animals of I\ argaia,
annectens, iargida and atteniada, have the ocular tentacles longer and more slender
than the other species, and the exudation of mucus is much more copious and more
viscid or tenacious than usual, reseiubliug in that respect the same difference as exists
between tlie typical Helices and the arboreal Naniiue.

P. Otaheitana, Bruguiere.

Jiulimus OlaheitanuK, Bruguiere, Enev Meth ; t i » •

ed u 281 Kiisior T>i y- ^eth., 1, p. 34u Lamarck, Anirn. sans Vert., Desli.

ed.,p.281. Kuster,I>l.XIV,figs.5-6. Pfeiffer, Mon. Hel., ii, p 71 part

JMi oTrT’ n f 108, PI. CXII, figs. 950, 951. ’

t ,r' “■ 1>- I»-'- Tow.. PI. XXXIV.

Parlula Otaheitana, Perussae Prr,a cp r. ^

CoTOh. loon., P,. lit 13. Ts’l, T ’ »8- >«:

ill, P. m. Couch n lof ’ fi ™ -

-oodent; Obc. Oo„. P.,„., B.„, c„,„, Lcl.X! ^1"”“’

TERRESTRIAL MOLLUSOA INHABITING SOCIETY ISLANDS.

47

Partulus Otaheitanus, Beck, Ind. Moll., p. 58.

Helix Vanicorenifis, Quoy and Gaimard, Voj^ Astrolabe, ii, p. 115, Bl. IX, ligs. 12-17.
Bulimvs Vanicorensis, Lamarck, Aiiim. sans Yert., Desk, ed., p. 282. Pfeiller, Mon. Hcl.,
ii, p. 71.

Partulus Vanicorensis, Beck, Ind. Moll., p. 57.

Partula Vanicorensis, Pfeiffer, Mon. Hel., iii, p. 446. Paetel, Gat. Conch., p. 104.

Buhninus isabelUnus, Pfeiffer, Proc. Zool. Soc., 1846, p. 39 ; Mon. Hel., ii, p. 70.

Partula tsa5eZZfna, Reeve, Conch. Icon., sp. 10, PI. II,flg. 8 6. Pfeiller, ^lon. Hel., iii, p. 448.
Paetel, Cat. Conch., p. 104.

Bulimics amabilis, Pfeiffer, Proc. Zool. Soc., 1846, p. 38 ; Mon. Hel., ii, p. 71.

Partula amabilis, Reeve, Conch. Icon., sp. 8, PI. II, ligs. Sa, 10. Pfeiffer, Mon. Hel., iii, p.

448. Pease, Proc. Zool. Soc., 1871, p. 473. Paetel, Cat. Conch., p. 104.

Partula ruhescens. Reeve, Conch. Icon., PI. Ill, flg. 12. Pfeiffer, Mon. Hel., iii, p. 446.
Pease, Proc. Zool. Soc., 1871, p. 473.

Partula Beeveana, Pfeiffer, Proc. Zool. Soc., 1852, p. 137 ; Mon. Hel., iii, p. 447. Chemnitz,
ed. 2d, Bid., PL LXV, ligs. 10, 11.

Partula Taheilana, Gould, Expl. Ex. Shells, PI. LXXXIV, lig. 91. Pease, Proc. Zool. Soc.,
1871, p. 473. Paetel, Cat. Conch., p. 104. Schmeltz, Cat. Mus. Godeff., v, p. 92.

Partula lignaria. Pease, Proc. Zool. Soc., 1864, p. 671 ; 1871, p. 473. Pfeiffer, Mon. Hcl..

vi, p. 160. Paetel, Cat. Conch., p. 104. Schmeltz, Cat. Mus. Godeff, v, p. 92.

Partula rufa. Carpenter (not of Lesson), Proc. Zool. Soc., 1864, p. 675. ( Helena) Hartman,

Cat. Part., p. 10.

Partula affinis. Pease, Amer. Jour. Conch., 1867, p. 224; Proc. Zool. Soc., 1871, p. 473.

Schmeltz, Cat. Mus. Godeff., v, p. 92. Pfeiffer, Mon. Hel., vlii, p. 204.

Partula sinistrorsa. Pease, MS. Coll. Pease, 1863. Paetel, Cat. Conch., p. 104. tschmeltz,
Cat. Mus. Godeff, v, p. 92. Pfeiffer, Mon. Hel., viil, p. 209. Gloyne. Q.uar. Jour. Conch.,
i, p. 337.

Partula sinistvalis, Pease, MS. Coll. Pease, 1863. Paetel, Cat. Conch., [i. 104. 1 feiller,

Mon. Hel., viii, p. 209.

Partula crassa. Pease, MS. Coll. Pease, 1863.

Partula brevicula. Pease, MS. Col. Pease, 1863.

Partula perversa, Pease, MS. Coll. Pease, 1863.

Partula turricula, Pease, MS. Coll. Pease, 1863 (not turricula, Pease, in Amer. Jour.
Conch., 1872).

Partula varia. Carpenter (not of Broderip), Proc. Zool. Soc., 1864, p. 675.

Partula Pacifica, Hartman (not of Pfeiffer), Cat. Part., p. 10.

Partula diminuta, Hartman (C. B. Adams ??), 1. c., p. 10.

The metropolis of the typical Otaheltana is about two miles up hautaiia valley,
on the northw’est part of Tahiti, where it is very abundant on the trunks ami folia)j;e
of trees and bushes. The above-mentioned valley being close to the principal harbor
whicli was frequented by the early navigators, it was undoubtedly wliere Bruguiere s
type was obtained.

The Fautana shells, which are very variable in size, shape, and color, are ne\er
ornamented by spiral bands, and about one-third of the specimens are sinistral. 'Fhe
parietal tooth is nearly always pre.sent in the adults, and the peristome, though usually

48

TEKKKSTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

wliitcN is frequently pinky flesh-color. The prevailing colors are straw-yellow, reddish
fulvous, light chestnut, frequently with the spire more or less tinted with reddish and
often with longitudinal strigations. The spire is more or less produced, and the
aperture varies some in size and shape.

The shape of the shell varies from abbreviate-ovate to elongate-ovate, as the
following measurements will show : —

Length 21, diam. 10 mill. Uextral sp.

Length 16, diam. 10 mill. Dcxtral sp.

Length 20, diam. 10 mill. Sinistral sp.

Length 16, diam. 9 mill. Sinistral sp.

All tlie old authors refer to sinistral forms. The elongated dextral shells were
described under the names Vonicorensis and Reeveana.

In a valley about two miles west of Fautana, there exists in abundance the variety ( ?)
lignarix. Pease, which, though described as dcxtral, is nevertheless very frequently
sinistral. Though not attaining quite so large a size as the Fautana shells, it differs
none in .shape, but is usually darker colored and more .strigated, as well as exhibiting
one to tliree transverse reddish chestnut bands. The lip is always white, and the
])arietal tooth is very seldom absent. The inosculation with OtaJieitana is so comphde
that it cannot be even separated as a well-marked variety.

To tlie eastward between Fautana and Papinoo valley, a distance of about eight
miles, there are three valleys, all inhabited by Pfeiffer’s amahilis, a sinistral form which
has not a single feature to distinguish it from some of the large turreted Fautana
sliells. In the first valley, Pfeiffer’s species, though not abundant, were very fine
specimens. The next valley, known as Pirai, the metropolis of the small dextral R.
jUooa, which occupy the lower part of the valley, is, in the upper part, which trends
towards the headquarters of Otaheitana, inhabited by the sinistral nmahilis. A few
immature examples were found which were banded like lujnaria. 'J'he only dextral
Partnln' taken in the two Aalleys were filosa, aitenuata and liyalina.

In the next valley, called Haona, I found the dextral P. (ijfinis abundant, and took
a few of timabilis.

Botli Dr. Pfeiffer and Reeve described the latter species from specimens in the
Cummgian collection, and both quote Anaa, a low coral island, as its habitat. Having
resided about five months on that island, and searched all parts for shells, I did not
find a single Pariula there, or on any other low coral island. Mr. Pease, in his list
of Polynesian land shells, assigns it to Tutuila, one of the Samoa or Navigator
Islands. on authority I do not know. The type is purely Tahitian. Dr.

” u "w J' r the correct loealitv. Though

prclent ^ very frequently

Pease’s which cannot be separated from

some of the small abbreviated

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

49

forms of Otalieitana, occurs in greater or less abundance in all the valleys from Haona
as far as the southeast end of Taiarapu peninsula, and round the opposite coast as far
as Papieri on the southwest of Tahiti proper. In Papinoo I discovered a large colony
of affinis, many of which had the pinky flesh-colored lip and sinistral form of Otuhei-
tana. Far up in the same valley, though common, none but dextral forms were found,
and out of thousands taken in the other valleys, not one sinistral example occun'cd to
my notice. In a valley several miles from Papinoo I Ibund a small colony of affinis,
which were marked by three transverse reddish chestnut bands like h’f/naria. And
most singular, no other handed specimens of affinis occurred to my notice in any other-
part of the island. It is the variety daSicf, Pse., and by Carpenter erroneously referred
to varia.

Reeve’s rubescens = tarricula, Pse., MS., is abundant in Papinoo, and occurs
sparingly in all the valleys as far as the southeast end of the island. Like amahilis
it cannot be separated from the sinistral turreted Otaheitana, inhabiting Fautana, It
is always sinistral, never banded, and, though usually of a reddish tint, is frequently
straw-yellow or fulvous, with or without a reddish or pinky apex. The lip is wliitc or
pinky flesh-color. Though described as edentate, some have a small parietal tooth.
Reeve gave no locality, and Pfeiffer erroneously cites the Marquesas as its habitat.

Pease’s sinistrorsa is confined to the south coast of Tahiti proper, where it exists
in the greatest profusion in all the valleys and lowland forests for a distance of ten or
twelve miles. In the valley which is the limit of the range of the dextral affimis 1
took several specimens of the sinistral sinistrorsa. The latter is invariably reversed,
dentate or edentate, fulvous with three more or less diffused reddish chestnut bands.
Reeve figures the same shell on Plate III, fig. 13 n, as Otaheitana. Bandlcss varieties
are frequent, and vary from straw-yellow to fulvous or light chestnut, frequently strigated
and the lip white. The latter varieties differ none from the true Otaheitana of
Fautana.

It is worthy of remark that in that part of the district of Papieri, occupied by
sinistrorsa, is also the headquarters of the terrestrial P. prodneta, a dextral s^x-cics,
which is always edentate, and exhibits the fasciation of the former.

After passing to the westward of the range of the typical sinistrorsa, which
presents the same features for a distance of ten or twelve miles, it sudderdy exhibits a
tendency to a change in its becoming more stunted, more solid, always dentated, and
the bands, one to three, are sharply defined on a pale ground. It is the sinistrahs of
Pease, MS., and occupies two valleys.

In the next large valley, called Faahuaite, on the southwest coast, we find Pease’s
(rrassa (MS.), which is also a sinistral shell, always dentated, solid, more tightly coiled
than sinistrorsa, and the body-whorl is more flattened. It is rarely marked by a single
narrow submedian chestnut band. In the same valley, but more inland, occurs a
smaller form, which is, I suppose, the P. hrevicida, Pse., MS.

50

TP]RKESTIIIAL MOLLUSCA

INHAIJITING SOCIETY ISLANDS.

The following > alley, named Punaavia, ie the metropolis ol the ^

which also cxhiht three bands. Far above the restricted miige of the latter where
the valley turns towards the head of Fautana, the home ol the typ.eal tWmdono I
took a fel e.xamples of a Mvh,, similar to, but larger than 1 he next valley

is the habitat of Kgnaria.

Perhaps it may, by some, be suggested that I ouglit to have been more conservative
in my treatment of the OtaheU<ma group, which, to say the least, is a very iM-rplexing
one to separate into species or even well-marked varieties. However, I think H
iiffmis, rnhescms, crassa, sinistrorsa, and perhaps Hgnaria, may rank as varieties which
intergrade with the typical Otaheitmia. But those who believe that siiecies, like
genera, have no sharply defined boundaries, but are connected to others by transitial
forms, will in all probability consider them distinct, but closely allied species, but of
less Aalue than P. Jiy<iKn<i, Jilosa and nodosa.

P. i.iNEATA, Ircsson. Plate III, fig. 83.

Partula lineata, Lesson, Voy. Coquille, p. 324, PI. VII, figs. 8, 9. Peeve, Conch. Icon.,
PI. II, fig. 7. Pfeiffer, Mon. Hel., iii, p. 449. Carpenter, Proc. Zool. Soc., I8C4, p. fi75.
Schineltz, Cat. Miis. Godeff, iv, p. 72.

Parlulus torosvs, Beck, Ind. Moll., p. 57.

Partulus linealus^ Albers, Die Hel., p. 187.

Partula strigosa, Pfeiffer, Proc. Zool. Soc., 185fi, p. 384; M.alak. Blatt., 185fi, p. 244 ; .Mon.
Hel., iv, p. 509.

Partula alternata, Pease, MS. Coll. Pease, 1863.

Partula vexillum, Pease, Amer. Jour. Conch., 18GG, p. 198; 18G7, p. 81, PI. 1, fig. 8; Proc.

Zool. Soc., 1871, p. 473. Pfeiffer, Mon. Hel., viii, p. 196.

Partula nodosa, Carpenter (not of Pfeifler), Proc. Zool. Soc., 1864, p. 675 (=- alternata).
Pease, Proc. Zool. Soc., 1871,'p. 473 (part). Schmeltz, Cat. Mas. Godeff., v, p. 92 (part).
Gloyne, (^uar. Jour. Conch., i, p. 337.

Partula stenostoma, Hartman (not of Pfeifler), Cat. Part., p. 10.

Partula suturalis, Hartman (Pfeiffer?), 1. c. •

lids beautiful arboreal species is found in great profusion in \'aianai valley, on
the southeast coast of Moorea. where it occurs in company with P. Mooreana and P.
elcmgatn. It also exists in considerable numbers in a small valley about ttvo miles to
the AvestAvard, associated Avith J\ Urmata and elongata.

I first discovered this species in 1861, and obtained several hundred siK^eimens,
all collected on the eastern .side of the .stream that flows through the vallev of Vaianai
I hey Avere dextral, and Avere so described by Pea.se, under the name'of veHlhnn.
Ol. a siToml visit, m 18 1.5, 1 took over 2000 examples, all gathered on the a-atern side
of the siren..,, and was surprised to find many sinistral forms among them. At the same

he‘oLl°s".' “i f M T »" somieircuhir valley on

.he opposite side of the island. They were probably stragglers from Vaianai.

IS noteworthy that no reversed Partutm were found in any other iiiirt of the
island exee,,t on the western .side of the stream in Vaianai, and the aboveonentioned

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

51

stragglers taken on the opposite coast. The same side of the stream is also tlie home
of the sinistral ]\ Mooreava.

Several miles to the eastward of Vaianai, in a large valley named Oahnmi, it is
found equally as abundant as in the former location. The Oahnmi shells, which are
slightly modified (= strigosa — alfernata), gradually inosculate with Uneata. It
occurs, also, sparingly in a ^'alley more to the eastward, where it is associated with P.
tceniuta and striolata.

The type is luteous, or straw-yellow, rather shining, and girdled by two or three
narrow, equidistant reddish chestnut bands. The shell is comparatively thin, com-
pressly perforated, more or less Avrinkled by incremental striic, and the tine spiral
incised lines are generally obsolete on the last whorl. The produced spire is a trifle
more than hall' the length of the shell. The rather small aperture is truncately oval,
and the parietal tooth is seldom absent. The white peristome is rather thin, mod-
erately expanded, slightly reflected, lightly labiated within, and rarely with a slight
sinus above. I'he columellar lip is receding above at its junction with the parietal
wall.

Length 19, diam. 10 mill., which are about the average dimensions.

The folloAving color-varieties occur ; —

Var. a. Uniform chestnut-brown, sometimes approaching blackish brown, with a
pale sutural line. Rare.

Var. h. Dark chestnut-brown, with a wide, median, luteous band on the body-whorl.
Rare.

Var. c. laiteous or straw -yellow, Avith a very broad, deep, chestnut band oh the
middle of the body-Avhorl. Rare.

Var. (1. Imteous, Avith faint, longitudinal, light fulvous-broAvn strigations.
Common.

The sinistral examples, of Avhich I obtained about fifty, exhibit the same A ariation
as the dextral shells.

Contrary to the opinion of Messrs. Pease and Hartman, I folloAV Reeve, Pfeiffer
and Carpenter in referring this species to Lesson’s lineata, AAliich that author erro-
neously accredited to Oualan or Strong’s Island, one of the Caroline group. Les,son
either collected his specimens at Moorea, or he received them from some of the foi'cign
residents at Tahiti, and, as was too frequently the case Avith the naturalists of the
exploring expeditions, had forgotten the correct habitat.

The folloAving is a translation of Lesson’s brief descriptioir :

“ Shell perforated, oblong-oval, luteous, with two fulvous bands ; spire conical ;
Avhorls six, slightly convex, last one as long as the spire ; aperture oval ; peristome
expanded ; columellar margin much thickened AAithin. Length 8, diam. 5 lines.
Hah. — Oualan Island.”

62

terrestrial mollusca inhabiting society islands.

So far as the description goes, it coincides with tlie pale, banded, edentate Moorea
shells.

Reeve describes it as follows : —

“ Shell acuminately oblong, umbilicated, rather thin, whorls six in number, spirally
very finely striated, light fulvous, subtransparent, encircled with two distant chestnut
])ands. Lesson, Voyage de la Coquille, p. 324, Plate \ II, figs. 8, 9. Hah. biiendh
Islands ” (Reeve).

Like I.esson, he does not mention the parietal tooth, which is well-expressed in
his figure. Ilis description is from examples in the Cumingiau collection, and is
certainly the Moorea shell. His habitat, “ Friendly Islands” = Tonga, is incorrect.
Only one species (P. suhgonoc7ieila) inhabits that grouji.

Pfeiffer, in his “ Monographia Heliceorum,” vol. iii, gives a more detailed descrip-
tion of Uneata, also from .specimens in Cuming’s collection, and cites “Oualan et
Eimeo ” (= Moorea) as location, but in his subsequent volumes omits the latter loca-
tion. Like the two former authors, he does not allude to the parietal tooth.
However, he makes tlie same omis.sion in two other dentated species.

A candid comparison of Pfeiffer’s descriptions of P. sfenostoma and lineata has
convinced me that they cannot refer to the .same species. I’hc latter uudoubtc'dly is
tlie Moorea shell. Tlie former, according to the measurements, refers to a larger and
more robust shell, being, in fact, the same size and proportion as J\ planilahnim. In
Pfeiffer’s original diagnosis he .says “ hete ca.staneo bilineata,” and, in his Monograph,

“ lacte castaneo trilineata.”

'I'he Oahumi shell which was described by Pfeiffer under the name of strigasa.
i.s, by some authors, afiiliated with P. nodosa, an entirely different species, inhabiting
a limited area in Tahiti. Mr. Gloync and Dr. Hartman first pointed out its very
close relationship with /-*. vexUlam = Uneata. Indeed, the inosculation is so complete-
that the} must be considered one and tlie same species.

Ihc Oalnimi shells me usually a tiifie smaller, not so frequently dentate.!, and are
mud, n.ore conspicuously strigated than the Vaiauai shells. The spiral la.nds, of
which there are one or two, seldom throe, on the body.whorl, are very lrc,,„eutly
ntarupted, which, with the conspicuous strigations, gives the shell a somewhat tessel-
lated appeamiue. All the eolor-varieties alluded to in inv remarks on the Vah.nai
diclls are also loun.l in Oahumi, hut the uniform dark-colored ones are more frequent

tris i:::f ^ took three e-Z^::.'
He gives the .ZiZ;' MZaZ ts ZZ

describes found in the western Picifie T. • ’ Zl' 'll’®

anil I fully agree with Dr Hartman ' • f » Society Islands species,

The .lescription is sufflcientlv near to iusKfvZ ‘d Z”

.1 ■ the identification. Rut I cannot share

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

53

the above author’s views in regard to Pfeiffer’s P. suturalis being = strigosa. There
is too much discrepancy in the two diagnoses to warrant their affiliation.

P. LUTEA, Lesson.

Farhila lulea, Lesson, Yoy. Coquille, p. 325. Pfeiffer, Mon. Hel., iii, p. 453. Pease, Proc.
Zool. Soc., 1871, p. 473. (Ilia) Hartman, Cat. Part., p. 8 (with woodcut); Obs. Gen.
Part., Bill. Mus. Com. Zool., ix, p. 184, part.

Bulimus luieus, Deshayes, Per. Moll., ii, p. 123, PI. CLVIII, figs. 17, 18. Pfeifter, Mon.
Hel., ii, p. 229.

Fartula solidula, Sclimeltz, Cat. Mus. Godeff'., v, p. 92 (not of Reeve).

Fartula lilacina, Pfeiffer, Proc. Zool. Soc., 1856, p. 334. Pease, Proc. Zool. Soc., 1871,
p. 334.

This, the only species of Partvla inhabiting Borahora, is peculiar to and widely
diffused throughout that island. They occur in larger numbers both on the trunks and
foliage of trees and bushes. Notwithstanding its wide range over the island, it has not
developed a single local variety. In fact it exhibits less variation than some of the
species at the other islands which are restricted to single valleys.

It mav be recognized by its rather solid texture, ovate-conical form, rather short
spire, large inflated body-whorl, small compressed perforation and white suboval
aperture, 'fhe parietal region is nerer toothed. The peristome is white, moderately
expanded, not very thick, labiated within, surface rather flat and sloping. Columellar
lip subnodose. Color whitish corneous, luteous, fuhous brown, with or without a
brown or purple-brown apex. It is never banded. Some are more elongate than
others, as the following measurements will show : —

Length 20, diam. IQt mill.

Length 16, diam. 1()| mill.

A careful comparison of lutea with Pfeiffer’s description of lilacina has convinci'd
me of the correctness of Dr. Hartman’s views in uniting the two species. I have no
examples of the “lilacina” color mentioned by Pfeiffer. If the determination is
correct, his habitat “ Marquesas ” is certainly wrong.

Reeve’s P. solidvla is decidedly distinct, and of a different type from lutea. Ih-eve’s
figure closely resembles Pease’s compacta, but wants the parietal tooth of that species.
Pfeiffer describes the peristome as “ late expansum, margine dextro superue sinuato,
turn strictusculo,” which agrees with Reeve’s figure, but not Avith lutea.

P. Hebe, Pfeiffer.

Bulimus Hebe, Pfeiffer, Proc. Zool. Soc., 1846, p. 39 ; Mom Hel.,ii, p. 68. Chemnitz, ed.
2d, PL LXIV, figs. 7, 8.

Fartula Hebe, Reeve, Conch. Icon., sp. 25, PI. lY, fig. 25. Pfeiffer, Mon. Hel., iii, p. 453.
Pease, Proc. Zool. Soc., 1871, p. 473. Paetel, Cat. Conch., p. 164. Schmeltz, Cat. Mus.
Godeff., V, p. 92. (tEnone) Hartman, Cat. Part., p. 9 (with Avoodcut) ; Obs. Gen. Part,,
Bui. Mus. Com. Zool., ix, pp. 183, 193.

8

JOUR. A. N. S. PHII.A., VOr. IX.

54

TKRnESTlUAI. MOLLUSCA INHABITING SOCIETY ISLANHS.

,.ar,..,a IWe. MS. <M„a Pee, Gloy„e, Q.,«r. .lour. Coucl.., i, 338.

Schmeltz, Cat. Mas. Godeff., v, p. 207.

uen/r/cosa, Garrett, MS.

Partula Hebe, var. bella, Pease, Proc. Zool. Soc., 1871, p. 473.

The snei ific ec.utre of the type of this small white species is in the laiRe valley of
Faaloa, on the eastern coast of Ratatea, where it is found iu great profusion on the
foliage of hushes. From this central point it has migrated to the northward, where
it is found, though less abundant, in an adjacent valley, associated with the typical
/>. dentifera. About two niile.s to the southward, on the same side of the island, m
a large valley called Opoa, is found in large numbers the pretty variety (=
glohoan. Pse.), which has passed over a range of wooded hills into a large valley on
the south coast, where it occurs in limited numbers in company with P.formoaa. In
another ^ alley, some distance to the northward, on the west coast, we find another
variety P. ventricosa, Garr.), which, though shaped like the type, in color closely
rc.si'inbles P. crassUahris, a ground species.

Th(‘ tyjie, which is (dmays decorticated, may be readily distinguished by its ovaU‘-
globose shajie, uniform white color, not shining, constant prominent parietal tooth and
subcirenlar aperture. Associated with the type are two varieties ; one, pinky white, is
very rare; the other, white with an orange-colored spire, is rather rare. Ihe variety
hella, l’s('., differs none from the type, except in having the spire more or less light
red and the body-whorl most generally Avith a very thin, smooth, pale yellowish horn-
(tolored ejiideriuis. The variety ventricosa, Garr., is usually a little smalh'r than tlu*
tyjH?, not decorticated, and is more variable in color, but never banded. 'I'he ground
color varies from whitish to fuhous, rarely with a reddish spire, but more frequently
with the apex of a purple-brown hue.

I’.'IMI-KRFOKATA, I’casc, MS. Plate III, fig. 53.

Partula imperforata, Pease, MS. Coll. Pease, 1863. Paetal, Cat. Conch., p. 104. Pfeitler,
Mon. Hel., viii, p. ‘209. (Astrsea) Hartman, Cat. Part., p. 8 ; Obs. Gen. Part., Bui. Mas.
Com. Zool., ix., pp. 183, 195 (part).

Partula dentifera, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675. Hartman,
Obs. Gen. Part., Bui. Mas. Com. Zool., ix, p. 186 (part).

Partula recta, Pease, MS. (not recta. Pease, in Amor. .Jour. Conch, 1868) Coll. Pease, 1863.

Partula auriculata, var., Carpenter, Proc. Zool. Soc., 1864, p. 675.

Partula liaiatensis, Garrett, MS.

Shell imjK'iforated or compres.sly umbilicatcd, solid, oblong-conic, sometvhat shining,
with rather smooth, irregular, incremental strite and closely set delicate spiral incLsed
lines, which are more or less evanescent on the bodjMvhori ; color, pale straw-yellow,
hiteous, or fulvous, with or without a rosy apex ; spire conical, tvith subplanulate
outlines, about half the length of the shell; suture sometimes margined by a ruo'ose
wliib line, n boils 5-5 1, flatly convex, the last one convex or convexly rounded; base

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

55

imperforate, rimate or compressly umbilicated ; aperture subvertieal, oblong, obauri-
forni, white, sides nearly parallel ; parietal wall with a more or less well-developed
tubercular tooth ; peristome white, thick, moderately expanded, surface concave,
heavily labiated within, strongly contracted above, forming a rather profound sinus,
and generally subdentate next to the emargination ; columellar lip subuodose.

Length 21, diam. 12 mill.

^'ar. a. Uniform chestnut-brown. Rare.

Var. h. Base and sutural band chestnut-brown. Somewhat rare.

A ar. c. With a broad, median, chestnut-brown band. Rather rare.

This species is restricted to Toloa and Hapai valleys on the west coast of Raiatea,
where it is abundant on foliage.

1 nke all the species, they differ some in size, shape, and some have the spire more
abbreviated than others. The type which inhabits llapai valley is nearly always
imperforated and may be distinguished from the imperforate formona by its smaller
size, gibbous columella and parietal tooth. Carpenter confust'd it with dentifern, an
allied species, confined to the opposite side of the island.

P. Raiatensis = recta. Pse., MS., which inhabits Toloa, was by Carpenter referu'd
to ((i/rictilain, a species of a different type. Dr. Hartman unites it to dehtifera. After
a careful study of about 2000 .specimens of the two species, I have annexed the Toloa
with the Hapai .shell. The only difference between the two is that Raiatensis is usually
lighter-colored, seldom imperforated, and the apex is much more frecpiently rose-red.
Tt is, I think, more nearly related to the dentated inhabiting the neighboring

island, than to dentifera.

The latter species is much more frequently edentate on the parietal wall, the lip
thicker, more angadated on the surface, and the labial tooth much larger and more
acute. It is never banded, and the ajiex is not rose-red, but is frequently tinged with
lemon-yellow.

P. COMPACT.^, Pease.

Partula comijacta, Pease, Amer. .Jour. Conch,, 1866, p. 200; 1867, p. 81, PI. 1, lig. 9 ;
Proc. Zool. Soc., 1871, p. 473. Paetel, Cat. Conch., p. 104. Sehmeltz, Cat. Hus. Godefl'.,
V, p. 92. Pfeiffer, Mon. Hel., viii, p. 207. (Nenia) Hartman, Cat. Part., p. 7 ; Ohs. Gen
Part., Bui. Mus. Com. Zool., ix, pp. 181, 192.

Partula auriculata, var.. Carpenter, Proc. Zool. Soc., 1864, p. 675.

Partula callifera, Gloyne (not of Pfeiffer), Qtiar. Jour. Conch., i, p. .338.

The metropolis of this common, solid, arboreal species is in Hamoa valley, on the
east coast of Raiatea, the home of P. callifera. It is confined to the lower half of
the valley and has not spread any to the southward, hut to the north it is found in
limited numbers in two small valleys.

Its ])rincipal features are its ovate-conic form, conshxnt parietal tooth, subauriculate
aperture, xvhicli is much contracted by a thick deposit of callus in the inner margin

56

■[■KUKKSTIilAL MOLLUSCA railABITlNG SOCIETY ISBANUS.

of 11.0 lip which latter is verv broad, dattoned and cons|.ic..ously sim.ous above.
The columella ia n.or,- or leas gibbous. Color yellowish corneous, very rarely fulvous
or fascia ted.

Had Keeve alluded to a parietal tooth in his description and figure of sohdola,
I would not have hesitated to refer compacta to that species.

P. CL.vRA, Pease. Plate III, fig. 75.

Partula clara, Pease, Proc. Zool. Soc., 1864, p. 671 ; 1871, p. 473. Pfeifter, Mon. Hel., vi,
p. 159. (Pasilliea) Hartman, Cat. Partula, p. 11; Obs. Gen. Partula, Bui. Mus. Com.
Zool., p. 181, vol. ix.

A rare specie.s, found on foliage in the upper portions of the valh;ys in the south-
west part of Tahiti. Like P. annectens, of Huaheine, and J\ furgida, of Raiatea, it is
gradually becoming extinct.

It is a small species (16 mill.), corneous, sometimes with darker stripes, and more
rarely with one or two transverse chestnut bands. The aperture is always (‘dentate.

P. G.^RRKTTir, Pease. Plate III, fig. 48.

Partula Oarrellii, Pease, Proc. Zool. Soc., 1864, p. 672; 1871, p. 473. Pfeiffer, Mon. Hel.,
vi, p. 158. Sehmeltz, Cat. Mus. Godeff., v, p. 207. {Helena) Hartman, Cat. Part., p. 10;
Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 182.

Partula gonocheila, Sehmeltz (not of Pfeiffer), Cat. Mus. Godeff., v, p. 92.

The sjK'cific centre of this small and Avell-marked species is Vaioara, on the west
coast of Raiatea, where it exists in prodigious numbers on bushes. It has spread
1101 th and south of its metropolis, and in the former direction has .slightly overlapped
the .soiitliern range of P. Thalia, and hybrids between the two species ar(‘ (piite
common. 'I’o the southward it ranges about one mile, where it extends a short
distance up a valley which is the home of P. cifrina.

Its princijial characters are its small size, contracted aperture, rounckKl or an<ni-
lated peristome and nodulous columella, which latter is, as it were, pushed in towards
the aperture. Tlie parietal region is very rarelv toothed. It is wliitish or pale
yellow,* hom-color, „.rely fulvous oi- light browu, and sometimes the apex is purple-
brown. A variety with a brown base and sutural band is not infrequent.

P.

TURiiiDA, Pease. Plate III, flg. 74.

Bulimus turgidus, Pease, Proc. Zool. Soc.

Ad, p. 12. ’’

Partula turgida {Echo), Hartman, Cat. Part,
ix, p. 188. ’

1864, p. 670; 1871, 473. Pfeiffer, Mon. Hel.,
p. 12; Obs. Gen. Part., Bui. Mus. Com. Zool.,

Tlioiigh widely diffused over Raiatea, it is nevertheless excessively rare It is

nearest „meV;:eies

ke p. rla a and P annecteas, it appears to be gradually becomiim extinct
It does not inhabit “ Tahiti,” as stated by Pease. "

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

07

P. FABA, Martyn. Plate III, figs. 78, 79, 80, Vars.

Umax faba, Martyn, figs., etc., PI. LXVII. Cliemi, Bibl. Conch., ii, n. 24, PI. XXIV,
fig. 2 a.

Anris Midse fasciata, Cliem., ix, p. 44, PI. CXXI, fig. 1041.

Helix faba, Gmelin, p. 3625. Dillwyn, Desc. Cat. Shells, ii, p. 906. Wood, Ind. Test., PI.

XXXIII, fig. 47. Enc. Brit., vi, p. 449, ed. 1817.

Valuta auris Malchi, var., Gmelin, p. 3437.

. Valuta fasciata, Dillwyn, Desc. Cat. Shells, i, p. 502.

Bulimus faba, Lamarck, Anim. sans Vert. (Desh. ed.), p. 284. Pfeiffer, Mon. Hel., ii, p. 73.
Biilimus Australis, Briigiiifere, Enc. Meth., i, p. 347.

Partula australis, Eerussac, Pro. p. 66. Chenu, Lee. Conch., p. 241, fig. 899. Jay, Cat.
Shells, p. 57.

Partula faba, Sowerby, Zool. Beech. Voy., p. 144, PI. XXXVIII, fig, 4. Reeve, Conch. Syst.,
ii, p. 175, figs. 13, 14. Pfeiffer, Mon. Hel., iii,p 446. Reeve, Conch. Icon., PI. I, figs. 5 a, 6, c.
Woodward, Man. Moll., p. 164, PI. XII, fig. 13. Chenu, Man. Conch., i, p. 434, fig. 3195.
Adams, Gen. Moll., ii, p. 145, PI. LXXV, fig. 2 ct. Pease, Jour, de Conch., 1870, p. 400 ; Proc.
Zool. Soc., 1871, pp. 458, 473. Paetel, Cat. Conch., p. 404. Schmeltz, Cat. Mus. Godeff.,
V, p. 92. Hartman, Cat. Part., p. 6 (with woodcut) ; Obs. Gen. Part., Bui. Mus. Com.
Zool., ix, p. 182. Excl. citrina.

Partulus australis, Beck, Ind. Moll., p. 37.

Bulimus incanstans, Muhlfeldt (teste Anton, p. 40).

Bulimus tricalor, Muhlfeldt (teste Anton).

Partula faba, var. subangulata,PesLse, Join-, de Conch., 1870, p. 401 ; Proc. Zool. Soc., 1871,
pp. 458, 473 (PI. Ill, fig. 79).

Partula venlricosa. Pease, MS. Coll. Pease, 1863.

Partula amanda, Garrett, MS., PI. HI, fig. 78.

Partula dulria, Garrett, MS., PI. Ill, fig. 80.

Partula bella. Pease, MS. (nat bella. Pease, in Proc. Zool. Soc., 1871, p. 473.) Ex. Hartman.
Partula brunnea. Pease, MS. Ex. Hartman.

Partula pallida. Pease, MS. Ex. Hartman.

Partula marginata, Garrett, MS.

Partula biangulata. Pease, MS. Ex. Hartman.

Partula propinqua. Pease, MS. Ex. Hartman.

The nictropoli.s of the well-known typical fahu is Utnloa, on the north end of
llaiatea, the specific centre of P. anriculata. It is very abundant on the trunks and
foliage of trees and bushes. From its headquarters it has migrated throughout all
parts of the island, and notwithstanding its wide diffusion it presents the same features
in every location.

It was first obtained when Capt. Cook visited Raiatea in 1769, and first figured by
Martvn in his unique “ Universal Conchologist.”

■ihc type varies from straw-yellow to bromlUh yellow or fulvous, with a broad basal
and narrow sutuml chestnut-brown band. The most common bandless vanety .s of
the normal color varied witli longitudinal darker strigations. A variety of a uniform,
whitish born-color, as well as one of a uniform ebestniit-browii, sometimes approaching

58 TERllESTKIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

black, is not infrequent. The lip is wliite, and the ai)ex frequently tinted with purple-
black.

They vary considerably in .shape, as the following measurements will prove : —

Length 25, diam. 14 mill.

Length 25, diam. 12 mill.

TJie average dimension is 25 by 13 mill. Out of about 6000 examples I found
but one possessing the parietal tooth. Hybrids between tliis species and radiata,
fiisca and navigatoria are not uncommon.

On the soutli end of Tahaa, an island inclosed in the .same reef which encircles
Kaiatea, is the headquarters of Pease’s var. sulxmgvJatu (PI. Ill, fig. 79), which has
spread throughout several valleys.

As compared with faha, it is smootlier, more glossy, thinner, and e.xhibits different
color-variation.s. 'Tlie type is reddisli brown, with a yellowish .sutural l)and, and the
peristome is jairple-brown, frequently spotted with white. A variety with a narrow
subsutural and subl)asal band ol a dark chestnut-color on a pale greenish yellow
ground is not uncommon. Uniform reddish chestnut and pale greenish yellow
varieties with white lips are fnjquent. lake the typical faha, it is frequently strigatf'd
and edentate on the wall of the aperture.

me speciftc centre ol the \ar. avianda = ventriema (PI. Ill, fig. 78) is on the
northeast ])ortion of Tahaa. where it occurs in the greatest profusion, and has migrated
throughout all parts of the island, except that portion inhabited by var. s,>hang„lata
In shape it .lifters none from the latter form, but is frequentlv dentated on the
panetal wall, and in some valleys on the north coast, the latter c-haraeter is c.mstant

ght or daik lulvous, with a white or flesh-tinted lip. A beautiful variety occurs
which has a wide, median, reddish chestnut band. A more common variety is found

inln ' Chestnut-brown varieties are not uneom

•non. ihe rarest variety is lasciated the same as the typical faha

J’. auriculata, Broderip.

Parlula auriculata, Jtroderip, Proo /nnl loo^

Reeve, Conch. Syst., ii, p. 1^5 0 t’ . ^ Syn. Test., p. 33.

Proc. Zool. Soc., 18G4, p. C75 (part)' ’paetal''cat c’

Conch., 186fi, p. 20. Schnicltz, Cat. Mus. Godeff ' a

p. 7, with ivoodcut; Obs. Gen Part Rni M ^ Hartman, Cat. Part.,

Parlula Anton, Verz Co„:h.’ ^40 "

Partulus auriculatus, Beck, Ind. Moll p 53
Bulimus auriculatus, Pfeiffer, Symb. i n so .

Buhmus Otaheitanus, Pfeiffer, Mon. Hel ii o’ T I'l

Partula Otaheitana, Reeve (not of U

Partula rohusta, Pease, Ms! Coll. Peas^S.’

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

59

Partula Tahitana, Schmeltz (not of Gould), Cat. Miis. Godeff., v, p. 92. Paetal, Cat. Conch.,
p. 104. Pease, Proc. Zool. Soc., 1811, p. 413.

Partula maura, Muhlfeldt (teste Anton).

This well-defined arboreal s])ecies is restricted to Utuloa, on the north end of
Raiatea, where it exists in great profusion, associated with the typical I\ faba.

In referring to the synonymy and references, it will be observed that this well-
characterized species has been frequently confounded with the widely different l\
OtaheHana^ a Tahitian species.

It is accurately figured by Reeve, in his monograph of Partula, on Plate II, figs.
11a and 1 1 h. llis fig. 1 1 c is P. crassilabris. Pease.

In all probability" Mr. Reeve had access to Broderip’s type specimens, so there
cannot bo much, if any, doubt of this being the shell the latter had before him when
he wrote his description. He may have, as the late Mr. Pease suggested, included
more than one species in his diagnosis. His habitat is certainly wrong. The shells
were collected by Cuming at Raiatea, not “ Huaheine,” and, as was too frequently the
case, he had forgotten the exact locfliity.

So far as I can ascertain, there has been no description published, except the briel'
diagnosis of Broderip. It may be characterized as follows ; —

Shell narrowly umbilicated, ovate -conic, scarcely shining, with rather rough incre-
mental striae, decussated by crowded spiral incised lines, which become evanescent on
the last whorl ; color varying from whitish to different shades of luteous horn-color,
frequently with longitudinal darker strigations ; spire rather short, plano-convexly
conical, half the length of the shell ; apex somewhat obtuse and frequently tinted
pnrple-brown ; suture impressed ; whorls five, shghtly convex, the last OJic more or
less turgid ; aperture rather small, subvertical, obauriforni, much contracted by the
labiated peristome; parietal wall with or without a white tubercular tooth; peristome
thick, moderately expanded, white, frequently margined with light brown, contracted
above, and the extremities frequently united by a ridge of callus.

I>ength 18, diam. 12 mill.

Tlu' above are about the average dimensions, though they vary some in the relative
proportions of height to diameter. Examples of a light brown, or deep blackish
brown, or the latter color with a median yellowish band on the body-whorl, are not
infrequent.

Dr. Hartman inadvertently cites “ Tahiti ” as its habitat,, and in his chart corn'ctly
assigns it to Raiatea.

P. Moorean.\, Hartman. Plate III, fig- 55.

Partula Mooreana, Hartman, Proc. Acad. Nat. Sci. Phila., 1880, p. 229 ; {Helena) Cal.
Part., p. 10 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p 184.

'rhis arboreal species is abundant, and restricted to Vaianai valley, on the southeast
coast of Moorea, where it shares the metropolis of P. vexillam, Pse.

60

terrestrial mollusca inhabiting society

ISLANDS.

. 1 * • A plouoatc-ovate Ibrm, ratlier thin texture, constant

parieLZS p"Licaf .pire, which c,„ah half the length of the shell pale
Leous color, with darker apex. It is ah.aijs sinistral, and the wlnte expanded hp

is rather thin and moderately incrassated, . ■ n

V variety with three narrow pale brown revolving bands is not nifrcHnent
It is closely related to some of the sinistral forms or varieties of /. Otahextarm,
particularly with Pease’s P. crassa, which, though of the same shape, is more solid,
rougher, and the fine crowded spiral incised lines which extend over the whole surface
of the former are nearly obsolete on tlie latter.

P. FORMOSA, Pease, MS. Plate III, fig- 49.

Parlula formom, Pease (Mas. Pease). {Asiraea) Hartman, Cat. Part., p. 8 ; Obs. Gen. Part,
Bui. Mus. Cora. Zool., ix, pp. 182, 191.

'fhe metropolis of this very distinct species is in Fatimu, or on the southwest part
of Kaiatea. It occurs in vast numbers on bushes on the lowlands near the seashore,
liecoming more .scarce inland, where it is found associated with J\ Hehe, var. hella.
It ranges north as far as A'aian talley, becoming less and less abundant as the
distance increases from its specific centre. It may hc’ characteri/cd as follows : —

Slu'll large, imperforated, solid, elongate-ovate, striated, shining, pale yellowisli
white, straw-yellow or ful\ ous ; spire conical, with nearly fiat outlines, sjiirally striated
with fine, crowded, incised lines, half the length of the shell, and frequently tinged
with rose-n'd ; suture slightly impressed, margined with a rugose, white line; whorls
five and a half, fiattc'ued, the last one large, convex ; aperture oblong, subvertical,
obauriform ; pf'ristome \\ bite, rather Avidely expanded, declivous, external margin
angidarly ridged, inner margin strongly labiated, acutely dentate, and contracted
above the denticle; jiarietal region thinly glazed, edentate; columellar lip closely
appressed over tlie umbilical region.

Lengtli 25, diam. 18 mill.

Its large .size, edentate parietal region, sharp labial tooth and closed umbilicus will
readily distinguisli it. It is neAer ornamented Avith bands.

P. CAI.LIFERA, Pleilibr. Pliite III, fig. 82.

ParluJa callifera, Pfeiffer, Proc. Zool. Soc., 1856, p. .333; Mon. Hel.,iv, p.51I. C.arpenter,
Proc. Zool. Soc., 1864, p. 675. Pease, Proc. Zool. Soc., 1871, p. 473. {Astrsea) Hartman’
Cat. Part., p. 8 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 180.

Fartula megasioma, Pease, MS. Sehmeltz, Cat. Mus. Godeff., v, p. 92.

Partula callistoma, Sclimeltz, 1. c., p. 207 ; vi, p. 81.

well-characterized species, r.'stricted to the higher portion of Haainoa valley,
on the east coast of Haiatea, Avhere it is not uncommon on foliage.

It may be easily toermined by its creamy white color, yellow apex, constant
parietal tooth, inflated body.whorl, oval or rounded .‘keyhole” a, torture, conspicuous
labial tooth and the total absence of epidermis in the adult shells. It is never banded.

TERKESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

61

P. tjmbilicata, Pease.

Parlula umhilioata, Pease, Amer. Jour. Conch., 1866, p. 200; 1867, p. 81, PI. I, flg. 7;
Proe. Zool. Soe., 1871, p. 474. Paetel, Cat. Conch., p. 104. Binney, Proc. Acad. Nat.
Sci. Phil., 1875, pp. 245, 247, PI. XIX, flg. 7 (anatomy). Schineltz, Cat. Mas. Godeff.,
iv, p. 71. Pfeirter, Mon. Hel., viii, p. 207. (Ghjtia) Hartman, Cat. Part., p. 8 (with
woodcut) ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 188.

Partula auricvlata, var.. Carpenter, Proc. Zool. Soc., 1864, p. 675.

Tlie metropolis of this well-defined species is in a large valley, called Haamene,
on the east coast of Tahaa, where they are found in prodigious numbers on the foliage
of low bushes. It has not spread any to the southward, but, on the other hand, ranges
in considerable numbers through all the valleys, except Faa-apa, the home of hilineata,
as far as Murifanna on the northwest coast, where it is found associated with P.
virglnea.

Its globose-conic form, large umbilicus, constant parietal tooth, rather narrow,
slanting lip, subnodose columella and yellowish or brownish horn-color will readily
distinguish it.

Var. a. Uniform chestnut-brown. Common

\^ar. h. V^ith one or two chestnut-brown bands. Rare.

P. viRGiNEA, Pease, MS. Plate III, flg. 54.

Partula virginea. Pease, MS. Coll. Pease, 1863. Binne}', Proc. Acad. Nat. Sci. Phil.,
1875, pp. 245, 247, PI. XIX, flg. 8 (anatomy). Schmeltz, Cat. Mus. Godeff., vi, p. 81.
{Astrxa) Hartman, Cat. Part., p. 8 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 189.

Partula solidula, var., Carpenter, Proc. Zool. Soc., 1864, p. 675. Pease, Proc. Zool. Soc.,
1871, p. 473.

The specific centre of this species is in Vaipiti valley, on the west coast of Tahaa,
where it occurs in the greatest profusion on the foliage of shrubs. It has extended
its range to the northward as far as Murifanna on the north coast, which latter is the
limit of the western range of P. umbiUcata.

It may be described as follows : —

Shell compressly urabiheated, solid, oblong-conic, somewhat shining, yellowish
corneous or light fulvous brown ; spire convexly conical, half the length of the shell ;
suture margined by a whitish line ; whorls 5-5|, slightly convex ; aperture subvertical,
oblong, obauriform, rounded below and much contracted by the strongly labiated
peristome: parietal wall with a white tubercular tooth which is rarely absent; peris-
tome white, sometimes tinged Avith carnation, widely expanded, subplanulate, slightly
contracted above, and the margins frequently nearly united by a ridge of callus;
columellar lip vertical, more or less distinctly nodose.

Length 18, diam. 9 mill.

Yar a. Uniform chestnut brown. Not uncommon.

^'ar. h. YeUowish corneous, with a basal and sutural chestnufibrown band. Very
rare.

9 JOUR. A. N. S. PHIIiA., VOL. IX.

62

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

They vary some in size and lengtli of spire. Ihe nearest allied species is 1 .
planiJabrnm, which is larger, differently colored and inhaliits a different station. I
have fonnd .several hybrids between this species and P. faha, var. mibangvhifa. Pease.

In referring to the synonymy it will be ob, served that Carpenter and Cuming
regarded it as a variety of Reeve’s P. solidnla. Mr. Pease, accepting their views,
catalogued it by the latter name in his list of Polynesian land shells (P. Z. S., 1871,
p. 473). Both Reeve’s and Pfeiffer’s description, as well as Reeve’s figure, refer to a
more robust species than virgivea. Moreover, neither of the above authors allude to
the parietal tooth, which is seldom absent in the latter species. Reeve’s figure very
nearly coincides with Pea.se’s P. compacta, but that species is always dentate. Hybrids
between P. foha, var., and virginea, which are edentate, very closely resemble Reeve’s
figure of solidnla.

P. AKOUTA, Pease. PI. Ill, fig. .57.

Dulimus argutus, Pease, Proc. Zool. Soc., 1864, p. 670; 1871, p. 473. Pfeiffer, Mon. Ilel.,
vi, p. 46.

J’artula arguta, Schmeltz, Cat. Mus. Godeff., v, p. 92. Martens and Langk., Don. Bismark.,
p. 55, PI. Ill, fig. 7. (Echo) Hartman, Cat. Part., p. 11 (with woodcut) ; Obs. Gen. Part.,
Bui. Mus. Com. Zool., ix, p. 179.

I he metro])olis of this very fragile species is in the upper portion of a mountain
ravine, on the west coast of Huaheine, where it is rather common on the leaves of low
shrubs and ferns. It occurs much more rarely in a neighboring valley south of its
specific centre. Mr. Pease’s habitat “ Tahiti,” as given in his list of Polyne.sian laud
shells, is decidedly wrong.

1 hough referred by the above author to the genus Bidimm, it is, nevertheless a
true The aiiimnl, which is viviparous, has verv long, slender, ocular tentacles

long lanee-pointed foot, and that portion of the animal occupying the whorls of the
translucent shells „ beautifully maculated with black and white simts on grayish
yellow ground. The shell, which is very uniform in all its specific characters, may Im
readily distinguished hy its very thin pellucid texture, ovate form, abbreviated sidre,

siXi-pel;::

P. bilineata, Pea.se.

Pariula ftiluieate, Pease, Amer. Jour. Conch. 1866 n 901- iss- m r r,

% loTanimyy' '^tifff "Z:

Porta/o C.rpeuter (not of Broderip), P,.„c, Zool. Soc., 1864, „. 615

This beautiful and well-marked species is couhned to Faa-apa valley on the east

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

(53

coast of ialiaa, where it occurs in abundance on tlie trunks of a species of wild
banana and at the roots of ferns. Mr. Pease cites “ Tahiti ” as the habitat of this
species, which is an error.

It is leadily distinguished by its smooth, glossy surface, ovate-conic form, yellowish
horn-color, and two revolving chestnut-brown bands, the upper one narrow and
subsutural. Ihe .subacute apex is sometimes purple-brown and the suture is margined
by a narrow, rugose, whitish line. The constant parietal tooth is prominent and the
broad white peristome is slightly emarginate above, strongly labiate within, and widely
expanded.

Var. a. With a single broad median chestnut-brown band. Not common.

Var. h. Chestnut-brown with a yellowish horn-colored sutural band, ^^ery rare.

Var. c. Uniform yellowish horn-color. Very rare.

They are all remarkably uniform in shape and size.

As compared with P. auriculata, with Avhich it has been confused, it is more
glossy, smoother, the lip broader, the umbilicus more open and the fasciation different.

It is more nearly connected with P. planildbrum and virginea.

P. PI.ANILABRUM, Pease. Pliite III, flg. 17.

Partula suturalis, Pease, MS. (not of Pfeiffer).

Partula planilabrum, Pease, Proc. Zool. Soc., 1864, p. 672; 1871, p. 473. Pfeiffer, Mon.
llel., vi, p. 156. Binney, Proc. Acad. Nat. Sci. Phil., 1865, pp. 245, 247. Schmeltz, Cat.
Mas. Godeff., vi, p. 81. Hartman, Cat. Part, p. 7 ; Obs. Gen. Part, Bui. Mus. Coni.
Zool., ix, pp. 185, 188, 190.

The metropolis of this species is Haamene valley, on the east coast of Tahaa.
where it is common, and, though usually lurking beneath decaying vegetation, is
sometimes found adhering to the trunks of the wild banana. It is found, though
less abundant, in a valley north of its specific centre, hut does not occur in the inter-
mediate valley Faa-apa, the home of hilineata.

It is larger and more elongated than the latter species, and the surface is not so
smooth and shining. The structure of the peristome is similar in the two shells, but
the aperture is more elongate. The parietal tooth is constant in adults.

'I'he type is deep chestnut-brown, gradually fading into yellowish corneous towards
the sutural line, and the whitish lip is frequently tinged with violet.

’S’ar. a Fulvous yelloAV, with the basal half of the body-Avhorl, and a revolving
subsutural band, deep chestnut-brown. Not infrequent.

^’ar. h. Uniform pale corneous or light fulvous. Rare.

Like the preceding species it is very uniform in all its specific characters. The
fasciation of variety a resembles the typical markings of hilineata.

04

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

P, Fiix)SA, Pfeiffer. Plate III, fig. 81.

Partula filom, Pfeiffer, Proc. Zool. Soc., 1851, p. 2fi2 ; Mon. Ilel., iii, p. 450. Chemnitz,
ed. 2d, Bui., p. 26V, PI. LXIV, figs. 3, 4. (Helena) Hartman, Cat. Part., p. 10; Obs.
Gen. Part., Bui. Miis. Com. Zool., ix, pp. 182, 183, 196.

Partula lineolata, Pease, Amer. Jour. Conch., 186V, p. 224; Proc. Zool. Soc., 18V1, p. 4V3.
Schmeltz, Cat. Mus. Godeff., v, p. 92. Pfeiffer, Mon. Hel., viii, p. 206.

Tins small and well-characterized specks is restricted to the lotver portion of Pirai
valley, on the northwest coast of Tahiti, where it is abundant on foliage. Pfeiffer’s
“habitat in insulis Navigatorum ” (= Samoa Isles) is decidedly wrong. The type is
peculiar to .he Society Isles.

It is a solid, ovate-conic, chestnut-colored shell, marked by longitudinal cinereous
strigations, and constant tuberculiform parietal tooth. The aperture is rather small,
semi-oval, considerably contracted by the white, convex outer lip. It is never
encircled by hands. Examples of a pale straw or fle.sh tint are not infrequent.

P. ciTHi.vA, Pease. Plate III, fig. 52.

Partula citrina, Pease, Amer. Jour. Conch., 1866, p. 195; Proc. Zool. Soc., 18V1, p. 4V3.

Schmeltz, Cat. Mus. Godeff., vi, p. 81. Pfeiffer, Mon. Hel., viii, p. 200.

Partula faba, var.. Carpenter, Proc. Zool. Soc., 1864, p. 6V5. Hartman, Cat. Part., p. 6 ;
Obs. Gen. Part., Bui. Mus. Cora. Zool., ix, pp. 180, 195.

'I’liis fine arboreal species is restricted to a single valley, called Uparii, on the west
coast of Kaiatea. I found it abundant in a limited area in the upper portion of the
valley. A few stragglers occurred lower down in company with faia and Garrettii.

Thotigh considered by some authors to be a variety of P. faba, I am, nevertheless,
fully convinced of its specific value. When I first discovered it in 1861, I took but
few examples, in consequence of not penetrating far enough into the valley to find its
licadquarters. A more extended research in 1873 revealed its specific centre, and I
took about eight hundred specimens in various stages of growth, and manv of the
adults were in a gravid condition.

I 1 1 ^ possession, and were so few that

There is not the least doubt that the

uted under\\ ^ of faba have repeatedly been confounded w ith and distrib-

uted undei the name of citrina.

1 on t n' iX?® ‘ “"'0 o'lier spocies.

I onl, not /„i,. an, I OarretHi in the lower part of the vaUey, and „ol in tl.e nnner
portion, which le the principal haunt of cknna “

yellow or Z , ; is eitller lemon,

invariably ode.. tate T"' P-ietal wall is

length of tl.e shell The iv””^ aperture is, mclnding the peristome, half the

g shell. Ihe ivory-white lip is broadly expanded, plannlate, deolivons.

TERRESTRIAL MOLLUSOA INHABITING SOCIETY ISLANDS.

65

stiongly labiated, slightly dentate and distinctly emarginate above. The slightly
gibbous columella is reflected over the small compressed perforation.

Its uniform straw-yellow color, more slender form, smaller perforation, more
reflected columella, and more decided labial tooth, and profounder emargination, will
distinguish it from the very variable faba.

P. NODOSA, Pfeitfer.

Partula nodosa, Pfeiffer, Proc. Zool. Soc., 1851, p. 262 ; Mon. Hel., iii, p. 449. Pease, Proc.
Zool. Soc., 1811, p. 4’73. Paetel, Cat. Conch., p. 104. Schmeltz, Cat. Mus. Godeff., v, p.
92. {Helena) Hartman, Cat. Part., p. 10 ; Ohs. Gen. Part., Bui. Mus. Com. Zool., ix, pp.
184, 188, 195.

Partula trilineata, Pease, Amer. Jour. Conch., 1866, p. 195 ; 186Y, p. 81, PI. I, fig. 1.

Partula nodosa, var. trilineata. Pease, Proc. Zool. Soc., 1871, p. 473.

This beautiful arboreal species is restricted to a limited area about two miles up
Punaavia valley on the west coast of Tahiti.

I first discovered the location in 1861, and gathered about three hundred examples.
On a subsequent visit, nine years later, I secured over eight hundred specimens. It
is entirely confined to the south side of the stream which flows through the valley,
and circumscribed in a narrow area about three-fourths of a mile in length.

When Mr. Pease described his trilineata, he gave the correct locality ; but, in his
list of Polynesian land shells, he wongly assigns it to Moorea. Dr. Pfeiffer gives
Tahiti and Navigator Islands as its habitat. The type is purely Tahitian, and does
not occur at the latter group.

It may be characterized by its ovately conical form, solid texture, constant parietal
tooth, nodose columella, and widely expanded white peristome, whicli is flatly convex,
very slightly con.stricted above and strongly lipped within. The color is creamy
white or yellow-corneous, generally with narrow, longitudinal strigations of a brownisli
color, and ornamented with three revolving, narrow, reddish brown bands. About one
in two hundred is sinistral. Bandless varieties are not infrequent, and some are fulvous
or light chestnut-brown, with a pale narrow sutural band.

P. HYALiNA, Broclerip.

Partula hyalina, Broderip, Proc. Zool. Soc., 1832, p. 32. Miiller, Syn. Test., p. 32. Reeve,
Conch. Syst., ii, PI. CLXXV, figs. 1,2. Jay, Cat. Shells (1839), p. 57. Reeve, Conch.
Icon pflll fw 14. Pfeiffer, Mon. Hel., iii, p. 451. Pease, Proc. Zool. Soc., 1871, p.
473. ’’ Paetel, Cal Conch., p. 104. Schmeltz, Cat. Mus. Godeff., v, p. 92. Garrett, Proc.
Acad. Nat. Sci. Phila., 1879, p. 18 ; Jour. Acad. Nat. Sci. Phila., 1881, p. 396. (Pasithea)
Hartman, Cat. Part., p. 2 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 183.

Bulinus hyalinus, Sowerby, Conch. Ulus., fig. 9.

Bulimus hyalinus, L.am., Ed. Desh., p. 284.

Partulus hyalinus. Beck, Index Moll., p. 57.

This well-known aihoreal species has its metropolis or specific centre in the Austral
group, some three hundred mdes south of Tahiti. It occurs also on Manga.a, one of

TKKKKSTKIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

()()

tlio Cook’s f,n-oup, about four hundred miles from its metroi)olis. It is also distributed
in limited numbers throughout every valley on Tahiti, but is not lound on any other
island in the same archipelago. Its extensive range is most remarkable, and it is the
only species known to be common to more than one group of islands.

P. PKODUCTA, Pease. Plate III, fig. 51.

Partula prodiwta, Pease, Proc. Zool. Soc., 1864, p. 671 ; 1871, p. 473. Pfeiffer, Mon. Hel.,
vi, p. 156. Schmeltz, Cat. Mus. Gocleff., v, p, 92. {Helena) Hartman, Cat. Partula, p.
10; Obs. Gen. Partula, Bui. Mus. Com. Zool., ix, p. 185.

This species only occurred to my notice in one valley, on the southwest coast of
'I'ahiti, where it is abundant, lurking beneath decaying leaves and under heaps of
loose stones.

The type is yellowish fulvous, and invariably marked by three narrow, revolving,
reddish brown bands in the body-whorl, and two on the spire. The rather narrow,
dull wliitish peristome is moderately reflexed, rounded, and the margins united by a
layer of callus on the parietal wall, which latter is edentate. It is always dextral,
and the rather long spire equals half, or a trifle more than half, the length of the shell.

"NAr n. Body deep chestnut-brown, with or without a pale .sutural band, pale base
and bilineated spire.

Var. h. Uniform pale fulvous or tawny, with a darker apex.

P. ANSECTKNS, Pcasc. Plate lit, fig. 70.

liulimus annectens, Pease, Proc. Zool. Soc., 1864, p. 671. Pfeiffer, Mon. Hel., vi, p. 48.
Partula annectens. Pease, Proc. Zool. Soc., 1871, p. 473. (Hcho) Hartman, Cat. Part., p.
12; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 179.

This dchciite arboreal species is excessively rare, and has only occurred to my
notice in two valleys on the west coast of Huaheine.

It is more fragile and more robust than P. atteriuata, the nearest allied form.
The spire is less tlian half the length of the shell, and the .suture is margined by a
white hue. 'I he dull ivliitish peristome is widely expanded. The aperture is newr
dentate, and tlie yellow- corneous shell is faintly tinged with greenish.

'1 he aiiiinal varies from pale luteou.s.yellow to light brownish yellow. The soft
parts, as seen through the transparent shell, are mottled with slate-colored spots The
loot IS about the same length as the shell, and the ocular peduncles are very long and
slender. • ®

P. CRAssiLABRis, Pea,se.

Partula crassilahris, Pease, Amer. Jour. Conch., 1866, p. 199; 1871, p. 81, PI. I fi.. 6 •
n'er'viirp 90r Clodeff., V, p. 207. Pfeiffer, Mon.’

.ooi:,,c,

Tl,e me„o„olisor.his .mall specie, 1, in Hapai valley, on the west coast of

terrestrial mollusca inhabiting society islands. 07

Raiatca, tlie home of P. imperforata and Juguhris. It is very abundant, lurkin*'
cneatli dec a} ing vegetation and found associated with the typical form of P. higtihriH.
It has not spread any to the northward, but to the southward it has migrated into
two small ravines.

It is shaped very much like Hebe, but is smaller, tbe lip less expanded and the
body-whorl not so much inflated. The parietal tooth, which is not constant, is not so
prominent as in that species. The color varies from pale horn-color to deep brown or
reddisli brown, with or without a purple-black apex. The peristonre is more rounded,
and not so pure a white as in Hebe.

A variety with a median yellowish band is not uncommon, wbich Mr. Pease
described as the type. Of the two flgures quoted in the synonymy and references, Mr.
Reeve’s is the most characteristic ; that of Mr. Pease is too much elongated.

P. EOSEA, Broderip.

Partula rosiea, Broderip, Proc. Zool. Soc., 1832, p. 125. Muller, Syn., p. 32. Reeve, Conch.
Sy.st., ii, PI. CLXXY, figs. 9, 10 ; Conch. Icon., PI. I, figs. 1 a, h, c. Jay, Cat. Shells,
p. 57 (1832). Pfeiffer, Mon. Hel., ill, p. 448. Pease, Proc. Zool. Soc., 1871, p. 473.
Paetel, Cat. Conch., p. 104. Schmeltz, Cat. Mus. Godeff., v, p. 92. (Matata) Hartman,
Cat. Part., p. 14 (with woodcut); Obs. Gen. Part., Bui. Mus. Com. Zool., ix, pp. 186, 191
(excl. simplaria).

Partulus roseus, Beck, Ind. Moll., p. 57.

Bulivius roseus, Pfeiffer, Mon. Hel., ii, p. 70, part.

Partula purpurascens, Pfeiffer, Proc, Zool. Soc., 1856, p. 333 ; Mon. Hel., iv, p. 511.
Partula cognata. Pease, MS. Coll. Pease, 1863. Schmeltz, Cat. Mus. Godeff., v, p. 92.
Gloyne, Quar. .lour. Conch., i, p. 338.

'I'he head()uarters of this beautiful and well-known arboreal species is in a large
forest at tlie head of Hatvai bay on the west side of Huaheine. From this region,
where tliey arc very numerous, they have spread over many parts of the island. They
differ but little in shape in the difterent localities, except in I’aahiti on the north coast,
where they are smaller, less angulated on the last whorl, and in the total absence of
the uniform dark purple-brown and rose-colored varieties which are so common else-
where. It is the P. cognata. Pease. The most numerous variety of the latter form
is straw-yellow with the sutural line tinted with rose or purple -rose. A rose or purple-
brown variety with a central yellow band is found in no other part of the island.

P. ro^ea exhibits the following color- variations :

Var. a. Uniform yellowish. Very numerous.

Var. h. Uniform dark purple-brown. Common. = P. purpurascens.

Var. c. Uniform rose or rose-red. Common. Type.

Var. d. Yellowish, with the base and narrow sutural band purple-brown or rose-

color. Common. „ . ,

Var. e. Rose or purple-brown, with the basal half of the body-whorl yellowish.

Frequent in the metropolis, but very rare elsewhere.

TERKKSTIUAL MOLLUSCA INHABITING SOCIETY ISLANDS.

()8

^'ar./. Yellowish, with the sutural line tinted with rose or pui'ide-brown. Very
coininon in Faahiti valley, but rare elsewhere. = P. cognota.

A'ar. g. Yellowish, with the spire more or less rose or purple-brown. Common.
'I'hey vary in a greater or less degree in the proportion of length to diameter, as
well as in the thickness of the shell ; and some are more distinctly angulated than
others.

P. DENTiFERA, Pfeiffer. Plate III, fig. 84.

Partula dentifera^ Pfeiffer, Proc. Zool. Soc., 1852, p. 85 ; Mon. Hel., iii, p. 447- Carpenter,
Proc. Zool. Soc., 1864, p. 675 (part). Pease, Proe. Zool. Soc., 1871, p. 473. Schmeltz,
Cat. Mils. Godeff., V, p. 207. {Astraea) Hartman, Cat. Part., p. 8, with woodcut; Obs.
Gen. Part., Bui. Mus. Com. Zool., ix, pp. 181, 183, 194 (excl. Baiatensis).

Partula decorticata, Pease, MS. Coll. Pease, 1863.

Partula labiata, Pease, MS. Coll. Pease, 1863. Paetal, Cat Concli., p. 104. Schmeltz, Cat.
Mus. Godeff, v, pp. 92, 207. Pfeiffer, Mon. Hel., viii, p. 209.

The specific centre of the type of this species is in the large valley of Vairahi, on
the cast coast of Raiatea, rvhere it occurs in vast numbers on foliage in company with
the typical P Hebe. It has not spread at all to the southward, but, on the otlier hand,
has migrated into a small adjacent valley, where it is much less abundant, and differs
from tlic type in about half of the specimens having a prominent parietal tooth, which
is ahoags absent in examples inhabiting Vairahi ; otherwise the shells are not dis-
similar.

It may be distinguished by its elongate-conical form, straw-yellow color, rather
shining surface, chink-like perforation, and small oblong obauriform white aperture.
Tlie peristome is ivory-white, heavily calloused, the surface angularly ridged, strongly
labiated within and armed with a median prominent acute denticle, above which
the hp IS strongly contracted, forming a conspicuous sinus. A very rare variety occurs
of a ruddy brown color, purple-black apex, and flesh-colored peristome. Examples
uith a white sutural line aie not infrequent; otherwise it is never ornamented with
bands The most pmfect specimens always have the body-whorl more or less decorti-
cated behind the peristome, which suggested the provisional name decorticata.

P. ELO.NOATA, Pe.ise.

Partula elongata, Pease, Amer. Jour. Conch., 1866, p. 196 • 1867
Zool. Soc., 1871, p. 473. Schmeltz, Cat. Mus. Godeff., iv’ p. 72.’

p. 81, PI. I, fig. 2 ; Proc.
Pfeiffer, Mon. Hel., viii,

Kn,ala, C.rpcrter „f Le.son), Zool, Soc., 1804. p. 076.

Tsl lTt) " «"»• 2»<»- P-

occ .r “<: bu „ I “’’“‘'•“‘■.••-“-‘Od witl. c n„eaia and P. Mooreana. It

con.p„;/:i.;:i:.:Tnd;:„ts .he_d,whete a i, fo„„d i„

«• The same valley, which is about two miles from

ilrrestrial mollusca inhabiting society islands. G9

1 species on that part of the island, and

7^ e^ongrato are rather common, the same as between Garrettii

an mm. at Kaiatea. To the eastward of Vaianai it ranges throughout the small

y oi a distance of several miles, as far as Ohanmi, the specific centre of
stngosa.

I cannot agree with Dr. Hartman in uniting this species with ia>niut<i. It is only
tlirough hybrids between the two species that the inosculation takes place. Examples
ta 'en in any of the valleys not inhabited by tainiaia prove at once its distinction.

1 he type is elongated, thin, translucent, corneous, straw-yellow or pale fulvous,
fiequently with narrow longitudinal darker stripes, and the rather ample aperture is
edentated. The outer lip is thin, simple, moderately expanded. The columella is flat,
not nodulous or gibbous. Examples with two to four narrow, light chestnut-brown,
more or le.ss broken, revolving bands are not infrequent. They vary in the length of
the spire, as the following measurements will show : —

I.ength 17, diam. mill.
Length 1.5, diam. 8 mill.

B. Thalia, Garrett. Plate III, fig. 46.

Partula abhreviata, Pease, MS. (not of Mousson) Coll. Pease, 1863.

Partula auriculala, var., Carpenter, Proc. Zool. Soc., 1864, p. 675.

Partula Peaxeana. Garrett, MS. (not Peasei, Cox).

Partula Thalia, Garrett, MS. (Nenia) Hartman, Cat. Part., p. 7; Obs. Gen. Part., Bui.

^Iiis. Com. Zool., ix, pp. 188, 191, 192.

Shell coinpressly jierforated, solid, ovate-conic, somewhat shining, lines of growth
rather smooth, and revolving incised lines very fine and crowded; Avhiti.sh or ynllowish
liorn-color, with or without a purple-black apex; spire rather short, conical, with
])lano-convex outlines, half the length of the shell; suture slightly imprcs.sod; whorls
five, flatly convex, the last one large, subglobose ; aperture subvertical, abbreviately
subauriform ; parietal region more or less glazed, and armed with a white tubercular
tooth ; peristome white, moderately^ expanded, thick, angularly ridged, strongly incras-
■sated witliin, sinuous above, and the margins frequently joined by a ridge of callus.

Length 17, diam. 11 mill.

^’ar. a. Fulvous brown, with or without purple-black apex. Eather rare.

Var. h. With brown base and sutural band. Not common.

The specific centre of this very abundant arboreal species is in Huarn valley, on
tlie west coast of Kaiatea. It has spread along the well- wooded lowlands about two
miles north and one mile south of its metropolis, slightly overlapping the northern

range of P. GnrreltH. . , , . , j ♦

It is s, nailer, smoother, more shining, much less variable m color, and the aperture

is les.s auriform than P. (Utriciilota. ...

The columella is fre,|nently slightly gibbous or nodulous in the inner margin.

10 JOUR. A. N. 8. PHILA., VOL. IX.

70

TERRESTRIAL MOLLFSCA INHABITING SOCIETY ISLANDS.

P. STOUUA, Pease. Plate III, fig. 58

Parlula stolida, Pease, Amer. Jour. Conch., 18G6, p. 198; Proc. Zool. Soe., 1871, p. 473.
ITeilt'er, Mon. Ilel., viii, p. 195. {Helena) Hartman, Cat. Part., p. 10; Obs. Gen. Part.,
Bill. Mus. Com. Zool., ix, p. 187.

Parlula Vanikorensis, Carpenter (not of Quoy and Gaimard), Proc. Zool. Soc., 1864, p. 675.

I took a few examples of this ground species about two miles up Papenoo valley,
on the northeast coast of Tahiti. They were all found lurking among the roots of
ferns. When Mr. Pea.se described it, he gave the habitat “ Tahitian archipelago,”
and in liis list of Polynesian land shells (Proc. Zool. Soc., 1871), he erroneously cites
“ Raiatea ” as its locality.

Unfortunately I liave only three examples before me, so I cannot decide on its
variation. All my duplicates, which Avere acquired by Mr. Pease, were A’ery uniform
in shape. It may he described as an elongate-ovate, rather thin, dull brownish or
olive-browii sliell, 18 to 20 mill, in length by 9 to 10| in diameter. The spire which
compri.ses half the length of the shell is more swollen than in the elongate dextral P.
Otuheitaua. Tlie parietal region is usually toothed, and the peristome is thinner, not
so much reflected, more flattened and oblique. No banded examples occurred.

])r. Hartman gives the wrong locality. The locality is rightly indicated on his
chart.

P. ATTENUATA, PeaSC.

Parlula allenuala, Pease, Proc. Zool. Soe., 1864, p. 672 ; 1871, p. 473. Pfeiffer, Mon. Ilel.,
Vi, p. 156. Schmeltz, Cat. Mus. Godeff., v, p. 92. Gloyne, Quar. Jour. Conch., i, p. 337.
{Pasilhea) Hartman, Cat. Part., p. 11 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, p. 179.
Parlula gracilix, Pease, Amer. Jour. Conch., 1866, p. 197; 1867, p. 81, PI. I, fig. 3. Binney,
Proc. Acad. Nat. Sci. Phil., 1875, pp. 244, 247, PI. XIX, fig. 6 (part of jaAv). Pease,
I roc. Zool. Soc., 1871, p. 473. Paetel, Cat. Conch., p. 104.

Parlula amahilw, Carpenter (not of Pfeiffer), Proc. Zool. Soc.. 1864, p. 675
Parlula Carleretensis, Reeve (not of Quoy and Gaimard), Conch. Icon., sp. 13, PI. lY,
fig. 13. Schmeltz, Cat. Mus. Godeff., iv, p. 72.

I ns small spades, whicl, has an extensive range, occurs in the upper portions

of all the central valleys on both the east and west sides of Baiatea. It is more

abundant m loloa and Hapai valleys than elsewhere. Owing to its peculiar habit of

mom -“P- observation. It occurs

Teonfl, d ,rtl ’ *olls,

I.s confined to the upper portions of tlie valleys.

trecs'^ndT its peculiar habit of concealment in the tops of

to the habits of other pecies, it is really remarkable to find it inhabiting two remote
dand especiaUv as a 1 the other species have a very limited range. It doe no to” n1
a. lahaa, which is only four miles from Baiatea, and enclosed to the same enldtog

iekrestrial mollusca inhabiting society islands. 71

reef. It is no less singular to note its absence from Huaheine and Moorea, though at
the former island we find the closely allied P. annectens.

Its most essential characters are its graceful oblong-conic shape, narrow body-whorl,
uniform wlutisli horn-color and broadly expanded white lip.

Reeve has erroneously described and figured this species under the name of P.
^^Carteretensiar Quoy and Gaimard. The latter author’s P. Carteriensis {mix) is of
an entirely different type.

P. FUSCA, Pease. Plate III, fig. 50.

Parlula fusca, Pease, Amer. Jour. Conch., 1866, p. 193; Proc. Zool. Soe., 1871, p. 473
Paetel, Cat. Conch., p. 104. Binney, Proc. Acad. Nat. Sci. Phil., 1875, pp. 245, 247,
Plate XIX, fig. 9 (anatomy). Pfeiffer, Mon. Hel., viii, p. 205. Schiiieltz, Cat. Mus.
Godeff., Vi, p. 81. Hartman, Cat. Part., p. 6 ; Ohs. Gen. Part., Bui. Mus. Com. Zool., ix.
p. 182 (excl. ovalis and luguhris).

Partula protea, Pease, MS. Coll. Pease, 1863. Sehmeltz, Cat. Mus. Godeff., v, p. 92.
Pfeiffer, Mon. Hel., viii, p. 209.

Partula faba, var.. Carpenter, Proc. Zool. Soc., 1864, p. 675 ( = protea).

Partula navigatoria, Carpenter, 1. c., not of Pfeiffer.

The metropolis of this very variable ground species is in Vaioara valley, on the
west coast of Raiatea, the headquarters of P. Garrettii and navigatoriu. It has not
migrated any to the soutliward, but to the northward it occurs sparingly far up in
Iluaru valley. On the opposite side of the island it is found in Tepua valley, and I
took a few in a small ravine more to the southward. The Tepua shell, which is the
jyrofea, Pse., differs none from his/M-ica.

Hybrids between j)rofea and the arboreal P. /aha are not uncommon, and are
usually found adhering to the lower parts of the trunks of trees.

In Vaioara, hvbrids between fttsca and navigatoria, and between the two former
and /aha, are so frequent as to be very embarrassing in the separation of the three
species collected in that valley. Like the Tepua hybrids, all those between the two
ground species and the arboreal /aha live on the lower parts of the trunks of trees.

P. /oftca. may be described as follows : —

Shell umbilicated, solid, varying from an abbreviate-ovate to oblong-ovate, roughly
striated by irregular lines of growth, and the usual fine spiral incised lines become
evanescent on the body-whorl ; spire convexly conical, less than half the length of the
shell; suture linearly impressed, frequently margined by a thread-like white line;
whorls 5-6, more or le.ss flatly convex, last one large, convex, rounded or turgid, .some-
times slightly angled just above the aperture ; base more openly umbilicated than usual
in the ground species ; aperture subvertical, oblong, sides nearly parallel ; parietal
region more or less glazed with callus, and sometimes dentate ; peristome rather broadly
expanded, moderately thick, slanting, flat or concave, strongly incrassated within and
sinuous above; columellar lip depressed, receding or transversely grooved above.
Color very variable : whitish corneous, straw-yellow, fulvous, light or dark chestnut,

n TKIUIESTIUAL MOLLUSCA INHAEITINO SOCIETY ISLANDS.

.omotimAs l,r,nvn-bla.k, and frequently atrigated. Yellowiah horn-colored examples
with the hase and the sutural band chestnut, are not uncommon. Ihe lip, though
usually white, is frequently margined with purple-brown.

Length 20, diam. 1 1 mill. .

'I'he above is about the average dimensions. My largest example is ^4 by 13^
and the smallest adult 1 7 by 10 mill. Sometimes, though rarely, the spire equals half
the length of the shell. Very old examples have a more or less nodulous columella
and a more or less distinct denticle on the outer lip.

P. TiENIATA, Miirch.

Bulimus (Partidus) tseniatus, Mfircb, Cat. Conch. Kjerulf., p. 29.

Bulimus Otaheitanus, var., Pfeitfer, Mon. Hel., ii, p. 72, part.

Partula tseniata, Pfeiffer, Mon. Hel., iii, p. 451. Carpenter, Proc. Zool. Soc., 1864, p. 675.

Hartman, Obs. Gen. Part. Bub, Mus. Com. Zoob, ix, p. 188 (part).

Partula utriolata, Pease, Amer. Jour. Coneb., 1866, p. 197 ; 1867, p. 81, Pb I, fig. 4 ; Proc.

Zoob Soc., 1871, p. 473. Pfeiffer, Mon. Heb, viii, p. 203.

Partula Himulans, Pease, Amer. Jour. Coneb., 1866, p. 202; 1867, p. 81, Pb I, fig. 11. Paetel,

Cat. Conch., p. 104. Scbmeltz, Cat. Mus. Godeff., v, p. 92. Pfeiffer, Mon. Heb, viii,

p. 206.

Partula nucleola, Pease, MS. Coll. Pease, 1863.

Partula decussatula, Carpenter (not of Pfeiffer), Proc. Zoob Soc., 1864, p. 675.

Partula fpadicea, Hartman (Reeve ?), Cat. Part., p. 11.

The metropolis of this truly protean species is in a very large semicircular valley
on the north coast of Moorca, where it occurs in prodigious numbers on the foliage
of bu.shes. In the western part of the same valley, where it exhibits less variation,
it gradually intergrades with the form which has been distributed under the name
of nucleoid. Pease, which has its headquarters in a small, but isolated, valley about two
miles west of Opunohu.

Pease s mtcleoln, which is quite abundant, is usually smaller, more solid, spire
shorter, aperture smaller and more rounded, and the columella is more distorted, than
in the t}])ical twmala. But in looking over a large number of specimens we notice
some examples which cannot be separated from some of the smaller forms of the
latter species.

On the southwest part of the island we find iceniata tolerably abundant in three
valleys, and, like the shells in the western part of Opunohu, it is subject to much less
variation than obtains in the eastern part of the same valley. The shells from the
southwest coast were described by Pease under the name of P. simulans.

In the third or more eastern valley, where they come in contact w ith P. elongata
and hneatn, hybrids between the former and tceniata are so numerous that anv one

collecting m that valley only would, without hesitation, pronounce them one and the
same species.

from tins point to a distance of several miles, the valleys are inhabited by lineata.

TERllESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

73

Mooreana, eJnngata and lineaia^ var. strigosa, only. But after passing Oahinni, the
home of the latter \ ariety, we again find tceniata, but nearly as variable as the eastern
Opunohu shells, and mixed with the form known as striolata, Pse., with which it inter-
grades. Here I found several unmistakable hybrids between strigosa and tcsniuta.
All the valleys between this latter location and the one nearest to Opunohu are
inhabited by the typical form striolata, which scarcely differs from micltola, except in
being smoother and more variegated with stripes. In a large valley adjacent to
Opunohu, we find these shells by thousands ; they differ in being beautifully striped
like strigosa. Here, again, it insensibly graduates into the typical tcenioia. Whether
the inosculation takes place through hybrids or not is a difficult question to decide In
looking over a large collection from the eastern part of Opunohu, I find some of the
small forms are not dissimilar to the typical striolata, which has suggested the pro-
priety of following Dr. Hartman in consolidating the three forms.

The typical tceuiata varies from abbreviate-ovate to elongaie-ovate, more or less
solid, scarcely shining, smooth or wrinkled with incremental strke, and the spiral
incised lines arc very fine, and crowded on all the whorls. The spire is more or less
produced half the length of the shell, sometimes shorter or a trifle longer. W horls
moderately convex, the last one convex or convexly rounded, frequently compressed m
the back and right side, which gives it a faint biangular appearance. Tlie subvertical
aperture, which is variable in size and shape, varies from subovate to oblong. 1 he
peristome is more or less expanded, sometimes considerably so, moderately thick,
slanting and lahiated within. Columellar lip more or less tortuous, abruptly receding
above, which gives it a nodulous appearance. About one m a hundred exhibits the
parietal tooth. The following measurements will illustrate the variability m shape:—
Length 17, diam. 9, aperture (including lip) mill.

Length 17, diam. 8, aperture (including lip) 8 mill.

I.ength 13, diam. 7, aperture (including lip) 8 mill.

The color is also variable : white, straw-yellow, lemon-yellow, light orange, corneous,
fiUvous, various shades of brown, sometimes with darker strigations, and frequently
snirallv banded. The most common style of fasoiation consists of from one to four
narrow, more or less broken, fulvous or Mvous-brown bauds on the borly-whorl
Fulvotis-brown examples, with two or three pale bunds, are not so common. Ihe last
appears to be Mbreh’s type, which he incorrectly assigns to the Vih Islands.

Pease's stnotata and nnefeoto exhibit the same coloration as the typical
hut are sometimes of a deeper brown, and the former is more conspicuously stnga^.

Dr lartmau, on the authority of Pfeiffer, quotes P.peraffims, P^., which he ados
.0 rsynonymyLf — I do not

neference to i. i" fjo.frMarquesas Islands as the habitat

:r h,aT:;“ :s, Ind Dc. cox mention having received it from the Solomon

74 TEKIIKSTIIIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

Islands. Judging from the description and figure sjjadicea, I am inclined to consider
it distinct and an inhabitant of the latter group of islands.

P. EADiATA, Pease, MS. Plate III, fig- 45.

rartula radiata, Pease, MS. Coll. Pease, 1863. Hartman, Cat. Part., p. 7 ; Obs. Gen. Part.,
Bill. Mus. Com. ZooL, ix, p. 185 (part).

Partula compressa, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675. Pease, Proe.

Zool. Soc., 1871, p. 473. Schmeltz, Cat. Mas. Gocleff., v, p. 207.

Partula microstoma, Pease, MS. Coll. Pease, 1863.

Partula vittata, Hartman (not of Pease), Cat. Part., p. 7 (part).

Shell rimately perforated, moderately thick, not shining, surface roughened by
unusually coarse, rude incremental striae, and tire spire marked by more or less distinct
crowded spiral incised lines; color whitish or pale luteous horn-color, with longitudinal,
irregular, narrow darker stripes ; spire conical, with planulate outlines, half the length
of the shell; apex subacute, concolored, white, or light brown ; suture linearly impressed,
sometimes whitish ; whorls 5-5|, flatly convex, last one large, convex, .sometimes
obsoletely angulated in front and generally a little compressed behind the outer lip;
aperture subvertical, oblong, obauriform, .sides parallel ; parietal region more or less
glazed, and, with few' exceptions, furni.shed with a white tubercidar tooth; peristome
whitish, frequently margined with pale purplish brown, rather thin, considerably
expanded, concave, very obliquely slanting, strongly and acutely labiated on the inner
margin, which is more or less distinctly toothed and sinuous above ; columellar lip
subnodo.st'.

Length 21, major diam. 10 mill.

Var. a. Uniform chestnut-brown. Frequent.

^ nr. h. ith a chestnnt-brow'n base and sutural band. Not uncommon.

\ ar. c. ith a median brown or chestnut-brown band. Somewhat rare.

The metropolis of this species is in Hamoa valley, on the east coast of Raiatea, the
home of callifera and compacta. It is quite common beneath decaying vegetation and
among pdcs of loose stones. It has not spread any to the northward, but occurs in
limited numbers in all the valleys south as far as Vairahi, the headquarters of P.
dmiifera.

P. microstoma, which inhabits the latter valley, though very frequently found
adhering to the lower portion of the trunks of trees and shrubs, can scarcely be
separated from radiata, which is strictly terrestrial in habit. Dr. Hartman unites it
with P. tnttafa. It appears to me more nearly related to radiata than the latter, which
IS smootlier, and the columellar lip is flat and simple.

• "’‘‘*'‘5' under the name of cmnpresea,

IB considered by Dr. Hartman to be entirely distinct from the latter, and I follow him
m restonng Pease s original name. Hybrids between these sheUs and P. /ala are not

terrestrial molltjsca inhabiting society islands.

P. VITTATA, Pease. Plate III, fig. 56.

H T' '*“• l>' '« ■ 2o»l- Soc., 1811, p. 473.

On V 1'"'- P 200. Hartman, Cat. Part., p. 7 ; Oils. Gen. Part., Bul. Mu8.

Com. Zool., IX, p. 169 (excl. microstoma).

Partula ierre.lrfa. Pease, MS. Coll. Pease, 1868. Pastel, Cat. Coneli,, p. 104. Gloj-ne,

Quar. Jour. Conch., i, p. 388.

Partula caslanea, Pease, Coll. Pease, 1863.

Partula f aha, var.. Carpenter, Proc. Zool. Soc., 1864, p. 675.

Partula approximata, Pease, MS. Coll. Pease. Schmeltz, Cat. Mus. Godeff., v, p 207

Gloyne, Quar. Jour. Conch., i, p. 338. Hartman, Cat. Part., p. 7 ; Ohs. Gen. Part., Bul.

Mus. Com. Zool., ix, pp. 179, 195.

The .sliape of the typical vittata is oblong-conic, more or less compressly umbili-
cated, and^ the spire, which equals half the length of the shell, has subplanulate
outlines. The ample, oblong aperture is considerably contracted by the intrusion of
callus on the inner margin of the peristome, and the sides are nearly parallel. The
peristome is rather thin, widely expanded and usually stained with brownish purple.
The superior inner margin of the hp exhibits a shallow sinus. The columella is
flattened, not nodose, and reflected over the umbilicus. The color is whitish, yellowish
corneous, fulvous or horn-color, frequently with the basal third of the body and sutural
band chestnut-color. Sometimes the apex is black or purple-black. The parietal
tooth, though small, is constant. My largest examples are 25 mill, long, and 11 in
diameter.

'I'he type is restricted to the higher portions of Toloa valley, on the west coast of
Raiatea, where it is not uncommon beneath decaying vegetation. It has not spread
any to tlie northward, but, on the other hand, occurs in greater or less profusion, in a
modified form (= approximata), in several small valleys on the southwest part of the
island. No examples were discovered in Hapai or Vaiau, the headquarters hignhria
and oralis, which two valleys are between Toloa and the small ones inhabited by
approximata.

The latter, which may be regarded as a variety of vittata, is characterized by its
inferior size, smaller umbilicus, which is frequently impervious, smaller aperture, and
less expanded lip. The parietal tooth is very seldom developed. The fasciation is
similar in the two forms, but occurs rarely in approximata. The latter differs, also, in
being generally a lighter or darker chestnut-color, though both have similar horn-
colored varieties.

In the valleys on the southern part of the island, we find a gradual change from
the typical P. approximata into the form known as P. terrestris. Pease, which latter
connects the former with vittata. It is of equal size, and exhibits a similar perfora-
tion, large aperture and widely expanded lip. The parietal tooth is seldom absent,
and in coloration we find the same style of fasciation, but, hke in approximata, it is
less frequent than in vittata. It differs from approximata in being generally light
horn-color, with darker strigations.

76

TEKRESTKIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

'I'lie rano-o of ferrestris terminates at Opoa valley, on the southeast coast. At
Faaloa on the cast coast, there exists a form which is the P. castnnea. Pease, and is
intermediate between ierrestris and vittata. It is usually chestnut-colored, constantly
toothed on the parietal wall, and the fasciation is the same as in the other varieties. It
has not spread any to the northward of Faaloa, but occurs more sparingly in a small
valley between Faaloa and Opoa.

P. NAViGATORiA, Pfeiffer.

Bulimus navigatorius (Partula), Pfeiffer, Proc. Zool. Soc., 1849, p. 131.

Fartula navigaioria, Reeve, Conch. Icon., PI. lY, fig. 21. Pfeiffer, Mon. Hel., hi, p. 449.
Carpenter, Proc. Zool. Soc., 1864, p. 6T5. Hartman, Cat. Part., p. 7 ; Obs. Gen. Part.,
Bnl. Mus. Com. Zool., ix, p. 184.

Partula variabilis, Pease, Amer. Jour. Couch., 1866, p. 203 ; 1867, p. 81, PI. I, figs. 12—14 ;
Proc. Zool. Soc., 1871, p. 473. Paetel, Cat. Conch., p. 104. Sehmeltz, Cat. Mus. Godeff.,
P..207. Pfeiffer, Mon. Hel., viii, p. 201.

This species has its headquarters in the lower portion of Vaioara valley, on the
west coast of Raiatca, where it is very abundant, associated with P. fusca. Though
usually found lurking beneath decaying vegetation, it is sometimes taken on the
trunks of trees. It does not occur in the next valley to the northward, the home of
P. Ihalid, l)ut has spread along the lowland forests south as far as Upara valley.
Hybrids between this species and fuscAi and faha are very frequent.

Mr. Pease states, in a letter received from him in 1870, that he had determined
narigatoria to be a small variety of P. /aha, and in the following year he published
liis list of Polynesian land shells, and excluded Pfeiffer’s species from tlie Partula.

According to the latter author’s description, and Reeve’s figure, it is undoubtedly
the same as Pea.se s rariahilw ; and, though a misnomer, must, according to the law
of priority, take precedence over the latter species,

'File parietal tooth mentioned by Pfeiffer, but not alluded to by Reeve or Pease, is
not constant, but exists in about two-fifths of the adrrlts. The former author’s “medio
subdentato,” likewise not mentioned by the latter two writers, is simply the lower
angle of the small labial sinus.

In shape it varies from ovate to oblong-ovate, as the following two measurements
will show : —

Length 25, diam. 13 mill.

Length 20, diam. 13 mill.

Mr. 1 ease s accurate figures represent the normal or usual form, and his figures 12
and 13 the typical color, which is luteous or yellowish hom-color, with longitudinal
strigalions. Uniform whitish corneous or chestnut-colored varieties occur, but are not

common A more ahiindant variety is the usual one of a chestnut-brown base and
sutural band.

ierrestrial mollusca inhabiting society islands. 77

P. EUSTICA, Pease.

Partula rustica, Pease, Amer. Jour. Conch., 1866, p. 199 ; 1867, p. 81, PI. I, fig. 5 ; Proc. Zool.
oc. , p 473. Schmeltz, Cat. Mus. Godeff., v, p. 207. Pfeiffer, Mon. Hel., viii,p. 205.
artula aunculata, Carpenter (not of Broderip), Proc. Zool. Soc., 1864, p. 675.

Partula crassilabris, Gloyne (not of Pease), Quar. Jour. Conch., i, p. 338. Hartman, Cat.

I art., p. 9 ; Obs. Gen. Part., Bull. Mus. Com. Zool., ix, p. 187 (part).

Partula pinguis, Garrett, MS.

The metropolis of this species is in a large valley called Toloa, on the west coast
of Raiatea, where it occurs in great abundance beneath decaying vegetation. It has
migrated to the southward into two small adjacent valleys, but does not extend its
range so far as Plapai, the next large valley, and the home of the allied P. crassilabris.

It IS larger, less globose, the aperture more oblong, than the latter species, with
which it has been confounded. Its chief character consists in the columellar region
being, as it were, pressed in towards the aperture, nodulous on the inner margin, and
subangulated at the base. The parietal tooth is less developed and more frequently
absent than in crassilabris. The coloration is the same in the two species. Like the
majority of the ground species, it varies in a greater or less degree in shape and size.
Some forms almost exactly simulate P. Garrettii, not only in the outline of the shell, but
in the peculiar shape of the aperture as modified by the columella being pressed inwardly.
Occasionally examples occur which are so much abbreviated that they resemble P.
crassilabris, but may readily be separated by the dissimilarity in the columeUar region.

My P.jnnr/His, of which I have seen only a dozen examples, was found under decaying
leaves in the mountain ravines, at the head of Vaioara valley. It certainly = rustica.

P. LUGUBEis, Pease. Plate III, fig. 47.

Partula lugubris, Pease, Proc. Zool. Soe., 1864, p. 672; 1871, p. 473. Pfeiffer, Mon. Hel.,
vi, p. 158. Schmeltz, Cat. Mus. Godeff., v, p. 207.

Partula ovalis, Pease, Amer. Jour. Conch., 1866, p. 194; Proc. Zool. Soc., 1871, p. 473.
Pfeiffer, Mon. Hel., viii, p. 205.

Partula dentifera, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675 ovalis).

Partula fusca, Hartman (not of Pease), Cat. Part., p. 6; Obs. Gen. Part., Bui. Mus. Com.
Zool., ix, p. 182 (part).

The six-cific centre of this ground species is in Vaiau valley, on the west coast of
Raiatea, the northern limits of the range of P. formosa. It has not spread any to the
southward, but, on the other hand, has migrated to the northward into Hapai vaUey,
the headquarters of P. crassilabris, with which it is found associated.

The Hapai shell was first described by Mr. Pease, under the name of lugubris,
and, although nearly as abundant as the Vaiau form (= ovalis, Pse.), is smaller,
thinner, more attenuated and more variable in color and fasciation.

However, the difference between the two species is so slight that I think it best
to unite the two forms.

11 JOUR. A. N. S. PHILA., VOL. IX.

78 TEEltESTIUAL MOLLTISCA INHABITING! SOCIETY ISLANDS.

In ,l,a,x. they vary from abbreviale-ovate to ohlong-ovate, no. solid ronghly
striated' spire usually half the length of the shell, sometime., shorter, and the base
more or less eompressl, umbilicated. The aperture is rather large, srthoval, edentate,
and the eolumella is depressed, not nodulous. Sometimes the hout of the bod^ mri
is faintly angulated. The outer lip is rather thin, moderately expanded, slant, n„,
concave, more or less stained with purple-brown, sometimes du l whitish or tawny,
and the inner margin, which is not very heavily labiated, is in adults .slightly sinuous

The color varies from light chestnut-brown to dark chestnut, sometimes fulvous.
Examples with a more or less broad, median, yellowish corneous band are not infre-
quent in botli the Vaiau and Hapai shells.

Tlie following hvo varieties occur in the typical hujulria only :

Uniform whitish horn-color, with pure white lip. Rather raie.

'i'ellowish liorn-color, with a median, narrow, reddish chestnut band. Rare.

My largest ^’aiau specimens are 20^ mill, long, and 11 mill, in diameter. Ihe
smallest adult from Hapai is 1 6 by 8 mill.

I have found hybrids between Uguhris and imperforato, the latter a strictly
arboreal species.

Dr. Hartman, overlooking the fact that luguhris, ovalis, 2>^ote(i and fiiaca inhabit
widely separated valleys, has suggested that the three former may be the juvenile and
adolescent forms of the adult //wcf*. The habitats of the Uvo former species are about
two miles apart, and five miles south of the location of fnsca. P. protea^ which =
/iiaca, is confined to the opposite side of the island, and is separated from the latter by
an almo.st inaccessible mountain.

1 cannot conceive how Carpenter could have referred Pease’s ovalis to Pfeiffer’s denti-
fera, a shell of an entirely different type. He also says, in a foot-note to the former
author’s diagnosis of hignhris: “ This species is regarded by Mr. Cuming as probably
a variety of P. pacijica, Pfr.,” which latter is by Dr. Hartman referred to P. Otaheitana.

P. VARIA, Prodeiip.

Partula varia, Broiterip, Proc. Zool. Soc., 1832, p. 125. Muller, Syn., p. 33. Reeve, Conch.
S3'st., ii, PI. CLXXV’^, figs. 5, G ; Conch. Icon., PI. Ill, figs. 17 a,b,c. Pfeiffer, Mon. Hel.,
ill, p. 448. Pease, Proc. Zool. Soc., 1871, p. i’l 3, et ysly. glutinosa, pulchra, simplex. Paetel,
Cat. Conch., p. 104. Schrneltz, Cat. Mus. Godeff, v, p. 92. {Matata) Hartman, Cat. Part.,
p. 14 ; Obs. Gen. Part., Bui. Mus. Com. Zool., ix, pp. 189, 191 (excl. strigata).

Bulimus varius, Pfeiffer, Symb., i, p. 86 ; ii, p. 124.

Bulimus roseus, var., Pfeiffer, Mon. Hel., ii, p. 70.

Partula glutinosa, Pfeiffer, Proc. Zool. Soc., 1852, p. 85 ; Mon. Hel., iii, p. 448. Paetel, Cat.
Conch., p. 104.

Partula mucida, Pfeiffer, Proc. Zool. Soc., 1855, p. 98 ; Mon. Hel., iv, p. 513.

Partula pulchra, Pease, MS. Col. Pease, 1863. Schrneltz, Cat. Mus. Godeff., v, p. 92.
Partula Huaheinensis, Garrett, MS. * ’

terrestrial mollusca inhabiting society islands.

79

1‘arlida bicolor, Garrett, MS.

Partula adusta, Garrett, MS.

Parlula lugubris, Gloyne (not of Pease), Quar. Jour. Conch., i, p. 338.
Partula simplaria, Schmeltz (Morelet ?), Cat. Mus. Godeif., v, p. 92.
Partula perplexa, Pease, MS. Coll. Pease. (Ex. Hartman.)

Huaheine, where they are very abundant on foliage. It was first discovered bv Mr.
Cuming, who gave the habitat “ Society Islands,” and gratuitously added that of the
“ Navigator Islands,” where it is 7iot found.

The type is very variable in coloration, and considerably so in size and shape.
The smallest form, which = P. pulchra, Pse., gradually merges into the type, and is
restricted to the largest of the two valleys called Hamene. The type which equals
my Hualieinensis and (idusta, is usually corneous, luteous, more frequently fulvous,
rarely white, and the most abundant variety is dark chestnut, sometimes nearly black
wth a pale apex and dark or pale lip. Deep chestnut-colored examples, with a wide
or narrow central pale band, are not uncommon, and are Avell represented by Reeve’s
fig. ITrt. Ills fig. 175, with an obscure central fulvous band on a pale ground, is
rather common.

In the liigher portion of Hamene may be found a large form = hicolor, Garr.,
which is either uniform straw-yellow, or greenish yellow, with or without a dark
chestnut spire. It differs from the typical varia in being larger, more robust, the
whorls more inflated and the aperture wider.

In a valley named Faahiti, on the northern part of the island, we find in the
greatest profusion, associated with P. cognata, Pse., a form shaped like Incohr, but
smaller and more variable* in color than the t}q)ical varia. The most common variety
is light yellowish, sometimes strigated, the lip, and sometimes tlie base, stained with
burnt-brown or violet-brown. Nearly half of the specimens are uniform fulvous brown,
or chestnut-brown approaching black. The variety with central pale band is also very
frequent, as well as the one of a uniform whitish or luteous with white lip. Ihe pale
variety with chestnut spire is somewhat rare, besides one with a dark spire and two
narrow hands on the body-whorl. A lot of these shells sent to the “ Museum
Godeffroy,” were by Prof. Mousson referred to Morelet’s P. simplaria, and have been
freely distributed under that name. Morelet cites “Tahiti” as the habitat of his species.
His “ apice obtuso rosaceo ” and “ sutura albo marginata ” do not occur in these
shells nor any of the varieties of varia. Mr. Pease did not identify it with any of the
Huaheine .shells; but Dr. Hartman, on the contrary, regards it as a variety of 7^.
rosea.

Resides the three valleys just alluded to, we find this species generally distributed
in greater or less numbers throughout all parts of the island, but subject to much less
variation in form and color. Like hicolor, and the generality of the Faahiti shells, they

80

TERKESTllIAL MOLLUSCA INHABITINGr SOCIETY ISLANDS.

are more robust and the whorls more swollen than the typical varia. The most common
variety is luteous, or straw-yellow, sometimes pale fulvous with the lip more or less
stained with violaceous brown. The variety with a white peristome is not uncommon,
and a beautiful variety, with a very dark violaceous black spire and wide band of the
same color on the middle of the body-whorl, is much more infrequent, as well as the
one with a dark spire, without the band. The dark variety with yellowish band, so
common in the type and the Faahiti shells, is rarely found elsewhere. The first men-
tioned variety, which comprises nearly 75 per cent, of the specimens, is probably
Pfeiffer’s P. glutwosa, which Pease qirotes as a variety of P. varia. Dr. Hartman, in his
Catalogue of Partula, records it as a distinct species, and in Observations on the Genus
Partula cites the Navigator and Solomon Islands as its habitats ; in the same paper
he states, in his remarks on Pease’s duplicates, that “P. glutinosa, Pfr., in one quart was
uniform in size and color,” which coincides with the Huaheine shells. Both Pease
and Dr. Cox have a.s.sured me that they have never received Pfeiffer’s glidmosa from
either the Navigator or Solomon Islands. The shells referred to were collected by me
on Huaheine, and, as just mentioned, were by Pease regarded as P. varia, var. glutinosa.
Pfeiffer, who erroneously cites the Solomon Islands as the habitat of the latter, remarks, ’
in his fourth volume, that Reeve’s P. varia, fig. IT 5, is the same as glutinosa.

I am unacquainted with Pease’s varieties simplex and perplexa — the latter quoted
on the autliority of Dr. Hartman, but not recorded by the former author in his list
of Partula.

I have followed Dr. Hartman in adding Pfeiffer’s mucida to the svnonvmv oi' varia.
which he says is represented in the British Mmseum by a dark variety of' the latter
species. The description and measurements harmonize well, but it appears strange
tlmt Pfeiffer should have compared his species to P. filosa, which belongs to an entirely
diffenmt type, instead of to the well-known varia.

1 cannot agree with Dr. Hartman in his affiliation of Pease’s P. strigata, a Mar-
quesas (“Marquesas! live.,” Hartman) species, with P. mnV,, which is an entirelv
d^tmet species. Pease’s shells were collected by a native missionarv residing on
Moapo, one of the former group, which is 850 miles distant from Huaheine

Ihe onb^ species likely to be confounded with varia is Pease’s P. assvmilis (= P

Ite taZt ofT V “0 from

I f . '"7 Partula) as a valid

i. Tobrfen'f “r '■

variety of P. raWa ” (i' ' To! “ local

terrestrial mollusca inhabiting society islands.

81

1 ^ "0 ess expanded, the spire more turgid, the apex more obtuse and the colora-

n IS compaiatively uniform. At any rate, the two species can bo distinguished at a

^11 considering the remote habitats, may be regarded as distinct but closely
allied species.

T. Philippi,, Pfeiffer. TORNATELLINA, Beck.

Tornatellina PhilippU^ Pfeiffer, Zeitsch. Malak.. 1849, p. 93 ; Mon. Hel., iii, p. 524. Pease,
Proc. Zool. Soc., 1811, p. 473. Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 22; Jonr.
Acad. Nat. Sci. Phila., 1881, p. 397.

Pupa Philippa^ Kiister, PI. XVIII, figs. 20, 21.

Leplinaria Philippii^ H. and A. Adams, Gen. Moll., p. 141.

Achatina Philippii {Leptinaria) , Pfeiffer, Vers., p. 170.

Cionella Philippii^ Martens.

This species, though distributed throughout the group, is not plentiful. They
were found adhering to the under side of loose stones, beneath dead wood and
decaying leaves. I also obtained examples at the Cook’s, Marquesas, and received it
from one of the Austral I.slands.

It may be readily known by its swollen whorls, turgid body, large, compressed,
parietal laminm, and somewhat tortuous columella.

T. OBLONOA, Pease.

Tornalellina oblonga, Pease, Proc. Zool. Soc., 1864, p. 673; Jour.de Conch., 1871, p. 93;
Proc. Zool. Soc., 1871, p. 473. Pfeiffer, Mon. Hel., vi, p. 264. Schmeltz, Cat. Mus.
Godeff., V, p. 89. Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 21 ; Jour. Acad. Nat.
Sci. Phila., 1881, p. 398.

Tornatellina bacillaris, Mousson, Jour, de Conch., 1871, p. 16, PI. Ill, fig. 5. Pfeiffer,
Mon. Hel., viii, j). 316. Schmeltz, Cat. Mus. Godeff., v, pp. 89, 90.

Plentiful, and distributed throughout southern Polynesia. Like the preceding, it
is a ground species, though sometimes found on the fronds of ferns, and ranges from
near the seashore to 2000 or more feet above sea-level.

Prof. Mousson gives an accurate description of ohionga, under the name of haciUaris,
from specimens collected by Dr. Graffe at the Samoa Islands.

I collected Mr. I’ease’s type examples at Huaheine. Its slender form and nearly
vertical simjile columella will easily distinguish it.

T. OONICA, ^lousson.

Tornatellina conica, Mousson, Jour, de Conch., 1869, p. 342, PI. XIY, fig. 8; 1870, p.
128; 1871 (vnr. impressa), p. 16; 1873, p. 106. Pease, Proc. Zool. Soc., 1871, p. 473.
Pfeiffer, Mon. Hcl., viii, p. 316. Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 21 ; Jour.
Acad. Nat. Sci. Phila., 1881, p. 399. Schmeltz, Cat. Mus. Godeff., v, p. 89.

Cionella conica, Paetel, Cat. Conch., p. 106.

Tornatella oblonga, Pease (part), Proc. Zool. Soc., 1864, p. 673.

Not uncommon, and ranges from the Paumotn to the Viti Wes, and was collected
by Dr. Graffe on the low coral islands of Ellice’s group in centi-al Polynesia.

82

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

I forwarded Mr. Pease a number of examples of this species intermixed with
obhiKja, and, supposing the two to be identical, he included it in his diagnosis of the
latter sjiecies. Having collected hundreds of specimens of both species at the different
groujis, I do not hesitate to consider them quite distinct. As compared to oUonga, it
is lighter-colored, more robust, spire more rapidly tapering, body- whorl larger and
more or less compressed in the middle. The parietal lamina is larger, and the
columella more tortuous.

Mousson’s var. impressa is not uncommon in eastern Polynesia.

T. SIMPLEX, Pease. Plate II, fig. 21.

Tornatellina simplex, Pease, Proc. Zool. Soc., 1864, p. 613 ; 1811, p. 413. Pfeiffer, Mon. Ilel.,
vi, p. 266. Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 22 ; Jour. Acad. Nat. Sci. Phila.,
1881, p. 398.

Tornatellina Newcomhi, var., Schmeltz, Cat. Mus. Godeff., vi, p. 80.

I'his species is distributed throughout all the groups of islands in southeastern
Polynesia ; on the ground, in forests.

Mr. Pea.se’s type specimens were collected by me at Tahaa. He either overlooked
or inadvertently omitted to mention the small, but constant, parietal lamina in his
brief diagnosis. The open umbilicus, small parietal lamina, smooth and simple colu-
mella, will distinguish it from any other south Polynesian species.

Though shaped like T. Newcomhi, which inhabits the Sandwich Islands, it is
smaller, tlie umbilicus larger, the columella simple, not biplicate, and the pariettd
lamina is smaller than in Pfeiffer’s species.

T. PERPLEXA, Garrett. Plate II, fig. 23.

Tornatellina perplexa, Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 24; Jour. Acad.
Nat. Sci. Phila., 1881, p. 398.

Tornatellina bilamellata, Schmeltz (not of Anton), Cat. Mus. Godeff., v, p. 90.

Not uncommon, and ranges throughout the group. Also common to the Austral
and Cook’s Islands.

As compared rvith nitUla, the iiearest allied species, it has a more dilated and
htdentato colnmella. The upper denticle is larger and not so acute as in nitida
Some exatuples have the palatal denticles mounted on longitudinal lines of callus

T. 8ERRATA, Pease. Plate II, figs. 22, 22 a.

Lamellina serrata. Pease, Proc. Zool. Soc., 1860, p. 439 ; 1871 p 473
Tornatellina serrata, Pfeiffer, Mon. Hel., vi, p. 265 ’

Lamellina leevis. Pease, Proc. Zool. Soc., 1864,’ p. 672 ; 1871 p 473
Tornatellina Iseois, Pfeiffer, Mon. Hel., vi, p. 216.

Not uncommon, and distributed throughout southeastern Polynesia.

Isl , r on the land shells of Rurutu and Cook’s

Islands, published by the Academy of Natural Sciences of Philadelphia

TEERESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

83

T. NiTiDA, Pease. Plate II, fig. 24.

Tornatellina nitida, Pease, Proc. Zool. Soc., 1860, p. 439; Jour, de Conch., 1871, p. 93;

Pi'oc. Zool. Soc., 1871, p. 473. Pfeiffer, Mon. Hel., vi, p. 264. Garrett, Proc. Acad.

Nat Sci. Phil., 1879, p. 22 ; Jour. Acad. Nat. Sci. Phil., 1881, p. 399.

rhi.s species is found abundantly on all the islands in southeastern Polynesia, and
ranges northwest as far as the Caroline Islands, where I obtained Mr. Pease’s type
specimens.

It is a thin transparent species, with a more tapering spire than ohimga, with the
twisted columella of conica, but readily distinguished by the acute plication on the
columella.

T. APERTA, Pease. Plate II, fig. 20.

Tornatellina aperta, Pease, Proc. Zool. Soc., 1864, p. 673 ; 1871, p. 473. Pfeiffer, Mon.

Hel., vi, p. 264.

Xot uncommon on foliage, and ranges throughout the group. A few examples
were taken by me at the Marquesas Islands.

It may be distinguished by its globose-ovate form and the peculiar vertical biden-
tate crest on the columella.

The animal, which is very active, is subpellucid with dusky tentacles. The foot
is oblong, rounded behind, and nearly as long as the shell. The eye-peduncles are
stout. Labial tentacles, none. Muzzle large, dilated, and aids in locomotion.

T. Peaseana, Garrett. Plate II, fig. 19.

Shell imperforate, oblong-ovate, smooth, thin, shining, 'faintly striated, dark brownish
horn-color ; spire conical, with nearly planulate outlines and subacute apex ; suture
faintly impressed ; whorls five and a half, convex, moderately increasing, last one large,
rounded, not descending in front; aperture large, oblique, truncately ovate, nearly
half the length of the shell; peristome thin, straight, regularly curved; parietal
region with a prominent, thin, revolving white lamina, which is slightly reflected pos-
teriorly ; columella armed with a prominent, nearly vertical, bidentate plait.

Length 5, diam. 2| mill.

JIab. — Moorea Island.

Very rare on foliage. Closely allied to aperta, but much larger, more elongate,
darker color and the spire more produced.

Genus VERTIGO, Muller.

V. pedicueus, Shuttleworth. Plate III, fig. 42.

Pupa pediculus, Shuttleworth, Bern. Mitth., 1852, p. 296. Pfeiffer, Mon. Hel., lii, p. 557.
Sclimeltz, Cat. Mus. Godeff, v, p. 89. Mousson (var. Samoensis), Jour, de Conch., 1865,
p. 117.

84

TEKIIKSTIIIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

Vertigo pediculus, Pfeiffer, Vers., p. in. (Alaea) H. and A. Adams, Gen. Moll., ii, p. 172.
Moiisson, Jour, de Conch., 1869, p. 341. Pease, Proc. Zool. Soc., 1871, pp. 463,474.
Garrett, Proc. Acad. Nat. Sci. Phila., 1879, p. 19; Jour. Acad. Nat. Sci. Phila., 1881,
p. 400.

Ihipa Samoensis, “ MSS.” Schmeltz, Cat. Mus. Godeff., iv, p. 69. (Sphyradium) Paetel, Cat.
Conch., p. 108.

Pvpa nitena, Pease, Proc. Zool. Soc., 1860, p. 439. Pfeiffer, Mon. Hel., vi, p. 335.

Vertigo nitena, Pease, Proc. Zool. Soc., 1871, pp. 463, 474.

Pupa hyalina, “ Zelebor” Pfeiffer, Mon. Hel., vi, p. 329.

Vertigo hyalina, Pease, Proc. Zool. Soc., 1871, p. 474.

? Vertigo nacca, Goidd, Proc. Dost. Soc. Nat. Hist., 1862, p. 280 ; Otia Conch., p. 237. Pease,
Proc. Zool. Soc., 1871, pp. 463, 474.

Pupa nacca, Pfeiffer, Mon. Hel., vi, p. 330.

With tlie exception of Stenogyra TucJceri, this minute shell has the widest range
throughout Polynesia of any species.

Its oblong-ovate form and hyaline texture will easily distinguish it.

For further information in regard to this species, see my paper on the Rurutu
Island land sliells.

V. TANTILLA, Gould.

Pupa {Vertigo) tantilla, Gould, Proc. Bost. Soc. Nat. Hist., 1847, p. 197. Pfeiffer, Mon.
Ilel., iii, p. 457. ( Vertigo) Mousson, Jour, de Conch., 1870, p. 127. ( Vertigo) Schmeltz,

Cat. Mus. Godeff., iv, p. 69. {Papilla) Paetel, Cat. Conch., p. 108.

Vertigo ta.ntilla, Gould, Expl. Ex. Shells, p. 92, fig. 103. {Aleea) H. and A. Adams, Gen.
Moll., u, p. 172. Pease, Proc. Zool. Soc., 1871, pp. 460, 463, 474. Garrett, Jour. Acad.

Nat. Sci. Phila., 1881, p. 400.

Pupa Dankeri, “Zelebor ” Pfeiffer, Mon. Hel., vi, p. 333.

Vertigo Dunkeri, Pease, Proc. Zool. Soc., 1871, p. 474.

Vertigo armata, Pease, Proc. Zool. Soc., 1871, pp. 461, 474.

Pupa armata, Pfeiffer, Mon. Hel., viii, p. 407.

Vertigo dentifera. Pease, Proc. Zool. Soc., 1871, pp. 462 474
Pupa dentifera, Pfeiffer, Mon. Hel., viii, p. 408.

Pit/ an‘‘ Hiaheine, Borabora and Mau.

group, where

plicate "trC' ‘h-t preceding apeoies by its dark color and thin.

Acadl/Ir/Nararsdercrj PWMeUia.

Genus SUCCINEA, Draparnaud.

wher/rM:;:: waupui,

and arboreal species. ^ PartulcB, they may be divided into ground

terrestrial mollusca inhabiting society islands.

85

There are twelve species recorded from this group, some of which arc undoubtedly
synonyms, and one or two are doubtful inhabitants. The specific characters of tire
various species are so feebly expressed that their correct determination, by the aid of
the brief Latin diagnoses alone, is an almost hopeless task.

S. HUMKROSA, Gould.

Succinea humerosa, Gould, Proc. Dost. Soc. Nat. Hist., 1846, p. 183 ; Expl. Ex. Shells, p. 18,
fig. 19. PfeiflFer, Mon. Hel., ii, p. 520. H. and A. Adams, Gen. Moll., ii, p. 128. Pease,
Proe. Zool. Soc., 1864, p. 671 ; 1871, p. 472.

Succinea Tahitensis, Pease (not of Pfeitfer), Proc. Zool. Soc., 1864, p. 677 ; 1871, p. 472.

Rather common and rvidely diffused over Tahiti, where it lives on the ground in
forests, and appears to be confined to that island.

It may be distinguished from any other Society Islands species by its broad ovate
form, very short mammillated spire, large depressed body-whorl, which usually exhibits
a roundly angular shoulder, which suggested the specific name. Dr. Gould gives three
whorls, though I can detect two and a half only in my numerous specimens. The
color is rufus, pale corneous, yellowish amber and whitish. The revolving sulcations
mentioned by the above author are not a constant character, and are common to other
Society Islands species.

S. Tahitensis, Pfeiffer. Plate II, fig. 2.

Succinea Tahitensis, Pfeiffer, Proc. Zool. Soc., 1846, p. 109; Mon. Hel., ii, p. 522. H. and
A. Adams, Gen. Moll., ii, p. 129.

Succinea ovata, “ Pease,” MS. Carpenter, Proc. Zool. Soc., 1864, p. 675.

Succinea papillata, Carpenter (not of Pfeiffer), Proc. Zool. Soc., 1864, p. 675. Pease,
Amer. Jour. Conch., 1867, p. 227 ; Proc. Zool. Soc., 1871, p. 472. Schmeltz, Cat. Mus.
Godeff., V, p. 89.

Abundant on the ground in moist places, and distributed throughout the island of
Iluaheine.

Dr. Pfeiffer’s description agrees much better with this shell than with humeroaa,
and, contrary to the opinion of Mr. Pease, I do not hesitate to consider my determina-
tion as correct. The locality “ Tahiti” is too frequently used for shells inhabiting
other islands in the group to deserve much attention. Mr. Cuming, who collected
extensively on Huaheine, could scarcely have failed to discover so common a shell, and
may have forgotten the exact locality. It is now well known that a large number of
his habitats of species discovered by himself are erroneous. Mr. Pease, who was well
acquainted with the locality of his ovata, gave the wrong one, “ Tahiti,” where it does
not occur.

It is more nearly related to JiuvneTosa than to any other species, but may be
distinguished by its larger, and more produced spire, more contracted body, and light
amber-color. Specimens with subangulated body-whorl are not infrequent, and some
have obscure transverse sulcations.

12 JOUR. A. N. S. PHILA., VOL. IX.

92

TEKKESTKIAL MOLLUSCA IxNlIAKlTING SOCIETY ISLAxVDS.

Jiaimodonla, conica^ Martens and Langk., Don. liisni., p. 57, I 1. HI, fljj* 13.

IHecotrema Anaaensis, Paetel, Cat. Conch., p. 114.

Melampus conic us, Pfeiffer, Mon. Pneiira., iv (Aui'iculacea)^ p. 319.

? Melampus Anaaensis, Pfeiffer, 1. c., p. 320.

This spocics, though ranging from the Paumotu to the Viti Islands, is rarely found
in the Society group. It is smaller and not so robust as L. Bronni of the Sandwich
Isles. The spiral impressed lines are more conspicuous, and the aperture exhibits a
heavier deposit of callus in the palate.

Genus PLECOTREMA, H. and A. Adams.

P. MORD.iX, Dolirn.

Plecotrema mordax, Dolirn, Mai. Blat., 1859, p. 204. Pease, Jour, de Conch., 1871, p. 93.

Martens and Langk., Don. Bisra., p. 55, PI. Ill, fig. 8. Paetel, Cat. Conch., p. 114.

A few dead specimens found on the seashore on the northeast coast of Tahiti. It
is not uncommon on the Paumotu Isis.

The examples now before me are more globose than any Polyne.sian species known
to me. 1 he riblets are rounded and rugose. My specimens average from 5 to 6
mdl. in length, and are nearly white with a very broad, light fulvous zone.

Genus DIADEMA, Pease.

Amer. .Tour. Conch., 1868, p. 158.

Oarrettia, O. Semper, Cat. Mus. Godeff., v, p. 100, 1874.

D. IIIANOULATA, Pease. Plato II, fig. 29.

Crjcloxtoma hiangulala, Pease, Proc. Zool. Soe., 1864, p. 674.

Genus OMPHALOTROPIS, Pfeiffer.

globose-turbinate to elongate-conical.

author for the reception of a group of
r the filiform carina which circumscribes
ed peristome, and in shape varying from

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

93

Tliey are distributed over a vast area extending from soxxtheastern Polynesia to
Mauritius and Bourbon. They are entirely absent from the Sandwich Islands, where
the only operculated land shells are Helicinoe. Two species of Atroins only are recorded
from the Marquesas Islands ; but their existence in that group certainly wants confir-
mation. Both Mr. Pease’s collector and myself searched in nearly all parts of the
group without discovering a single example. In all probability the Society Islands
are the eastern limits of this group of shells. At any rate I utterly failed to detect
them at the Gambler and Paumotu Islands.

In the Society Islands the typical form is represented by a group in which the keel
gradually becomes evanescent, as in Huahemensis and scitula, or entirely absent, as in
terebralis and producta. The three latter were classed by Mr. Pease in his genus
Atropis. All the above species, together with Borahorensis and oblonga, usually
have the body or penultimate u horl more or less angulated and frequently with a
periphery keel.

The animal of HvaJieinemis varies from pale cinereous to tawny flesh-color with
blackish tentacles, which latter are short, conical, blunt and transversely wrinkled.
Eyes very conspicuous, black on enlargements at the hinder base of the tentacles.
Head broad, emarginate in front. Muzzle slightly dilated and bilobed in front, and
used in aiding locomotion. Foot small, oval, nearly half the length of the shell.

0. Huaheinknsis, Pfeiffer.

Hydrocena Iluaheinensis, Pfeiffer, Proc. Zool. Soc., 1854, p. 308; Mon. Pneum., ii, p. 163.
11. and A. Adams, Gen. Moll., ii, p. 300.

Omphalotropis Huaheinensis, Pfeiffer, Mon. Pneum., iii, p. Iff. Mart, and Langk., Don.
Bism., p. 58, PL III, fig. H. Pease, Jour, de Conch., 1869, p. 148, PI. VII, fig. 9.
Schmeltz, Cat. Mus. Godeff., v. p. 101. Pease, Proc. Zool. Soc., 1871, p. 476.

Assiminea Huaheinensis ^ Marten, Ann. Mag. Nat. Hist., 1866, p. 206.

. Realia Huaheinensis, Pfeiffer, Mon. Pneum., iv, p. 221. Carpenter, Proc. Zool. Soc., 1871,
p. ()76.

Hydrocena robusla, “ Pease,” MS. Carpenter, Proc. Zool. Soc., 1864, p. 676.

Omphalotropis robusta, Crosse, Jour, de Conch., 1869, p. 148 (foot-note), PI. VII, fig. 3.
Schmeltz, Cat. Mus. Godeff., v, p. 208.

Occurs in abundance, and widely diffused over Huaheine. It is also plentiful
and of larger size in three or four valleys on the west side of Raiatea. At Moorea,
where I obtained a few examples, it is of small size (5 mill.) and has the basal keel
nearly or quite obsolete. On the groxind in forests.

Pfeiffer’s type specimens (9 mill.) were collected at Raiatea, and his var. /9(6 mill.)
at Htiaheine. In one valley on the former island I discovered a large variety which

attained a length of 1 1 mill. i, • i j

They vary considerably in color: pale luteous, corneous, broxvn, brownish red,
reddish horn-color, rarely with a transverse brown or reddish band on the middle of
the body-whorl, which latter is sometimes sUghtly angulated. The epidermis is very

13 JOUR. A. N. s. PHILA., VOL. IX.

94

TKRllESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

thin, concolorccl, and the surface is generally more or less eroded. The basal keel is
not so distinct as in the typical species inhabiting the western groups.

0. PRODUCTA, Pease.

Itealia producta, Pease, Proc. Zool. Soc., 1864, p. 673. Pfeiffer, Mon. Pneum., iv, p. 217.

Omphalolropis producta, Pease, Jour, de Conch., 1899, p. 151, PI. \ II, fig 8.

A tropis producta, Pease, Proc. Zool. Soc., 1871, pp. 471, 476.

Realia elongala. Pease, Amer. Jour. Conch , 1867, p. 225. Pfeiffer, Mon. Pneum., iv, p. 218.

Omphalotropia elongata, Pease, Jour, de Conch., 1869, p. 152, PI. VII, fig. 4 ; 1871, p. 95.

Atropis elongata, Pease, Prec. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godetf., v,

p. 101.

Realia scitula. Carpenter (not of Gould), Proc. Zool. Soc., 1864, p. 676.

Hydrocena Raiatensis, Mousson, Jour, de Conch., 1869, p. 67, PI. V, fig. 5.

Realia Raiatemns, Pfeiffer, Mon. Pneum., iv, p. 215.

This variable species is confined to Raiatea and Tahaa, where it is found on the
ground in forests, and is widely diffused over both islands.

Mr. Pease’s measurement, 10| mill., is probably a mistake. I have now before
me over 500 examples, the largest of which is 9, and the smallest adult is 6 mill, in
length. The first has eight, and tlie latter seven whorls. I note the following colors ;
whitish, pale lutcous, corneous, different shades of brown, reddish brown, and very
rarely with a narrow transverse reddish band on the body-whorl. The aperture varies
from jiale yellowish white to dark ochraceous, sometimes reddish brown or whitish.

Tlie penultimate whorl is frequently slightly exserted over the body-whorl, which
latter is rounded, very rarely subangulated, and the base very narrowly perforatc'd or
rimate, but not keeled or angulate. The epidermis, which is very rarely present, is
thin and smooth. Sometimes the peristome is considerably expanded and tbe lip
duplicated. There is also considerable variation in the convexity of the whorls
Mr. Pea.se’s which he first described, differs none from his eiovffa/u, except

having the whorls more flattened, a character which gradually merges into the latter
species. I he same variation obtains in Borahorensis txndC terehralis.

0. Boraborensis, Dohin. Plate HI, flg. 60.

“7n5°'TLf7''Tt' "• «»■’■ I’"""”-, ‘ii.

P. 175. I ease. Jour de Conch., 1869, p. 151. Schmeltz, Cat. Mus Godeff v n 208
Atrop^s Boraborensis, Pease, Proc. Zool. Soc., 1871 p 476 ’ ’

Reaha Boraborensis, Pfeiffer, Mon. Pneum., iv p 217

midd^ who*

pole corneous, soinetimes widtir hr ^'"7
or less distindv ongllTela “mL m" ” "r”*

keel which winds up tlie spire Th l"' '''■'=9"™")' "'i'll a thread-like

>P spire. The penultimate whorl is often imbricated or e.vserted.

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

95

Adults are nearly always decorticated. The minute perforation is never carinated,
but sometimes exhibits a slight marginal pinch. The vertical aperture is whitish or
pale yellowish brown, and the peristome is slightly expanded. The epidermis in young
examples is thin, smooth, and the same color as the shell.

0. TEREBRALIS, Goulcl.

Cyclostoma terebralis, Gould, Proc. Dost. Soc. Nat. Hist., 1847, p. 206 ; Expl. Ex. Shells, p.

106, fig. 120. Petit, Jour, de Conch., 1850, p. 47.

Omphalotropis terebralis, Pfeiffer, Proc. Zool. Soc., 1852, p. 151. H. and A. Adams, Gen.

Mol., ii, p. 300. Pfeiffer, Mon. Pneum., i, p. 307. Pease, Jour, de Conch., 1869, p. 151.

Paetel, Cat. Conch., p. 124.

Bealia terebralis. Gray, Cat. Phan., p. 219. Pfeiffer, Mon. Pneum., iv, p. 217.

Atropis terebralis, Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godeff., v,

p. 102.

Atropis Oouldii, Garr. MS.

Atropis Dohrniana, Garr. MS.

I found this species plentiful on the ground in a lowland forest on the coast of
Moorea, and did not find a single example in any other part of the island. It occurs,
also, somewhat rarely in three valleys on the northwest side of Tahiti, and more
abundantly in the mountain forests of Borahora. On the two latter islands it is confined
to an elevation of about 500 feet above sea-level.

The presence of this species in Borahora is somewhat remarkable, as it does not
occur on the three intermediate islands. Examples from the latter island, which I
have distributed to my correspondents under the name of Dohrniana, differ none from
Gotild’s species, except in having a velvety epidermis.

The Moorea shell, to which I gave the provisional name of Ootddi, varies from the
type in its more attenuated form, the whorls less “imbricated,” and the angle on the
last one nearly obsolete. It was found associated with the typical terebralis, into which
it gradually merges.

The color is corneous, grayish olive, rarely luteous under a thin brown or horn-
colored smooth or velvety epidermis. In the type the whorls have, as Gould states,
an imbricated appearance, but the character is not constant and is more or less evident
in several other species inhabiting the group. The last whorl is more or less distinctly
angulated and the axis is rimate or imperforate. In old examples, which are more or
less decorticated, the aperture is sometimes ochraceous with a pale hp. The size of
adults ranges from 41 to 7 mill. The peristome is frequently obscurely duplicated.

0. sciTui.A, Gould. ^ „

Cyclostoma scitulum, Gould, Proc. Dost. Soc. Nat. Hist., 1847, p. 206 ; Expl. Ex. Shells, p.

108 fi" 123. Petit, Jour, de Conch., 1850, p. 47.

Pfriffer. Proc. Zool. Soc, 1862. p. 151 ; 1854 p^307 ;

I, p. 308. H. onil A. Adonis, Gen. Moll., ii, p. 800. Peiue, Jour de Conch., 1869, p. 155.

96

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

Itealia scitula, Gray, Cat. Than., p. 220. Pfeiffer, Mon. Pneum., iv, p. 220.

Hydrocena acitula, Pfeiffer, Mon. Pneum., ii, p. 162.

Atropis scilula, Pease, Proc. Zool. Soc., 1871, p. 476. Schineltz, Cat. Mus. Godeff., v, p. 102.

This protean species is very common and widely diffused throughout all the valleys
on the northwest part of Tahiti, and is equally as plentiful in the various valleys on
Moorea. On the ground in forests.

'I’hough usually cited as Gould’s scHuJa, I have serious doubts of the correctness
of the identification. His diagnosis is as follows : —

“ T. parva, elongato-conica, tenuis, rufo-cornea, striis incrementi tenuibus solum
inscidpta, arete umbilicata ; spira elevata, anfr. 6-7 rotundatis, supernis subangulatus ;
sutura profunda; apertura rotundato-ovata, parva, trientum longitudinis adaequans;
perist. simplex, pallidum. Long. 1-5, lat. 1-10 poll.” (Gould).

In his remarks he says: “Almost exactly like Amnvola Suyana, Anth. It is
larger and more ventricose than C. vallatvm, and is distinguished from C. terebrale by
its le.ss slender form and unexpanded lip.”

The above .short diagnosis docs not agree very closely with the numerous specimens
now before me. His dimensions are too small to accord with our shells. Neither do
they resemble Binney’s figure of Amnicola Sayana. The only Tahiti shell that
re.sembles Binney’s figure is Atropis BythineVoeformis, which is the same size as Gould’s
species, but the whorls are not “supernis subangulatus.”

'Die species under consideration is 6 mill, long and 3 mill, in diameter. The spire
is oblong-conical with slightly convex outlines ; whorls six, convex, smooth, the penul-
timate frequently i)ro>>cting over the suture as in terehralis, and sometimes filocari-
nated at the angle. The last whorl is more or less distinctly angulated, rarely with
a thread-like keel; sometimes rounded. The axis is rimate or minutely perforated
and the margin slightly compressed, rarely filocarinated, sometimes .simple, as in
Atropis. 1 he nearly vertical aperture is ovately rounded, with a .slight posterior angle
and about one-third the length of the shell.

0. OBLONQA, Pfeiffer. Plate III, fio- 59

- ^ - -

Omphalolropis oblonga, Pease, .lour, de Conch., 1869 p 154
Atropis oblonga, Pease, Proc. Zool. Soc., 1871 p 476
Heaha oblonga, Pfeiffer, Mon. Pneum., iv, p. 213.

nZk PfZ''" i” of Moorea.

Moore,! shells Merqr.esas Islands. The

in referring them to his species I am^^] ^ ^^e least hesitate

My largest exnmi.les are 7 mill' I ^ believe it only a form of soMa.
g oxa, miles are 7 mill, long by gj in diameter, being a little larger th,an

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

97

scitula. The shape is oblong-conical, rimately peilorated, whorls six, moderately
convex, margined by a thread-like keel, which latter is very conspicuous on the sub-
angulate body-whorl. The base is more or less compressed on the margin of the
perforation. Nearly all my examples are decorticated and have a whitish or yellowish
aperture. The general color is pale corneous or pale fulvous.

The peristome is slightly expanded at the base and over the perforation, and the
margins united by a deposit of callus.

Color variable ; whitish, corneous, fulvous, brownish, ruddy brown, rarely pale
luteous. Aperture concolored, sometimes ochraceous. The thin brownish epidermis
is rarely present on adults. The striae of growth are scarcely visible under a strong
lens.

Genus ATROPIS, Pease.

The above genus was instituted by Mr. Pease (Proc. Zool. Soc., 1871, p. 463) for
the reception of those species of OmpJialotropis which are devoid of the basal carination.
Although he ranked the eliminated group as subgeneric, in the same paper (p. 476)
he used the name in a generic sense and records eighteen species. His “A. affinw ”
is, by Von Martens, Paetel, Schmeltz and myself, referred to the genus Scalinella.
His “A. ochrofitrema ” has, like Omphalotropis Hnaheinensis, a more or less obsolete
keel and should be transferred to that genus. His “A. insularis,” and probably A.
exigiio, are Chondrellce.

After eliminating all the Society Islands species of the scihda and terehndis type
there remain several species which are nothing more than smooth ScaUnellcB. 1 hese
only I retain under the name of Atropis, and it may be characterized as follows

Shell small, rimate or minutely perforated, ovate-conic or elongate-conical, smooth ;
whorls rounded, suture profound, body-whorl usually turgid ; aperture subciicular ,
peristome simple, sometimes indistinctly duplex, continuous and briefly adhering to
the penultimate whorl.

A. ABBRKVIATA, Pease.

Realia abbreviaia, Pease, Proc. Zool. Soc., 1864, p. 614. Pfeiffer, Mon. Pneuin., iv, p. 212.
Omphalotropis abbreviata, Pease, Jour, de Conch., 1869, p. 155, PI. VII, fig. 5.

Atropis abbreviata, Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godeff., v,

p. 102.

A ,ome«hat rare species, found on the ground on the northwest side of Tahiti.

It may be distinguished by its oblong-ovate form, rounded whorls and yentrieose
body. The axis is subperforated or rimate and the apex rounded. Under the
brownish or olivaceous epidermis tlie shell is pale horn-color, rarely light olive or
ruddy corneous. The aperture is concolored or pale yellowish brown.

98

, MOLLUSCA INIIAmTING SOCIETY ISLANDS.

TEKHESTUIAI

A. Vkhooi, i)olirii. Mi.uTSKtt 1859 p. 202. Pfeiffer, Mon. Pneum., Hi, p, 172.

Sf M-i™ LTL^,it,Don. BTm.'’p. 68. PI. Ill, «g. 2». Pfeiffer, Mon. Pneum.,

More rlrc than the preceding species, and only occurred to my notice in one valley
on the north side of Tahiti, where they were found on the side of a ravine about 1500
feet above sea-level

Smaller and more solid than abbreviatn, and more or less decorticated. UsuaUy
ruddy corneous with a luteous or ochraceous aperture.

A. viKii)E.soKNS, Pease.

Cyclostoma viridescens, Pease, Proc. Zool. Soc., 1861, p. 243.

? Rcalia viridescens, Pfeiffer, Mon. Pneum., iii, p. 171 ; iv, p. 209.

Blanfordia viridescens, Carpenter, Proc. Zool. Soc., 1864, p. 676.

Omphalotropis viridescens. Pease, Jour, de Conch., 1869, p. 153, PI. YII, fig. 7.

Atropis viridescens. Pease, Proc. Zool. Soc., 1871, p. 476.* Schmeltz, Cat. Miis. Godeff., v,

p. 101.

Not uncommon, and widely diffused over Huaheine. It also occurs sparingly, of
larger size, in a single valley on the southeast part of Raiatea. On the ground in
forests, and ranges from 100 to 500 feet above sea-level.

Mr. Pease’s type specimens were collected by me at the former location. Ilis
description being very short, I redescribe it as follows : —

Shell rimate, elongate-conic, rather thick, smooth, under the lens finely striated,
corneous, rarely brownish or olivaceous, aperture whitish or pale luteous; spire
elongate-conic, with slightly convex outlines ; apex subacute ; suture deep ; whorls
I~8^. strongly convex or convexly rounded, slowly and somewhat irregularly increasing,
last one rounded at tlie base ; aperture vertical, orbicular-ovate, nearly one-fourth the
length of the shell ; peristome continuous, straight or slightly expanded at the base,
rarely dnidicated and briefly adhering to the penultimate whorl.

Lenglli 7-8, diam. 2i-2f mill.

They are frequently denuded of the thin, smooth epidermis, and some have a more
rapidly tapering spire than others. The Raiatea shells are usually corneous, rarely
brownish and never olivaceous

A. HythinelliEformis, Garrett. Plate III, fig. 13.

Shell perforated, oblong, conical, rather thin, scarcely shining, smooth, corneous,
or light bron ms h under a thin epidermis ; spire oblong, convexly conical, apex rounded,
of the convex, last one rounded, one-third the length

c n ni on sP T t "" n ^ °bsoletely doubled,

I ::;h -panded.

Tahiti and Moorea Islands.

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

99

This small species, which is somewhat rare, Avas taken in a single valley on the
noith side of Tahiti, at an elevation of about 1500 feet above sea-level. A few
examples were found in a small area in a lowland forest on the north coast of Moorea.

It is shaped almost exactly like Binney’s figure of BythineIJa NickUneaoa. All the
specimens, ten in number, now before me, have the peristome slightly doubled or
duplicated. As compared with ahbreviata, it is smaller, more slender, the aperture
smaller, the whorls more rounded and basal perforation larger.

A. OBESA, Garrett. Plate III, fig. 12.

Shell small, perforated, solid, ovate-globose, decorticated, smooth, dull Avhitish horn-
color, with a whitish or yellowish aperture ; spire abbreviately conical, with an obtuse
apex ; sutm-e profound ; whorls fit^e, convex, last one large, rounded ; aperture vertical,
orbicular-ovate, nearly half the length of the shell ; peristome continuous, sim])le,
straight, regularly curved, base slightly expanded.

Height 4, diam. 3 mill.

7/ab. — Tahiti, rare, in a single valley on the northwest part of the island.

As compared with Vescoi, the nearest allied species, it is more abbreviate, the body
more turgid and the spire shorter.

Genus SCALINELLA, Pease.

S. Tahitensis, Pease.

Cyclostoma Tahitensis, Pease, Proc. Zool. Soc., 1861, p. 243.

llydrocenat Tahitensis, Pfeiffer, Mon. Pneum., iii, p. 173.

Scalinella Tahitensis, Pease, Jour, de Conch., 1869, p. 58, PI. YU, fig. 1 ; Proc. Zool. Soc.,
1871, p. 475. Mart, and Lang., Don. Bisni., p. 59, PL IV, fig. 3. Scliineltz, Cat. Mus.
Godeff., v, p. 102.

Bealia Tahitensis, Pfeiffer, Mon. Pneum., iv, p. 216.

Not uncommon, and widely diffused over Huaheine, Avhere it occurs on the ground
in forests. So far it has not been detected on any other island in the greup. It
appears strange that Mr. Pease should have named this species Tahitensis, Avhen he
was well aware that his type specimens were collected by me at Huaheine and not
“ Tahiti.” His description being very brief, I add the folloAving : —

Shell rimate, elongate-conical, moderately thick, pale cinereous or whitish liorn-
color beneath a brownish epidermis, Avhich is rarely present ; aperture concolored or
various shades of ochraccous with a whitish peristome; spire elongate, convexly conic,
apex obtuse; whorls 6-7, rounded, the first two or three smooth, the following ones
with small longitudinal compressed ribs, about twenty on the body-Avhorl, which latter
is rounded at the base; aperture slightly oblique, subcircular, nearly one-third the
length of the shell ; peristome continuous, slightly expanded and usually adhering to
the penultimate Avhorl.

Length 6, diam. '2\ mill.

Generally decorticated and more or less eroded.

100

tekrestkial mollusca inhabiting society islands.

S. oosTATA, Pease.

llydrocena costala, Pease, MS. Coll. Pease, 1863.

Jlydrocena Taheilenais, Carpenter (not of Pease), Proc. Zool. Soe., 1864, p. 676.

Realia (Scalinella) costata, Pease, Amer. Jour. Conch., 1867, p. 216.

Scalinella costata, Pease, Jour, de Conch., 1869, p. 158, PI. VII, fig. 2. Schmeltz, Cat. Mus.

Godetf., V, p. 102.

Realia costata, Pfeiffer, Mon. Hel., iv, p. 216.

Very immeroiis on tlie ground in the lowland forests of lahaa, where it is
peculiar. It differs from Taheifensis in its larger size, more robust form, more turgid
body, and the ribs are more numerous.

S. Mousso.vi, O. Semper. Plate III, fig. 71.

Taheitia Moussoni, O. Semper,” Schmeltz, Cat. Mus. Godeff., v, p. 102. Pfeiffer, Mon.

Pnenm., iv, p. 21 (name only).

Not uncommon, and confined to the small island of Maupiti, where they occur on
file ground in forests.

'I'lio al)ore name appears without description. I describe it as follows : —

Shell rimate, rather slender, elongate conical, rather thick, cinereous, beneath a
brownish or olivaceous epidermis; aperture rarely yellowish ; spire elongate, obtuse,
with subplanulate outlines ; whorls six and a half, strongly convex, apical ones smooth,
the others with crowded, longitudinal ribs, about thirty on the rounded hody-whorl ;
aper'ure roundly ovate, vertical, nearly a third the length of the shell ; peristome
continuous, somewhat patulous, adhering to the penultimate whorl.

Length 5, diam. 2 mill.

More .slender and smaller than Taheifensis, riblets more crowded and more
numerous, body smaller and the aperture generally more oval.

Cl., XjctlUill'liK,

n. MACGEKt.*, Gray. Plate III, figs. 64, 65, vars.

fs”"' it’ “•

30). ra.|ir«r, Mo„. pi„„ , "f J , ) . ” ’’ "• "■

.... sC’.;’,?; r:-,e."r™;.rc5: r

Imslierandls “e

me ,v'‘e i/:;''”""'*.'"' “““

C. L niform lemon-yellow
d. White, with reddish spire.

All the above varieties ‘iro c-. j

amber-color. associated with the type. Operculum pale

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

101

Var. RUBICUNDA, Pease. Plate III, fig. 65.

Eelicina ruhicunda, “ Pease,” Carpenter, Proc. Zool. Soe., 1864, p. 616.

Eelicina Maugerix, var. ruhicunda. Pease, Amer. Jour. Conch., 1861, p. 227 ; Proc. Zool.

Soc., 1871, p. 476.

Eelicina ruhicunda, Schmeltz, Cat. Mus. Gocleff., v, p. 99.

I first discovered this well-marked variety in 1871, at Fatimu, on the southwest
coast of llaiatea, where the typical Maugerice does not occur. I took about 200
examples from beneath dead wood and loose stones. In 1874, during a spell of heavy
rains, I visited the same location and found the place converted into a swamp, and
gathered nearly a thousand specimens from the tranks of trees, the rains having
driven them from their usual shelter. At Viaau, a few miles to the northward of
Fatimu, 1 found a second colony drowned out and crawling up the tranks of trees.
Both locations are on the lowlands, near the seashore, where the type with a yellow
base does not occur.

It may be distinguished hy its red or orange red callus ; otherwise tlie coloration
is similar in the two varieties.

Var. ALBiNEA, Pease. Plate III, fig. 64.

Eelicina hella, “Pease,” Carpenter, Proc. Zool. Soc., 1864, p. 676.

Eelicina Maugeria, var. alhinea, Pease, Proc. Zool. Soc., 1871, pp. 466, 476.

This variety is restricted to a single valley on the east side of Tahaa (not “Raiatea,”
as stated by Pea^e). It may be characterized by its more depressed form, sharper
keel and white hasal callus ; otheiwise the coloration and markings are the same as
the typical Mangerim.

II. FLAVESCENS, Pease.

Eelicina Pacifica, Pease, Amer. Jour. Conch., 1865, p. 291 ; 1866, p. 82, PI. V, fig. 7.
Eelicina fiavescens. Pease, Amer. Jour. Conch., 1867, p. 228, PI. XV, fig. 25 ; Proc. Zool.
Soc., 1871, pp. 467, 476. Schmeltz, Cat. Mus. Gocleff., v, p. 99. Pfeiffer, Mon. Pneum.,
iv, p. 260. Garrett, Jour. Acad. Nat. Sci. Phil., 1881, p. 381.

Eelicina pisum, Homhr. and Jacq. (not of Philippi), Yoy. Pol. Sud, v, p. 44, PI. XI, figs.
18-22. PfeiflTer, Mon. Pneum., ii, p. 185.

Eelicina straminea. Pease, MS. (not of Morelet), Schmeltz, Cat. Mus. Godeff., v, p. 99.
Eelicina Tahiteneis, Pease, Proc. Zool. Soc., 1871, pp. 466, 476. Schmeltz, Cat. Mus.
Godeff., V, p. 98. Pfeiffer, Mon. Pneum., iv, p. 256.

This, the most abundant species, is not only generally difiiised throughout the
group, but is also equally as common and widely distributed throughout the Harvey
Islands, 500 miles to the southward and westward. It is confined to the lowlands in
close proximity to the seashore where it is gregarious beneath stones.

II. ALBOLABRIS, Homhron and Jacquinot.

Eelicina alholahris, Homb. and Jacq., Yoy. Pol. Sud, v, p. 45, PL XI, figs. 23-26. I feifle,.

Mon. Pneum., ii, p. 186. Pease, Proc. Zool. Soc., 1871, p. 476.

Eelicina xolida, Pease, Proc. Zool. Soc., 1864, p. 673. Mart, and Lang., Don. Bism., p. 60,
PI. Ill, fig. 24. Pfeiffer, Mon. Pneum., iv, p. 252.

14 .TOUR. A. N. s. PHILA., VOL. IX.

102

TEKllESTKIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

Helicina .olidula, Frauenfeld (not of Gray), Vcrh. Zool. Dot. Gch. Wien, xix, p. 879.
llelicina cransilabris, Schmeltz (not of Pliilippi), Cut. Mus. Goileff., v, p. 99.

A conimon species, peculiar to dahiti, wliere they aie found on the trunks of trees
and Imshes, and are widely diffused throughout the island. They exhibit considerable
variation in size, color and in the height of the spire. The prevailing tint is wdiitish
or yellowish white, rarely lemon-yellow or uniform reddish of various shades, or the
tw'o former colors with reddish spire, and more rarely with a dorsal reddish band.
The peristome is thick and white, and the basal callus, which is usually of the latter
color, is sometimes pale bluish white or lemon- yellow. Operculum light yellowish
hom-color.

Major diam. 5-9 mill.

H. CORBUOATA, Peuse. Plate III, fig. 62, 62 a, 62 b.

Jfelicina corrugala, Pease, Proc. Zool. Soc., 1864, p. 673. Pfeiffer, Mon. Pneum.,iv, p. 252.
Not abundant, and, so far as known, is confined to Eaiatea, where it occurs on
the ground, and sometimes on tlie trunks of trees.

It may be distinguished by its more or less depressed spire, thin texture, sharp,
slightly expanded lip, wiiich is cmarginated above the carinate periphery, and by the
slight groove which circumscribes the basal callus. The color is pale reddish brown,
corneous or pale straw-yellow, rarely variegated.

Diam. 5 mill.

H. KusTiCA, Pfeiffer.

! . „„ uoay-wiiorl.

H. miniata. Lesson. Plate III, fi^s. 6.^ fi.q .

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

103

Helicina Rolvii, Carpenter (not of Pfeiffer), Proc. Zool. Soe., 1864, p. 616. Schmeltz, Cat.
Mus. Godeff., v, p. 207.

Helicina albolabris, Schmeltz (not of Homb. and Jacq.), Cat. Mus. Godeff., v, p. 98.

M. Lesson’s description, which Pfeiffer has copied, being very brief, I redescribe it
as follows : —

Shell solid, conoid, opaque, smooth, somewhat shining, with crowded, faint strim ;
color variable, generally brownish red, gradually fading on the body-whorl into
whitish, pale yellowish or corneous ; aperture and basal callus white or bluish white ;
spire convexly conoid ; whorls 4|— 5, flatly convex ; aperture very oblique, small, semi-
oval ; peristome slightly expanded, thickened, somewhat labiate, emarginate above the
periphery ; columella short, arcuate ; callus semicircular, thickened towards the
extremities of the peristome. Operculum yellowish horn-color.

Major diam. 9, less. diam. 7, height 6 mill.

Hab. — Borabora Island.

Lesson’s shells were procured in the same location, where it is peculiar. They
occur abundantly on the trunks and foliage of trees and bushes in the mountain
forests.

It is subject to the following variations : —

a. Uniform white.

b. Uniform yellow, with white callus.

c. Pale lemon-yellow, with a spiral brownish red band.

H. iNCONSPicuA, Pfeiffer.

Helicina inconspicua, Pfeiffer, Zeits. Malak., 1848, p. 86 ; Mon. Pnenm., i, p. 357. Chem-
nitz, ed. 2d, p. 26, PI. IX, figs. 18-21. Gray, Cat. Phan., p. 258. (Idesa) H. and A.
Adams, Gen. Moll., ii, p. 304. Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus.
Godeff., v, p. 99.

Helicina exigua, Hombron and Jacquinot, Voy. Pol. Sud, v, p. 46, PI. XI, figs. 32-35.

Pfeiffer, Mon. Pneum., ii, p. 187. Pease, Proc. Zool. Soc., 1871, p. 476.

Helicina minuta, Carpenter (not of SowerbyJ, Proc. Zool. Soc., 1864, p. 676.

Helicina decolorata, “ Mousson,” Schmeltz, Cat. Mus. Godeff., v, p. 99.

This, the smallest species inhabiting the group, is not uncommon, and is diffused
throughout all the islands, where they occur on the ground in forests, and range from
near the seashore to 1000 feet above sea-level. I also obtained examples at the
Gambier Islands = Mangareva, which differed none from Society Islands specimens. It

is n. exigim, H. and J. . „ v

The peristome, though usually straight and simple, is occasionally slighth

expanded, and they vary slightly in the depression of the body-whorl. The coloration
is uniform reddish brown, brownish horn-color, corneous, and more larely luteous
horn-color. The operculum is corneous, with a wide Hat external ridge. Specimens
collectetl at Maupiti are frequently marked by fugations, delicate spiral lines similar
to II. flavescens.

104

TEKUESTKIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

II. MiNOTA, Sowerby. t

miicina minuta, Sowerby, Proc. Zool. Soc., 1842, p. 7; Thesaur. Conch., p. 13, PI. I, figs.
40, 41. Pfeiffer, Mon. Pneuin., i, p. 391. Chemnitz, ed. 2d, p. 54, PI. IV, figs. 24-27.
Gray, Cat. Phan., p. 281. (Fachysloma) H. and A. Adams, Gen. Moll., ii, p. 285. Pease,
Proc.’ Zool. Soc.,’ 1871, p. 476. Schmeltz, Cat. Mus. Godeff., vi, p. 99. Garrett, Proc.
Acad. Nat. Sci. Phil., 1879, p. 29.

Helicina discolor, Muhlfeldt, MS., Anton, Vers., p. 53. (Ex. Pfeiflfer.)

Helicina flammeata, Muhlfeldt, MS., 1. c. (Ex. Pfeiffer.)

This small species is confined to Tahiti and Moorea, where it lives beneath decaying
vegetation.

Sowerby’s type .specimens were collected by Cuming at Rurutu = “ Oheatora,”

one of the Austral Islands.

Some e.xamples exhibit the delicate pilose fugacious striae as mentioned in my
remarks on inconspicua and flavescena. The color is reddish brown, straw-yellow,
corneous or dull reddish.

Major diam. 4^ mill.

H. DI800IDEA, Pease. Plate III, figs. 67, 67 a, 67 h.

Helicina discoidea, Pease, Amer. Jour. Conch., 1867, p. 226 ; Proc. Zool. Soc., 1871, p. 476.

Pfeiffer, Mon. Pneum., iv, p. 286.

Helicina albolabris, Carpenter (not of Homb. and Jacq.), Proc. Zool. Soc., 1864, p. 673.

A somewhat .scarce species, found only at Tahaa, where it lives on the ground in
the lowland forests.

hen Mr. Pease described this species he gave the correct locality ; but in his
catalogue of Polyne.sian land shells he give, the wrong habitat, “ Tahiti,” where it
does not occur.

It has the sulcate base of corrugata, but is more depressed, and the upper surface
of the whorls is more or less corrugated by coarse transverse ribs or undulations,
r le periphery is carinated, and the color is dull reddish brown, rarely pale yellowish

M. 8UBRUFA, Pease, MS. Plate III, figs. 68, 68 a 68 5

Helicina subrufa, “ Pease,- Carpenter, Proe. Zool. Soc., 1864, p. 676.

Hehctna minuta, Carpenter (not of Sowerby) • 1 c
Helicina turbinella, •< Pease,” Carpenter (not of Pfeiffer), I. c.

vnri hT thin, somewhat shining, faintly striated- color

X ravely with a dorsal reddisl, band ,■

in front, rounded or obscrreVa^IZed oMr descending

very oblique, snbtrinngnlar-ovate • peristome ‘'“‘'J' “”''ex : aperture

recoding above the peripl.ery,obtuJv arrt f .^ ’^ expanded, sometimes slightly

columella ; ba.sal callus thin, concolorL. ^ ^ ® ^ junction with the short receding
Major diam. 4|-6, height 3-31 mill.

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

105

Hah. — Raiatea and Borabora.

On the ground in forests. Raiatea examples are larger and more depressed than
Borabora specimens. It is very closely allied to minuta, but may be distinguished by
its more effuse aperture, more expanded lip and larger size.

H. FABA, Pease, MS. Plate III, figs. 61, 61 a, 61 b.

Helicina faba, “ Pease,” Carpenter, Proc. Zool. Soc., 1864, p. 676. Pease, Amer. Jour.

Conch., 1867, p. 226. (Name only.)

Helicina albolabris, Carpenter (not of Philippi), 1. c.

Shell depressly conoid, rather thin, slightly shining, smooth, faintly striated ;
reddish brown, corneous, pale straw-yellow, rarely bifasciate ; spire depressly conoid or
convex, apex subacute ; whorls four, subplanulate or slightly convex, rapidly increasing,
last one not deflected in front, depressed above, with a more or less prominent com-
pressed keel on the periphery ; suture linearly impressed ; base convex ; aperture very
oblique, subovate ; peristome slightly expanded, thickened within, slightly emarginate
above, a little produced at the carination and angulated at its junction with the short
receding columella ; callus rather thin, spreading, concolored or whitish. Operculum
corneous or amber-color.

- Major diam. 6, less. 5, height mill.

Ilab. — Raiatea and Moorea.

The above is the size of my largest Raiatea specimens. They are not very
plentiful, and are found adhering to the trunks of trees. The Moorea shells are
more rare and more globose in shape as well as smaller than the Raiatea examples.
The banded variety occurs at Moorea.

As compared with albolabris, it is smaller, thinner, more shining, and the shape of
the peristome is quite different in the two species. In size, texture and color it is
more nearly related to corrugata, but may be distinguished from that species by its
more turbinate form and the absence of the basal groove.

H. simulaXs, Garrett. Plate III, figs. 66, 66 a, 66 b.

Shell depressed, lenticular, rather thin, faintly striated, pale brownish horn-color,
or light straw-yellow; spire depressly conoid; suture linearly impressed; whorls four,
very slightly convex, last one depressed, not deflected in front, carinated on the per-
iphery, keel rib-like, obtuse ; base convex ; aperture very oblique, rather large, semi-
eUiptic’al ; peristome expanded, thin, very slightly receding above, angulate at the
junction with the short receding columella ; basal callus thin, concolored.

Major diara. 6, height 3 mill,

jjab. — Tahiti. On bushes.

Shaped like corrvgata, but wants the basal groove of that species.

106

TEKKKSTKIAL

MOLLUSCA INHABITIiNG SOCIETY ISLANDS.

II. Raiatknhis, Garrett. Plate III, figs. 69, G9 a, (>9 6. ^ i ^ f 1 f

Shell depressly conoid, rather thin, slightly shining, consinciiously striate, liiteous
or whitish horn-color, marbled and spotted with opaque white; spire depressly
conoid; suture linearly impressed; whorls four and a half, convex, regularly and
rapidly increasing, not deflected in front, last one depressed, rounded on the per-
iphery, flatly convex beneath ; aperture oblique, wide, semioval ; peristome straight,
slightly thickened; columella short and receding; basal callus thin, nearly concolored.

Major diani. 5, height 3 mill.

Ilah. — Raiatea.

A few examples were found amongst decaying vegetation, on the west side of
Raiatea, but not detected in any other part of the group.

It is closely allied to rustica in the form of the shell, and the shape of the peris-
tome is quite similar in the two species. It may, how'ever, be at once distinguished
by its larger size, lighter texture, smoother and more shining surface and different
color, as well as the more receding columeUa.

Genus CHONDRELLA, Pease.

C. PABVA, Pease. Plate III, fig. 41.

Cyclostoma parvum, Pease, Proc. Zool. Soc., 1864, p. 674.

Chondrella parva, Pea.8e, Proc. Zool. Soc., 1871, pp. 465,476. Pfeiffer, Mon. Pneum., iv,
p. 294.

Not uncommon, and ranges throughout the group. I also took a few .specimens
at the Marquesas Islands. They occur amongst dry dead leaves, under stones and
dead wood.

About the size and .shape of Afisiminea nitida, with rounded w'horls, pale horn-
color, soTiietimes ruddy corneous, and varies in size and length of the spire.

C. iNSULAiiis, Crosse.

llydrocena insularis, Crosse, Jour, de Conch., 1865, p. 223, PI. VI, fig. 7.

Omphalotropis insularis, Pease, Jour, de Conch., 1869, p. 154.

Atropis insularis, Pease, Proc. Zool. Soc., 1871, p. 476.

Rp.alia insularis, Pfeiffer, Mon. Pneum., iv, p. 212.

'fhis species, which I first discovered at the Gambier Islands, where M. Crosse’s
examples were collected, is also common to Tahiti and Moorea. In size it is inter-
mediate between parva and striata, but is of a more ruddy color, and, like the former,
IS smooth.

C. STRIATA, Pease. Plate III, fig. 40.

‘’7!; P- «’• Pfeiffer, Mon. Pne,™.. iv. p. 29i.

p Ts! >’■ Sel- riPle-, 1881.

Hydrocena striata, Schmeltz, Cat. Mus. Godeff., v, p. 100.

Hydrocena subinsularis, Mousson MS '

He en, alien si^e, ruddy color and spiral stri* will readily distinguish it from O. parva.

tp:rrestrial mollusca inhabiting society islands.

107

Genus TAHEITIA, H. and A. Adams.

Ann. Nat. Hist., 1863, p. 19.

This genus was established for the reception of those specimens of Truncatella
characterized by the more or less porrected peristome and the elevated laminte on the
operculum. The shell is always thinner and the costse more compressed than Trun-
catella. The lip is sharper, more expanded, and they inhabit a different station, being
found far inland, and not near high-water mark, as in the latter genus.

Mr. Pease, in his list of Polynesian shells, erroneously refers T. Vitiensis, Gld.,
to Talieitia.

T. PORRECTA, Gould.

Truncatella porrecta, Gould, Proc. Bost. Soc. Nat. Hist., 1846, p. 40; Expl. Ex. Shells, p.

8, fig. 121. Pfeiffer, Mon. Pneum., ii, p. I.

Taheitia porrecta, Pease, Proc. Zool. Soc., 1811, p. 4YI.

Ihis species only occurred to my notice in one location, about one mUe up Papenoo
valley, Tahiti.

It is 6 mill, long, pale luteous horn-color, the costae rather distant, and sixteen or
seventeen on the last whorl.

T. PALLIDA, Pease. Plate III, fig. 76.

Taheitia pallida, Pease, Amer. Jour. Conch., 1867, p. 229; Proc. Zool. Soc., 1871, p. 477.

Truncatella porrecta, Schmeltz (not of Gould), Cat. Mus. Godeff., v, p. 104.

'Truncatella pallida, Schmeltz, 1. c., p. 208. Pfeiffer, Mon. Pneum., iv, p. 20.

Very abundant in the lowland forests, and is generally distributed throughout the
group. I have found them half a mile inland associated with Helices and cyclosto-
moid shells.

It is larger and not so much porrected as the preceding species.

Genus ASSIMINEA, Leach.

A. NiTiD.A., Pease.

Hydrocena nitida. Pease, Proc. Zool. Soc., 1864, p. 674.

Assiniinea nitida. Pease, Jour, de Concli., 1864, p. 165, PI. YII, fig. 11 ; Proc. Zool. Soc.,
1871, p. 476. Schmeltz, Cat. Mus. Godefi'., v, p. 103. Garrett, Proc. Acad. Nat. Sci.
Phil., 1879, p. 29 ; Jour. Acad. Nat. Sci. Phil., 1881, p. 408.
f Realia nitida, Pfeiffer, Mon. Pneum., iv, p. 212.

Hydrocena parvula, Mousson, Jour, de Conch., 1865, p. 184; 1873, p. 108.

Omphalotropis parvula. Pease, Jour, de Conch., 1869, p. 155; Proc. Zool. Soc., 1871, p. 476.

Paetel, Cat. Conch., p. 124.

Assiminea parvula. Pease, Proc. Zool. Soc., 1871, p. 476. Schmeltz, Cat. Mus. Godeff., v,

p. 103.

Realia parvula, Pfeiffer, Mon. Pneum., iv, p. 213.

Assiminea lucida. Pease, Jour, de Conch., 1869, p. 166, PI. VII, fig. 10; Proc. Zool. Soc.,
1871, p. 476.

Assiminea ovata, “Pease,” Schmeltz, Cat. Mus. Godeff., v, p. 103.

Hydrocena similis, Baird, Cruise of the Curacoa.

Generally distributed throughout southern Polynesia. For further information in
regard to this species, see my paper on the Cook’s Island shells.

108 teruksteial mollusoa inhabitino societv islands.

Recapitulation.

The following list will show the distribution of the land shells over the seven
islands : —

Tahiti.

Moorea.

Microcj'stis vertieillata, Pse., .....

X

.Microcystis simillima, Pse., .....
Microcystis normalis, Pse., .....

X

X

Microcystis Discordise, Garr.,

) X

X

.Microcystis ciiltrata, Gld., .....

Microcystis angustivoluta, Garr., ....

X

1

X

Microcystis scalpta, Garr.,

Trochonanina conula, Pse., .....

X

X

Trochonanina calciilosa, Gld., .....

! X

X

Trochonanina Taheitensis, Garr., ....

1 ^

Trochonanina snhnigosa, Garr., ....

X

X

Zonites Moorcana, Garr.,

1

X

Trochomorpha trochiformis, Fer., ....
Trochoinorpha pal lens. Pease, ....

! X

X

Trochomorpha Cressida, Gld., ....

1 ^

Trochomorpha a.ssimilis, Garr., ....

Patiila modicella, Per.,

Patuin acnticosta, Mouss., .....

Patula lamellicosta, Garr., .....

I’itys .Manjiiensis, Garr., ....

X

Pitys jiarvidens, Pse.,

Pita'S consobrina, Garr., ......

Pitys imiicti perforata, Garr., . . . . "

Pitys Horaborensis, Garr., • . . . !

Ijibcra Inirsatella, Gld.,

Libera ooarctatn, Pfr., • . . . '

Libera retunsa, Pse.,

X

X

X

X

X

Libera lleynomanni, Pfr., ’ ’ i

Libera gregaria, Garr., . ' ’ i

X j

Liliera recedens, Garr., ’ ' '

Kndodonta Iliiahcinensis, Pfr , ’ ' !

X

Endodonta ficta, Pse., . . . ' ' j

Endodonta fabrefacta, Pse., . ! '

Endodonta obolus, Gld., . . . ‘ ^

Endodonta cretacea, Garr., . !

Endodonta Taneaj, Garr., .’ . ’ ' ‘

Stenogyra Tiickeri, Pfr.. . ! ! ' ‘ ‘ |

Partnia Otalieitana, Brno- ’ ' ' ’ I

X

X

Partula filosa, Pfr., .

X

Partnia hyalina, Brod. ' ‘ ' 'I

X

Partula clara, Pse., ' ’ ' ‘

X

Partula producta, Pse., ' ’ ' '

X

Partula nodosa, Pfr., ‘ ‘ '

X

Partula stolida, Pse., ' ' ' ' ’

X

Partula attenuata, Pse

X

Partula lineata, Less., . i

X

X

X

X

X

noilAUOKA.

TERRESTRIAL MOLLUSCA INHABITING

SOCIETY ISLANDS.

109

S

H

1

d

w

<

<

<

<

w

j H

§

A

o

pq

p

<

Partiila elongata, Pse.,

I' “

— -

-- -

Partula tseniata, Morch, . ‘ '

X

Partula Mooreana, Hart.,

X

Partula rosea, Brod., . \ ‘ '

X

Partula varia, Brod.,

X

Partula arguta, Pse., . . ] ' '

X

Partula anneetens, Pse., . . | |

X

Partula faba. Mart.,

X

Partula auriculata, Brod., . . . ' ' ’

X

X

Partula turgida, Pse., • . ! !

X

Partula radiata, Pse., . .

X

Partula compacta, Pse.,

X

Partula callifera, Pfr., . . . . ' '

X

Partula Thalia, Garr., . . . ' ‘

X

Partula Garrettii, Pse., . . . . ' '

X

Partula citrina, Pse.,

1

X

Partula dentifera, Pfr.,

X

Partula Hebe, Pfr.,

X

Partula fusca, Pse.,

X

Partula navigatoria, Pfr., .... 1

X

Partula i in perforata, Pse., . . . . !

X

Partula rustica, Pse., ......

Partula vittata, Pse., ’

Partula crassilabris, Pse

Partula formosa, P,se.,

Partula lugubris, Pse.,

X

Partula planilabrum, Pse., .....

Partula biliiieata, Pse.,

Partula virginea, Pse., ......

X

Partula umbilieata, Pse., ......

X

Partula lutea. Less.,

X

Tornatellina Philippii, Pfr., .....

X

X

X

X

X

X

X

Tornatellina oblonga, Pse., .....

X

X

X

X

X

X

X

Tornatellina simplex, Pse., .....

X

X

X

X

X

X

X

Tornatellina conica, ilouss.,

X

X

X

X

X

X

X

Tornatellina perplexa, Garr., .....

X

X

X

X

X

X

X

Tornatellina serrata, Pse., .....

X

X

X

X

X

X

X

Tornatellina nitida, Pse., ......

X

X

X

X

X

X

X

Toniatellina aperta, Pse., ......

X

X

X

X

X

X

X

Tornatellina Peaseana, Garr.,

X

Vertigo pediculus, Shutt.,

X

X

X

X

X

X

X

Vertigo tantilla, Gld.,

X

X

X

X

Succinea humerosa, Gld.,

X

Succinea costulosa, Pse., ......

X

Succinea subglobosa, Garr., .....

X

Succinea pudorina, Gld.,

X

X

Succinea infundibuliformis, Gld., ....

X

Succinea Taheitensis, Pfr., . . . : .

X

Succinea pallida, Pfr.,

X

X

Succinea papillata, Pfr., ......

X

Limax Rarotonganus, Heyn.,

X

Melampus luteus, Quoy and Gaimard,

X

X

X

X

X

X

X

Melampus Philippii, Kust.,

X

X

X

X

X

X

X

Melamjius fasciatus, Desh.,

X

X

X

X

X

X

X

15 JOTJK. A, N. S. PHILA.,VOL. IX.

tekkestuial mollusca inhabiting society islands.

Melampus caffer, Knst., .

Melanipus striatus, Pse., .
Laiinodonta conica, Pse., .
I’lecotrema mordax, Dohrn,

Diadeina biangulata, Pse.,
Omplialotropis scitula, GId.,
Oniplialotropis terebralis, Gld.,
Oniphalotropis Ilnaheinensis, Pfr., .
Omplialotropis jirodiicta, Pse.,
Omplialotropis oblonga, Pfr., .
Omjihalotropis Boraborensis, Dolirn,
Atropis.abbreviata, Pse., .

Atropis Vescoi, Dobrn,

Atrojiis obesa, Garr.,

Atropis Bytbiiielbeformis, Garr.,
Atropis viridescens, Pse , .

Scalinella Talieitensis, Pse.,

Scalineila costata, Pse.,

Scalinella .Moussoni, 0. Semp., .
Ilelicina albolabris, II. and J., .
Ileliciiia simulaiis, Garr., .

Heliciiia miniita, Sowb., .

Ilelicina (lavesceiis, Pse., .

Ilelicina rustica, Pfr.,

Ilelicina inconspicua, Pfr.,

Ilelicina .Maiigerin;, Graj',

Ilelicina eornigata, Pse., .

Ilelicina discoidea, Pse., .

Ilelicina subrufa, Pse.,

Ilelicina faba, Pse., ....
Ilelicina Ilaiatensis, Garr.,

Cliondrella parva, Pse.,

Choiidrella striata, Pse., .

Cliondrella iiisularis, Crosse, .
Talieitea pallida, Pse.,

Talieitea porrecta, Gld., ,

Assiininea nitida, Pse.,

X

X

X

X

X

X

29

Tahiti, 64 species, 22 peculiar.
Moorea, 51 species, 11 peculiar.
Huaheine, 42 species, 10 peculiar.
Raiatea, 61 species, 23 peculiar,
lahaa, 38 species, 8 peculiar.
Borabora, 34 species, 4 peculiar.
Maupiti, 29 species, 2 peculiar.

Borabora.

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS.

Ill

Out of the 139 species collected by the writer, 108 are peculiar to the group.
They are all embraced in 25 genera, 7 of which are opcrculated. The excessive
preponderance of indigenous species in the archipelago clearly demonstrates its claims
to a special land-shell fauna.

With the exception of the species of Melampus and Partuki Injalina, all the land
shells which are common to other groups are invariably small species. Mycroeijstis
conula and M. Discordtee are common to the Cook’s, and the latter also occurs in the
Marquesas Islands. If. calculosa is found in the latter group and the Viti Islands.
Stenogyra Tuckeri and Vertigo pediculus are diffused throughout Polynesia. Vertigo
tantilla inhabits the Cook’s, Samoa and Viti Islands. TornatelHna aperta occurs in the
Marquesas. T. Philijpii extends its range to the Austral, Cook’s and Marquesas. T.
conica, ohionga and nitida live on all the south Polynesian groups; and T. serrata,
together with ohionga, also occur in the Kingsmill and Caroline Islands. T. perplexa
inhabits all the southeastern groups. Partida hyalma is common to the Austral and
Mangaia, one of the Cook’s Islands. Patida modicella ranges from the Paumotu to
the Ellice’s group. Limax Raratonganus inhabits the Cook’s and probably the
Gambler Is. Chondrella parva is common to the Marquesas, and G. insularis occurs
in the Gambler group. G. striata is abundant in the Austral and Cook’s Islands.
ILlidna miniita is found in the Austral, and IT. flavescens in the Cook’s group.
A’-siminea nitida ranges from the Paumotu to the Viti Islands. Plecotrema mordax
occurs in the Paumotu, and I think inhabits the Gambler Islands. Laimodonta
conica ranges from the Paumotu to the Cook’s, and occurs on the islands in central
Pacific. All the Melarripi, except striaius, have a more or less wide range.

The following species, unknown to the writer, are accredited to the Society
Islands : —

Helix (ceanica, Lc Guillou. “Taiti.” Is a Libera and probably = L. Heyne-
manni. No mention is made of internal lamella

Helix Jacquinoti, Pfeiffer. “ Tahiti ” and “ Marquesas.” In his Mon. Hel., vii,
he qnotes “ Taheita ” only. It is a Libera with the peculiar sculpture of L. fratercula,
and probably inhabits the Austral Islands.

Helix dejrressi/ormis. Pease. “ Tahiti.” May be a Zonites.

Succinea procera, Gould. “ Eimeo ” = Moorea. Possibly a large elongate form
of the variable S. pudorina. ■

Snccima Bernardii, Recluz. “ Oceania ” (Recluz) ; “ Tahiti ” (Cuming).
Gyclostoma ventricosa, Hombron and Jacquinot. “Taheiti.” Pfeiffer quotes the
“ Marquesas.” Should be compared with Atropis viridescens.

Hydrocena Scherzeri, Zelebor. “ Tahiti.” Is, I think, a variety of Omphalotropts

scitula.

112

TERRESTRIAL MOLLUSCA INHABITING SOCIETY ISLANDS.

Helirina KnsteHana, Pfeiffer. “Tahiti.” I doubt this and the following being
Tahitian 8{)ecies.

IMicina hicolor, Pfeiffer. “ Tahiti.

Auricula viola. Lesson. “ Borabora.’

In addition to the species unknown to me, I may mention the following Partuloi:
P. crniirressa, Pfeiffer. “ Society Islands.” Referred by Carpenter to P. radiata.
Dr. Hartman records it as a distinct species inhabiting the “ Fiji Islands = Viti
Isles.

P. solidula. Reeve. “ Society Islands.” Referred by Carpenter to P. virginea, and
by Dr. Hartman to P. lutea. This and the following are undoubtedly s}'nonymous
with some of the species recorded in this paper.

P. simplaria, Morelet. “ Tahiti ” Referred by Mousson to P. varia, and by Dr.
Hartman to P. rosea.

P. Erhelii, Morelet. “ Morea, Society Islands.” Dr. Hartman thinks this wdl
prove to be one of the forms of P. tceniata.

P. stenostoma, Pfeiffer. “ Habitat. ... 1” Dr. Hartman refers it to P. vexillum
= Ivieata.

P. suturalis, Pfeiffer. “Habitat. ... 1” Referred by Dr. Hartman to P.
Btrigom = lineata, var.

TERRESTRIAL MOLLTJSCA INHABITING SOCIETY ISLANDS. 113

EXPLANATION OF PLATES.

Plate II.

Fio.

Page.

Pig

Page.

1.

Succinea papillata Pfr.,

. 86

19.

Tornatellina Peasiana Garr.,

. 83

2.

“ Tahitensis Pfr.,

. 85

20.

“ aperta Pse.,

. 83

3.

“ subglobosa Garr., .

. 88

21.

“ simplex Pse., .

. 82

4.

“ costulosa Pse.,

. 87

22.

“ serrata Pse.,

. 82

5.

“ pallida Pfr.

. 88

23.

“ perplexa Garr.,

. 82

6.

Libera gregaria Garr.,

. 36

24.

“ nitida Pse.,

. 83

7.

“ recedens Garr.,

. 36

25.

Endodonta ficta, Pse.,

. 38

8.

“ retunsa Pse.,

. 35

26.

“ Huahinensis Pfr.,

. 37

9.

“ Heynemanni Pfr.,

. 35

27.

“ cretacea Garr., .

. 41

10.

“ coarctata Pfr., .

. 34

28.

Zonites Mooreana Garr.,

. 23

11.

Partula lamellicosta Garr., .

. 30

29.

Diadema biangulata Pse.,

. 29

12.

“ consimilis Pse.,

. 29

30.

Microcystis scalpta Garr., .

. 21

13.

“ acuticosta Mouss., .

. 30

31.

“ verticillata Pse.,

. 19

14.

Pitys parvidens Pse.,

. 31

32.

“ simillima Pse., .

. 19

15.

“ subtilis Garr.,

. 31

33.

“ normalis Pse., .

. 19

16.

“ punctiperforata Garr.,

. 32

34.

“ angustivoluta Garr., .

. 20

17.

“ consobrina Garr.,

. 31

35.

“ discordise Garr.,

. 20

18.

“ Boraborensis Garr.,

. 32

36.

Trochonanina conula Pse.,

. 21

Plate III.

37. Trochonanina obconica Pse.,

38. “ subrugosa Garr., .

39. “ Tahitensis Garr., .

40. Chondrella striata Pse.,

41. “ parva Pse.,

. 22

. 22

. 22

. 106

. 106

42. Vertigo pediculus Shuttl., .

43. Trochomorpha pallens Pse.,

44_ “ assimilis Garr.,

45. Partula radiata Pse., .

46. “ Thalia Garr., .

. 83
. 25
. 27
. 74
. 69

114

TKKRESTHIAL

MOLLUSCA INHABITING SOCIETY ISLANDS.

Fio.

47.

'

Paob.

Fig.

Pag*.

Partula lugubris Pse., .

77

66. Helicina siniulans Garr.,

. 105

48.

“ Garretti Pse., .

56

67. “ discoidea Pse.,

. 104

49.

“ foimosa Pse.,

60

68. “ subrufa Pse., . .

. 104

50.

“ fusea Pse.,

71

69. “ Raiatensis Garr., .

. 106

51.

“ proclucta Pse.,

66

70. Partula annectens Pse.,

. 66

52.

“ citrina Pse.

64,

71. Scalinella Moussoni Semper,

. 100

53.

“ imperforata Pse.,

54

72. Atropis obesa Garr.,

. 99

54.

“ virginea Pse.,

61

73. “ Bythinellaeformis Garr., .

. 98

55.

“ Mooreana Hartm., .

59

74. Partula turgida Pse., .

. 56

56.

“ vittata Pse., . . . .

75

75. “ clara Pse.,

. 56

57.

“ arguta, . . . . •

62

76. Taheitea pallida Pse., .

. 107

58.

stolid a Pse., . . . .

70

77. Partula planilabrum Pse.,

. 63

69. Omphalotropis oblonga Pfr.,

96

78. “ faba, var. Amanda Garr.,

. 57

60.

“ Boraborensis Dohrn, .

94

79. “ subangulata Garr., .

. 57

61.

Gelicina faba Pse., . . . .

105

80. “ dubia Garr.,

. 57

62.

“ eorrugata Pse.,

102

81. “ filosa Pfr.,

. 64

63.

“ miniata Lesson,

102

82. “ callifera Pfr., .

. 60

64.

“ Maugerise Gray, var. albinea

83. “ lineata Lesson, %

. 50

Pse.,

101

84. “ dentifera Pfr., .

. 68

65. IlelicinaMaugerisBjVor. rubicundaPse., 101 I

[115]

THE TERTIARY GEOLOGY OF THE EASTERN AND SOUTHERN UNITED STATES.

By Professor Angelo Heilprin.

The United States Border Tertiaries and their European Equivalents.

The marine Tertiary deposits of the eastern United States occupy the outermost
border (barring the post-Tertiary formations) of the Atlantic slope in a continuous
extent from the neighborhood of Long Branch, N. J., to near, or quite to, the
extremity of the peninsula of Florida. Beds referable to the same geological period
have been identified on Martha’s Vineyard, Mass., and good grounds exist for the
supposition that similar beds extend beneath the water surface between this island
and the New Jersey coast, and further to the northward. On the Gulf border the
Tertiary deposits extend continuously through the States of Florida, Georgia, Alabama,
Mississippi and Louisiana to a point on the Rio Grande in Texas at least (if not
considerably more than) 60 miles N. W. of Laredo. Tennessee, Kentucky, Blinois
and Missouri likewise contribute to the Tertiary area, while about one-half of the
State of Arkansas is occupied by deposits of this age. On the Atlantic border the
inner boundary line is removed from the coast by from about 25 miles, at a point
opposite Trenton, to 160 miles in Georgia (near Macon). The deposits on the Gulf
slope occupying the Mississippi embay ment extend northward from the Gulf fully
seven degrees, or about 500 miles, or nearly half way to the Canadian boundary line
in Wisconsin.

The beds composing these deposits are in the north largely in the form of loose
sands, clays, and marls, but in the south solid rock— shelly limestones, “buhrstone ”

enters largely into their composition, more particularly of the older series. Ihe

dip on the Atlantic border, as also in Texas, Louisiana and Arkansas, is uniformly
towards the S. E. ; more nearly S. in Georgia, and S. by W. over a considerable
portion of Alabama and Mississippi. Regarding the same in Florida little has been
accurately determined. No disturbances of any moment appear to have, intervene
between the period of the deposition of the oldest member and the present day. In
New Jersey, Delaware and Maryland, and again in Alabama, INIississippi, Tennessee,
Arkansas and Texas, the depo,sits abut wholly or in part against those of the Greta-
ceou, period (Sennonian and M=eslrichtian)-lying in son.e mstances conformably
upon them-while in some of the other States these last are completely (or nearly so)

°'”Asto'’fhe'Iges indicated by the different members constituting the entire marine

the tertiary geology op the

IK)

Tertiary aeries, it .aay be premised at the outset that unequivocal representatives of
both eIcuc and Miocene exist; scarcely less posit.ve ts the ex.stence of Ohgoccne
l lits, whereas no satisfactory evidence has as yet been adduced pmv.ng he
pr sencc; of Pliocene on our coast. The starting pent rn the correlat.ou of the
Lenes is afforded by the well-known shell-sand layer of Cla.borne, AU who^
equivalency, at least in part, with the Calcaire Grossier of the Pans basm (Pans.an),
has long been recognized. The general similarity and identity existing between the
fossil remains of the two localities hem indicated place this determination beyond
question. Beds representing the true “ Claibomian ’’ have been recognized m South
Carolina, Georgia, Alabama, Mississippi and Texas, and doubtless some of the Eocene
deposits ill Arkansas and North Carolina belong to the same period. Underlying the
“ Clilibornian ” in the south are a series of clays, sands, and lignites, or in other
localities, more or less siliceous and impure shelly limestones known as buhrstones —
the “ chalk hills ’’—.several hundred feet in thickness, whose exact equivalence it is
not Jis easy to demonstrate as those of the overlying sand beds, but which appear to
hold a position somewhat parallel to that of the London clay (Londonian), or to the
upiKT (and lower?) Suessonian of France. The “ Buhrstone ” (Siliceous Claiborne of
Ililgard) occupies a considerable portion of the southern Tertiary area, attaining its
principal development in Alabama, Georgia and South Carolina. In Alabama and
Mississippi, as best studied in those States, with a probable development of 200-
;}()() or more feet, we find at the base of the Eocene, a series of interstratified clays,
sands and lignites, my “ Eo-Lignitic,” which seem to represent the most ancient of
our cis-Mississippi Tertiary deposits. It appears pi'obable that the oldest Eocene
deposits occurring in New Jersey — those, for example, exposed on Shark River —
belong here, and po.ssibly also the Piscataway and Marlborough beds of Maryland
and tlie Pamunkey sands of Virginia, which I have claimed to be the probable
equivalents either of the British Thanet sands (or those of Bracheux, France), or of
''the British Bognor rock (lower I,ondonian). Not impossibly, however, they may
prove to be the equivalents of a portion of the '‘Buhrstone.” Immediately overlying
the “ Claibomian ” in Alabama, Mississippi and South Carolina, Avith a considerable
development in Louisiana and Georgia, and evidently also, although not as yet
distinctly marked out, in Texas and Arkansas, are the deposits that have been desig-
nated the “Jacksonian,” .so named from the town of Jackson, in Mississippi, whence
the fossils considered typical of this group were first obtained. In this series are
included the so-called “white limestones” of many geologists, in which (and elsewhere)
have been found, more or less abundantly, the remains of the Zeuglodon, the most
distinctive fossil of the formation. No precise comparison between the fossils of this
formation and those of correspondingly situated trans-Atlantic formations has as yet
been institvited, and, therefore, it may perhaps be premature to assert with positiveness
what the exact homcon represented by them may be. But as the beds occupy a
position immediately overlying Avhat is generally considered to be the next highest

EASTERN AND SOUTHERN UNITED STATES.

117

member of the typical European Eocene, as developed in the British and Paris basins,
and underlying what can, I believe, be proved to be true Oligocene deposits, it may
be reasonably inferred that they represent what in the basins referred to constitute the
uppermost member of the entire series — the sands of Beauchamp and the Barton clay
( = Upper Bagshot sands 1). Confirmation of this view is afforded by the discovery
in the Barton clay of Hampshire of the remains of a Zeuglodon {Z. WanMyni,
Seeley),* the only individual of the genus that has hitherto been found in any
European formation. No really satisfactory evidence as yet exists as to the occurrence
of Zeuglodon in any American formation but the “Jacksonian.”

The so-called Oligocene deposits, to which reference has just been made, occupy
in Alabama, Mississippi and Louisiana a narrow band of territory immediately to the
south of, and bordering the “.Jacksonian,” which, as already stated, they also overlie.
They occupy the greater portion of Florida, and doubtless also have a considerable
development in southern Georgia and southeastern Texas, but in these last two States
their areas have not as yet been accurately determined. They were originally called
by Conrad, who first characterized them, the A^icksburg beds, and by me have been
designated the “ Orbitoitic,” from the great abundance of Orhitoides Mantelli, their
most distinctive fossil. Conrad referred the deposits in question to the Oligocene age
not because they contained fossils in any way indicative of deposits of the same age in
other countries, but merely for the reason that their contained fossils, as he supposed,
were almost entirely distinct from those of the subjacent Eocene deposits, and equally
distinct from those characteristic of the formations which he correctly surmised to be
of newer date — the Atlantic Miocenes. This inference, I believe, can now much
more satisfactorily be shown to be true. The Oi'bitoides Mant'-lli occurs in very
considerable abundance in several of the AVest India Islands — Jamaica, Antigua,
Trinidad— where the beds containing them are doubtless of equivalent age, and of the
same age as the orbitoitic beds of Florida, and other 'of the southern States.f In the
island of I'rinidad they enter largely into the composition of the San Fernando rocks,
which are by Guppy considered to represent the base of the Tertiary series of the
islands, and which, together with the Chert formation in Antigua and the Anguilla
beds, constitute a portion of his lower West Indian Miocene (m distinction to the
principal Tertiary deposits of the island of Jamaica, the middle Tertiaries of San
Domingo and Cuba, those of Cumana, and the Caroni beds of Trinidad, which
together form the upper or later part of the West Indian AIiocene).J Ihese San
Fernando beds have been more recently correlated by Duncan with the deposits
occurjing on the island of St. Bartholomew, which are emphaticaUy stated to be of pre-
Aliocene age, and where no Miocene deposits have thus far been discovered to exist.§

fB"i;oTu:;d"n1Ld.a„c^ m the lower limestone deposits of the island of Malta (T. R. .Tones),
16 JOUR. A. N. S. PHILA., VOL. IX.

118

THE TERTIARY GEOLOGY OF THE

The fossil coral fauna of this island is closely related to that of well-known Oligocene
localiti(>s in Italy, as the Crosara and Castel Gomberto district, whose position in the
geological scale they undoubtedly represent. This relationship is indicated by Duncan
and oUier authors, and the writer is Informed to the same effect by letter from Prof.
Edward Suess, of '^"ienna, one of the profoundest workers in the field of the Tertiaries.
'I'he same eminent authority informs me that the Vicenza deposits above indicated are
the unquestionable equivalents of the sands of Fontainebleau and of the marine
Oligocene sands of the Mayence basin, and we thus have the parallelism established
between our Vicksburg or orbitoitic beds and those of the typical Oligocene of
southern Europe. The Orbitoides ManfeUi, as already stated, also abounds in the
lower limestone layer of the island of Malta,* and this layer has likewise been iden-
tified to be of Oligocene age, and to represent a part of the “ Bormidian ” of Sismonda,
the older marine molassc of Bavaria and Switzerland, and probably also the Sotzka
beds of the Vienna basin.f The relationship existing between the Florida orbitoitic
rock and the deposits in some of the West India Islands which have been referred to the
true Oligocene, is shown, irrespective of the great development of Orbitoides Mavtelli,
in the general character of the associated foi’aminiferal fauna. Thus we have in some
l)laces a sufficient abundance of Opercidinm {CristeUaria rotella of Conrad) and
Numvinrniw,X and of species only doubtfully distinct from those found in Antigua,
Trinidad or Jamaica. One or two other species of Orbitoides also occur, one very
much of the 0. dispamais type, and the other severely recalling 0. ejdiippium. A
further relationship with the equivalent St. Bartholomew deposits is established by
the pre.sence of at least two of the distinctive echinoids described from that island by
Cotteau§ — Euspataugm Clevei and E. Antillarum — and doubtless other identical
forms will be Ibund.

No unequivocal deposits of Miocene age have thus far been detected on the Gulf
slojic, although strong grounds exist for the supposition that the formation designated by
llilgard as the “Grand Gulf Group” belongs to this period of geological time, but to
which division or horizon of the same, it is as yet impossible to state. 0;i the Atlantic
border the Miocene extends through the States of New Jersey, Delaware. Maryland,
V irgmia. North and South Carolina, and Georgia, following in a general way the trend
of the Eocene, and, where not completely overlapping this last, lying between it and the
coast. In North and South Carolina, also elsewhere, it is very largely obscured by
c posits o post- Pliocene age. A patch of Miocene has been determined in the
peninsula of Honda, near Rock Spring, in Orange Co., and not improbably a more or
less continuous strip will be found to extend to this point southward from the

* Geol. Mag., i, p. 104, 1864.

GeoI.^2cha!; ^ ^oemes, Jahrb. K. K.

I N. Sciences of Philadelphia, July, 1882

§ K. Svens. \ et.-Akad. Hand!., 1874. ^

EASTERN AND SOUTHERN UNITED STATES.

119

Georgia line, and possibly much further. A slight unconformability has in some places
been detected between the Miocene and the Eocene. In a paper entitled “ On the
Relative Ages and Classification of the post-Eocene Tertiary Deposits of the Atlantic
Slope ” * I have given what I considered to he good reasons for concluding that the
Miocene deposits of North and South Carolina, my “Carolinian,” were of newer date
than those of Virginia and Maryland, and that not improbably they represented the
deposits of the lower^ (“ Black ”) Antwerp crag, the Diestian of the Belgian geologists,
although the percentage of recent forms is considerably higher in this last than that
which has been shown to be the case with the Carolinian fauna. The Virginia and
Maryland deposits, on the other hand, and doubtless with these also those occurring
in Delaware and New Jersey, represent approximately the “ Mediterranean ” (■erics of
the Austrian geologists, and in their two divisions, the “ Marylandian” (or older deposits
of Maryland, and probably also the lower bed in Virginia) and “ Virginian ” (as
developed in the typical Miocene area of Virginia, and in the upper Maryland series)
we have the correspondents, at least in part, of the “ First Mediterranean ” (and the
faluns of Lcognan and Saucats), and the “Second Mediterranean” (and the laluns of
Touraine) respectively. The southeast corner of Virginia, with the towns of Norfolk,
Portsmouth, Suffolk, etc., appears to belong to the “ Carolinian ” horizon, or that of
North and South Carolina. Comparing the Atlantic Miocene with deposits referred
to the same age as occurring on some of the West Indies, Trinidad and San Domingo
for example, we find that out of ten species of mollusca obtained from the Caroui beds
of the first named island. Guppy identified no less than six as identical with forms
found in the eastern United States : Petaloconchus sculpturatus, Dosinia acetabulum,
Tellina Uplicafa, Pecten compariVs, Ostrea Virginica, and Teredo fistida.-\ ^ 'Ihis
number is about equally distributed between the States of North and South Carolina
and Virginia, and hence no absolute indication (by comparison) of the horizon is
afforded by their presence. Petaloconclms scidptnratus. Teredo fistula and Telhna biph-
cata are also found in the Miocene of San Domingo, and with them Chama ardndla
and Area pe:rata,X but most of the sp icies occurring here are described as being distinct
from North American forms. Further investigation, however, will doubtless reveal
a greater number of identical forms. While, therefore, it is still impossible from
paleontological data to establish a strict correlation between the Caribbean and Atlantic
Aliocenes, yet probably we will not be fiir from the truth in assuming that the former
^present a part of the Virginian or Marylandian series, seeing that the percentage of
living forms in the contained fauna is only 20, or possibly stiU lower (8 or 9 according
to Carrick Moore).§ They would, therefore, correspond to some part of the Medi-
terranean ” as well.

* Proc. Acad. Nat. Sciences of Phila., June, 1883.
t Q. J. Geol. Soc., xxii, p. 576, 1866.

t Guppy. Q- J- P'

§ Guppy, op. cit, p. 575.

120

THE TERTIARY GEOLOGY OF THE

Fn.ni what lias preceded, the following table of the Atlantic and Gulf Tertiaries
may be constructed : —

Post-Pliocene. |

'j

Pliocene. | ?

i ^

ICaroltnian.

Deposits of North and South

(Upper Atlantic

[ Carolina (“Sunqiter” epoch

. Miocene.)

1 of Dana).

'Virginian.

;Deposits of Virginia, and the

(Middle Atlantic

j newer group in Maryland

1 Miocene.)

(“ Yorktown” epoch, in part,

1

of Dana).

Miocene.

Marylandian.
(Lower Atlantic!
Miocene.)

Older Miocene deposits of
Maryland, and possibly^ the
lower beds in Virginia
(“Yorktown” epoch, in
part, of Dana).

Foreign Equivalents.

Diestian ?

Probably of the age of the
“ Second Mediterranean ” of
the Austrian geologists, and
of the faluns of Touraine;
Caroni beds of Trinidad;
and Miocene of San Dom-
ingo, Jamaica and Curaana?

Probably (or at least partially)
the equivalent of the “ First
Mediterranean ” of the Aus-
trian geologists, and of the
faluns of Leognan and
Saucats.

1

Dlioocene. Orbitoitic.

Jacksonian.

Cl-AIIIOBNIAN.

Buubstone.

Eocene.

Eo-Liqnitic.

i

Strata characterized by^ species
of Orhitoides. Vicksburg,
beds, Florida nummuliticj
beds, etc.

Aquitanian. Deposits of CrO-
sara and Castel Goraberto
(Vicentin), Oligoccne of the
Mayence basin, sands of
Fontainebleau, lower lime-
stone of Malta, Fernando
beds on Trinidad, Antigua,
Chert, St. Bartholomew
Oligocene.

Jackson beds of Mississippi. Barton Clay (Bartonian).
“ White Limestone ” of Ala- Sands of Beauchanqi?

I bama.

jFossiliferous arenaceous de-
posit of Claiborne, Ala., etc.

Beds below the true Clai-
bornian on the Alabama
River, “Chalk Hills ” of the
southern part of the State'
etc. “ Siliceous Claiborne ”

(Hilgard) of Mississippi.

Maryland Eocene, in part?

Lignite, sands and clay-s situ-
ated at the base of the

Age of the “ Calcaire Gros-
sier ” of France (Parisian).
Londonian ?

Thanetian ? Bognor rock ?

Tertiary 'series in Alabama,
etc. Marlborough and Pis-
cataway beds of Maryland?
Shark River deposits of New
J ersey.

' ovrsey.

coJJ' AtT” foimations in this State follow in a general parallel

upon which Th ° ° ” Cretaceous deposits (Majstrichtian and Sonnonian),

u,K,„ winch they can he shown i„ some places to lie conformably, or very nearly so!

EASTERN AND SOUTHERN UNITED STATES.

121

riicir inner border may be said to correspond in a general way with a S. W.-N. E.
line connecting Long Branch, on the Atlantic coast, with a point on the Delaware
Biver, situated almost due west of the city of Salem, or opposite Delaware City in the
State of Dclawai'e.* The surface embraced between the sea-border and this line
comprises between one-third and one-half the area of the entire State, and presents
in its physical features the characters of gravelly sands and clays.

Eocene. — There can be no question but that the deposits of this period, forming
part of the “ Upper Marl Bed,” so called, which appear along Deal Beach on the
Atlantic coast, on Shark River, in isolated patches about Farmingdale, Sqnankum, and
elsewhere, and in a more or less continuous belt from near New Egypt to Clementon,
represent in part, if not in whole, approximately the lowest of the entire Eocene
series occurring in the eastern United States. Their chronological equivalence with
the oldest Tertiary beds occurring in some of the other States — as the Piscataway beds
of Maryland, and the lower beds exposed on Bashia Creek, Clarke Co., Ala. — has not
yet been definitely made out, but the evidence that has thus far been addneed is
sufficiently strong in support of Conrad’s original surmise as to the existence of such
equivalence (Proc. Acad. Nat. Sciences of Philadelphia, 1865, p. 71 ; Smithsonian
Misc. Coll., 200, 1866, p. 1). The fossils occurring in the New Jersey strata are
mainly in the form of casts, and their precise determination is consequently involved
in a considerable amount of uncertainty. It appears sufficiently clear, however, that
many, if not most, of the forms are such as have not yet been found in the other
States, although they represent distinctly Eocene types, but which approximate very
closely certain trans-Atlantic species.

Tliose (invertebrate) specifically determined are, according to Conrad, the following;

Naritihts {Ahiri(i) Vanvx^mi^ Conr.

Nautilus {Cymoynia) Bartini, Nyst.

Nautilus (^Cyrnomia) Lamarckii, Desh.

? Bosfellaria {^ITippochrenes') columbaria,

Desh.

? Yoluia ( Volutilithes) mutata, Desh.

Pleurotoma {Surcula) annosa, Conr.

? Pyrula {Pyrificus) Smithii, Sow.

Pleurotomaria perlata, Conr.

Architectonica idonea, Conr.

(Cook, Geology of New Jersey, 1868, pp.

Misc. Coll., 1866.) - u,

To the.se are sometimes, but erroneously, added Area quindecemradiata, Gabb,

Crassatella Delawarensis, Gabb, and TerArahda glossa, Conr.

It yfiYi thus be seen that the most distinctive Eocene forms found elsewhere, such
as Ostrea sellce/ormis, Ostrea compressirosfra (= 0. Bellovacina ?), Cwndlwa gygautea,
* Geologic^ Map of Now Jersey, 1882. Prepared by the Geological Surv;^f the State, under the direction

? Onustus {Phorus) extensus. Sow.
Actceonema prisca, Conr.

Thracia modesta.

Caryalis Delawarensis, Gabb.
Protocardia curia. Com.
Crassatella littoraVs, Conr.
Venericardia perantiqua, Conr.
Yoldia protexta, Conr,

Avicula annosa, Conr.

731-2; Check List of Eocene Fossils, Smiths,

122

THE TERTIARY GEOLOGY OP’ THE

or Otirtli/ti pliinicosiu, lla^'e not yet been discovered in this State. AVhile, therefore,
from ])jdeontolo"ical evidence alone it would be impossible to indicate with precision
the horizon which the New Jersey deposits hold relatively to the other Eocene deposits
of the Atlantic and Gulf borders of the United States, yet from the presence of a
numb(‘r of organic forms which would appear to be indicative rather of an older than
of a newer period, the absence of distinctively Upper Eocene species, and the circum-
stance? that the beds in question occupy a position directly in line with the similarly
placed older Tertiary deposits of Maryland and Virginia, whose age has been more
definitely fixed (Thanetian ?), it may safely be premised that the horizon is near the
base of the entire Eocene series.

Miocene. — Whatever may be the exact nature or age of some of the superficial
deposits, as the “ glass sands,” occupying that portion of the State lying between the
Eocene line and the coast, there can be little or no doubt existing as to the direct
continuity throughout that portion of the State of the strata that have in Maryland
and \'irginia been designated the Miocene. Beds referable to this period have been
identified in numerous areas throughout the region, and have in various localities been
described as lying unconformably upon the Eocene, i. e., withli less pronounced dip
toward the .sea. The fossils hitherto discovered in the deposits of this period are
conqinratively few in number, and have been obtained in principal part, from the
southern sections of the State, from the marl exposures in Salem and Cumberland
(Shiloh) Counties.

Among the forms that have been identified with species occurring in other Miocene
localities are : —

■Ostrat I7r^m/ca (including 0. Mauri-
t'ennift).

Vetien Ilitmjihrei/sii.

y MytUm ivjhtm. j

? AMtarte exaUxta (A. TJiomaaii). j

AnUirte iimhila/a (A. dia(am). j

Other species, apparently confined to the
Oetrea jfercmaaa.

Plicatula rteiisata.

Carrfitamerd acnleaia.

Mysia pari/ is.

Venus Ducate/lii.

Venus p/ena.

MercenarUi cancei/afa, Gabb.

Tel/ina Shilohensis,

Throcia myreformis.

Crassatella melina.

Carditamera arata.

Yoldia limabda.

Corhula elevata.

Natica cdtenoides.

State, are : —

Anatina alia.

Saxicava (?) parilis.

Fascio/aria ( Tur/nnella ?) Mnoilii.
F idgur scalariform is.

Turriteda cequistriata.

Tarritedla CumberJandiana.
Turritella secta.

Fissurella Gris(omi.*

• Specimens of most of the
Natural Sciences.

species enumerated in the above lists

are in the possession of the Academy of

EASTERN AND SOUTHERN UNITED STATES.

123

It is very likely that hoth divisions of the Miocene indicated by me as occurring in
Maryland and Virginia,* and by me designated as the “ Marylandian ” and “ Vir-
ginian,” or the lower and middle Atlantic Miocenes respectively,! will eventually be
found to be-equally well marked off in New Jersey, although up to the present time,
from the sparseness of the fossil remains that ha\"e been collected, no such subdivision
could be satisfactorily attempted. But from what material we have at hand, it may
be safely asserted that the localities which have been so assiduously searched in the
neighborhood of Shiloh, and elsewhere in Salem and Cumberland Counties, belong to
the older or “ Marylandian” division. J

No satisfactory evidence has yet been brought forward proving the existence of
any marine Pliocene deposits in the State.

Delaware.

We possess but very little precise information respecting the Tertiary formations
of this State ; no really accurate survey has here ever been carried info effect, and our
present geological and paleontological knowledge of the region is based largely upon
the “ Memoir of the Geological Survey of the State of Delaware,” of Prof. J. C.
Booth, published in 1841. I am not aware that the Eocene formation has been abso-
lutely identified by its fossil remains as occurring in the State, but no reasonable
doidit can be entertained as to its existence there (although possibly entirely obscured
bv the newer Miocene deposits) as a dnect continuation of, or connection between, the
belts developed in Maryland and New Jersey. The northern boundary of the forma-
tion, corresponding to the southern boundary of the parallelly trending Cretaceous
formation, will be found to lie along and somewhat to the north of the Appoquini-
mink, holding, probably, a more or less S. W.-N. E. direction. The southern third
of the State appears to be in principal part covered by either very late Tertiary, or,
what seems more likely, by post-Tertiary deposits ; these are described as occupying
the whole of Sussex County and the southern portion of Kent, defining the southern
limit of the Miocene along the Murderkill and its tributaries. Prof. Booth recognizes
two principal divisions in the Delaware Tertiaries, which he designates the northern
and southern Tertiaries, but these have no special significance, being founded on
purely geographical and lithological, and without reference to paleontological, char-
acters. Still, more careful examination may prove them to correspond in a general
way with the two Miocene divisions to which reference has already been made when
treating of the geology of New Jersey. The invertebrate fossils specifically identified
by Boo'th as occurring in the Miocene deposits are : Yenm alveata, Vemis inocerami-

* Proo. A. N. S., 1880, p. 20, et seg. ; 1882, p. 150, et sfg.

S neUprti Iht^sLugrapliical Evidence afforded by tbe Tertiary Fossils of the Peninsula of Mary-

1-24

THE TERTIARY GEOLOGY OF THE

formh (F. Uoceroidea), Namla Iwvh, MijoconcJm, WohoXAy M. incnrva, and Pecten
MudUonina.

Maryland.

With respect to the Tertiary geology of this State we have very much more
precise information than in the case of Delaware, although it must be confessed that
a great deal still remains to be accomplished before an even approximately accurate
delineation of boundary lines can be presented. This applies more particularly to
the region of the East Shore, where the geological work done has been of a decidedly
unsiitisfactory character — a character that unfortunately only too well distinguishes
the exploration of a very considerable portion of the Atlantic border. It is lamentable
to find in the report of a survey published as late as I860,* that work had not yet
proceeded sufficiently far to permit of the subdivision of the Tertiary series into its
primary component members (Eocene, Miocene and Pliocene), and this thirty years
aOer the publication of Conrad’s paper on the “Geology and Organic Remains of a
Part of the Peninsula of Maryland ” ! f

'I’he Cretaceo-Tertiary boundary line enters Kent County from Delaware at a point
.situated a few miles north of Millington, bisects in a southw'esterly direction the
peninsula formed between the northern head of Chesapeake Bay and Chester River,
mid continues on the west shore from a point a little outside of Annapolis to the
neighborhood of Fort M'ashington, on the Potomac, a few miles below the city of
Mhishington. South of this line to about the Little Choptank in Dorchester County,
the region is occupied by the older and middle Tertiary depo.sits; the rest of the State
southward and southeastward, con.sisting of loamy clays and sands, is considered to be
of post-Tertiary date. The combined Tertiary and post-Tertiary areas cover nearly
one-half of the entire State.

EocK.vK._The development of this formation on the East Shore has thus far not
been afcurately traced, but it may be assumed that its southern boundary lies some-
«l,nt hclwoe,, Cl, ester Itiver and Ccnlreville. Cliostertown and Millington doubtless
10 Mt lin its area. Gn the West , Shore the formation has been more accurately
Studied, at least from a paleontological standpoint, but even here the exact boundary
me, separating it on the southeast from the adjoining Miocene, has never been
accura e } ( e ned. It may be said to correspond in a general way with a X. E.-S. W.

Pori S'" u" ™ Chesapeake, to the .nouth of

consists of Hav”"’ 1" occupied by this formiition, which

fossil remains * hi""' h "" sands, and, in some places, compact siliceous rocks,

I, rr . f c abundant. „nl

ompiisc number of forms, prominent by size, which are more or less distinctiveof

1 Chemist, p. 43.

EASTERN AND SOUTHERN UNITED STATES.

125

the State. The best known fossil-bearing localities are Fort Washington, situated a
few miles below the city of Washington, Piscataway, on Piscataway Creek, and Upper
Marlborough, in Prince George’s County, which have been made known principally
through the labors of Mr. Conrad.

The positive determination of the relation which these older Tertiary deposits hold
to the typical American Eocene series as exhibited in Alabama, can only be arrived
at when a direct stratigraphical continuity can be traced between the deposits of the
two States, or between their previously recognized representatives in the intervening
States. This is due to the fact that several members of the Eocene serie.s appear to be
absent from this portion of the Atlantic border, but exactly which it has as yet
been impossible to determine. The presence of strata of Jacksonian age has never
been detected, nor have we any positive knowledge concerning the existence in the
State of any beds which may be looked upon as the equivalents of the Orbitoide lime-
stone, although Oligocene (Vicksburgian) strata may exist along the Chesapeake.
But whether the deposits in question — Fort Washington, Piscataway, and Upper Marl-
borough— represent the Claibornian, Buhrstone or Eo-Lignitic is a matter of consider-
able uncertainty, perhaps largely due to their comparatively feeble development.
Almost the only evidence we have bearing upon this point is derived from the character
of the contained fossils, but even here the results obtained are far from satisfactory, and
for two reasons : in the first place, the character of the Eocene fossils is largely uniform
throughout the greater portion of the entire series, as is shown by nearly the lowest
and highest exposures in the State of Alabama ; and in the second place, the great
distance interv^ening between the two localities — Alabama and Maryland may readily
account for certain differences in the general aspect of the two fossil faunas, which
otherwise would probably be attributable to a non-contemporaneity in the periods of
their introduction. The evidence afforded by lithological characters is almost equally
iinsatisfiictory, since there is a frequent repetition of the general rock aspect— green-

sands, clays, and siliceous marls— observable at different stages of the series. Conrad,

the only investigator whose observations on this subject are of scientific value, affirms
that the majority of the fossil mollusca are of the Claiborne type, and he consequently
..K- i-'j. t, o-pnoral wav with those exposed on the Ala-

17 JOUR. A. N. S. PHILA., VOL. IX.

TUE TERTIARY GEOLOGY OF THE

1‘2(J

clue to the exact determination of the age of the deposits in wliich they occur. It is
true that an examination of the liomotaxial deposits of Europe shows the genera
Phohuhmya and Panopea to be more especially characteristic of the lower or even
lowermost liorizon, of the Eocene series, as in the English and French basins, but no
special inference can be drawn from this circumstance, since the species are not the
same, and the genera survived through the succeeding periods to the present day.
In the case of Odrea comjireasirodra, however, we have a much more tangible, point.
The species, first described and figured by Say (.7 ournal of the Academy of Natural
Sciences, iv, p. 1 o3), is certainly very intimately related to the Odrea BeUovwma of
Lamarck, and apparently undistinguishable from certain varieties of that species.*
Now this sjiecies, although not exclusively restricted to the lowest Eocene beds, is
nevertheless highly characteristic of the Thanet sands, below the London Clay proper

and also Iwlow what was formerly designated as the “Plastic Clay” series, where it

constitutes a true basement accumulation ; and it holds almost precisely the same
n'lation to the beds of the Paris basin, where, according to Deshayes i^Auimnux s.
Verthhrta, Basdn <1e Paris, ii, p. 117), it occupies the horizon of the Bracheux sands,
'file specie.s, wherever found, appears to be considerably restricted in its vertical range,
and its occurrence, therefore, in some of the American deposits would seem lo afford
some more decided indiration of the true age of those deposits than could be obtained
from the characti'r of the limited number of its contained fossils taken as a whole.
.\sso( iate<l with Odrea compresdrostra were found casts of the large Gvcallma gajantea
(C onrad, Journ. Acad. Nat. Sciences, vi, p. 215, 1830), a species which appears not to
Ik‘ rc-preseuted in any of the equivalent European formations. But in Virginia, in
Ix-ds which can be .shown to be the direct equivalents of those of Maryland, there

occurs, in ad.lition to the C. gigantea of Conrad, a second species of CucuUcea' Wve C.
oaochda of Rogers (Trans. Am. Philos. Soc., new ser., vi, p. 373; Latiarca idonea,
(our., Proc. .\cad. Nat. Sci., 1872, p. 53— no locality stated), which, if not identical
with the C. crassa/ina or Lamarck, from the Bracheux sands of the Paris basin, is
C( rtnin y mo.st intimately related to it, and can be considered in every way as its
ro,,re8ont„.ive.t It sl.onl.l also be stated tl,at the only other species of

EASTERN AND SOUTHERN UNITED STATES.

127

and, likewise, the single species described by Searles.AVood from the older Tertiaries
of England is a lower Eocene form.

If such comparisons are of any value stratigraphically we may fairly look upon the
Maryland Eocene deposits — the Piscataway sands below, and the Marlborough rock
above — as representing a horizon nearly equal to that of the Thanet sands of England
and the Bracheux sands of the Paris basin, or of the British Bognor rock (= London
Clay).* In either case they would be near the base of the Eocene series.

In the scale of the American series as exhibited in Alabama they would occupy
a position probably near the base ofjhe “Buhrstone,” or possibly even lower, as the
equivalents of the beds exposed on Bashia Creek, and Ca\e and Knight’s Branches
(“Eo-Lignitic”).

Miocene. — All the rest of the State southeast of the Eocene line, except such
parts as may be covered by post-Plioceiie deposits — Worcester, Wicomico, and portions
of Dorchester and St. Mary’s Counties — belongs to the Miocene formation. As in
the case of New Jersey, no satisfactory evidence has as yet been brought forward
proving the existence in the State of the Pliocene.

In a former paper t I have, attempted to show that the po.st-Eocene Tertiary
deposits of this State are divisible into two groups — an older and a newer, one of which
— the newer — is unequivocally Miocene, and the other, possibly, Ohgocene; both
belong to a period antedating the principal post-Eocene deposits of the States of North
and South Carolina. The deposits of the older group, which I have since designated
as the “ Marylandian,” X and have recognized as constituting the Lower Atlantic
Miocene of the American coast, are best exhibited in the oyster banks, ri.sing a few
feet above tide-water, in Anne Arundel County, along the western shore of the Chesa-
peake, in the exposure of Calvert Cliffs, and in the Perna beds of the Patuxent River
near Benedict.

Localities of the newer group are found at or near Cove Point, Calvert County,
the Patuxent River, below and above Benedict (in the deposits overlying the Perna
beds), and at numerous points along the St. Mary’s River, in St. Mary’s County. The
proportion of recent species in the fossil fauna is here very much higher than in the
deposits of the older group, and clearly indicates a considerable interval between the
periods of the respective depositions. Beds belonging to the newer period, which I
have elsewhere correlated with the principal Miocene deposits of Virginia (tlie
“Virginian”), also occur on tlie East Shore, at Easton, on the Choptank, ivhere the
molluscan fossil fauna corresponds very closely with that observed on the west bank of
the Patuxent. Connecting the points where the two series of deposits occur, it will

* The similarity existing between the Marlborough and Bognor rooks has been pointed out by Conrad (Proc.
National Institution, p. 173, 1841'.

\ “X the^RettW^Ages^aud'ciLsification of the post-Eocene Tertiary Deposits of the Atlantic Slope,”
Proc. A. N. S., June, 1883.

THE TERTIARY GEOLOGY OF THE

I -.>8

Im- sc‘cn that the older group ( Mar y land ian) occupies a northwestern area, or that
adjoining the Eocene ; and tlie newer group (Virginian) the area included between this
last and that occupied by the post-Pliocene beds to the southeast.

.\t the time that I prepared the article above referred to on “The Stratigraphical
Evidence afforded by the Tertiary Fossils of the Peninsula of Maryland,” wherein I
indicated the existence and positions of the two divisions of the Maryland “ Medial
'I'ertiary,” I was unaware that Conrad, some forty-five years before, had arrived at
conclusions approximately identical with my own (although the data supporting his
position were of a rather fragmentary and not exactly satisfactory character), but which
he aj)pears to have completely ignored at a later day. Thus in a paper on the
“ 'I’ertiary Strata of the Atlantic Coast,” published in 1835,* it is stated that between
the Chesapeake Bay and Potomac River two classes of deposits occur “ besides the
■ ecpii valent of the London C'lay or Eocene, the first of which, lying most to the westward,
contjuns fewer recent species than the other, and is well characterized by the gigantic
Perna maxiUata." Tn my paper already referred to I have also stated that the lower
or older beds are those which arc characterized by Perna maxillata,^ and it is just
this species which is likewise largely disseminated through well-known Oligocene and
older Miocene deposits of Europe. With it occurs Mijlilus iricurva, a large mytiloid
f()rm, which may be taken to be the representative of the Mytilxis llaidingeri or M.
Favjasi, forms also distinctive of the European Oligocene and Miocene.

Virginia.

The Tcrlimy formntious of this State, for tvhose tlclineation we arc principally
indebted to the labors of I’rof W. I!. Rogers and Mr. Conrad, pursue a more nearly
meridional direction than in any of the other States that we have thus far been
considering. The region occupied by them, designated also as the “Tertiary marl
mgioii, has hecii dofiliod by Rogers J as embracing “ nearly all that portion of the
Sti, e inclnded between its eastern boundary, the Chesapeake Bay and the .\tl,ai.tic
and a hy|mthet,ral line intersecting the principal rivers at their lowest bills. Various
b, sis of clay and wand, nearly horizontal in position, abounding in fossil shells, and the
3 wll """■'r'i “"i™"'*’ '’°™ 'h.nracteristic strata of this division of the

of gvn" mT””"" •

ate m^ongits oZmalZ^f '°v':.;^“

mouth'orrcquta Creek “ K'tetal way with a line passing from the

Fredericksbur- and th ’ neighborhood (a little outside) of

inncksbiirg, and thence through Wes, at the junction of the North and Smith

* of an, I Arts, v.,1. xxViii, p. 106.

“nsMortng tl.» M. mnUining iW

eastp:rn and southern united states.

129

Anna Rivers, tributaries of the Pamunkey, Richmond and Petersburg to the North
Carolina frontier. For a considerable distance south of Petersburg this line has not
been accurately traced, but its course shows a southwesterly deflection.

Eocene. — From the line above indicated as forming the western boundary of the
Tertiary in general the Eocene extends eastward in a narrow meridional strip, with a
breadth varying from about 5 miles in the south to 12-15 miles in the north. On the
west in its northern half it abuts upon the Trias, and in its southern half upon rocks
of Ar.choean age. The absolute thickness of the formation appears nowhere to have
been determined, and until more satisfactory data as to the amount of dip and the
exact boundary outcrops be afforded, no reliable calculation can be made. But it
would appear that in no locality where the beds are exposed does the visible develop-
ment much exceed 30-40 feet. On the James River between Coggin’s Point and
City Point the thickness of the exposed strata is about 20 feet, and in the neighbor-
hood of Mathias’s Point, on the Potomac, opposite Port Tobacco in Maryland, which
marks the eastern boundary of the formation, the thickness of the strata, as ascer-
tained by Rogers, was very nearly the same, or 25 feet.

There is no reason for doubting that the Virginia Eocene deposits are a direct
continuation of those of Maryland, as the position of the beds would readily suggest,
and that consequently they represent an equivalent horizon. This conclusion is
further borne out by the character of the fossil remains, which approximate closely to
those of the State referred to, and among which we find such prominent large forms
as Oxtrea compressirostra* Cardita pJanicosta (including Fc?ierma)-rff« axda of Rogers),
Turriiella Mo/iuiii, CncuUcea gigantea, the related Cucidlaa onochela (Rogers;
Latiarca idmen of Conrad), the last but doubtfully distinct from the C. craxsatina,
Lam., from the Bracheux sands of the Paris basin. Tire large saddle-shaped oyster
{Ostrea aellccformis) which becomes such a prominent feature in the Eocene fauna
of the more southern States, and one of whose deposits forms the basement la\ei in
the famous Claiborne bluff on the Alabama River, appears to have- had a much greater
development here than in Maryland, where the remains of the species are very scanty.

Miocene.— The Miocene area extends from the Eocene boundary already defined
to the sea, occupying what in principal part constitutes the tidal districts of the State.
\s in the case of the Eocene, there can be no question but that the deposits of this
age form a direct continuation of the similar deposits of Maryland, and that conse-
quently we have here approximately the same horizon oi^horizons represented. 1 he

. S,K.cimen in the possession of the Academy of Natural Sciences from near Ale^andna right bank of the
Potomac. Conrad, in his list of the Eocene fossils

species to Maryland exclusively. Rogers, in his reports pi singularly enough, credits it with a

(new .series, vols. v and vi), makes freiiuent reference to a may have been

liosition ill the Miocene. It is not imlikely tha in resemblance. Nor does it seem unlikely that the

mistaken for the form iu question, to which it rears . . o . ^ t,, come from the Eocene green-

O. i is mom nearly 0. dUpariU^^ than 0. conipremToUra, although stated

sands iRogers, vol. v, p. 340 ; vol. vi, 11. xxvii, fig. 1).

130

THE TERTIARY GEOLOGY OP THE

division info the “lower” and “middle Atlantic Miocene,” or what I have designated
the “ Mar)’landian ” and “ Virginian,” does not, however, appear to be as distinctly
marked oflf as in that State, the fossils indicating a more nearly uniform age (Vir-
ginian), hut this seeming divergence may possibly be attributed to imperfect observa-
tion, or to a lack of observation. The discussion of the age of the beds here referred
to, as well as of the equivalent deposits of Maryland, and their relations to the French
faluns and the older Tertiary deposits of the Vienna basin, is fully set forth in my paper
“ On the Relative Ages and Classification of the ])Ost-Eocene Tertiary Deposits of the
Atlantic Slope” (Proc. Acad. Xat. Sciences of Phila., June, 1882). It is not unlikely
that the extremity of the State lying south of the James River, and including partly
or wholly the counties of Southampton, Isle of "Wight, Nansemond, Norfolk and
Ihincess Anne (with the towns, among others, of Wakefield, Smithfield, Suffolk and
Norfolk), as well as the extremities of the peninsulas included between the James,
■^'ork and Rappahannock Rivers, belongs to a somewhat newer period than the region
lying farther ’to the west, or more nearly that represented by the later Tertiary
deposits of North and South Carolina — the “ Carolinian ” or upper Atlantic Miocene

whos(? continuation appears to be found here. The “ fragmentary rock,” consisting
largely of comminuted and clo.sely cemented shell fragments, described by Rogers* as
occurring at various points on the eastern portion of the Miocene district, at Yorktown
and llellcficld on the York River, and “near the extremity of all the iieninsulas,” and
whcn'ver occurring forming a distinctive feature in the stratigraphy of the region, is
an indication of this newer formation. The existence of a newer division of the post-
Koccne 'I’crtiary in southeastern Virginia, although erroneously referred to the
“ Medial Pliocene,” was alre'ady indicated by Conrad in 1835,t who assigned as
localities lor the same Yorktown, Suffolk and the James River near Smithfall
(Smithfield ?). A somewhat .similar division of the Tertiary is made by Rogers who
however, refers the newer division, with West Point, Norfolk, Suffolk, YVakefield’
etc., to the Pliocene.J

One of Ihe most interesting components of the Virginia Miocene formation is the
h 0x1“ ‘'■'""T;!'™'" “ ■ievelopment in some places of 30 feet, which

tl.e I aso ofT' ’'iotao'xi earth ”) and Petersbnrg, and which lies near

1 1 , di r f", : ' of Miocene shells, ;vhich

1 am Tolr r" “"“T- “> *o-P tnxen.

ling m Fm 1 Md.. and has been s.rnck in an .artesian

upon the Pocono ^ " w'T “l '*'*’*'' likewise resting

* Rvp. Owl. Rooonn., 1836, pp. 33_4.
f Am. Joum. Science and Arts, xxviii, p. 106.

t Macfarlane’s “Geological Railway Guide,” ISia p. 184.
t Rogers, in Macfarlana’s Guide, p. 183.

EASTERN AND SOUTHERN UNITED STATES.

131

Miocene deposits, and an indication of the dip of the underlying Eocene beds. If we
assume with lingers that the eastern outcrop of the Eocene formation above tide-water
on a line west of Fortress Monroe is located at about the town of Waverly,* then we
have for a horizontal distance of about 42 miles a descent of between-550 and 600 feet,
or an average dip of 13-14 feet to the mile.f

North Carolina.

Most of the 1 ertiary deposits of this State are obscured by a capping of Quaternary
gravel, sand and clay, which extends inwards for a distance of upwards of 100 miles
from the sea. Beds belonging to both the Eocene and Miocene series occur in
disconnected and limited patches, exposed principally in river excavations and bluffs.
The exact horizon or horizons in the typical series which the Eocene beds represent,
has not yet been satisfactorily ascertained, the paucity of fossil remains, and their
divergence from the representative Eocene forms, preventing an absolute determination.
Tlie following list embraces most of the invertebrate forms, beyond indeterminable
casts, that have been referred to the formation : —

Gklaris Mitchelii.

Cidaris CarolinensU.
Sadella Lyelli.

Mortonia {PeHarchus) altus.
Microcrinvs conoides.
Echinocyamus parvus.
Gouinclypeiui suhangulatus.
Flabellum (1) cuneiforme.
Dendrophyllia hevis.
Caryophyllia subdichotoma.
Luuulites contitjaa.

Lunulites sexangulata.
Lxmxdites distuns.

Eschara iuhulata.

Terehratula Wilmingtonensis.
Terehratula demissirostra.
Pecten membranacea.

Pecten anisopleura.

Pecten Carolinensis.

Nucula magnifica.

Lucina pandata.

Cardita rotunda.

Vivipara Lyelli.

Oliva Alabamensis.

Natica mtites.

Infundibulum trochiforme.^:

The Miocene clearly belongs to a period ulterior to the deposition of the principal
Maryland and Virginia deposits, and represents approximately the South Carolina
series (“ Carolinian”). Owing to the superficial covering of Quaternary material it
has been thus far impossible to determine with the desired precision the contour lines
of the two formations, and hence on the accompanying map these (the inner
boundaries) as represented must be considered as being largely hypothetical.

* “Lower 19 Tertiary here probably above tide-level,” in Maefarlane, p. 184.

t Through the kindness of Dr. Guillou the writer has obtained specimens from an artesian boring conducted
at Newport News (.June, 1883), in which he has been able to recognize fragments of Pecten Samphreysu a. foim
characteristic of the lower Atlantic Miocene (“Marylandian”) of Maryland. The depth md.cated for the

fragments was 410 feet. • aer no

t The non-italicized names are given on the authority of Lyell, Q. J. Geol. Soo., i, pp.

132

THE TERTIARY GEOLOGrY OP THE

The following descriptions are borrowed from Kerr’s report on the geology of the
State * : —

j^ocKNK.— The distribution of the rocks of this subdivision is more limited than
that of the Cretaceous, and much more so than that of the Miocene, which overlies
it. 'I'he boundaries of it, north and south, are the Neuse and the Cape Fear; and
it is found on the Neuse to within 2 or 3 miles of the railroad crossing, near
Goldsboro’, and at one point, in an isolated outcrop on the river bluff 7 or 8 miles
further west; and it occurs in limited outcrops throughout the triangular region
between Newbern and Goldsboro’ and Wilmington. It consists of light-colored and
yellowish consolidated marlites (bluffs of the Neuse 10 miles below Goldsboro’, above
Newbern, Natural Wells near Magnolia), shell conglomerates (about Newbern, Trent
River), siliceous buhrstones, calcareous sandstone (near Goldsboro’, Wilmington, etc.),
gray and hard limestone, coarse conglomerates of worn shells, sharks’ teeth, and
fragments of bones and stony pebbles (upper part of MTlmington and at Rocky Point),
or fine shaly, light-colored infusorial clays, as seen in Sampson County. Outside of
the region bounded by the above points there are two or three patches of Eocene, one
capping a hill 350 feet above the sea, on the railroad 7 miles east of Raleigh, a siliceous
shell conglomerate of 2 or 3 acres in e.xtent and 6 to 10 inches thick; the second, a
ferruginous and calcareous sandstone of 4 or 5 feet thickness, on the top of a hill in
the southeastern corner of Moore; this last containing some shells and many
cchinoderms. These fragments, or outliers, show that this formation, limited as it
was in thickness, had a vastly greater horizontal extent than would have been
suspected, and they carrj' the shores of the Eocene seas quite into the hill country of
the State, and nearly 150 miles from the present coast line, and to an elevation of
nearly 400 feet.

sul.div.sion of the Tertiary extends over nearly the whole seaboard
region, from the sea-shore and the western margin of the sounds, 50 to 75 miles inland,
t .as a nmeh peater horizontal extent than the preceding, and a greater thickness,
...t IS less contmnous, being found in disconnected patches, often of quite limited area,

”"‘y ravines, ditclies, ivdU, etc. It

iTe " - 3 to 6 or 8 feet, and occasionally io or 20.

beiiiK much tliick"' •°'™r<l the northern border of the Stute, the bedt

fact iK-hiK of I rivers south of them, and in

crrcZ:: -r: r;r.: -- - -

EASTERN AND SOUTHERN UNITED STATES.

133

South Carolina.

The Tertiary deposits of this State occupy considerably more than one-half the
superficial area, the territory comprised by them having a pretty nearly uniform width
of 100-110 miles. The inner boundary line (as indeed is the case for almost the
whole Atlantic border) conforms generally with the coast contours, and crosses the
State in an almost direct northeast conrse from about opposite Augusta, in Georgia, via
C'olumbia, to the North Carolina frontier. Throughout its entire extent the formation
abuts upon granite or metaniorphic rocks, gneisses, schists, and slates, whose exposures
mark the first or lowest falls of the descending streams. The line of junction of the
rocks of this series, consisting of sands, clays, marlites, and compact siliceous shell
conglomerates, or “ buhrstones,” with those of the Archaean series, is indicated along the
entire distance by deposits of sandy strata, which mark the line of distribution of the
long-leaved pine {Pitius palustris), and support a vegetation essentially distinct from
that of the rest of the State.

Eocene. — Mr. Tuomey* recognizes three distinct divisions in this formation,
respectively in the order of their position, beginning with the oldest, the Buhrstone,
the “ Santee beds,” and the “Ashley and Cooper beds,” the last two principally of a
calcareous character, and corresponding to the “Carolina bed” of Ruffin. They form
the basement of the so-called “Charleston Basin.” The Buhrstone occupies the inner
area of the Tertiary formation, extending over a continuous tract between the
Savannali River and the Congaree, northwest of a sinuous line connecting Lower
(Upper) Three Runs and Vance’s Ferry on the Santee and passing on the inside of
Allendale, Barnwell and Orangeburg. The thickness of this formation, which at
many points along its southern edge and elsewhere can be seen to dip beneath or
underlie tlie Santee beds, has been stated by Tuomey to be upwards of 200 feet, or as
much as 400 feet. Its upper member is frequently a layer of greensand, which may
be the representative of the similar layer that further to the south, in Alabama and
Mississippi, marks the position of the true “ Claibornian.” However this may be, it
is practically certain that the Buhrstone of Tuomey and the greensand together
represent a very considerable, if not the greater portion of the deposits which in this
State underlie the horizon of the typical “ Jacksonian,” as the character of the con-
tained organic remains clearly indicates. Their approximate equivalency with the
Buhrstone and ‘ ‘ Claibornian ” may therefore be assumed. Whether the calcareous strata
occurring on the Santee below Vance’s Ferry, and bordering upon the southern edge
of the Buhrstone, be also referable to the “ Claibornian ” or not, or whether they
constitute the correspondent of the “Jacksonian,” we have as yet no satisfactory
means of determining. It is true that a general similarity exists between their fossil
remains and those of the older strata, yet there are a considerable number of forms

» Report of tlie Geology of South Carolina, 1848.

18 JOUR. A. N. S. PHILA., VOL. IX.

thk tertiaky geology of the

«r,. not contained in the older rocks, as Pceto memkraumm P .ahain,,
TlrvUnn.. C.,„. ,yr,.n„, several of the Ech.nodermata, etc, hnt wh.ch, or a
,her of n hich, on the contrary, are to be fonnd tn the s«pi>osed newer strata o he
Conner Hirer, presently to be noticed. Furthermore, ,f the remains of Zc^Mon
referred to by ■luomey as having been found in these deposits actually belonged there,
and there appears to be no reason for supposing that the observation rests on erroneous
data then we are forced to admit that the beds in question represent a horizon above
that'of the Clailiorne sands on the Alabama Eiver, and more nearly that of the over-
lying white limestones. The evidenee, then, is strong for concluding that the Santee
calcareous strata form part of the true Jackson series.* In separating the Ashley
and CoopiT series from the .Santee Mr. Titomcy appears to have been influenced
principally by paleontological considerations, rather than by considerations draw-n from
stratigrapiiical position, although he alludes to the superposition of the beds in question
over tho.se of the Santee.f Hut if, as is contended,^ many of the fossils of the Ashley
arc found on the Cooper, and elsewhere, but as a group they are very distinct from
those of every other bed in the State, might it not be assumed, in the absence of facts
jiroving direct stnitigraphic continuity, that the two members (the Ashley and the
Cooper) of the scries indicated are in themselves distinct 1 But yet they are grouped
as one by 'ruoiney, and not improbably so with reason. And if one, why separate the
scries from the Santee ? We fail to discover from Tuomey’s writings that any material
difference e.xists lictwecn the faunal facies of this last and the deposits exposed on
('oo]>er River ; on the contrary, a very considerable number of the forms are common
to both, and among these we have the forms that have already been referred to,
Pecten memhranftxns, P. calvatm^ P. perplanus, Conus gyratus, etc., besides the Zeu-
glodon, which ranges through the Santee, Cooper, and Ashley beds. There appears
to me to l)e no good reason for separating the above deposits from each other as indi-
cative of special horizons, although they may occupy different stratigrapiiical positions
in the geological .scale, and, therefore, I have retained them as one group, the cor-
respondent of the “ Jacksonian.”

Oi.iGOCENE. — hat the precise age of the beds on Tinker’s Creek and along the
Savannah opposite and below Shell Bluff, in Georgia, containing Ostrea Georgkma,
is — whether upper Eocene (“ Shell Bluff ” group of Conrad) or Oligocene — still
remains to be determined. It appears not unlikely that Hilgard’s supposition as to
their being of \ icksbnrg age,§ and their correspondence (as was maintained by Conrad)
with the oyster-bed underlying Vicksburg Bluff on the Mississippi lliver, whose
position is iK’twecn the Jackson and the Vicksburg, is a correct one, although the

* 0$trtn panda, one of the d sfnetive Santee fossils, is
St. Stephen’s Bluff, on the Tomhigbee R:ver, Ala.
f Op. eit., p. Ica.

I Am. Joum. Science, new series, vol. xlii, pp. 68-70.

found abundantly in tl:e basal portion (Jackson) of
t Op. eit., p. 163.

EASTERN AND SOUTHERN UNITED STATES.

135

evidence on this point is not yet absolutely confirmatory. Most of the fossils*
obtained by Lyell from the face of Shell Bluff are forms that have been identified as
exponents of the typical Eocene — “ Claibornian ” and Buhrstone — but we are not
clearly informed what relative position these held to the Georgiana layer, or the layer
containing the giant oyster. More direct information on the point in question is given
by E,uffin,t who asserts that the oyster-bed, with a development of 4-6 feet, occupies
the top marl layer of the bluff overlying what he unhesitatingly calls the “ Great
Carolinian bed,” and which, as we have already seen, is the correspondent in part or
in whole of the “Jacksonian.” If these observations are to be trusted in their entirety,
then there can be but very little room left for speculation on the subject — either
the oyster layer forms a part of the Jackson series, or belongs to a deposit of newer
age, doubtless the Vicksburg (or Oligocene).

Miocene. — The post-Eocene Tertiary deposits of South Carolina, considered by
Tuomcy and Holmes to be of Pliocene age, but here referred to the Miocene, occupy,
as seen by their outcrops, principally the northeast section of the State, and are most
largely developeii in Horry, Marion, Darlington, and Sumter districts. As in North
Carolina they appear mostly in isolated patches, filling depressions in the underlymg
Eocene or Cretaceous strata, either along exposed river sections, or on elevated spots
that have effectually resisted denudation. South of the Santee River the formation
lias been traced on the Cooper and some of its tributaries, extending within a few
miles of the city of Charleston, and an outlier is noted by Mr. Tuomey as existing on
the Edisto below Givham’s Ferry. Unfortunately the actual extent of the formation
under consideration is not sufficiently well known to permit of its accurate representa-
tion on the map, and, therefore, the boundaries there indicated must still be considered
in a measure hypothetical. It appears not unlikely that a connecting tract of Miocene
exists between the Georgia and South Carolina areas ; at any rate, the Edisto deposit
above referred to would seem to indicate such connection.

Georgia.

No accurate detail work on the Tertiary geology or paleontology of this State
has thus far been attempted ; at any rate, no results of such work, if made, have
as yet been published. Our knowledge of the subject is still, therefore, mainly
of a general or fragmentary character, and not sufficiently precise to permit of its use
in either definitely locating the boundaries or defining the approximate extents of the
various formations. It is, however, positive that we have here representatives of both
Eocene and Miocene, and not unlikely the former is represented in all or nearly all the

* Oliva Alabamensis, Pyrula sp., Tiirb nella (Voluta) prisca, Melongena alveata, Infundibuhim trochiforme,
Natica ffitites, Crepidula lirata, Dentalinin tballoides, Ostrea sellssformis, Niicula magnifica, Cardita rotimda, C.
planicosta, Cra>satella protexte, Lucina pandata, Cytherea perovata, C. Poulsoni, Lutraiia lapidosa. Lyell, Q.
J. Geol. Soc., 1, p. 437.

f Kept. Agriciilt. Surv. of South Carolina, 1843, pp. 33-3 and 34.

THE TP3RTIARY GEOLOGY OF IHE

I3r)

vaviou, division, -vhiol, collec.ivoly cl.amcterize the formation along tlm Atlantic and
, ; c .>v„ I i„„itic “Buhrstone,” “Ckibornian,” and “Jacksonian -

ullirtLe hav; ..ot ^t been clearly made out. The Buhrstone app^rs to

" p the greatest extent; at any rate, whether correctly or incorrectly it is hefoi^a-

Tn generally referred h. as the typical Georgia Eocene. 'Ihe Jackson doubtless enters
lie Le along the southern border, although I am not aware that it, existence there
has been deflnltelv determined through the character of its fossil remains. Mr. Ruffin s
detc-rmination (1) of the “Great Carolinian Bed” (= Jacksonian) in Slid Bluff,
on the Savannah River, has already been referred to in our description of South
Carolina and needs no further comment here Leaving aside the probable existence
in' tlie State of the Oligocene formation, as would seem to be indicated by the Georgiana
bed or bed containing tlie giant Ostrea Georgiana, overlying the marl deposits
(Ruffin’s “ Great Carolinian ”) of Shell Bluff, it is almost positive that the formation
in qiK'stion occupies some little, if not a considerable section of the lower Tertiary
area, continuous with the area occupied hy the same formation in Florida The later
Tertiary deposits occupying the Atlantic border, and having an extent landward of
about (iO miles, ore probably continuous with, and doubtless of the same age as the
later Tertiary deposits of South Carolina, and are accordingly referred to the Miocene.

'I'Ik’ 'I’ertiary deposits, which in their entirety occupy considerably more than one-
half the area of the State, doubtless rest upon a Cretaceous floor, and abut for the
greater part of their extent upon rocks of Archman age. Their inner boundary cor-
responds approximately with a moderately sinuous line running from near (a little
outside of) Augusti, on the Savannah, hy way of Macon, Fort Valley, Montezuma,
Americus and Cuthbert, to Fort Gaines, on the Alabama frontier.*

* Siiu-«" tlic i>rfi>arntion of tlic alwve the writer has received, through the kindness of the author, Dr.
l.oiighridge'R notes on tlie geology of tlie State (Keport on the Cotton Protluction of the Stale ot Georgia, pp.
14-1(1; extracted from tlie Teiitli Census Reports, 1884), which, unfortunately, are too brief to add very
ninterinlly to our knowleilge of tliis division of the geological history. The following section, taken from Mr.
t^ingleton. is given of Shell Uluff, Burke Co. : —

1. Resl loam hill tops, ....... 15-25 feet.

2. White sandy marl, coarse sand and oysters — Oitrea Oeorgiana, . 10 feet.

8. Coarse drift and shell fragnients, ..... 2 feet.

4. Shell licil — 0. Ueorgianii, . . . . , . 13 feet.

6. White sandy marl, ....... 00 feet.

6. Indurate marl, with casts of small shells, .... 2 feet.

7. AVhite sandy marl, ....... 6 feet.

8. Indurate marl, with casts of shells and few 0»trea sellaformis, . 3 feet.

9. llanl yellowish white marl, ...... 4 feet.

10. Oyster-lH'd— O. trUtrfonnin, ...... 1 foot.

11. llanl marl, ........ 5 feet.

12. OysU-r-lxHl— O. neUtpformis, , . . . . . 6 inches.

13. Hard yellowish-white marl, ...... 10 feet.

14. Fine yellowish sandy marl, ...... 6 feet.

15. Yellowish-white clay marl, ...... 2 feet.

10. Indurate marls, with shells, ...... 2 feet.

17. Whitish-gray clay marl (to water), ..... 15 feet.

The beds containing 0,lrm Gtorguma arc referred to the Vicksburg series ; Xo. 5 not improbably represents,
e t or n part or in whole, the “Jacksonian,” while the lower portion of the blulf is doubtless largely of the

EASTERN AND SOUTHERN UNITED STATES.

137

Florida.

The geological relations of the rocks of this State, as well as the history of .then-
exploration, are clearly set forth in a paper by Prof Eugene A. Smith, entitled : “ On
the Geology of Florida,” and published in the American Journal of Science, 3d series,
vol. 21. It is there conclusively shown that the -views entertained by Louis Agassiz
and Joseph Le Conte as to the recent and coralline formation of the peninsula are
essentially erroneous, and that, as a matter of fact, the greater portion of the peninsula
dates back to the Oligocene period, or to the period of the Orbitoitic limestone.
Substantial proof of this fact is afforded by the numerous localities where fossils —
very largely the genus Orhitoides itself, with the species 0. Mantelli, and others — dis-
tinctive of the Orbitoitic formation have been discovered, as in the stretch betw-een
Tampa Bay, where they were first identified by Conrad nearly forty years ago, and
the Georgia line. Beside the localities where fossils of this class were determined by
me to characterize the rock formation, to which reference is made by Dr. Smith,
other areas of a like nature have since been discovered, and most notably, perhaps,
the territory about Cedar Keys, where, from rock specimens submitted to me by Mr.
Joseph M'illcox, I was enabled to detect the existence of a true Nummulitic rock, or
a rock made up very largely of the united tests of principally one form of Nummulite.*
This rock, which is found in the immediate neighborhood of the Cheeshowiska River,
in Hernando County, about four miles from the coast, contains in addition to the mass
of Nummulites of which it is so largely made up, a sufficient abundance of Orhitoides,
and also the foraminiferal form which Conrad described as Cristellaria rotella, but

which I have referred to Opercidina.f From a locality further to the north, Waca-
sassa in I.cvy Co., rock specimens submitted to me were found to contain a number
of Echinoids of the genus Euspatangns,X referable specifically to the forms described
by Cotteau from the Oligocene deposits of the island of St. Bartholomew, as E. Clevei

and E. AntiUarum.%

From what has preceded, taken in connection with the observations that have been
made in western as well as in northern Florida, it may safely be conceded that the
underlying rock of the greater portion, if not of nearly the entire State, is of Oligocene
age, and therefore no countenance is given to the theory which assumes a recent for-

“ Claibomian ” ao'p The Miocene tract, whose rock masses are stated to closely resemble the Grand Gulf sand-
stone of the Gulf '’states, is claimed to have a much broader extension than we have above indicated, for if the
outcrops observed in Irvin and Dodge Coimties really belong to the period in question, which m.ay perhaps still
be considered as not yet satisfactorily established, then the imier boundarj' of the formation will be removed
from the coast by about 130 miles. [The Miocene area on the map is according to Loughndge.] The rocks
have a slight dip to the southeast, and on the Oconee, where they have been traced for a distance of 00 nnles,

their develoinneiit is stated to be 200 feet. . t^i .i i xr. a

* Nummuhtes milroxi. Heilprin, “On the Occurrence of Nummulitic Deposits m Florida, and the Asso-
ciation of Nummulites with a Fresh-water Faima,” Proc. A. N. S., July, 1883.
t Tlic .species is not impossibly identical with 0. cmnplanata.
t The generic determination kindly made for me by Prof. Alexander Agassiz.

§ K. Svens. Vet.-Akad. Ilandl., 1874.

138

the tertiary geology op the

.nation I low far south the Orbitoitic limestone extends has not yet been determined,

but there appear to be no reasons for assigning it to a limit far removed from the
border line of the Everglades. For aught we know to the contrary it may extend

quite or nearly to the peninsular extremity. , .

Ib.rrimr the post-Pliocene of the coast, the only indication that we as yet have of the
existence of any marine formation in the State newer than the Oligocene is the patch
of limestone referred to by Dr. Smith ’"^-as occurring at Rock Spring, Orange Co.,
from which Imve been obtained specimens identified by me as belonging to the Miocene
period— Madisoniiis, Venus alveata, Cardita gramdata, Carditamera arata,
and doubtfully, Mgtilo<-oncJia incurva, Cardium suUineatum and Oliva litterata. Other
Miocene areas will doubtless be discovered, and not impossibly a more or less con-
tinuous belt will be found to unite the Rock Spring patch with the Miocene area in
Georgia.

Alahama.

'ri.e 'I'ertiary formations of Alabama, which occupy a tract in the southern part
of the State with a general width varying from about 55 to 90 miles, seemingly
exhibit eipiivalents of all the various subdivisions that have been recognized on either
the .\tlantic or Gulf borders as intervening between the base of the system and the
\’icksburg IhxIs (Oligocene). The Eocene appears here clearly defined in its four
divisions, the Eo-Lignitic (Thanetian 1), Buhrstone (Londonian ?), Claibornian
(Parisian, or Calcaire Grossier), and Jacksonian (Bartonian), which follow each other
in a general succession (commencing with the lowest) from north to south. Covering
the Jacksonian, and occujiying a belt immediately to the south of it, are the Vicksburg
iK’ds, who.se most southern exposure on the Alabama River is at or near Gainestown,
some eighty miles north of the Gulf, where the strata pass under the beds that have
bi'en designated by Ililgard as the “Grand Gulf Group.” Whatever the exact age of
the deiHisits of this grouj) may be, they are the only ones of marine or fluvio-marine origin
that indicate along the Gulf border a Tertiary formation of newer date than the Vicks-
burg : whether they belong to the Miocene period, as has been suggested by Ililgard, or
to the Plioeene, can only be ascertained when a more thorough examination of their
fossil remains will have been attempted than has heretofore been practicable. For
their entire extent the Tertiary deposits abut against those of Cretaceous age, the two
having a very nearly equal development, and together occupying about one-half the
area of the State. In their eastern half the outcrop or strike of the strata is more
nearly due east and west, with a moderate dip to the south, while in the western half
the line of outcrop is W. by N.— E. by S., with a dip S. by W. of about 10 feet to the
mile.

A convenient starting point in the Tertiary stratigraphy of the State is afforded

Loc. cit., p. 303.

EASTERN AND SOUTHERN UNITED STATES.

139

by the famous bluff exposed on the Alabama Elver near Claiborne, which has yielded
the fossils known to geologists and paleontologists as those characteristic of the “Clai-
borne Group.” Probably the most trustworthy section of this hluff is that given by
Tuomey,* * * § as follows : —

9

Red sand, loam, and pebbles.

Feet.

30

f

Mottled clay.

8

e

Limestone, with grains of greensand.

54

d

Ferruginous sand ; numerous fossils.

c

Whitish limestone.

62

^ 1

Bed of clay 15 feet thick, with seam of limestone on top.

15

Note. Tuomey does not give the thickness of bed “d,” but it appears from the concurrent statements of
different observers to be about 17 feet. The total height of the bluff above the Alabama River would therefore
appear to be in the neighborhood of 190 feet.

The measurements and descriptions of Conrad, f Hale,f and LyeU,§ do not differ
very materially from the data given by Tuomey. The arenaceous bed “ d," about 80
feet above water-level, has yielded the vast majority of fossils for which the locality
is famous, and is that which has been identified as the equivalent of the “ Calcaire
Grossier” (Upper Eocene of France = Bruxellian of Belgium). Although formerly
considered to be near the base of the system, there are now very strong grounds for
concluding that these beds are underlaid by older Eocene strata, having a thickness
at least 300 feet, and, possibly considerably more. The age of the limestone bed “ e,”
although perhaps the character of its contained fossils does not permit of absolute deter-
mination, is doubtless at least in part Jacksonian, and will be found to correspond with
a portion of the bluff exposed at St. Stephen’s on the Tombigbee Kiver, about thirty
miles almost due west of Claiborne. At any rate, a portion of the white limestone west
of Claiborne lias been found to contain several of the characteristic fossils of the Jackson
group, and these associated with the remains of Zeuglodon; there is, tlierefore, no
doubt as to the age of at least this portion of the white limestone, nor can there be

* First “Biennial Report of the Geology of Alabama,” 1850, p. 152.

t “Fossil shells of the Tertiary Formations,” 1833, p. 32 ; Pioc. of the Nat. Institute, 1841, p. 174.

t “Geology of South Alabama.” Am. Jour, of Science, new ser., vi, p. 354.

§ Q. J. Geol. Soc., iv, p. 10, et. ieq.

140

THE TERTIARY GEOLOGY OP THE

any rcaKonablo doubt as to the continuity existing between these deposits, and the
similar ones exposed on Claiborne bluff.

Skjtion on Basiiia Creek, Clarke Co. — Probably the section representing the
oldest Eocene deposits of the State is that exposed on Bashia Creek, detailed by
Tuomey in his “First Biennial Report,” p. 145 :

1

Hard Limestone.

4 feet.

s

Marl, highl)' fossiliferous.

25 feet.

3

Blue sand.

Variable.

4

Lignite and elay.

6 feet.

5

Laminated clay, sand, and mud.

Thickness undetermined.

6

Lignite.

do. do.

Notk.— HwIs 5 and 6 do not properly belong to the section, but “ represent beds seen on another part of the
Htreain below the preceding” (Tuomey, ioe. eit., p. 146).

Beds corresponding to No. “ 2 ” of the above section are likewise exposed on Cave
and Knight’s branches, tributaries of Bashia Creek, and have been shown by Dr.
I'.ugene Smith to underlie the base of the “ Buhrstone ” proper by nearly (if not
more than) 200 feet.* The relations of these various beds will be best understood by
a reference to the sections exposed on the Tombigbee River.

Sections on toe Tomrigbee River.— At Wood’s Bluff, near the mouth of Bashia
Creek, we have the following e.xposure : —

No.

7

1

1 Orange sand, or stratified drift.

Peet.

10-20

6

5

_C^yi8h or greenish laminated clays, colored brown by iron.

10 '

Ledge of bluish or greenish sand, fossiliferous— capped by a
j letlge of hard nodules.

2

4

_2Mui8h laminated clay, with few fossils.

5

8

Indurated greenish sand, full of the same shells as marl bed

No. 2.

2

1

Greensand marl, quite soft, and full of shells.

3

Indurated greensand with shells, and a stratum of oyster-
shells at water’s edge— said to extend 10 feet further down 1

1

10-15

of its fos 1 reV^TTb c ‘Character

anj it r ,rr ^ -posed on Cava and Knight’s branches,

— unlikely that the series 1-5 correspond in the main with No. 2

* Ileilprin, Proc. Acad. Nat. Sciences, 1881, p. 369.

EASTERN AND SOUTHERN UNITED STATES.

141

of Tuomey’s Bashia section * The basal lignite would then probably ba found to
underlie the lowest stratum exhibited at the Bluff. Bed No. 6 (Wood’s Bluff section)
can be traced down the river for a distance of two or three miles, when it dips beneath
the water’s level. Somewhat below this point, and beyond the month of Witch Creek,
the stratigraphical relation of the different beds is beautifully exhibited in a prominent
cliff (“White Bluff”), rising from 250 to 275 feet above the river. The upper-
portion of this bluff is constituted by the characteristic siliceous clay-stones and
- silicified shell deposits of the southern “ Buhrstone ” formation, which make up fully
100 feet of the vertical height. Laminated lignitic clays (bearing numerous leaf
impressions), with occasional intercalated beds of pure lignite, enter mainly into the
composition of the intermediate portion, i. e., from the water’s level to the base of the
buhrstone above mentioned. Allowing a uniform southerly dip of 10 feet to the mile,
which appears to be consistent with obtained data, it is manifest that at this point the
lowest fossiliferous strata exposed at Wood’s Bluff (and consequently the equivalent
deposits on Bashia Creek and its tributaries, Cave and Knight’s branches) must lie
from 175 to 200 feet below the base of the siliceous mass constituting the true
buhrstone ; or in other words, we have here a series of deposits aggregating about 300
feet in thickness, which can be shown to be of an age anterior to the deposition of the
Claiborne fossiliferous sands. At Baker’s Bluff, a few miles above St. Stephen’s
(which is situated some twenty-eight miles south of Wood’s Bluff), the buhrstone,
according to Tuomey, appears in a vertical escarpment rising only 50 feet above the
water, a low height perfectly in accordance with the loss occasioned by the general
dip extending over nearly twenty miles. At this point, moreover, occupjing a position
above the buhrstone, Tuomey (o/j. cit., p. 148) identifies a bed of greensand, 8 feet in
thickness, as the equivalent of the Claiborne fossiliferous sands (“ d ” of his section),
and containing numerous fossils identical with tho^ e found at Claiborne. Still further
south, and occupying a considerably lower level, the same bed is described as having
a development of 12 feet, and immediately above St Stephen’s was seen to dip beneath
the water’s edge. At this last locality we have a beautiful exhibit of what has
generally been designated by the name of “ White Limestone. ”t

There can be not the least doubt, however, that this “ White Limestone,” which
has most frequently been taken to represent bodily the Vicksburg (Oligocene or “Or-
bitoitic ”), is in reality, as has been long ago insisted upon by Winchell,:}: a combination
of strata belonging to two distinct groups of deposits. The lower moiety, dipping
into the river, and resting upon the subjacent Claiborne sand (Tuomey, op at., p. 157 ;
Lyell, Q. Journ. Geol. Soc. Lond., iv, p. 15 ; Hale, A. J. Science, new ser., vi, p. 359),

* The relations of the Bashia and Wood’s Blnff sections, as well as those of Cave and Knight’s branches,
are fully set forth in my paper above referred to, Pros. A. N. S., 1880, pp. 364-70.

f I have been unable to discover the exact height of this bluff. Neither Lyell nor Tuomey mentions it ;
Conrad, in the appendix to Morton’s “Synopsis ” (p. 33), .states it is about 100 Let.

I Proc. Amer. Assoc., 1856, part h, p. 85.

19 JOUR. A. N. s. PHILA., VOL. IX.

142

the tertiary geology op the

is tl.e true » White Limestone,” an exponent of the Jacksonian group of deposits, as
is clearly indicated by the character of its contained fossils * Were it otherwise the
case it would be very difficult to explain the total disappearance over a distance of
only thirty mUes (and with but exceedingly moderate dip) of the equivalent beds
exposed on the Alabama River at Claiborne. The upper moiety, on the other hand,
is a portion of the well-known Orbitoide (Vicksburg or Oligocene) rock, and is that
which alone contains specimens of OrUtoides Mantelli (Winchell, loc. cit, p. 85).

From the data here presented, a section of the Tertiary strata traced along the
Tombigbee River from Wood’s Bluff to St. Stephen’s, may, with considerable approach
to truth, lie constructed as follows : —

Wood’s Bluff-

iU

/oo Jt.

C\t.y (so.ys)
I Llipilto

I Lam Clay
/OOjt.

^ See-tUn^ abauir^Sfn, — "Dip

Bt Stephens

Cla-iitom* SanJs.

Orbit

Baahia :

•Cy-M* Bluff

Tombigbee Biver >-

Baker’s Bluff

Glaib-

tf-yoo

Wood’s

T lie foregoing section shoirs almost conclusively that the Eocene deposits of Ala-
hania have a thickness of very nearly 400 feet ; and, indeed, Dr. Smith, State Geolo-

flo^J ,r"” "o that Tertiary beds occur

" mT Tn'T'’'’'’- >50-180 feet heloiv the

proZr rir a i ' «« “Claihornian” (or Claiborne

near llie ton of Ih ^ fossihferous greensands) holds a position decidedly

■‘CnleaireGroa,ier'”7l'rrManrof°Ftatrr' «'"*'ar to that occupied by the

— ) France, more properly Upper than Middle Eocene,

(upper “thn^utherTuS”^^^ «tescribed as cbaracteri.stic fossils of the newer Cretaceous

n.ted States, have been found abundantly near the base of the bluff.

EASTERN AND SOUTHERN UNITED STATES.

143

which last it has very generaUy been considered. What relation beds » h ” and “ c ”
of the Claiborne Bluff hold to the sub-Claibornian (“ Buhrstone ” in part) deposits of
the Tombighee River has not yet been absolutely determined ; but there can be no
legitimate doubt that they represent, in a modified form, the upper moiety of those
deposits. Although the marked difference in the lithological character of the strata
of the two localities as compared with each other (and, indeed, it must be confessed,
this is much greater than coidd have been reasonably inferred from the general con-
stancy of the deposits in this region) would seem to militate against such a view, there
is, nevertheless, sufficient evidence, both stratigraphical and paleontological, to support
this conclusion. In the first place, by determining the position of the buhrstone rock
near St. Stephen’s as immediately underlying the highly fossiliferoiis greensand lay^,
Tuomey has proved that the two series of deposits (the “Buhrstone” on the fombig-
bee, and bed “c” on the Alabama) hold relatively the same position to the true
Claibornian, lying immediately below it. In the second place, the argillaceous strata
at the base of Claiborne Bluff (bed “4” of Hale’s series) have been identified by
Hale, both on lithological and paleontological evidence (A. J. Science, new ser., vi, p.
356), as occurring at Coffeeville Landing on the Tombigbee River, about fourteen
miles north of St. Stephen’s, what might very readily have been expected from an
inspection of the general lay of the different formations.* No data are given relative
to the position of the “ Buhrstone ” at this last locahty, but hypotheticaUy considered
(as deduced from its position at White Bluff, and its general dip), its summit must
still occupy a position fully 100 feet above the level of the river; and this ffiickness
(100 feet) coincides very closely with the thickness (80-90 feet) of the deposits below
the true Claibornian (bed “ i”) as exposed in the bluff on the Alabama River. And
finally, that at least a very considerable portion of the inferior beds at this last-named
locality represent strata of a different lithological character in other portions of the
State-and consequently, that they are local deposits-is proved by the concurrent
statements of Hale {loc. cit, p. 356) and Winchell {loc. cii., p. 86), both of whom
assert that the calcareous deposit below the arenaceous bed (not the “ White Lime-
stone ”) is not known to occur at any other locality.

From the data here presented, it will be seen that the Alabama Eocene formation

comprises :

4. “ White Limestone ” (Jacksonian), best exhibited at Claiborne (upper portion of
bluff) and St. Stephen’s (lower moiety of bluff), not very abundant in fossils--
Pecten memhrartosus, P. Poulsmi, Ostrea panda, Spondylm dumosus, ScideUa^’

Lyelli, etc. — 50 — 1 feet.

* A line uniting Claiborne and Coffeeville Landing would run almost precisely parallel with the line
the junction of the Cretaceous and Tertiary deposits lying hence due north. The contour ^

would indicate a true dip west of the .southerly line, and that this is actirally the case ,s

(80-90 feet) between the actual heights at which the equivalent betls at St. Stephen s and hnnf strata

kis also agrees with Hilgard’s observations in Mississippi, where the dip of the Jackin and Vicksburg straU
was found to be about 10 to 12 feet per mile S. by W. (A. J. Science, new ser., xUu, p. Sb).

144

THE TERTIARY GEOLOGY OF THE

3. 'I'lie fossilifcrous arenaceous deposit (Claibornian), best shown at Claiborne-
subaqueous at St. Stephen’s— very rich in fossils, and of the age of the “ Calcaire
Cirossier” of France. — 17 feet.

2. “ Huhrstone ” (Sihceous Claiborne of Hilgard), comprising siliceoas clay-stones'
(buhr-stone proper) densely charged with fossils or their impressions, laminated
clays, sands and calcareous deposits — beds “5” and “c” of the Claiborne section,
the cliff at White Bluff, and the so-called “ Chalk Hills ” of the southern part
of the State. At Claiborne the representative beds consist of aluminous and
calcareous deposits, poor in fossils, but containing occasional layers of Ostrea
neVcpformis. — About 250 feet"?

1. The Wood’s Bluff and Bashia (with Cave and Knight’s Branches) deposits (Eo-
lignitic), consisting of alternating dark clays, greenish and buff sands, and
numerous .seams of lignite, partly very rich in fossils, and as far as is yet posi-
tively known, the oldest Tertiary deposits of the State. — 50 — 1 feet.*

'I’he exact development of the Vicksburg (Oligocene) and Grand Gulf (Miocene ?)
deposits, has not yet been determined.

It apiK-ars very probable, from the investigations of Prof L. C. Johnson, that the
limits of the Tertiary formation extend considerably farther to the north than have
generally been represented on the maps, the northward extension at Allenton being
ten miles, six at Camden, and seventeen at Butler Springs f

Mississippi.

'fhe Mississippi Tertiary formations, which cover by far the greater portion of the
State, exhibit csscmtially three different facies: variously colored lignitiferous clays
and sands— black, brown, blue, green, yellow, gray, and impure white; siliceous
samistones and clay.stones containing marine fossils; and limestones and calcareous
marls, also with marine fossils. Lignitic clays occur intercalated throughout almost
t u on 1 1 rt .series of deposits, and conversely, small estuarine deposits of marine shells
a-casmnally appear in the true lignitic strata.J All the subdivisions recognized in
Alabama are also to be met with here, and as in that State, they follow each other in
.u<Tc,s.on from north to south. The dip appears to he nearly conformable to
l Cretaceons deposits, being tvostward-

fnvcmeet'f northern part of the State, and southward— 10-12

^ite) feet per m.le S. by W._i„ the southern part.§

iU cnm.Hj,oiiik.nt, Uopb not apttear to vl.’ f entnobly falls into this group, but its exact position, or
anci IB consItleitMl by Win. holl to renrestwit f i ^ determined. It is seen to underlie the “Buhrstone,”

IMair. Wileox Co., it is BtaU.l to regime ^tate. At Black’s

we iiifonnod that, aecoitiinir to Tiiom.ax/*n ""^’Jacent Cretaceous limet-tone, but in a foot-note (p. 90),
T«rti.r7. ^'haracterisfe fossil of this limestone, an is probably

oi ociencc, new ser., xbii, p. 36, 1867.

EASTERN AND SOUTHERN UNITED STATES.

145

The following generalized section, slightly emended from Hilgard, is given upon
the data furnished by that authority; the approximate thicknesses may be taken as
minima, being often greatly exceeded.

1. Grand Gulf Group, or southern Lignite (Miocene 1)— variously colored sandstones,

with small lignite beds, tree-palms, exogenous trees, Arundinacece.— 150 feet.

2. Vicksburg beds (Oligocene — “ Orbitoitic ”).

a. CrystaUine limestones and blue marls, with Ostrea Vkksburgmsw, 0. gigan-

tea, Pecten Poulsoni, Gardmm diversum, Area Mimssippiensis, Navimla
Missmippiensis, N. lima, Grassaiella Missisdppiensis, Panopea oblongata,
Fulgoraria Mississip^jiensis, Gtypreea lintea, Dentalium Mississippiemis,
Madrepora Mississippiensis, Orhitoides ManteUi. — 80 feet.

b. Ferruginous rock of Red Bluff (“ Red Bluff Group ” of Hilgard, typically

exposed in the bluffs of Chickasawhay River, near Red Bluff Station,
Wayne Co. — the correspondent of the “ Shell Bluff Group of Conrad 1),
with Plagiostoma {Spondylus) dumosa, Gardita planicosta, G. rotunda,
Rostellana velata, Fulgoraria Mississippiensis, Mitra Mississippiensis,
Gassidaria lintea, Gonus sauridens, Busycon spiniger, Natica Vicksburgensis,
Trochita trochiformis, Dtntalium thalloides, Osteodes, Madrepora, Flabellim
Wailesii. — 12 feet.

c. Lignitic clay and lignite, as shown at the base of Vicksburg bluff. 20 feet.

3. Jackson beds (» Jacksonian ”= Bartonian). White (often indurate) and blue

marls, underlaid by lignitic clay and lignite, with Zeuglodon macrospondylus,
Gardita planicosta, Gardium Nicolleti, Leda multilineata, Gorbula bicarinata,
Rostellaria velata, Oastridium vetustum, Morio Petersoni, Valuta dumosa, Mitra
Millingtoni, M. dumosa, Gonus tortilis, Gyprma fenestralis, Trochita alta.
Umbrella planulata, Flabellum Wailesii, Osteodes irroratus.—SO feet.

4. Calcareous Claiborne (“ Claibornian ” — age of the “Calcaire Grossier”)- White

(sometimes indurate) and blue marls, with the well-known Claiborne fossils.
— 1 feet.

5. Siliceous Claiborne (“ Buhrstone”— Suessonian in part) .^Sandstones and claystones

with Claiborne fossils. — I feet.

6. Lignitic or Northern Lignite (“ Eo-Lignitic ”)— Basal lignites, with mterstratified

clays and sands, containing marine fossils, and (Tippah) plant remains—

Garya, Populus, MorusF, Ficus, Laurus, Persea, Gornus, Olea, Rhamnus,
Terminalia, Magnolia, Dryandroides ?, Rhus. — 425 — % feet.

14G

THE TERTIARY GEOLOGY OF THE

Considerable uncertainty still exists relative to the age and position of the deposits
eonstitnting the Northern Lignite. Their local variability, uniformly moderate dip
(or even horizontalitv), and dearth of fossil (animal) remains, combined with the cir-
cumstance that at only a few localities is a superposition of strata distinctly observable,
render a positive determination difficult, if not impossible. That the region of the
“ Flatwoods ” bordering the Cretaceous formation on the west, and extending to the
nortliern boundary of the State, is of the same age as the formation occurring in
Liuderdale and Neshoba Counties, which can be distinctly traced beneath the
Siliceous Claiborne or “ Buhrstone,” there can be but little or no doubt, and, there-
fore, as far as the age of this section is concerned, nothing further need be said. But
whether all the lignitic territory lying north of the marine Tertiary bomidary, and
occupying nearly the whole northern half of the State, belongs to the same geological
period (Eo-lagnitic), as Hilgard appears disposed to believe,* may well be considered
doubtful. On the contrary, it appears far more reasonable to suppose, seeing the
position occupied by the outlier of the Siliceous Claiborne in Carroll, Holmes, Attala
and Choctaw Counties (Shongalo, Valden, etc.), that the lignitiferous deposits, or at
least a portion of them, of these counties, as well as of Amazon, Madison and Leake,
and possibly also of A’allabusha, belong to a much newer period, not improbably the
Jacksonian. Hilgard clearly affirms that the marine outlier here referred to is as well
over as underlaid by lignito-gypscous strata ;t again in a boring made in the Jackson
penitentiary well, and i)enetrating, as stated, to a depth of 470 feet, what would
a])pear to lx; a continuation of the Shongalo (Siliceous Claiborne) deposits was struck
at 450 feet, or 418 feet below the strata recognized to be of Jackson age. Granting
the correct determination of the Shongalo deposit, it is evident that the 418 feet of
lignitic clays passed through before the 20 foot shell-bed was reached, and regarding
which “ there can be little doid)t that it, also, is of the Claiborne age,” must represent
something much newer than the basal lignites, and not improbably, as has already
been suggested, the Jacksonian (at least in principal part).J Such a reference woidd
be much more nearly in accord with the disposition of the Jackson beds in the
adjoining State of Louisiana, where, according to Hopkins, the strata are also veiy
lar^dy lignitic, and where they occupy the greater part of the area included between the
ic 'sbuig line and the Arkansas boundary.§ They doubtless extend for a con-
sidenible distance into Arkansas, largely entering into the formation of the Mississippi

* P. 109 ; Am. J. of Science, new ser., vol. xlili, p. 35.

the Silireo!!!! aaih„n.ri7 hTs gl^fogiclT considering it an exponent of

and Alabama” (Am. .1 of Sci^^ r -*!^ State, m a later article, “On the Tertiary Formations of
p. 34, and, again, on the follow iim ,.n.r« deposit in qmstion is referred to the Lower Lignite on

and Attala. ” '’"S'* " “«***«» of “the marine outlier of the Claiborne age, in Carroll

I A..™., .r .U. G.o,„e„., s„„,, „r Lo„, p. 8, „,o.

EASTERN AND SOUTHERN UNITED STATES.

147

embayment, and meet tbeir continuation on the other side of the river in the State of
Mississippi.

Siliceous and Calcareous Claiborne. — There can he no question that the deposits
we have recognized in Alabama and elsewhere as the “ Buhrstone ” and the “ Clai-
bornian ” have their exact counterparts in Mississippi, and that these correspond in a
general way with what Hilgard has designated the “ Siliceous Claiborne ” and the
“ Calcareous Claiborne ” respectively. The former extends in a belt, some twenty
miles wide, westward from the Alabama line nearly half across the State, reappearing
as outliers in Carroll and Attala counties in the deposits of (near) Valden and Shongalo,
to which reference has already been made in the discussion of the Northern Lignite.
Among its commoner fossils are Cardita plan'costa, G. rotunda, Gardium Nicolleti,
Ostrea divaricata, Pecten Lyelli, and Voluta petrosa. From the locality of Enterprise,
on the Chickasawhay River, Clarke County, situated on the line of contact of the
“ Siliceous ” and “ Calcareous Claibornes,” as indicated by Hilgard, Mr. Conrad in
1865 described the following species of mollusca, claimed to be all new, “ and
distinct from those of any other locality from which fossils have been sent to the
Academy ; ” * Ostrea faldformis, Ehurneopecten scmtillatns, Arcoperna filosa, Nacula
spJieniopsis, Leda linifera, Axincea {Pectuncrdus) inequistria, A. dupUstria, Gonldia
pygmoea, Grassatella producta, Protocardia lima, Gyclas curta, Sphcerella hidla, Alvei-
nus minuta, Gytherea securiformis, G. annexa, Tellina eburneopsis, T albaria, TelUnella
linifera, Gorhula filosa, Doliopsis quinquecosta, Turritella perdita, and Mesalia?
arenicola.^

The true “ Claibornian,” consisting of blue marl and white marlstone, is but very
feebly developed in the State, occupying a narrow strip, some thirty to forty miles in
length, mainly in Clarke County, wedged in between the Buhrstone and Jackson. The
fossils, in distinction to those of the corresponding Alabama deposit, are very imper-
fectly preserved, and in most cases specifically unrecognizable. The leading forms
are: Ostrea sellceformis, 0. divaricata, Pecten Lyelli, Gorhula gihhosa, (C. onisus,
Conr. ; G. rugosa, Lam.) and Voluta petrosa.

Jackson and Vicksburg. — The deposits of the Jackson and Vicksburg (Oligo-
cene) periods occupy parallel bands passing across the State, disappearing in the west
under the Mississippi alluvium. The most distinctive fossil of the former is the
Zexiglodon, and of the latter Orhitoides, represented by two (0. MantelU, 0. nupera),
or more species. Although by several observers, including Conrad, the fossils here
indicated have been at various times referred to as occurring together in the same
deposit, there can be but little question, as has been insisted upon by Hilgard, that

* Am. Joum. of Conchology, i, pp. 137-41.

f Most of these are doubtless distinct, but it would be difidcidt, if not impossible, to distinguish between
Ostrea falcifornm and 0. dkaricata, Nucula sphceniopsis and N. omla, and Cytherea annexa and C. pcrovata,
common Claiborne fossils.

148

THE TERTIARY GEOLOGY OP THE

eitlier sucli reference lias been based upon error, or that tlie interassociation, where it
actually exists, dates to a period subsequent to that of the original deposition of the
strata. At any rate, the painstaking investigations of the geologist last mentioned,
have failed to reveal a single instance where an “ Orbitoid has been found associated
with either the Zeuglodon, or any of the characteristic fossils of the Jackson group.”*
From the neighborhood of Jackson, on the Pearl River, Conrad, in 1855, described
the series of fossils which led him to institute a distinct division of the Eocene under
the name of the “Jackson,” and which he correctly located between the Claiborne
and Vicksburg beds. Of the forty species described from this locahty f thirty-four
were considered to be peculiar, and only five — Rostellaria velata, R. staminea, Scalaria
misfiula, Pscudoliva vehisia, and Endapachys expansum — common to the Claiborne
series. None of the Vicksburg fossils were considered to be represented. From the
nature of his collection, which was a selected one, Conrad was led to infer that a far
greater dissimilarity existed between the Jackson and Claiborne series on the one side,
and the Jackson and Vicksburg on the other, than the actual facts warranted. In
addition to the Claiborne fossils already mentioned as occurring in the Jackson beds.
Prof. W. 1). Moore J mentions Cardita planicoata and Gardita rotunda; and as
common to the ^’icksburg series Cardita rotunda, NavicuJa {Area) lima, Cytherea
sofjrina, C. imiiahiHs, Mactra fanerata, Psammohia lintea, Turhinella Wilsoni, Cypraa
Hntea, C. spJarroides, Nafica Viekshnrgensis, and Dentaliuni Mississippiense. §

That a much closer connection exists between the deposits of the Jackson and
^hcksburg scries than was supimsed by Conrad is proved by the character of the
fossils occurring at or near Red Bluff Station, on the Chickasawhay River, in deposits
lying intermediate' between the Jackson and the typical Vicksburg, and considered by
llilgard to repre-st'nt a subordinate group (Red Bluff Group) of the Vicksburg series.
Of twenty siH'cifically identified forms, || Prof. Moore enumerates ^ four,—
2>hiuicosta, Clacelithes hamerosas ?, Rostellaria velata and Flahellum Tfe/tfesfi— as
iH-mg common to the Jackson beds, and twelve to the Vicksburg- CarchVa rotunda.
Card, urn dnu^rsurn, Falgoraria Mississippiensis, Turhinella protraeta, T. perexilis,
JU,a>mum M,ssm,pjriensis, Cassidaria lintea, Mitr a Mississippiensis, Busycm spiniqer.
Conus saundens y, Natica sigaretina and N. V ichsburgensis

* A. .T. Science, new ser,, xliii, p. 30.

fomjveo-imj,era^tly described and Hlentiflcation from scanty materials, especially in the case of

Oardimn ditersum, Rostellaria velata, Fnlgoraria Missis-
(^uUirui linUa, Mitra Missisi,^itusU Conus sau^rn spiaiger, Buccinum Mississim'ense,

and M. sigaretina,

EASTERN AND SOUTHERN UNITED STATES.

149

The following section of the bluff at Vicksburg, on the Mississippi, whence
Conrad obtained the fossils characteristic of the Vicksburg group, described in the
Proceedings of the Academy of Natural Sciences of Philadelphia, for October, 1847
(and Journal of the same institution, vol. i), is given by Hilgard :

g. Calcareous silt with snails — Bluff formation. — 10-20 feet.

f. Bluish and yellowish hardpan, often pebbles — Orange sand. .5-20 feet.

e. Alternating strata, 1 to 6 feet thick, of limestone and marl, containing the Vicks-
hurg fossils, and some bands of non-effervescent gray sand and clay.— 60-65 feet.
d. Black lignitic clay and gray sand, with Ostrea gigantea, Corbula alta, Natica
Mississippiensis, Oytherea sohrina, Madrepora Mississippiensis.—b feet.
c. Gray or black lignitic clays or sands, with iron pyrites ; exuding salts and sulphu-
retted hydrogen. — 25 feet. ,

h. Solid, lustrous lignite, with whitish cleavage planes.— 3 feet.

a. White limestone of the Jackson group 1 — 3 feet.

The white limestone a of the above section, which “ is visible only at extraordinary
low stages of water,” appears to be of Jacksonian age, although conclusive paleonto-
logical evidence on this point is stiU wanting. Stratum d, containing Ostrea gigantea

Q Qeorgiana), is that which has been identified by Conrad as corresponding to
the Georgiana bed of Shell Bluff, on the Savannah River (“ Shell Bluff Group ”),* and
which is erroneously stated to underlie the J ackson beds. The fossils associated with
the large oyster in the Vicksburg Georgiana hed—CorUda alta, Meretrix sohrina,
Natica Mississippiensis, Natica Vickshurgensis, Fidgur nodulatum, Madrepora, etc., show
affinities alike with both the Jackson and Vicksburg faunas, and in this respect, as
well as in stratigraphical position, would seem to point to a deposit, as has been urged
by Hilgard, the correspondent of the “ Red Bluff” series (as restricted to the Red
Bluff group) on the Chickasawhay. At both localities the position is immediately
below the Orbitoides rock, but at Red Bluff Station, the large oyster is wanting.

The relations of the Jackson and Vicksburg series of deposits to the geological
scale have been discussed in the introductory portion of this paper.

Grand Gulf Group (Miocene 1).— The newest Tertiary formations of Mississippi
are constituted by the deposits of the “Grand Gulf Group” of Hilgard, which
immediately succeed the Vicksburg beds to the south, and constitute the highest
ridges in the southern portion of the State. “ At their lines of contact, the Vicksburg

* A. J. Science, new ser., xli, p. 96.

20 JOUB. A. N. S. PHILA., VOL. IX.

150

the tertiary geology of the

and Gmnd G«lf rocks consist olmost throughout of hgnr. o-gyp^ous lam, nated clays,
Ising upwards into more sandy materials ; they are not sensibly unconformable
lee but while the Vicksburg rocks show at all long expos, .res a distinct southward
L of some three to five degrees, the position of the Grand Gulf strata can ramly he
shown to be otherwise than nearly or quite horizontal on the average; although in
many cases faults or subsidences have caused them to dip, sometimes quite steeply, in

almost any direction.”* ,

Towards the sea-coast, the lithological transition into the post-Pliocene is about
equally well marked as the transition into the older deposits in the north. The most
remarkable circumstance connected with the Grand Gulf deposits is the almost total
absence of zoogene fossUs, whether land, marine or fresh-water. Up to 1881 it
appears that only one solitary fragment of such fossil, determined to belong to
a turtle, had been discovered ;t and even the plant remains are in most cases
unrecognizable, although the general regularity of the strata, as well as their litho-
logical character, would seem to indicate that they were laid down under most stable
conditions, or such as would be most conducive toward animal or plant preservation.
Whether the temporary seclusion or cutting off of the Gulf from the Atlantic, as has
been premised by Ililgard, was a, or the primary cause in bringing about this
anomalous condition, still remains to be proved, and it further remains to be proved
that any such seclusion actually took place.

Lonifiiana.

The general features of the Tertiary formations of this State are very much like
those of Mississippi, and call for no special consideration. Only three divisions of the
scries, the Jackson, Vicksburg, and Grand Gulf, are officially recognized,! but it is
not improbable that the Claiborne enters the northwest corner.

The expo.sures of the Vicksburg beds occupy a belt 10-15 mUes or more § in
width extending in a west— southwest direction from the Washita to the Siibine River.
The distinctive fossUs of the group are sufficiently abundant, and we find, as in Missis-
sippi, a frequent association of Orhitoides MantelU, Osfrea Vlckburgtnms, and Pteten
I ouhom. Isorth of the ^ icksburg line to the Arkansas boundary the strata are largely
of a lignitic character, anu indicate distinct alternations of marine and brack ish-water
conditions. They are coUectively grouped under the Jackson period (“ Mansfield
Group, in part, of Ililgard), a position seemingly indicated by the character of the
fossd remains. The remains of Zeuglodo,, have been found at Montgomerv, in Grant
parish, and at Grandview, on the Washita, a few mdes below Columbia. Of about 150
apavioa of inveitebnikifo^aa collected fiom these deposits, it i, claimed that at leas, nine

T A. J. Science, new ser., vol. ixii, p. 59.

§ to mUet’S

} augaro, A. J. Science, new. ser., vol. xlviii, p. 839, 1869.

EASTERN AND SOUTHERN UNITED STATES.

151

occur, that in Mississippi are found in the Vicksburg beds alone, viz. : Madrepora Missis-
sippienm, Orbitoides Mantelli, Avicula argentea;Terehra tantida, T. divimra, Pleurotoma
porctllana, Pyrula (2 species, undetermined), Phorus Immilis, and Rmgicula Alissis-
sippiensis. To this is also added Ostrea Georgkma. The occurrence here claimed,
of Orbitoides Mantelli and Ostrea Georgiana, two forms whose horizons in Mississippi
appear to be so trenchantly severed from the Jackson, would seem to throw some
doubt upon the accuracy of the boundaries of the various formations as laid down.

South of the Vicksburg line the deposits of the Grand Gulf group, destitute of
fossil remains just as in Mississippi, extend across the State ; they are succeeded to
the south by the deposits of what Hilgard has termed the “ Port Hudson Group ”
(Post-Pliocene ; “ Coast Pliocene ” of Mississippi).

ArJcansas.

About one-half of this State is occupied by the Tertiary formation, concerning
whose development we are unfortunately provided with but very few reliable data.
The various divisions have not yet been paleontologically defined, but probably the
series includes the pre-Claibornian, the Claiborne, and the Jackson. The presence of
the last is inferred from its position in the State of Louisiana, where, as it has been
seen, it extends to the Arkansas boundary. Lignitic deposits occur largely throughout
the Tertiary area, and while some of these doubtless represent the basal beds of the
Eocene, as has been premised by Owen,* * * §, others (of the S. E. section of the State) not
improbably form the continuation of the Jackson lignites of Louisiana. Claiborne
{ossAs—Cardita planicosta, Cytherea (probably C. NuttaiK), Corbula oniscm, PsetidoUva
vetusia, Turritella (probably T. carinata), and Voluta (F. Sayana?)—ha.ve been
obtained, among other localities, at “ White Bluffs ” on the Arkansas Biver (about
latitude 34° 27'), and much the same assortment from the neighborhood of Madison,
St. Francis Co., on Crow creek.f

Texas.

The Tertiary formations of this State are as yet too imperfectly known to admit
either of an absolute localization of the various boundary lines, or of an accurate
subdivision into the minor geological groups. It may be safely assumed, however,
from the geological conformation of the neighboring States, that all, or nearly all of the
divisions ranging from the Eo-Lignitic to the Grand Gulf inclusive, are represented,
and that the position occupied by these follow each other in regular succession,
beginning with the oldest, from the interior coastward, with a general dip to the
southeast or east. The geological notes on this region by Schott, Hall, and Conrad,^
and of Shumard§ and Buckley H are exceedingly meagre and unsatisfactory, and give
us barely more than a general idea as to Avhere the Tertiary formation exists.

* “Second Kept. Geol. ReconTofthe Middle and Southern Counties of Arkansas,” 1860.

t Owen, op. cit., pp. 35, 152, and 417 ; Plate IX.

\ Emory’s Report, Mexican Boundary Survey, i, 1857.

§ First Report of Progress, Geol. and Agr. Survey of Texas, 1859.

II First Annual Report, 1874 ; Second Annual Report, 1876.

152

the tertiary geology of the

According to

c -i^c «hnvp Texarkana, on the Arkansas frontier, and taking a generally
:: :c*n:dL.ion_passing „t or near aarksvn.e (^d Krver Co., Cordcana
(Navarro Co.), Marlin (Falla Co.), Cameron (Milam Co.), Elgin (Bastrop CoO, Scguin
Guadeloupe Co.), and the northwest eorner of Ataseosa-erosaea the Rio Grande at
almiit the mouth of Las Moras Creek, a little south of the Pecos Rtver, and to the

north of Eagle Pass.* c a . •

TJ.e westerly deflection indicated as beginning a few miles south of San Antonio,

and e.xtending to the Kio Grande, can scarcely be said to be definitely proved as yet,
although Loughridge affirms t that “the glauconitic sandstones, mentioned by Mr.
Schott as occurring along the river [Rio Grande] from the Cretaceous rocks at the
mouth of Las Moras Creek, north of Eagle Pass, southward to Roma, near Rio Grande
City, are doubtless of Tertiary age.” Further evidence is needed on this point, however,
although some confirmation of the supposition is lent by the discovery of fertiarj'
fossils {Cartiifa y>?rt«icos<a, among others), in a locality, Arroya las Minas, situated
between El Paso and Leon (where 1) +

Among the common Tertiary fossils occurring in Texas Ruckley identifies § Ostrea
BeUo'formis, Peden LyelH, Astarte Conradi {= young of Crassatella alto), Cardita
jdanit-osta, and TiirriteUa curinafa; and there can be but little doubt, as claimed by
Huckley, that the Eocene of Bastrop, Robertson, and Leon counties, and thence along
tlie eastern border of the Cretaceous, northward to Red River County, belongs, if not
mostly, at least in considerable part “ to the lower Eocene, as seen at Claiborne,
Alalmma, and in Clark County, west of Claiborne.” How much of it belongs to the
true “ ( laibornian,” .still remains to be determined. luoughridge states that “the
Claiborne group of white lime.stones and fossils has not been recognized in Te.xas;”
the word “ Claiborne ” probably here stands for either “ Jackson ” or “ Vicksburg,”
although there can be little, if any, question as to the existence of both of these
formations, if nowhere else, at any rate along the Louisiana boundary.||

t PP. 18,21, 1882, fo.mingpa.tofyol.yoftl.e Tenth Census Repo.te.

I The series of ,1 y Report. § First Annual Report, p. 64.

Iv) from WUiculock RoliertsT^^e ^ Gabh in the Journal of the Academy of Natural Sciences (new ser., vol.
fm'm any hitherto found in tl ^ ’ f Caldwell County, although comprising many forms (piite distinct

The author has been able to idenli/ f ®t‘c\v forms recalling a newer horizon.

County, almut 50 miles southeast of artesian well-boring in Palestine, Andersen

540-610 feet (or 50-120 feet below fVi ™ °'^***^P of the Eocene, and from a depth beneath the surface of

TurM carinata ^ to Cardita planiccs, a. Valuta Sayana, and

TurrittUa earinafa and other Clailinrn f *1“* iorin known as G. dennata, associated with

Laredo, on the Rio Grande, and he haK*'T' detected by the author in limc-stone blocks from

■VamaeU and Tere^ra pliHftra from AtaJlotl'^pr , ’ f fonns, Pleuroloma platyaoma, Fwm* (Streptidura)

ftcqueutly refcrrvd to by geologists is in reality an alin'd improbable that the Cardita planicosta

Hr Lou-hridge, who, more than any other geologist, has closely
of the different formations occurring throughout the State,

EASTERN AND SOUTHERN »UNITED STATES.

153

Immediately to the south of the Eocene, according to Loughridge, a belt of sand-
stone, extending completely across the State, and probably referable to the Grand
Gulf Grorrp (Miocene 1), makes its appearance. Beginning at the lower part of
Sabine County, it outcrop.s on the Trinity River near Trinity Station, in the county of
the same name, where it forms a bluff some 100 feet in thickness, near Chapel HiU
and Burton in Washington County, at La Grange in Fayette, where it also forms a
bluff 100 feet in height, and at various points in De Witt, Live Oak (passing near
Oakville) and Duval counties, reaching the Rio Grande at Rio Grande City.
Buckley also mentions the existence of “ hard siliceous limestones and sandstones,”
referable to the newer Tertiary series, in Washington and Fayette counties, which
evidently form part of the series described by Loughridge. They are stated to be
practically devoid of fossils, only a few specimens of a bivalve {Meretrix) having been
found near the centre of Washington County.* The formation here referred to is
covered all along the coast hne by the deposits of the Port Hudson Group (post-
Pliocene) .

Tennessee.

The Tertiary formations of Tennessee, occupying a tract some 60-75 miles in
width in the western part of the State, consist of variously colored sands and clays,
and lignitic deposits, from which traces of zoogene fossils are for the most part absent.
Plant remains, on the other hand, are sufficiently abundant, clearly indicating the
conditions under which the deposits in question were laid down.

The following subdivisions are recognized by Safford,t although the upper and
lower groups are but provisionally indicated :

3. Bluff Lignite.

2. Orange Sand, or La Grange Group.

1. Porter’s Creek Group (oldest).

The Porter’s Creek Group, with a stated development of 200 or 300 feet, is
doubtless, as is suggested by Safford, the northern extension of the “ Flatwoods ” of
Mississippi, constituting the base of Hilgard’s “Northern Lignite.” Casts of shells
occur in some of the sandy rocks, but their bad state of preservation precludes the
possibility of their determination. The belt of surface occupied by this group is along
the line of the Memphis and Charleston Railroad about eight miles wide, narrowing
towards the north. The outcrop of the Orange Sand, whose thickness is assumed to
be about 600 feet, covers a tract some 40 miles in width, the beds dipping at a slight
angle to the west.J Vegetable remains belonging to fourteen § or more species of

» Buckley, First Annual Report, p. 63. f “Geology of Tennessee,” 1869, p. 423, et seq. t Salford, op. ciL, p. 425.

§ Quereus erassinenis. Q. Saffordi, Q. myrtifoUaf, Q. Lydli, Pmnus Caroli, liana, Fagus ferrugmea,
FAaagnm inaqualis, Andromeda mennifolia (form related to), A. dubia, Sapotacites Amerkanus, Saltx r deniOr-
nereis, Salix Worthenii, Cemothus Meigsii, Jaglana Saffordiana.

21 JOUR. A. N. S. PHILA., VOL. IX.

154

the tertiary geology, etc.

I)laut8 have been described from the deposits of this group by Lesquereux, by whom
tliev were considered to indicate a horizon more nearly Miocene than Eocene, but
tl.ere can be but little doubt from the position of the beds containing them that they
belong to tlie same period to which the greater part of the northern Mississippi lignite
itself belongs— tlie lower Eocene. The Bluff Lignite, underlying the Quarternary
gravels of the Mississippi Bluffs, consist in large part of a series of interstratified
sands and clays, “ characterized by the presence of well-marked beds of lignite.” Its
development appears to be at least 100 feet.

Illinois.

'I'he Tertiary deposits of Arkansas and Tennessee are continued through the south-
east and southwest extremities respectively of the States of Missouri and Kentucky
into Illinois, where they form the head of the Missi.ssippi embayment. The series,
represented by variously colored sands and clays, and ferruginous conglomerates, has
thus far been identified only in the southern part of the State (with a principal
development in Pula.ski County), but not improbably, as has been suggested by
M'orthen, marine or Huvio-marine deposits of the same ago may occur considerably
higher up the Mississippi valley. * A green marly sand, resembling in its lithological
characters the Cretaceous greensand of New Jersey, constitutes a marked feature of
the formation in Pulaski County, and from it have been obtained casts of fossils
IH-rtaining to the genera Cncullwa and Tarritella.'\

\ thin iM'd of lignite is stated to underlie the formation along the edge of the
Ohio at Caledonia, constituting in that vicinity the lowest visible member of the
s<'ries.

XoTK Sim-0 llio .].n-i.iiratiou of the forogomg article, I am informed by Piof. Sues.s, of Vienna, that the
lower liinoxtoiio UsU of the ihland of Jlalta, which were originally referred by Fuchs to tlie ‘-Aquitanian ”
( < >ligo<-ene), and as tlie partial e<iuivalents of the Sotzka beds of the Vienna basin, belong in reality to the “First
MiHllUTranean.” If this K- the case, then the OrUtoides Mantelli beds of the island represent a newer horizon
lower >Ii(K-ene-thaii they do in our own country and the West Indies. In material recently received from
t londa I Ibid gn-at quantities of Ortdtoidet epUpinam associated with the other forms.

h.-U the “Virginias,” for February, 1883, and October, 1883, will bo found detailed accounts, by Prof. W.
.1. lontane and the laU- Prof. W. B. Rogers, of the 907-foot artesian boring at Port Monroe, on the peninsula,
alsnit 0 inih-s to the east of Newport News.

fart.bi.Ti I.lv ! 'r map the Cretaceous exposures in the Tertiary area (North Carolina, South

e H-en, or convenience, omitted ; likewise the exposures of the Eocene in the Miocene tracts.

* “treologieal Survey of Illinoi.s,” i, p. 46, 1866.

7 u JiVertT u*'refV.mTl*''a^ considered to be specifically unidentifiable, but on p. 423, the

urrUcHa is ixfern-d, although with doubt, to T. Mortmi, a distinctively lower Eocene fossil.

JOURN ACAD NAT SCI PHILAD SER.VOL.IX,

PL 1.

URNATELjLjA gracilis

Jour Acad. Nat. Sci Philaf Ser. Vol. IX. PI. 2.

garre'iT on society island shells.

PI. 3.

Jour Acad Nat. Sci. PMa§ Ser. Vol. IX.

EJ V*U&d«letlith

GARRE'IT ON SOCIETY ISLAND SHELLS

Acad. Nat. Sci. 5er. Vnl TX

nrTiTYT^ Ai n

mi

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; rw <? ^

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^ OF EASTERN AND SOUTHERN UNITED

PpST-PlilOCBKB.

Pliocknb.

Miocbnb. ''

Casounian

(Upper Atlantic
Miocene).

Miocene).

Martlandian ( I

(Lower Atlantic^ '

Miocene).

Oligocbnk. Ohbitoitic.

Jacksonian.

CSl.AIBORNIAN.

Buhrbtonb.

Lo-lignitio.

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[ 155 ]

ON SOME NEW AND LITTLE KNOWN CREODONTS.

By W. B. Scott.

Genus MESONYX.

I. Mesonyx obtusidens.

The Princeton Scientific Expedition of 1886 had the good fortune to obtain at
Twin Buttes, Wyoming, an unusually perfect skeleton of Mesonyx obtusidens, from
which all the important characters of the genus may be made out. This will enable
us to clear up some of the confusion which still prevails as to the early eocene flesh-
eaters of North America. The few deficiencies in the chief specimen are nearly all
supplied by other individuals from the same region. The only bones not represented
in the collection are : (1) two sacral and (2) several caudal vertebra}, (3) the distal end
of the femur, (4) the central, (5) the rudimentary 1st metacarpal, (6) the entocun-
eiform. A restoration may thus be made which offers very little opportunity for
error (PI. V).

The Skull. — This is the most remarkable part of this very pecidiar animal; the
exceedingly small brain capacity, (less even than in Thylacymis), the immense sagit-
tal cre.st, the very long and wide zygomatic arches, the narrow and lofty occiput, and
the great length of the muzzle, strike one at the first glance (PL ^ I.)

The hasi-occipital is broad and flat, the exoccipitals very narroAv, the condyles small
and directed strongly outwards; the paroccipital processes are short and stout and
arise very close to the condyles. The supra-occipital is very high, narrow and re-
curved, so that when the skull is in a horizontal position the summit of the occiput pro-
jects considerably beyond the condyles. The supra-occipital is shaped like a narrow
lanceolate Gothic arch, and as a whole the occiput is in strong contrast to that of
the Carnivora.

The base of the cranium is somewhat injured, so that it is difficult to make out
the relationships of the tympanic and periotic. A very small and apparently undivided
bulla is present.

The hasi-sphenoid is likewise broad and flat ; the aU-splienoids small and appar-
ently pierced by an ali-sphenoid canal. The parietals are very large, but comparatively
little of them is applied to the wall of the brain cavity, the greater part going to the
formation of the very high and thin sagittal crest, which gives much of its most curious
physiognomy to the head. The appearance of this part of the skull is very similar

22 JOUR. A. X. S. PHILA., VOL. IX.

ON SOME NEW AND LITTLE KNOWN CREODONTS.

l0()

to tliat of St!ii>oloi>lrm as sliowu by the figures of Professor Cope and M. Filhol, except
that in this genus tlie brain case is much more capacious.

Owing to the exceedingly fragile condition of the pterygoids the matrix could
not b(.> rcnm\-ed from tlie posterior nares, so that the presphenoid is concealed, nor
could the limits of the orhitosphenoids be satisfactorily made out. The frontah are
very large. Posteriorly they are wedged in between the parietals by narrow processes
ami then widen rapidly to form the broad, nearly flat forehead. They arch over the
eves, forming the upper and part of the front boundary of the orbits. The post-oi'bital
])roces.s is not very conspicuous.

The htclupmal is large and as in Hi/cenodon, Thylacynus and many Insectivora
extends somewhat on the face. The foramen is single and just inside the orbit. The
malar is long and slender, forming the entire lower bpinidary of the orbit, but
extends very little on the fixee. It arches strongly outwards and, making a very long
contact with the zygomatic process, passes as far back as the anterior edge of the
glenoid fo.ssji. The po.st-orbital process is very feebly indicated.

'I'lie M/aamofHil forms the side wall of the cranium more extensively than the pari-
etal. The zygomatic process is at first directed at right angles to the axis of the skull;
this ]M)rtion is ma.ssivc and projects fixr outwards. The remaining part of the process
is iM'iit forwards at right angles to the first and is much more slender. Its upper sur-
liu-e is nearly straight, the lower arches strongly upwards. The glenoid fossa re-
sxMnbles that of A ref or yoa with prominent pre-and post glenoid crests. As a whole
the zygomatic arch is exceedingly wide and long, though rather .slender ; its xxpper
edg(* is vt'ry nearly straight and the glenoid fossa with its massive support projects
much Im-Iow the level of the arch.

The aantd» are xery long and narrow. Posteriorly they are broad and just ox'er
the orbits are wedged in between the diverging frontals; ixarrowing rapidly, they pass
forwanls as slender splints to the nasial opening. The anterior ends are not emargin-
at<*«l, nor do they project far beyond the edges of the premaxillaries.

'I'he premaxilUv are shaped much as in the dogs. The ascending ramus is thin ;
it arches around the nose, and reaching the nasal, sends back a tapering process which
is in contact with the nasjil for about an inch. The alveolar portion is stouter ; the spine
is well develo|M'd, and the incisive foramina are long narrow ox'als.

'File inajrdhr are very large bones, forming almost the whole of the fiice. The
two Inmes are not lar from ])aralljel, as the molar series do not dix-erge much. The
large inlraorbital foramen is placed aboxe the last premolar. The palatine plates are
broad ; they shoxv no x acxiities.

I he ]»alatincs are large bones, extending forxvard to the 1st molar, joining the
plates of the maxillas by a rounded suture. The posterior palatine foramina are x^ery
small. Along the front margin of the posterior nares the palatines are thickened and
in the middle there is a short stout spine. They are also produced far back to enclose

ON so:me new and little known creodonts.

157

tlie unusually long- and deep posterior nares. The limits of the pterjmoidfi are not
very clear. These bones are long and high, hut as their margms are somewhat broken
the presence or absence of hamular processes cannot be stated.

Tlie mandible is very long and rather shallow ; both the alveolar and lower bor-
ders are strongly curved antero-posteriorly ; the condyle is transverse, strongly convex
and placed very low, considerably below the level of the teeth. The angle is pro-
longed into a stout hook, much like that of Stypolophns ; the coronoid process is very
broad but not high, and rises obliquely from the horizontal ramus. The masseteric
fossa is large but not deep ; not nearly so marked as in Hyamodon. The symphysis
is much shorter and broader than in M. lanius. The mandible of Pachycena ossi-
fraga is very different, aside from its greater size. The angle is not prolonged into a
hook, the condyle is placed higher, the coronoid notch is wider, and the symphysis is
much longer.

The Brain. Owing to the thinness and fragility of the bones, a cranial cast
could not be attempted, but the partial exposure of the natural cast allows some facts
to be made out. The cerebral hemispheres are very small, but show some convolu-
tions ; the cerebellum is relatively large, is lodged in a distinct fossa, separated from
the cerebrum by a tentorium.

Dentition. Professor Cope has described the dentition in part, but as this is the
first specimen in which nearly all the teeth have been found in place it will be neces-
sary to give some account of them.

(1) Upper Jaw. The median incisor is small, has a very compressed fang and a
simple crown ; the second is somewhat larger and the outer very much larger, with a
long pointed crown, worn on its external side by the lower canine. A considerable
diastema exists between the outer incisor and the canine. The latter is a powerful
tooth, in size and proportions much like that of the black bear, though somewliat
more compressed ; it is very different in appearance from that of M. lanius. The 1st
premolar follows immediately after the canine without diastema, and in this differs
from Pachywna which shows diastemata both before and behind the 1st premolar ; it
has two fangs and its crowm is small and compressed, with the merest rudiment of
a posterior tubercle. After a small interval, Avhich does not deserve the name of a di-
astema, comes the 2nd premolar, which is much larger than the finst; it is conical also,
but has a more developed heel and a distinct cingulum. An interval occurs between
the 2nd and 3rd premolars, about equal to that between the 1st and 2iid. The 3rd
premolar is larger than the 2nd and the heel is now almost as. high as the main cusp ;
there is also a marked increase in thickness ; a small internal tubercle appears opposite
the heel and a very small anterior basal cusp is present. The homologies of the suc-
ceeding tooth are somewhat doubtfrd ; I am inclined however, to consider it as the
4th premolar for the following reasons : (1) In the flesh-eaters, both creodonts and car-
nivores, the 3rd molar is usually the first tooth to disappear ; (2) the tooth in ques-

1.08

ON SOME AND LITTLE KNOWN OJiEODONTS.

tion is not quite like tlie molars in pattoru, but altogether like the 4th premolar of
PacJuj,Huf (3) the last molar of Mesonyx is very different from the 3rd molar of
Puchyana'-miX entirely like the 2iid molar. It seems reasonable therefore to infer
that the missing tooth in Mesonyx is the 3rd molar. This 4th premolar, as I shall
call it, re.sembles the molars in having a large internal cusp, but differs from them in
the conformation of the outer part of the croivn, which is not so plainly divisible
into two cusps ; the cingulum is confined to the outer face of the crown. The molars
are es.sentially alike, though the first has a somewhat greater antero-posterior and pro-
portionately smaller transierse diameter; there are two external cusps, with a cingu-
lum on the outer side, and anterior and posterior basal tubercles (the posterior is not
jiresent on the 2nd molar) ; the internal cusp is very large and placed opposite the
antero-external one.

Ixm-er Jan:. Tlie incisors are A ery small and simple with compressed fangs and
without cingulum. Tlie canine is bear-like and is somewhat ev erted. The 1st pre-
molar is missing from the specimen ; the 2nd has tAvo fangs, a small conical croAvn
Avith rudimentary heel. The 3rd and 4th are essentially like the molars, consisting of
a thick retroverted conical cusp and lieaA y blade-like heel ; the anterior basal tuber-
cle apiiears only on the 4th. The molars decrease in size posteriorly ; the main cu.sp
is larger and thicker than on the premolars ; on the 3rd molar the heel is much re-
duced and the anterior basal tubercle rudimentary. These molars differ from those of
Parhya tm in the much greater development of the heel and the reduction of the an-
terior basid tubercle. In Pacliyama the tubercle and heel are about the same size,
giving the tooth a very different appearance. (See Cope, PI. XX^TII h. Fig. 1).
All the molars of Mesonyx are Avorn at the tips, so that they have become more and
more blunted Avith advancing age.

M. >J>insu1ens differs from M. lanins chiefly in the canines and incisors; the for-

mer are much flattened and worn on the sides, the latter .seem to be entirelv absent
from the lower jaw, though this is not certainly determined, the shape of tlie sym-
physus IS also Aery different, and more perfect specimens than have yet been obtained
Anil very probably necessitate the revival of the genus Synoplotherinm, which Pro-
les.sor C'oiie considers a snionym of Mesonyx.

iHE ^ EKTEBK.VI. CoLu.AfN.— The atlexs is remarkable for the smalhie.ss of thetrans-
Aerse proce-ssc^s which are nearly straight in direction and produced very little behind

emarldrVT for the vertebral artery and are deeply

tvnica r " appearance very unlike that in the

and itlrtelT TKyUeynus. The superior arch is broad,

»rch i, rfcmlor Zi ,hc LXfe I'T '

nnltaltn- 1' J’I'-'T': i"'? " W. a strou, keel,

ON SOME NEW AND LITTLE KNOWN CKEODONTS.

159

up around tlie neural canal, which eiuarginates them. The postzygapop]iy.scs arc prom-
inent and directed but slightly outwards. The neural spine is very curious. It is
produced hut little in front of the pedicels, and the upper edge rises steeply from the
front until it forms a thick, bliuit spine, ending slightly behind the centrum. This is
very different from the hatchet-shaped structure of the ordinary Carnivora and Insec-
tivora, but it is approached in My dans and Meles.

The remaining cervicah are not especially remarkable. The centra are long,
slender and somewhat opisthocoelous, with faces oblique to the long axis of the cen-
trum. On some there is a strong hypapophysial keel expanding behind into a pair of
rugose processes. The cervical s]3ines are unusually long and indicate muscles of
great size.

Tlie dorsal vertebrae, 14 in number, are remarkable in many ways. In the anter-
ior region, the centra are small, somewhat opisthocoelous and of sub-triangular section ;
the spines are exceedingly long and stout. These decrease rapidly as we pass back-
wards imtil on the 11th or anticlinal vertebra the spine is hardly a third as long as
on the 1st. Behind the 11th the spines point forward, are short and compressed and
occupy the Avhole length of the neural arch, as in the lumbar region. The centra in
the posterior region are much larger and heavier than in the anterior and are consid-
erably de])ressed. The transverse processes are short and heavy and, except on the
13th and 14th, with large round faces for the tubercles of the ribs. The zygapophy-
ses in the anterior region, are long, narrow ovals, are flat and present directly up
wards and downwards ; from the 10th the postzygapophyses becomes cylindrical, and
the prezygapophyses of the remaining vertebrm are deeply concave and have strong
mcta])ophyses; anapophyses are also present on some. The posterior dorsals of Pach-
ya>na differ from these chiefly in the absence of metapophyses and the much greater
obliquity of the faces. The disparity in the length of the limbs would necessitate a
strongly arched back.

The lumlar vertebrm, numbering six, are very large with broad, depressed, and
nearly plane centra, which are contracted in the middle. The spines are long, broad
and thin, inclining forward; the transverse processes are very long, slender, and
curved forwards and downwards. The zygapophyses are like those of the posteiior
dorsals, with prominent metapophyses ; anapophyses are absent, except perhaps on the
1st. As Professor Cope has j)ointed out, the articulations of these vertebr® show a
greater degree of specialization than is found in any living carnivore.

The sacrals are not all preserved. They probably were three in number. The
first lias a short and flat centrum and short expansions for the ilium ; the last has a
low spine and small rounded post-zygapophyses.

The caudal vertebree, of which some 14 are preserved, indicate a very long tail,
much as in the leopard. The anterior vertebrae are short and fiat with well developed
zygapophvses and short backwardly directed transverse processes. Passing backwards.

KJO

ON SOME NEAV AND LITTLE KNOWN CREODONTS.

the cfiitra rapidly eloiifjatc and the processes become rudimentary. Tlie distal end of
th(‘ tail is (•omi)()s(>d of numerous very slender joints. Strong chevron bones are found
under some of the anterior vertebrae.

Tjie Ribs. — The ribs are like those of the bears ; the anterior ones, especially the
first, are remarkably .short and hat; about the 7th they become slender and oval
in section and from the 9tli decrease in length. Heads and tubercles are well de-
velojKjd except on the last two or three, when the tubercles become rudimentary. The
la.st rib is very .slender.

The .Stekxum. — Of this bone only one complete and parts of two other segments
are preserved, enough to show that the sternum was comparatively broad and flat
slightly concave on the upper surface and convex on the lower, very much as in Arc-
tictiM. 'fhe .segments are also of rather unusual length.

The Fohe-Limb. — The scapula is in general much like that of Hyaena and the
cats. 'I'lie glenoid cavity is deeply concave antero-posteriorly, but rather .shallow
transversely: the coracoid is very small. The neck is constricted and very narrow,
and the coraco-scapular notch correspondingly deep. The coracoid border is curved
Hi»wards and backwards from the edge of the notch, enclosing a large prescapular
fossji. 'fhe supni-wai>ular border is thickened, rugose, nearly straight, and inclined
somewhat downwards. The glenoid border is also nearly straight, but with an un-
usual oblifpiity. The siiine is jn-ominent, ending in a stout curved acromion which
<1*K^ not proj,x>t o^er the glenoid cavity. The pre and post-scapular fossa are of very
nearly .upud extent. Compared with the other limb-bones, the scapula is very loim,
longiT than the radius, which is a rare proportion among the Carnivora.

-ni.. h„mrr,,. i» Sl„.rt ,uul not vory stout, and in general resembles tliat of Hm nn

:'7 "" quite distinct; the enter tuberosity pioiects

.11 S Iglitlj iila.v 111,, bead, mill is less prominent than in the hvama, but more dis-
til.,-lly dividisl into ,iv„,s,r,s; the inner tulKirosity is very small and the bicipital
grisivc bn, ad ...Id s lalloiv. The shall is strong above and rather slen.ler below the

Z Icl,'^ ir being inconspicnons.

^ . Ihc, ■Menial condyle is small, the internal quite large; the anconeal fossa is

no .supracondylar fonunen, and the trochr' conspicuous, there is

is pro|K.rtioniilely short, much shorter tb ” ** ° “'‘ape. The radius

broad, iind occniivino most of tb 1 7 carnivora. The proximal end is

■tation. The si a : eZ Z , r T TT

eilunirical and strongly bowed; the distal end is heavy, shows

ON SOME NEW AND LITTLE KNOWN CREODONTS.

161

an external facet for the ulna and two distal concave faces for the scaphoid and lunar.

In Pachyama the radius is relatively shorter, more flattened, and the facets for
the scaphoid and lunar are not separated.

Tlie ulna is slender with a snbtrihedral curved slraft, and long very stout olecran-
non. The distal end is a narrow convex surface for the cuneiform. In Pachycena
the ulna is straighter, the olecrannon not so hroad, and the distal end acuminate.

The carpus (PL VII.) is of extraordinary interest, and is distinctly like that of the
Insectivora. The scaphoid, which is separate from the lunar, has very little dexAh ; the
tuberosity is smaller than in the Carnivora ; the surface for the radius narrow and con-
vex. Distally there are three facets ; (in M. Icmhis those for the trapezium and trape-
zoid are confluent), a small internal one for the trapezium, a larger median one for the
trapezoid, and externally a narrow and deeply excavated one, which Professor Cope
considers to be for the magnum, but which is really for the central. The lunar has a
very convex upper surface, the radial articulation extending over the front face. The
distal end is wedge-shaped, formed by two deeply conca^'e facets, a larger one for the
magnum and a smaller one for the cuneiform. Professor Cope’s restoration of this
bone (Tertiary Vertebr. PL XXIX, Fig. 3) is much too large and entirely incorrect in
shape.

The cuneiform is very unlike that of the Carnivora. The ulnar surface is narrow
and concave ; posteriorly there is a broad face for the pisiform, which rests against and
not upon the cuneiform. The uneiform surface is also concave.

The pisiform is very stout and has a hea\7 knob at the distal end. The ulnar
facet is reversed D shaped, that for the cuneiform more quadrate in outline, the two
meeting at an angle of about 45° The trapezium is high and narrow, and has four
articular surfaces, one small and round for the scaphoid, a larger concave facet joins
the trapezoid ; beneath is a flat quadrate surface for metacarpal II, and distally is a
very small saddle-shaped facet for the rudimentary metacarpal I. The trapezoid is a
stout bone, broader in front than behind. It rises considerably above the level of tlie
magnum. Its metacarpal is the stoutest of all.

The magnum is the smallest bone in the carpus, except perhaps the central ; the
A^ertical diameter is its least dimension, and is much exceeded by the unciform and
trapezoid. The magnum possesses flve articular surfaces, for the lunar, central, trape-
zoid, imciform and metacarpals II and III. The upper facets are strongly convex,
that for the lunar is the larger, that for the central very narroAv. The articulation
Avith metacarpal II is someAvhat. larger than Avith III.

The centred. I haA'e spoken confldently of the presence of this element, although
it is not preserved in any specimen I have yet seen. Its existence is hoAvever made
A’ery clear by the folloAAdng facts: (1) The scaphoid is prevented from reaching the
magnum by the height of the trapezoid and by the mode of articulation Avith the lu-
(2) On the distal face of the scaphoid is a facet Avhich is not occupied by tlie

nar.

ON SO^rK NE\Y AND LITTLE KNOWN CREODONTS.

1<J2

tni]H'ziuni or trapezoid. (3) The lunar loaves a proximal facet of the magnum un-
touched, corresponding to that on the scaphoid ; the two, however, cannot possibly
come in contact. (4) When the carpal bones are put in their natural position, a va-
cancv is seen to occur betw^een the scaphoid above, the lunar and trapezoid at the
sides, and the magnum below. This is exactly the position which the central should
occupy, and by no other assumption can the relations of the other carpals be ex-
jdained.

The unciform is the largest of the elements. The proximal surface is mostly oc-
cupied by the cuneiform, but rising aboA'e this is a narrow, convex, and oblique facet
for the lunar. A considerable facet for metacarpal III is to be seen below the magnum,
and distally are two broad and somewhat concave surfaces for metacarpals IV and V.

The metacarpals, as Professor Cope has remarked, resemble those of the hv®na,
tliougli they are shorter and more perfectly interlocked ; II and lY are short and
stout. III and IV longer and much more slender. No. II overlaps III and sends a
strong process to the magnum. III overlaps IV and sends a similar process to the un-
ciform. No. IV has no such process, but on its external side is a cavity which re-
ceives a i)rojection from V. Professor Cope’s figure of the metacarpals of M. lanlus
is incorrectly drawn. He has kindly allowed me to examine his type specimen and it
agr«><-s with that here described. The metacarpals of Paclujccna are shorter, stouter,
and not .so much interlocked as in Mesomjx ; indeed the latter shows a degree of inter-
IcK-king which is more pronounced than in any modern carnivore except the cats.

'fhe i.roximal phalatajes of the lateral digits are stout, depressed and curved, those
of the iiK'dian digits long and more slender; the same statement holds good of the
stvond row. In both .scries the distal articular surface is reflected on the upper face
of the lH)ne, more so than in the hyaena. The ungual phalanges, as long ago pointed
out by Profe.s.sor Cope, are very peculiar and remotely like those of the seals. They
are nither more like small hoofs than claws, are broad, depressed and deeply cleft at
the end. A wedge-shaped thickening passes along the under surflice giving the bone
greater stmigth.

'I HE IIi.VD Limb. 'The pelvis is most like that of the bears; the ilium and isch-
ium are in the same straight line and of about equal length. The former is stout and
somewhat everted anteriorly, with concave iliac sm-face and a tubercle representing
he anterior inferior spine. The ischium is a stout trihedral rod expanding po.sterior-
into a very large but not thick tuberosity. The pubis is short and heavy, meeting its ,

< ow in a ong simphysis. The obturator foramen is a long narrow oval. The acet-
abulum is rather small. J-ncacet

tl.o Except for the presence of

™,hcr 1 "n’ great trUantor i,

rather small and has a rngose edge ; the shaft is rounded and slender. >• The rotukr

groove ts narmw and elevated, the inner margin a little higher. The condyles are

ON SOME NEW AND LITTLE KNOAVN CREODONTS. l(i;]

rather narrow, the inner with less transverse and antero-posterior extent, and separated
by a wide dtx'p frroove. The patella is narrow, thick and truncate at one end.” —
(CoiK‘).

1 he tUna is in size and shape like that of the hysena, but is considerably longer
than tlie mdiiis. Tlie femoral faces are separated by a prominent spine. The cnemial
crest is heavy and conspicuous, extending far down the shaft. Above the shaft is
large and ot trihedral section, below more slender and rounded. The distal end
shows a heavy internal malleolus and two quite deep astragalar facets separated by a
low but distinct ridg(>. This is quite as in the digitigrade Carnivora and quite difter-
ent from the ordinary creodonts in which the astragalar face is nearly flat.

'\'\\v Jihula is very slender. Its proximal end is applied to the under surface of a
projection of the tibia; distally it expands into a very large external malleolus.

Tin? tarmiit. The aj<tragahw is well known from Professor Cope’s description.
It is remarkable l()r the deeply grooved trochlea and the articulation with the cuboid,
which, as ^Ir. \A'ortman has shown, is approximated in some of the Arctoidea. The
neck is long, the navicular face narrow and strongly convex. As a whole the bone is
\-ery different from that of' the Creodonta ordinarily, and most like that of the digiti-
grade C'arnivora. The same is true of the calcaneum, which is long and strong. The
iqqK'r condyle is prominent and sharply rounded, the sustentaculum large, and is re-
moved further from the distal end than in the Arctoidea. The distal end has two
articular faces, a broad one for the cuboid, and a narrow one on the inner edge for the
astragalus, giving three distinct articidations with that bone, a peculiarity which I
have not found in any carnivore. The calcaneum and astragalus of Padiycena are in
essentials like; tho.se of Memnyx, though with some minor differences. The cuboid is
very long and heavy. At an acute angle with the broad calcaneal facet is a narrow
astragalar one. Distally the facets for metatarsals IV and V may be distinguished,
that for the latter.is very small. On the internal face of the cuboid is a projection
which passes Ix'tween the navicular and external cuneiform. The nm'icuiar is a
narrow and shallow bone, with its astragalar facet concave in both directions. In
verti(-al height it is -scarcely more than that of the cuboid. Distally throe small
facets for the cuneiforms are visible. The external cuneiform is very high and nar-
row, articulating with the navicular by a small rounded surface and with the ledge of
the cuboid. The middle cuneiform is much smaller than the external. A small con-
vex head fits into a depression in the navicular, and distally there is a narrow wedge-
sha|X'd surface for mctatansal II.

The internal cuneiform is missing, but the navicular facet shows it to have
l)ccn \cr\ small. It could not have supported a functional digit.

The metatarsals are longer and much more slender than the metacai-pals, but arc
arranged in much the same way. III and IV longer, II and V shorter. The inter-
locking is but slight, II rising above the level of the other three on account of the

23. JOCK. A. X. 8. PHII.A., VOL. IX.

ON somp: new and little known ceeodonts.

KM

shortness of tlic middle cuneiform. Nos. V and IV have an inwardly directed
proj'ection whicli fits into a corresponding cavity in tlie adjacent metatarsal. Nos. II
and 111 are not interlocked at all.

The phalanyes are like those of the fore-foot, but longer and more slender.

As a whole, the high and narrow' pes is A'ery different from that of the planti-
grade and much like that of the digitigrade CarniA'ora, especially Hyama, to wdiich
the resemblance is very close, even in details.

(Vhat I believe to be the distal end of the os lyenis is represented in the speci-
. men. It is curved ni)w ards and ends in a small knob, resembling the corresponding
l)one in some of the Mustelidm.)

Restokation. — The skeleton of Mesonyx as a whole is very curiously propor-
tioned. The head is very large, the trunk very long, with prominent spines in the
dorsal region, the flanks slender, and the tail long and cat-like. The thorax is
shallow and compressed. The limbs are very short and the feet especially -weak.
AN'ith a body as long as that of a full-grown black bear, the animal did not stand as
high from the ground as a large dog, and compared with the bear the limbs were not
mu.scnlar, not more than in the hytena. When alive, the creature must have had a
very grotesque a])pearance. Indeed its peculiarity might excite the suspicion that the
drawing was incorrect, but the specimen is .so perfect that the only room for que.stion
is as to the length of the femur and of a few ribs, and the exact number of joints in
tin* tail. Possibly also the animal possessed a greater number of dorso-lumbar
vertehne ; but this is very unlikely, as those pre.served seem to indicate an unbroken
series, without any percejdible gaps. It is also, perhaps, a question as to w hether the
animal was jdantigrade, as Professor Cope believes, or digitigrade as I have repre-
sented it. My rea.sons for this course are: (1) The length and narrowness of the
feet, which are in sharp contrast to the feet of the plantigrades; (2) the reduction in
the «ligits, wliich .seems to have gone as far as in any living carnivore; (3) the extra-
ordinarily iKM-fect interlocking of the metacarpals, which is not a'pproached in the
Arctoi(h.a and excelled only in the cats; (4) the very long narrow tarsus and cliarac-
tei ol the astragalar trochlea; (o) the very close general resemblance to the feet of
itl, the iiossible exception of Pachycena no known creodont can show
such a sjieciahzed foot structure as Mesonyx.

-Vekinities.— The relations of tlie Mesonychidee to any other group are very
osc-ure. -rom tlie .study of imperfect specimens I w as formerlv led to consider them
clostdy allied to //yovuWou, but as Profe.s.sor Cope has shown, the resemblance in the
dentition IS rather a .supeihcial than a fundamental one, and the limbs are very differ-
ent 1,1 the two forms, llya^nodon has five functional digits in the manus, with a short
bioad plantignnle foot. Mesonyx cannot be regarded as an ancestor of Hycenodon, a.s
the latter ,s in many respects more primitive than the former.

In Me>.nn,x we are presented with a most curious assemblage of characters.

ON SOME NEW AND LITTI.E KNOWN CREODONTS.

1(55

Together AAdth an exceedingly small brain, and a primitive type of dentition and
carpus, we find associated a highly differentiated metacarpus and tarsus, a reduction
of digits like that of modern carnivores, and finally a mode of articulation in the
lumbar and posterior dorsal vertebrae more perfect than in any existing carnivore. I
cannot confirm Professor Cope’s and Mr. Wortman’s suggestion of a relationship
between Mesonyx and the seals. A certain similarity in the claws and teeth is
undoubtedly present, but the characters of the skull, brain, vertebra? and limbs are
altogether different. The ancestry of the seals is more probably to be looked for in
the Bridger genus Megenceplicdon. Altogether, then, it would seem that Mesonyx and
Paclvymno, form highly specialized side branches of the Creodonta which died out
without successors. No living animal seems to stand in direct relationship with these
extinct genera.

History. — The genera Mesonyx and Synoplothermm were established by Profes-
sor Cope in 1872 upon specimens from the Bridger Eocene, Pachycena in ISTC to
receive certain species from the Wahsatch of New Mexico. Subsequently Professor
Cope concluded that all three forms belonged to the same genus. But as we have
seen, Mesonyx is very different from Pachycdna, and more perfect specimens wnll very
probably show that Synoplotlierium is also distinct. But this question cannot be
decided at present.

Mesonyx, Cope 1872 (=1 Synop>lotherium., Cope 1872,) MesonycMdce with the den-
tal formula: IH, C}:}, Pm. 4:| Mfif^ 40; no diastemata behind canine; fore and hind
limbs of nearly equal length, metapodials elongate, and animal probably digitigrade.

Pachywna, Cope 1874. Dental formula; I|:|, CJj, Pm. tl, MU = 42;' dias-
temata in front of and behind 1st premolar ; hind limbs much longer than fore limbs ;
metapodials short, and animal probably plantigrade.

Tlie family Mesonychidcz may be defined as: Creodonta with trochlear ankle
joint ; “ molar teeth in both jaws consisting of conic tubercles and heels ; none
sectorial ; a preglenoid crest.” (Cope.)

So far as is at present known, Mesonyx seems to be confined to the Bridger and
Uinta formations, and Pachycena to the Wahsatch.

Measurements.

Mesonyx

OBTUSIDENS

Z •

§ H

^ g

tf

W ^

Length of skull (along base) ........

M.

.279

M.

.227

“ cranium .........

.125

.114

“ face ..........

.154

.113

Breadth across zygomatic arches .......

.165

—

“ of forehead .........

.080

.075

“ of cranium (greatest) ....... I

.055

.054

ON SOME xNEW AND LITTLE KNOWN CREODONTS.

KiG

MeasureSients.

Height of occiput . •

Depth of face (from above orbits)

Lengtli of mandible (from condjde)

Height of coronoid
Depth of mandible (below m. 3
“ “ m. 1

“ “ pm. 2

Length of symphj'sis • ^ ^

Diameter 3rd incisor (long.) Lpper J
“ “ “ (trails.)

Height 3rd incisor. Upper Jaw.

Diameter canine (long)

“ “ (trans.)

Height

Length molar series
“ premolar series
“ true molar “

1.. cngth' premolar 1

Hrcndth
Height “

Length “

lireadth “

Height “

1.. cngth “

Hrcndth “

Height “

Length “

Hrcndth “

Height “

Length molar 1
Hrcndth
Height
I/cngth
Hrcndth
Height

Diameter of canine (long.) Lower Jaw
" “ (trans.)

Height “

Ixmgth molar series
“ premolar scries
" true molar “

I.«ngth premolar 2
Hrcndth “ "

Height " “

I/Cngth “ 3

Hreadth “ “

Height “ “

Ixm^h “ 4

Breadth “ "

Height “ “

I.ength molar 1
Breadth “ “

Height “ “

Length “ 2

Breadth “ “

Height “ “

lajngth “ 3

Breadth “ “

Height “ ‘‘

'Lrnffth in tooth measurements is used in the sense of antero-posterior diameter,

M.

M.

.088

—

.073

.068

.22.5

.187

.087 (?'

)

.050

.038

.037

.033

.037

.031

.067

.009

.005

.008

.004

.010

—

.019

.013

.013

.011

.038

.032

.098

.108

.067

.067

.030

.040

.010

.012

.000

.006

.008

.008

.015

.015

.008

.008

.010

.014

.016

.018

.008

.010

.008

.013

.015

.018

.013

.012

.010

.017

.017

.018

.016

.008

.009

.012

.013

.023

.017

.012

.(08

.018

.016

.015

.013

.011

.027

.032

.108 (?)

.117

.057 (?)

.062

.051

.0»)

.013

.014

.006

—

.009

.018

.017

.008

.008

.013

.013

.019

.017

.008

.010

.012

.016

.019

.012

.009

.007

.015

.009

.018

.018

.008

.008

.015

.013

.014

.025

.007

.010

.010

.014

ON SOME NEW AND LITTLE KNOWN CEEODONTS.

1G7

Measueements.

° a

Atlas, breadth
Axis, length, centrum .

_ “ odontoid .
diameter spine (antero-posterior)
length transverse process
breadth atlanteal facets
6th cervical, length centrum
■’ height “

“ spine
1st dorsal, length centrum
height “

“ spine
diameter spine
length transverse process
diameter “ “

7th “ length centrum
height “

“ spine .
diameter “

2nd lumbar, length centrum
height “
breadth “
height spine
diameter “

6th lumbar, length centrum
height
breadth “
height spine
diameter “

length transverse process
Sacrum, length

1st sacral, breadth (inch pleurapophyses]

2nd caudal, length
12th (?) » “ . .

Last “ ” . .

3rd(?) sternal segment, length
“ “ “ breadth (anterior edge)

Scapula, height

“ greatest breadth

“ height acromion

“ diameter glenoid cavity
Humerus, length

“ diameter of head (ant. post.)

“ breadth of trochlea .

Ulna, length

“ “ olecranon

“ breadth trochlea

“ “ distal end

Kadius, length

“ breadth proximal end

“ “ distal end

Carpus, breadth
“ height

Pisiform, length,

“ diameter of free end (vertical).
Metacarpal I, length,

“ breadth, proximal end,

II, length, ,

‘‘ breadth •' ‘

III, length, .

“ breadth, “ ‘

M.

M.

.100

.102

.041

.039

.017

—

.075

—

.023

.036

.041

.040

.032

.030

.018

.020

.053

.027

.024

.019

.020

.083

.019

.018

.020

.020

.014

.018

.025

(6th) .021

.016

“ .018

.049

“

.017

“ ,017

.029

.036

.016

.021

.025

.032

.034

—

.026

—

.032

.032 •

.017

.018

.025

.025

.043

1 .052

.024

1 .022

.049

i(3rd) .046

1 .071

.046 (?)

.059

.024

'

.039

—

.011

—

.045

—

.025

—

.167

—

.094

—

.026

—

.032

.194

200 (?)

.036

—

.027

.031

.207

.200

.048

.047

.024

.026

.015

.016

.160

.150

.023

.026

.024

.022

.038

.043

.021

.021

.025

.027

.016

.017

.034

—

.012

.062

.056

.014

.014

.070

.066

.011

—

ON SOME NE\y AND LITTLE KNOWN CEEODONTS.

1G«

Measurements.

Metacarpal IV, length, . . •

“ “ breadth, “ ‘ .

“ V, length,

“ “ breadth, “ “ •.

Phalanx, length, proximal (lateral digit),

“ “ median, “ “

“ “ ungual, “

Pelvis, length.

Ilium, length,

“ width (greatest), .

Ischium, length, .

Acetabulum, diameter, .

Tibia, length,

“ breadth proximal end,

“ “ distal “

Fibula, length,

“ breadth proximal end, .

“ “ distal “

Tarsus, height (from astragalus),

“ breadth, .

Calcancum, length.

Astragalus, “

“ breadth,

CulK)id, length.

Metatarsal III, length, .

“ V,’

Cerebral hemispheres, length,

■■ “ greatest breadth,

Olfactory lol)es, length. .

■' breadth.

Cerebellum, breadth,

(Measurements marked (?) are approximate only.)

M.

.065
.010
.050
.014
.023
.012
.016
.205
.115
.046
.090
.027
.205
.042
.025
.191
.011
.017
.046
.039
.056
.031
.018
.013
.070 (?)
.076 (?)
.068

W a

M.

.064

.012

.039

.009

.019

.020

.062

.054

.024

.040

.064

II. Mk.soXY.\ (?) Ul.NTE.NSIS, sp. nov.

I he first s|MH'iinens of flesh-eaters known from the Uinta formation are portions of
three hulividntils rolleeted by the Princeton Expedition of 1886. One of these, con-
sisting ol an incisor, portions of a canine, one upper and two lower premolars and three
lower molars, and portions of the mandible, is doubtfully referred to Mesonyx, and
differs from all known species in its very much greater size, and in the reduction of
the anterior tubercle of the molars. The incisor is peculiar and consists of a broad
ami roumled simple crown ; it is of large size and contrasts strongly with the incisors
of the Pridger sin-cies. The canine is very large ; the upper premolar differs from the
corresiKinding tooth of the Bridger species only in size. The lower premolars are much
smaller than the molars and are composed of a compressed cone with anterior and pos-
terior ba.sal cusps ; the posterior cusp is much less developed than in the other species of
Me^nyx, thus making a much greater difference in shape between the molars and
premolars. In the Bridger species all of the inferior molar series are essentially alike.
Tlie molars are very large and consist of two lobes, of which the anterior is a heavy,

ON SOME NE^Y AND LITTLE KNOWN CREODO.NTS.

169

compressed and backwardly directed cone, and the posterior is a much lower trenchant
heel, convex externally and concave internally. The attrition takes place on the sum-
mits and not on the sides of the lobes, so that they become more and more blunt with
age. The ordinal arrangement of these teeth cannot be certainly determined, as they
are all detached, but judging front the amount of wear, the first is the largest and the
third the smallest, though there is much less difference in this respect than in the other
species of the genus. The anterior basal tubercle is small on the first, still more
reduced on the second and entirely absent from the third. This reduction gives the
molars a somewhat different appearance from that seen in the species from the Bridger.
The mandibular condyle differs in no respect except size from that of the other species.

I have referred this animal to Mesmyoc, because the parts preserved do not show
any differences of generic value. But in view of the character of the incisor and pre-
molar teeth, it is quite j)robable that more perfect specimens wdll necessitate the form-
ation of a new genus for its reception. At all events it certainly is a member of the
MesonycfiidcB and w^ould seem to be the last variation which occurred before the extinc-
tion of this peculiar type.

Measurements.

M.

Diameter of incisor (fore and aft) . . .011

“ “ (transverse) . . .011

Length of lower premolar (1st 1) . . .014

“ “ “ (2nd1) . . .018

Length 1st lower molar . . .• . .031

Thickness “ “ . . . . .015

Length 2nd “ . . . . .029

Thickness 2nd “ . . . . .015

Length 3rd “ . . . . .028

Thickness 3rd “ . . . . .012

Transverse diameter mandibular condyle . .037

Genus DIDYMICTIS.

III. Didymictis altidens, Cope.

The MiacidcE approach nearer to the true carnivores than do any other creodonts.
and consequently even very imperfect specimens are worthy of careful description.
A fragmentary skeleton of Didymictis altidens obtained by the Princeton Expedition
of 1884 in the Big-Horn basin of Wyoming (Wasatch formation) will serve to shed
some additional light upon the characteristics of this flunily.

With regard to the dentition I can add nothing to Professor’s Cope’s account
except to say that lower incisors were very probably present, as is shown by a loose
tooth occurring with this specimen ; it is very small and has a simple crown and strongly
curved fang, but no cingulum. The number of lower incisors cannot be made out,
but as the space between the approximated canines is much reduced, it seems probable
that not more than two were present in each ramus.

17(1

ON SOxAIE NEW AND LITTLE KNOWN CREODONTS.

Vvrfihne Iroin nearly all the regions arc represented in the specimen. The atlas
is viverrine in character ; the transverse processes are moderately exjjanded, rather
more so than in the MusteUda>. and less than in the Ganidce, and perforated for the ver-
tebral artery ; the anterior condyles are quite deep, the neural arch broad and stout and
the inferior arch slender. The axis has a short conical odontoid process ; the centrum
is broad, depressed and strongly keeled ; the atlanteal faces are transversely directed and
not emarginated by the neural canal, as in Mesonyx ; the post-zygapophyses are placed
low on the arch. The spine is missing from the specimen. The dor. sal vertebrae have very
small centra, which are subtriangular in section and have nearly flat faces. No pro-
cesses arc preserved on any of them. The lumbars are of particular interest as show-
ing the typical creodont structure of concave prezygapophyses interlocking strongly
with the sub-cylindrical postzygapophyses. The metapophyses are inconspicuous
and the ana{)ophy.ses small. No vertebrae from the sacral or caudal region are
preserved in the specimen.

.\ fairly complete account of the fore-limb may be given, as portions of the scapula,
liumerus, ulna, radius and manus are represented. Of the scapula only the distal end
is preser\ecl, enough, however, to show a broad shallow glenoid cavity and stout
eonicoid h(K)k ; the spine commences very far back from the glenoid cavity and prob-
ably tlie acromion, if present at all, did not project over the cavity. The liumerm is
(put(> viverrine in character, and in a less degree like that of some of the Mustelidce,
but stouter; the head is flattened, the tuberosities low and the bicipital groove wide;
the shaft is strongly curved and the very prominent deltoid ridge runs far down; an
epitrwhlear foramen is present. The ulna is peculiar for the great length of the olecran-
on. much exemliug that found in the recent carnivores. This would seem to be a
chanicter very prevalent among the creodonts, as well as certain insectivores, e. g., Cen~
Mrs. The sigmoid notch is deep, but the humeral facet is small— most of the humeral
tr(K-hlea lH‘ing occupied by the radius; the shaft is very broad, rounded on the internal
surface and channelled on the e.xtemal ; the distal end is expanded, but unfortunately
the articular face is broken off. Of the radius only the proximinal end is preserved.

I he head is transversely extended and occupies most of the trochlea of the humerus,
t)ms allowing no movement of supination. The carpus is creodont in character. The
s<-aphoid is ver)- low and flat ; its proximinal surface is rounded and shows a small inner
tul)erosity ; distallly there* are three articidar faces ; the shape of the bone is very much
as lu Mrsouyx. The lunar is very small, it is not co-ossifled with the scaphoid, which
It but slightly exceeds in vertical diameter ; distally it shows a small facet for the mag-
num and a larger one for the unciform. The pisiform is short and stout. The only
other carpal bone present in the specimen is the unciform which is verv peculiar.

1C proximal surface shows a strongly convex facet for the lunar, and the radial side
of the cuneiform facet is also strongly convex, while its ulnar side is concave ; the distal
surface is concave from side to side so that the outer edge of the bone is very thin. In

ON SOME NEW AND LITTLE KNOWN CREODONTS.

171

the absence of tlie magnum it cannot be decided whether a separate central was
present.

Metacarpal I is short and rather stout, the others very slender. The manus
was evidently plantigrade and pentadactyl. Though proportionally very much
weaker the general character of the metacarpals and phalanges is quite like
that of the ViverridxB, the metacarpals interlocking to about the same extent,
no. II touching the magnum and no. Ill the unciform, but not by extended
surfaces. The ungual phalanges are compressed and sharp and shaped much as
in Cynogale.

The ilium is short and little expanded ; the outer surface is convex and of the ordi-
nary creodont character, and the acetabulum is shallow. Of the fermir only a small
fragment of the upper portion is preserved, which shows, however, a very large second
and small but perfectly distinct third trochanter ; the shaft is slender and compressed.
The tibia is long and slender, and shows a slight double curvature above forwards and
below backwards ; the shaft is broad and trihedral at the proximal end with prominent
cnemial crest, distally it becomes subcylindrical ; the distal end is not greatly expanded ;
a very low ridge divides the astragalar facets and makes an inconspicuous tongue ; the
internal malleolus is very large and has what seems to be an articular face at its distal
end. The tarsus is at first sight much like that of the Viverridm, but presents some
important differences. Professor Cope states that the astragalus has “ two entire
trochlear faces, the wider external and directed intero-superiorly, the inner presenting
supero-interiorly. They are separated by an obtuse longitudinal angle, and are
little or not at all concave transversely.” The species to which this astragalus
belongs is not stated, but the astragalus of D. aUidens is very different from that
described by Professor Cope. It possesses a distinct trochlea, of which the external
portion is the larger; the neck is long and directed obliquely inwards, and on
its inner side is an excavation, apparently for the malleolus of the tibia, a very
characteristic creodont feature ; the head is rounded and narrow, articulating only
with the navicular and not coming in contact with the cuboid. The calcaneum
is short and stout, with very small sustentaculum, an expansion near the distal
end and a concave cuboidal facet. The cuboid is shaped much as in Cynogale
but without the distinct excavation for the navicular ; the proximal facet is
convex and the distal concave. The navicular is short with deeply concave
proximal face into which the convex head of the astragalus fits; the distal surface
shows three well-marked facets for the cuneiforms, and from the shape and position
of the inner facet, it is plain that a hallux was present. Only the external cuneiform
is preserved in the specimen; it is high and narrow, extending somewhat below the
level of the cuboid ; it is obvious from the facets on the inner surface that the
middle cuneiform was shorter and that metatarsal II abutted against the external
cuneiform.

24 JOUR. A. N. S. PHILA., VOL. IX.

172

ON SOME NEW AND LITTLE KNOWN OREODONT8.

Genua MIACIS.

'nrsil^teTo’rti.rMger basm of Wyoming, dittta from those hithe^o ,
known chiefly in its greater sise. It belongs with the other Bridge.- sucres to the
division of tiigcnns in which the last lower molar has a single root although on one
side of the jaw a very imperfect division of the alveolus is visible. The specif may
be thus defined: Length of lower molar series, ra. .0.50, of premolar series, .027, of
true molars, .023 ; depth of ramus below second molar, .020 ; no diastemata in lower
dentition ; mental foramina below second and third premolars ; chin abruptly rounded.

The specimen upon which this species is founded consists of the left mandibular
ramus in which all the alveoli are preserved, part of the right ramus retaining the
first and second molars, a dorsal vertebra, portions of ulna, radius, tibia, fibula, and
several metajiodials and phalanges.

The inferior dentition of the genus is well known, and the only features of
interest in this specimen are the absence of diastemata and the incisor formula,
which can now be given. The closed dental series is repeated in the Uintacyon
( edax of Leidy, but the type specimen of this species shows eight teeth in
the molar series. Professor Cope regards the additional tooth as abnormal, but
this may not lie a correct view. An analogous case is found in among recent

dogs. The symphysis in Miacis hathygnathus is narrow and the incisors closely
crowded togidher ; as Dr. Schlosser ^ has conjectured, they are three in number and

are small and have very compressed fangs. As in several other genera, the first and
third of the series ari.se at the same level while the median one is forced out and
upwards. In view of the very small space occupied by these teeth, it may well prove
to Ik* the ca.se that other creodonts which have been supposed to have a reduced
numlM'r of incisors, in reality po.ssess the full number.

'I'he masseteric fossa is deep, with very prominent anterior edge ; the condyle is
heavy and iK'neath it on the inner side the ramus is ver\' concave, almost like an incip
ient intlection ; the angle ends in a short slender hook ; the horizontal ramus is stout,
tkx'p and nithcr short, and the chin abruptly rounded ; the canine is directed upwards
and not obliquely forwards as in Uintacyon edax.

'I'he doi-sal vertebra, which is from the anterior part of the region, has a small,
slightly opisthoccrlous centrum ; the transverse processes are short and stout ; the prezy-

gaiKiphyscs unusually large and quite strongly convex in the anterio-posterior direc-
tion, the jiostzygapophyses of corresponding size and concave in the same direction, the
sjiine is trihedral, long, stout and directed strongly backwards. This vertebra resem-
bles quite closely the third dorsal in the dog, but with proportionately stouter spine.

The fragment of idna, comprising a portion of the shaft and the lower half of the
sigmoid notch exactly resembles the corresponding part in Didyrnictis. The lower part

* Morph. Jahrb. Bd. xii., p. 293.

ON SOME NEW AND LITTLE KNOWN CEEODONTS.

173

of the radius shows a broad, flattened and curved shaft with expanded and thick-
ened distal end ; the articular face gives but very faint indication of division into sca-
phoid and lunar facets. The character of this radius is decidedly more feline than canine.
The first metacarpal is short and stout with a convex head for the trapezium ; it is pro-
portionately longer, heavier and with a better developed trochlea than in the dog. The
fourth metacarpal is very slender ; its surfaces for the adjoining metacarpals and for the
unciform are almost exactly as in the dog. Professor Cope states that a specimen of
Miacis in the Princeton museum shows the separate scaphoid and lunar bones, but this I
think must be a mistake, as no such specimen is known to me. However, it is alto-
gether probable that these bones are separate in Miacis, for I find them to be so in the
closely allied genus Limnocyon, which Professor Marsh has very kindly enabled me to
examine.

The proximal end of the femur exhibits a small head, a moderate great trochan-
ter, a large second and very distinct third trochanter ; the distal end shows nothing
worthy of special mention. The tibia is shaped much like that of Didymictis, but
has an almost flat astragalar face, with no tongue ; this corresponds with Professor
Cope’s description of the astragalus. The internal malleolus is large and may have
had a distal articular facet. The shaft of the fibula is slender, but the distal end is
very heavy and forms a massive external malleolus Avith a large facet for the astrala-
gus. A phalanx of the second row is rather long and compressed and resembles the
corresponding bone in Mustela. The pes was obviously plantigrade and probably pen-
tadactyl.

The systematic position of the Miaddce has been much disputed. They differ
essentially from all other creodonts in having but one sectorial in each jaw and these
homologous Avith the sectorials of the Carnivora. On this account Dr. Schlosser*
proposes to remove the Miaddce to the Carnivora, and this vieAV has much in its
favor. Still important objections exist, particularly in the case of Didymictis. (1)
The scaphoid and lunar are not co-ossified, and perhaps a central is present ; (2) the
femur has a Avell-marked third trochanter ; (3) the astragalus possesses the typical
creodont character of a pit for the malleolar process of the tibia ; (4) the specializa-
tion of the lumbar zygapophyses is such as is found in no carnivore. To my mind
these characters outAveigh those derived from the dentition.

In the case of Miacis the material is not yet sufficient to enable us to
decide its position. The presence of the full number of loAver incisors is, as
Dr. Schlosser points out, shared by such forms as Stypolophus, Hyamodon, and
probably many other genera. The dentition is certainly very closely like that
of the true Carnivora, but * the structure of the feet wordd seem to be that of the
creodonts.

* Loc. cit.

174

ON SOME NEW AND LITTLE KNOWN CRLODONIS.

MEASUREMENTS.

Length of ramus mandibuli
Length of symphysis
Lreadth of incisor alveoli .
Canine, longitudinal diameter
“ transverse “

Premolar 1, length (alveolus)

“ 2, “

“ 3, “

“ 4, “

Molar 1, length

“ 2, “ . • .

“ 3, “ (alveolus) .

.098

.028

.006

.009

!oo6

.004

.006

.006

.009

.011

.008

.004

Genus PROTOPSALIS.

V. PuOTOI>SALIS TIGRINUS (?), Cope.

This very interesting and little known genus is placed by Professor Cope between
Oxi/mut and Pterodon, a determination which is in accordance with the known facts
of its structure. It differs from the latter genus in the fact that at least one of the
lower molars has an internal cusp, and from the former in the absence of such a cusp
from the last lower molar. Frotopsalis has hitherto been found only in the M'ind
River l)eds, hut in 1885 the Princeton party obtained a large creodont in the Bridger
basin, which shoidd probably be referred to here. The bones indicate a large animal of
great mu.scular development. A fragment of the humerus shows a heavy shaft with a
vcr>- i)rominent deltoid ridge extending nearly its entire length ; the supinator ridge
is likewise very conspicuous and a large epicondylar foramen is present. The radius
has a transversely extended head, divided into two nearly equal concave facets,
which must have covered the entire humeral trochlea ; the shaft is hea\y and flattened
and shows jirominent ridges for muscular attachments. Of the femur the articular
surfaces are wanting, but so far as it is preserved, it agrees almost precisely Avith
Profes.sor Cope’s figure; it is a long and heavy bone of transversely oval section.

'J he fragments preserved indicate that the hind limb was considerably longer than
the forc-hmh. The navimdar is. small with a deeply concave fiicet for the head of
die i^tragudus. The mdmd resembles that of Oxyema in having a large oblique facet
for the calcaneum and at an acute angle with this another for the astragalus. Meta-
tarsal III s^ws that the foot was lighter and Aveaker than Professor Cope has
supiKAsed. l\x^^phalan<jes are stout and depressed, andean ungual is thick and
ounc ed, somewhat hke that of a dog. Unfortunately the distal end is broken off so

lotlml”;.^^ ^ -tebra indicates a

ON SOME NEW AND LITTLE KNOWN CREODONTS.

175

If this specimen actually belongs to Protopsalis, there can be no doubt of the
correctness of placing this genus among the OxyoBnidoe ■, its relations to Pterodan
will be considered in another place.

Genus HY^NODON.

Four well marked species of Hycsnodon occur in the White River beds of North
America ; of these H. horridus and H. crucians Leidy are accurately characterized.
H. cruentus, however, has hitherto been imperfectly known and in his last publication
Dr. Leidy inclines to the view that it is only a smaller variety of H. horridus} A
very fine skull in the Princeton museum shows that the two are, nevertheless, distinct.
Aside from the diflerence of size the face is more depressed than in H. horridus, the
last lower molar lacks the external buttress on the anterior lobe, and the posterior
lobe of the last upper molar is externally concave and strongly curved outwards, as
in n. crucians. The fourth species, for which I propose the name ff. leptocephalus,
is new. It is founded upon two excellent skulls belonging to the Museum of Com-
parative Zoology, and for an opportunity to study these very interesting specimens I
am indebted to the kindness of Professor Agassiz.

This species is somewhat larger than H. crucians, which it resembles in dental
characters and in having the cranial constriction in advance of the fronto-parietal
suture. On the other hand the cranium is narrower and less rounded, and the posterior
nasal canal much more prolonged, being enclosed by the whole length of the palatines
and the pterj^goid plates of the alisphenoids. The American species may be tabulated
as follows :

I. Posterior nares opening between posterior part of palatines ; pterygoid plates of
alisphenoids not in contact below.

A. Cranial constriction in advance of fronto-parietal suture, H. cruciaris

B. Cranial constriction at fronto-parietal suture.

a. Face very deep; an external buttress on anterior lobe of

last lower molar, H. horridus

b. Face shallower; buttress absent, H. cruentus

II. Palatines in contact throughout; pterygoid plates of alisphenoids

meeting below, H. leptocephalus

The structure of the skull of Hyoenodon has not been completely described as
yet, and an attempt to do so may be of some value, even though repeating some
points already determined by Dr. Leidy. In what follows H. cruentus is taken as a
standard, reference being made to other species only when they depart from it in some
particular.

The basi-occipital is short, broad, very thin and slightly convex from side to side.
The limits of the other occipital bones cannot be very clearly made out, but as a
whole the occiput is low and broad, somewhat like that of the opossum; the con-

^ Ext. Mam. Faun. Dak. and Neb., p. 48.

17G

ON

SOMK NKW AND LITTLE KNOWN CREODONTS.

, , 11 „,i nnitP ^troii.'lv divergent; the paroccipitnl processes are short and

1«L t le occiput and is about as broad as in the dog; fte process is almost obso-
l’r,md is hardly at all in advance of the condyles. The region of the cmnium behind
the iwst-glciioids is exceedingly short compared with the same part m the Carnivora,
the Lme is true of some other creodonts (e. g. Uemny.) as well as of the carnivorous

marsupials and the insectivores. , , , -ji e

The basi-sphenoid is very long; posteriorly it is broad but narrows rapidly for-
wards- the alisphenoids are large and form eonsiderable part of the side waUs of the
cranium; near the anterior edge is a strong overhanging ridge which runs obliquely
forwards and upwards, and is continued on the frontal to the post-orbital process; the
pterygoid plates are large and in all the species closely approximated; in H. lepto
ccphalm they are actually united suturally, thus concealing the pterygoids and
bringing the posterior nares very far back. The parietals are long but not very broad
iKines and do not extend very far down on the sides of the cranium; this extension is
least in H. horrid^is, somewhat greater in H. crtientus and still more so in H. crucians
and Jl. leptocephalm. In front of the squamosal the parietal sends down a process
to meet the alisphenoid; the sagittal crest is not strongly developed except posteriorly.
The s(piamosals are large, extending well up on the side of the cranium and back to
the crest of the inion; they vary in size in the different species, of course inversely as
the extension of the parietals, as given above; the zygomatic process is heavy and
dirt-ctcHl outwards and then curves forwards; the glenoid cavity is broad and concave
in l)oth directions; the post-glenoid process is shaped much as in the dogs, but is con-
tinueil as a low ridge the entire width of the cavity; this ridge is least marked in H.
leptfx'ephalus; no preglenoid ridge is present.

I'he pre-sphenoid is narrow and but little exposed, as the vomer conceals it. The
limits of the orbito-sphenoids are not easy to make out, but they are obviously very
small. 'fhe Irontals, on the other hand, are exceedingly large. In H. cruentus and
II. horridus the cnmial constriction occurs at the fronto-parietal suture, in advance
of this the frontals expand rapidly and inclose large frontal sinuses; in the smaller
species the con.striction is just behind the orbit and the sinuses smaller. Prominent
post-orbital processes are present, and as in Thylacynus, the nasal processes extend
much in advance of the orbits.

The mes-ethmoid is exceedingly large, even more so than in the carnivorous mar-
supials; its size is most marked in the vertical direction, owing to the great height of
the nasjil chamber. The vomer is long and high. The ethmo-turbinals are well
dcvclo])cd and complexly folded, but none of the specimens I have examined enable
m<‘ to state the condition of the maxillo-turbinals. The nasals are long, broad and
archcnl from side to side; posteriorly they are wedged in between the frontals and
reach their greatest breadth at the fronto-maxillary suture; the free ends are emar-

ON SOME NEW AND LITTLE KNOWN CREODONTS.

177

ginated and the internal processes extend beyond the edges of the nares. The differ-
ent species vary chiefly in the length of the portion enclosed between the frontals;
this is greatest in H. horridus and least in H. leptocephalvs, where also the expansion
at the fronto-raaxillary suture is least marked.

The premaxillaries are shaped very much as in the dogs but are somewhat small-
er, and have short nasal processes; the palatine plates are much reduced. The
maxillaries are of great size; the two molar series diverge rapidly, so that the distance
between the last molars is three times that between the first premolars; the alveolus
projects far back and the palate is deeply notched on each side internally; the pala-
tine processes of the maxillaries are slightly concave from side to side, and are
nowhere very broad.

The peculiar structure of the palate in Hycenodon has long been know. In
H. horridus and H. crucians the hinder ends of the palatines are separated by a narrow
fissure which gradually broadens, thus forming the narial opening. I have seen no
specimen of H. cruentus in which the relations of those parts can be certainly made out,
but from the structure of the portions preserved it is very probable that their condition
is the same as in the species just described. In H. leptocephalus, as already mentioned,
the posterior nares are brought very far back by the meeting of the alisphenoids and
probably had no inferior opening at all.

As in Thylacynus and many Insectivora the lachrymal has a considerable exten-
sion on the face. The malar is rather slender, it is applied to the alveolar ridge
rather close to the line of molars, but it does not form any portion of the anterior
edge of the orbit which is occupied by the lachrymal; the malar arches outward from
the maxillary, little if at all upwards; there is no post-orbital process.

The mandible consists of a long slender horizontal ramus which gradually dee^)-
ens posteriorly and forms a very long symphysis with its fellow. The differences
exhibited by the various species are chiefly iu the ascending ramus. In U. horridus
the coronoid is high and pointed, its hinder edge very oblique and its summit much
in advance of the condyle; in II. crucians and leptocephalus the coronoid is much
broader, its posterior edge is nearly vertical and almost overhangs the condyle; the
masseteric fossa also differs in shape; in i/i cracmns it is rather shallow and most
extended vertically, in the other species it is very deep and extends far forwards. H.
horridus shows two mental foramina, the other species three; their position does not
seem to be constant. In all the species the condyle is placed low, below the line of
the teeth, and in all there seems to be an angular hook, though I have made it out
with certainty only in H. cruentus.

Foramina. M. FilhoD has described the foramina of H. hrachyrhyncus and
states that the condylar foramen, foramen lacerum posterius and carotid canal are all

' Filhol, M4m. sur quelques Mam. Foss., 1884, p 19.

17H

SOME NEW AND LITTLE KNOWN CREODONTS.

scpanite and that an alisplienoid canal is present. The American species present
some imi>ortant deviations from this arrangement. The condylar foramen is situated
ncfirer the medium line than in M. Filhol’s specimen and in H. cruentus there is an
e.Kcc‘(‘dingly minute foramen immediately in advance of it, which does not seem to
occur in //. horridus. The foramen lacerum posterius is placed as in the cynoid
series close behind the tympanic bulla, instead of being isolated as in H. bracliyrhyn-
chiis, and the carotid canal seems to be found with it, though this I cannot definitely
state. Tlie foramen lacerium medium is situated as in the dogs and the same may be
said of the stylo-mastoid foramen. The foramen ovale is placed opposite the glenoid
cavity and owing to the breadth of the basisphenoid at this point is widely separated
from its fellow of the opposite side. I have examined many skulls of the four
American species, but none of them show any alisphenoid canal, a very important
deviation from tlie species described by M. Filhol. In some American specimens a
shallow pit occurs where the posterior opening of the canal would be, and this may
possibly represent the remnant of such a canal. An unusually wide interval occurs
Ix'tween the foramen ovale and the foramen rotundum, which is close to the sphenoidal
fissure anti this to the optic foramen. These three foramina are enclosed in a com-
mon groove formed by the ridge already mentioned which runs downwards and back-
wards along the frontal, orbito- and ali-sphenoids. The posterior palatine foramina
are placetl opjwsite the interval between pm. 4 and m. 1 ; the anterior are narrow
ovals and reach close to the incisive alveolus. The infra-orbital foramen is placed far
forward immediately over pm. 3 ; the lachrymal foramen is single and opens within
the orbit. As Professor Cope has shown, three venous foramina connected with the
lateral sinus are present in Hyofiiodon, the postglenoid, postparietal and mastoid.

The lirain. Gervais^ has figured and described a cranial cast which he attributes
to 11. leptorhynckus. “ J’ai pu observer une partie d’un moule cerebral naturel de
1 Iliprnodon lepforhynchris et y constater la presence de circonvolutions bien plus
semblables a celles des carnivores des deux groupes des Felis et des Hyenes qu’ a
relies du Thylacyne. C’est le moule de la moitie posterieure d’un hemisphere cerebral
de ce (amivore extrait de la partie correspondante de la boite cranienne sur une piece
recuedlie dans la lamagne d’Auvergne par I’abbe Croizet.

‘ On y volt la moiti6 iwsterieure de la circonvolution de la faux ou quatrieme
circonvohition de la face convexe qui s’ aargit en avant pour recevoir le sillon crucial,
mais sans que ce sillon ait ete conserv^ et la troisieme circonvolution ou circonvolu-
tion internu-diaire inteme bien nettement separee de laprecedente ainsi que de ce qui
reste arricrc de la seconde circonvolution ou circonvolution intermediare extenie.

, . . ^ ^ ondre, comme chez les Felis et les Hyenes, avec la branche montante

im.^-rieure de la circonvolution sylvienne dont la branche anterieure n’est pas visible.

t. VI, p. 127, pi. VI, fig. 5.

Gervais, Nouv. Arch. d. Mus. 1^= Sr.

ON SOME NEW AND LITTLE KNOWN CREODONTS.

179

La scissure semble plus elargie que d’habitude et les plis ofFrent moins d’ondulations
que sur les cerveaux de meme taille appartenant aux espjces actuelles; mais le
caractere fondamental des cerveaux du quatrieme groupe de Leuret subsiste, et c’est
pres des Fells et des Hyenes que I’on doit placer le genre Hyenodon.”

Gervais does not state whether this fragmentary cranium was associated with
teeth, which would render its reference to Hymnodon unquestionable, and its shape
does not agree very well with that of the crania figured by De Blainville and Filhol.
At all events this cranial cast is very ditferent from the characters exhibited by the
American species, of which I have examined two, H. crucians and H. horridus, the
former in the Academy’s collection and the latter in the Princeton museum. One is
forced to conclude either that the brain figured by Gervais belongs to some other
genus or that the American species differ from the European much more widely than
has been supposed.

The cranial cast of H. crucians (partially figured by Dr. Leidy in his Ext. Mam.
Faun, of Dak. and Neb., PI. II, fig. 2) is essentially unlike Gervais’s specimen. The
hemispheres are long and narrow, with straight and not very strongly marked convolu-
tions ; no indication of the crucial sulcus is to be seen ; the limits of the frontal lobes
are not very clear, but they must have been very small; the temporal lobes are large
and the sylvian fissure widely open; the olfactory lobes are large and completely ex-
posed. It is rather difficult to make out the exact number of longitudinal convolu-
tions ; probably, however, there are three : the sylvian gyrus has a broad posterior
branch, the anterior being absent. The intermediate and internal gyri are straight
and show no tendency to undulate or divide, nor are connecting gyri to be seen. This
brain is not in the least like that of the cats and hyenas, but is more like that of
Stypolophus ( Cynoliymnodon') as figured by M. Filhol.

The cranial cast of H. Itorridus, compared with that of H. crucians, is an excellent
example of Gervais’s principle of an increase in cerebral complexity accompanying an
increase in the stature of the species. This brain is long and narrow, broadest poste-
riorly and tapering regularly forwards ; the olfactory lobes are very large and not over-
lapped by the hemispheres, which also leave the cerebellum entirely uncovered ; the
temporal lobes are very large and the frontal exceedingly small. Four longitudinal
convolutions seem to be present; the sylvian gyrus has only the hinder branch de-
veloped, which bends around posteriorly and joins the external median gyrus ; the
latter is straight, runs obliquely forward and inward, and at its anterior end joins
the internal gyrus. The internal median gyrus is very short and joins the internal
both behind and before ; perhaps it would be better to consider this as simply a par-
tial division of the internal one. In addition to these a small curved gyrus occurs
on the frontal lobe. The great difference between this brain and that of H. crucians
consists in the connection between the convolutions. There is no indication of a cru-
cial sulcus, and no outward curvature of the median gyrus. Indeed, all the convolu-

26 JOUR. A. X. S. PHILA., VOL. IX.

ON SOME NEW AND LITTLE KNOWN CREODONTS.

IKO

tions.,r,- Slmi"ht .md show no umlnlations, except the small ciitved frontal gyms,
•riie eercliellum is large, being l.roader than the hemispheres; the vermis is rather
narmiv and not very prominent, but the lateral portions are very large and obscuiely

convoluted. (Sec I’l. VII, Fig. 4). , m „ ■ r

The brain of II. horrklm is strikingly small when compared with the size of the

skull : it is proportionally but slightly longer than the brain of Thylacjjnm, and not
quite so broad; the latter also shows considerable similarity in the pattern of the con-
volutions, though these are very obscure in a cranial cast. (See Gervais Nouv.
Arch. d. Mus., t. v., I’l. XIV, Fig. 5).

Thus Gervais’s specimen is seen to differ from the American species in shape, in
the much narrower cerebellum, and in the character of the convolutions.

Skf:i,eton.-:-A most important and valuable specimen of H. horrklus, belonging
to the Museum of Comparative Zoology, has been very kindly sent to me by Professor
Agassiz. This specimen, I think, will decide the disputed question as to the syste-
matic jiosition of this curious genus.

The adds has rather small transverse processes, which do not seem to be pierced
by the vertebral canal ; the superior and inferior arches are slender. The axis is in
some rcsiKJcts like that of Mesonyx ; the centrum is broad and much depressed, with a
strong keel ; the atlanteal faces are narrow, transversely directed and not emarginated
by the neural canal, which is small ; the transverse processes are long, stout and per-
forat(Hl at the base ; the spine is high and thin, and posteriorly forms a stout rod which
])rojccts to the 4th vertebra ; this rod is horizontal instead of oblique, as in Mesonyx.
\ somewhat similar arrangement is seen in Lutra. This specimen shows clearly that
tlie axis doubtfully attributed to Hyamodon by M. Gaudry (Ench. d. INlonde Anim.,
fig. 9) must belong to some other genus. No resemblance to the opossum’s axis is to
lx; found in the specimen before us. The other cervical vertebrae are rather long, with
opistluKJcelous centra, and large, very oblique zygapophyses ; the spine of the 3rd is a
low ridge, that of the 7th long and stout; the others are too much broken for deter-
mination.

The dorsal vertebra;, of which the anterior seven are represented, hav^e rather
sliort, heavy and depressed centra, and very strong neural spines ; but, as none of the
latter are complete, their length cannot be stated; all the spines incline strongly
backwards. 1 he first dorsal is remarkable for the large size of the transv^erse process,
and its strongly concaA e facet for the tubercle of the rib ; the second has a similar but
somewhat smaller process, and in the other vertebrae the process becomes of the ordi-
nary size, though conspicuous in all. In proportion to the size of the skull, these
vertebra* arc larger and have heavier processes than those of Mesomjx, indicating a
more jOTwcrful animal.

Of the Inmlmr scries five are preserved; they have very large centra which are
)road, depressed, slightly opisthoccelous and, except the last, provided with keels ; the

ON SOME NEW AND LITTLE KNOWN CEEODONTS.

181

tl•ans^erse processes are long, but not very broad; they are curved sharply forward and
terminate in a point ; the spines are of moderate height, but have great antero-poste-
rior extent and incline strongly forward, that of the last vertebra is nearly vertical.
HycBaodon shows in a very marked degree the creodont peculiarity of the lumbar
zygapophyses ; the prezygapophyses are exceedingly concave and curve far over; into
these the convex, nearly cylindrical postzygapophyses, fit. The metapophyses are
small and in the last three vertebrae rudimentary ; small anapophyses are present.

The sacrum consists of three vertebrae ; the first has a broad and depressed cen-
trum, with very large pleurapophyses and long oblique transverse processes ; the pre-
zygapophyses are shaped as in the lumbar region, but are much lower ; the spine is
low and not ankylosed with that of the succeeding vertebra. The second sacral is of
about the same length as the first, but much narrower ; only the anterior comer of the
pleurapophysis is in contact with the ilium which is carried almost entirely by the
first vertebra ; the spine is low. The third sacral is the smallest of all. No caudal
vertebrae are preserved, but Hycenodon probably possessed a long tail.

Ribs. — The anterior ribs are very broad and flat; this flattening is marked as far
as the sixth; behind that the ribs become more rounded. The first rib is especially
broad and has an exceedingly large and convex tubercle ; the second is similar but
has a smaller tubercle ; in the others the tubercle is less conspicuous and somewhat
saddle-shaped.

Tlie fore-limb is proportionally longer and heavier than in Mesonyx, but strik-
ingly weak when compared with the modern Carnivora. The humerus (which is
somewhat crushed and has lost its proximal end) has a long and rather slender shaft,
with a prominent deltoid ridge; the supinator ridge is low; an epicondylar foramen is
present, as is also the supratrochlear; the anconeal fossa is broad and very deep; the
trochlea has a prominent ridge and the internal edge is prolonged downwards ; the
condyles are not very prominent. This humerus agrees quite well with that of II.

( Taxotherium) parisiensis, as figured by De Blainville (Subursus, pi. xii), but differs
in the presence of the supratrochlear foramen and the greater prominence of the
intertrochlear ridge.

The xdna is rather short and stout ; the shaft, though flattened, is heavy, and is
convex on the inner, deeply channelled on the outer side ; the olecranon, as in the
creodonts generally, is very prominent; the sigmoid notch is deep and the radial
facets occupy nearly the entire anterior face of the lower end, only a small portion of
this face is in contact with the humerus. De Blainville’s figure differs from this
specimen only in the somewhat reduced radial surface. The distal end is much com-
pressed and ends in a rounded-convex facet for the cuneiform.

The radius has a broad proximal end, Avhich occupies nearly the whole breadth
of the humeral trochlea; the upper part of the shaft is broad and flattened; below it
becomes rounder and much stouter ; the distal end is expanded and thickened, espc-

ON SOME NEW AND LITTLE KNOWN CKEODONTS.

cially oil the outer or ulnar side, giving a very similar shape to that seen in the large
cats.

The carpus is entirely creodont in character, and differs from that of any known
carnivore in the presence of a central and the separation of the scaphoid and lunar.
The scaphoid has a very small vertical diameter ; its proximal surface shows an inner
concave surface and an outer convexity; the distal facets meet at a low angle. The
lunar is narrower but of greater height than the scaphoid, and the radial surface
comes far down on the anterior face ; it has not the regular wedge-shape seen in
Memnyx, but shows an infero-lateral surface for the central, a verj’ small inferior face
for the magnum and a still smaller one for the unciform. The cuneiform is a large,
square bone; on the external side it gives off a strong recurved hook-like process; the
ulnar and unciform facets are both concave. The pisiform is very large and is espe-
cially expanded at the free end. The trapezium is of very unusual size ; it descends
below the level of the trapezoid and abuts against the radial side of the second meta-
carpal. The trapezoid is smaller; it has little contact wdth the scaphoid, being
almost completely separated from it by the central; its metacarpal facet is saddle-
shaiMxl. The central has a more internal position than va. Mesonyx, being wedged in
between the scaphoid and trapezoid and touching the magnum and lunar by small
^surfaces; it is wedge-shaped, with the edge placed anteriorly ; posteriorly it thickens
rapidly. The magnum is missing from the specimen, but from the relations of the
surrounding parts it was obviously small. The unciform is large and has a sub-
quadrate anterior face ; nearly all the proximal surface is covered by the cuneiform,
leaving a ver>’ small facet for the lunar; the surfaces for the fourth and fifth meta-
carpals are plainly marked; the latter is altogether distal and does not extend on the
external side.

-\s a whole, the carpus is very low and broad. (See PI. VU, Fig. ,5).

The mciacarpah are five in number, and, as in Mesomjx, show’ a greater degree of
interlockmg than in any carnivores except the cats. In order of length they are III,
1 ' , 11, \ ,1. No. I is quite short, but stout, especially proximally, and fits into the
tm,Hv.ium by a convex head. No. II is the stoutest of the series; on the radial side
of the proximal end it has a facet for the trapezium; the ulnar side is somewhat ex-
ca^ated for No. II, and sends out a strong process, which abuts against the magnum.

iu'l oil "PI*' end is mutilated, butlt ob-
it X TV .* ^ elttitted against the unciform, which shows a facet for

tlic u"iiciforiii'*nn,l'"’^-r"'‘i'“ ’’'“P®’ articulates with

'l!ort I^^steltt t r T V This last is

face of the unciform ''”11^™ ‘*1 'Tf "’i‘>> «« aisW sui-

no moiliau pltalangcs arc inC^Z” and somewhat depressed;

heavv modcratelv pnm . ^ j tmguals are peculiar. They are short,

pi esse and blunt; the proximal facet is deeply concave and

ON SOME NEW AND LITTLE KNOWN CEEODONTS.

183

shows beneath it a tubercle for the attachment of the tendon, -which, however, forms
no such process as in the cats. At its free end the phalanx is deeply cleft for nearly
half its length. This claw tends to confirm the inference drawn by Gervais and
others, from the structure of the palate, as to the aquatic habits of the genus, and it
proves conclusively that the hind leg and foot which I formerly referred to Hycenodon,
belongs to some very different form.

There is still much doubt as to the structure of the carpus in the European
species Hycenodon, Professor Cope states’ that in a specimen of H. requieni, from
Desbrusges, in the Jardin des Plantes, the scaphoid and lunar are coossified. On the
other hand De Plain ville’s figure of H. parisiensis agrees very well with the speci-
men just described, and seems to show the impression of a separate lunar.

The only part of the hind-limb preserved is the ilium; this is rather feline in
character, being but slightly expanded and showing a deep gluteal surface.

This survey of the osteology of Hycenodon brings out some important and, appar-
ently, constant differences between the American and European species of the genus.
More perfect knowdedge of the French species will not improbably necessitate the di-
vision of the genus Hycenodon as now understood, and the revival of De Blainville’s
name Taxothermm ; his figure of T. parisiensis shows no alisphenoid canal, agreeing
with the American species; though this may, of course, be an oversight. The name
Taxotherium would, in this case, include those species which have separate scaphoid,
lunar and central bones in the cai-pus, no alisphenoid canal, cerebral hemispheres not
broader than the cerebellum, and with straight convolutions. The name Hycenodon
would then be limited to the species with coossified scaphoid and lunar, an alisphe-
noid canal, hemispheres with winding convolutions and broader than the cerebellum.
It would be premature to make this division until the reference of the French speci-
mens of carpus and brain can be cleared up.

As far as the American species are concerned, their systematic position can now
hardly be a matter of doubt. M. Gaudrey’s view as to the marsupial character of the
genus is definitely disproved by the abundant material now at command. Some resem-
blances to Thylacynus, it is true, are apparent: but these features are also common to the
Insectivora, and only the dentition can be supposed to indicate remote marsupial affini-
ties. M. Filhol,^ on the other hand, contends that Hycenodon is a true carnivore, but
the teeth, the carpus and the vertebrae forbid any such reference of the American
species, and even if furthur investigation should show that most of the French species
have the scaphoid and lunar cobssified and thus necessitate the revival of Taxotherium,
it would be a very unnatural and arbitrary mode of classification to place two such
closely allied genera in different orders. The character of the dentition is alone suffi-
cient, it seems to me, to forbid the reference of Hycenodon to the Carnivora.

1 Tert. Vert., p. 256.

Loc. (it.

184 ON SOME NEW AND LITTLE KNOWN CREODONTS.

Mr M'ortnian* places the -enus among the Inseetivora ; but this I consider to be
altogOher untenable, as is shown by the convoluted brain, the sectorial dentition, and
the structure of the vertebr®.

The origin of the Hycenodoniidce offers a more difficult problem. I was formerly
inclined to fSlow Professor Cope in deriving them from the Mesomjclddce, but the
more perfect specimens described in this paper have convinced me that this view is
erroneous, as the structure of the feet prove, not to mention other characters. The
evidence now available would seem to point to the Oxycenidce as the family among
which the ancestors of Hycenodon are to be sought. M. Filhol has shown the close
relation which exists between Hycenodon and Pterodon ; the latter is distinguished
by the formula pm. m. |, the presence of internal cusps on the upper molars, the less
extensive union of the palatines, and by the union of the foramen lacerum posterius
with the carotid canal. Most of these distinctions are primitive and the only speciali-
zations which Pterodon shows are .the coalescence of the foramina and the loss of the
first lower premolar. It seems therefore reasonable to regard the two genera as de-
scended from a common ancestor very similar to Pterodon. This genus is plainly al-
lied to Oxymui, indeed Cope includes them in the same family ; between these two
genera comes P-otopsalis. Oxymna itself cannot be the ancestral genus, on account
of tlic reduced dentition; but probably some Oxyaena-like form, with full dental series,
will prove to be the desired ancestral type.

(The measurements of Hycenodon are included in the same table with those of
Memnyx.)

The definition of the group Creodonta is by no means easy, as the order is such a
large and heterogeneous one. Professor Cope informs me that the only diagnostic
character which he can find is the involution of the posterior dorsal and lumbar zy-
gajwphy.ses. A provi,sional definition may be attempted as follows : Unguiculate
mammals having separate scaphoid and lunar bones in the carpus ; a central bone
(probably) pi’cscnt in all ; brain small, but in most cases more or less convoluted ;
molar teeth usually all sectorial or tuberculo-sectorial ; interlocking of posterior dor-
sjil and lumbar zygapophyses very perfect.

In conchision I wish to express my thanks to the Academy, and to Professors
Agassiz and Cope for the loan of valuable material, and to Professor Marsh for allow-
ing the opportunity to study some of his unique specimens.

* American System of Dentistry, p. 420.

ox SOME NEW AND LITTLE KNOWN CEEODONTS.

185

EXPLANATION OF THE PLATES :

Plate V.

Mesonyx obtusiJens. — Cope. Restoration of skeleton about i natural size ; mostly from one indi-
vidual found at Twin Buttes, Wyoming, and now in the Princeton Museum.

Plate VI.

Fig. 1. Mesonyx obtusidens ; side view of skull, two-fifths natural size.

\a. Base of same skull.

Fig. 2. Hyanodon cruentus. — Leidy. Side of skull two-fifths natural size.

2«. Base of same skull.

Plate VII.

Fig. 1. Mesonyx obtusidens; left manus.

Fig. 2. Mesonyx obtusidens ; left pes. In this figure the artist has omitted to indicate that the
length of the metatarsals, except No. V, is conjectural. Proximal and distal ends and
most of the shafts are present in the specimen for all the metatarsals, but only No. V is
complete.

Fig. 3. Mesonyx obtusidens ; phalanges of 3rd digit of manus.

Fig. 4. ^ Hyanodon horndus—lx-mx . Natural cranial cast.

Fig. 6. Hyanodon horridus ; right manus from a specimen belonging to the Museum of Compara-
tive Zoology, at Cambridge, Mass.

Fig. 6. Hyanodon horridus ; phalanges of pollex of same sj)ecimen.

(Figures of Plate VII all natural size).

18G

ON THE STRUCTURE AND CLASSIFICATION

ON THE STRUCTURE AND CLASSIFICATION OF THE MESOZOIC MAMMALIA.
liY Henry Fairfield Osborn.

In 1871, when Profes.sor Owen completed his “ Monograph upon the Fossil Mam-
malia of the Mesozoic Formations,” there were but twenty genera of this period known
to science, two of which only, Dromaiherium and Miorolestes, were from Triassic beds,
and tlie remainder from the Jurassic. The genera have now been increased to over
thirty-five, five of these coming from the Trias. These numbers alone cause us to
modify our former ideas as to the paucity of mammalian life in the Mesozoic period.
In a rapid survey of this ancient fauna, we are at first struck with the very great
diversity which prevails in the form and arrangement of the teeth, consisting of six or
seven wholly distinct types ; and this at a zoological period which we have been
accustomed to consider as the dawn of mammalian life. The above types, although
jirimitivc, are essentially mammalian. In one genus only, Dromaiherium, do we find
clear evidence of reptilian affinity in the dentition. Then we are surprised to discover
a very close zoological relationship betiveen fossil faunae of the same age, but having
a wide gi'ographical distribution. The most striking instance of this is the parallelism
iM'twemi the American and British upper Jurassic fauna. For, among the thirteen
gencni discoveri'd by Professor Marsh in the Atlantosaurus Beds, or American Upper
.Bira.ssic, six have their counterparts in the English Middle Purbcck, and the family
characters arc very close as regards the remainder. The two American triassic
gmicra, Dromaiherium and Microconodem, are isolated, but the genus Witylodon, from
the South .\frican Irisis, has a close ally in Triglyphus from the Rhaetic beds near
Stuttgart, as Ncumayr has pointed out ; it is also related to the genus Bolodon from
the 1 urhock, and probably lias a lateral successor in Polymastodon, a highly modified
form found in the .\merican Puerco beds. The-inost remarkable distribution, both
geographically and stratigraphicaUy, has, however, been enjoyed by Plagiaulax, which
extends froin Microlesies, in the Trias of Germany and England, to Ptilodus in the
I ucrco of New Mexico, and Neoplagiaulax in the lower Eocene of France, probably
terminating, by a side branch, in Thylacoleo of the Australian Quaternary. The fol-
lowing table shows the geological and geographical distribution of the known meso-
zoic genera and of their tertiary descendants:

OF THE MESOZOIC MAMMALIA.

J87

ENGLAND.

NOKTH AMERICA.

GERMANY

AND

FRANCE.

AFRICA

AND

AUSTRALIA.

Quaternary.

Australian Bone
Caves.

Thylacoleo.

Eocene.

Lowermost Eocene,
Puerco.

Polymastodon,

Ptilodus,

Chirox,

Neoplayiaulax.

Lower Eocene,
Cernaysienne.

Neoplagiaulax.

Cretaceous.

Uppermost Cretace-
ous, Laramie.
Meniseoessus,

Jurassic.

Upper Jurassic,

M iddle Purbeck Beds.

Spain coiherium, . .
Amblotherium,
Achyrodon,
Phnscolfsleg, . . .

A throdon,

Stylodon, ....
Peraleateg,

Ptragpalax,
Lfiplocladus,
Trieonodon, . . .
Triacanthodon,
Plagiaukix, . . .

Bolodon,

Peramug,

Lower Jurassic,
Stonesfield Slate.
Aniphitherium,
Amphilestes,
Phascoloihemim, . .
Slereognaihus,
Amphitylug.

Upper Jurassic,
Atlantosaurus Beds.

Paurodon,

Menacodon,

Diplocynodon,

Docodon,

Dryolestes,

Stylacodon,

Priacodon.

Asthenodon,

Laodon,

Trieonodon,

Enneodon,

Ctenacodon,

Alio don,

Tinodon.

(Tinodon.)

Triassic.

Uppermost Triassic
or Rhaetic.

Microlesies.

Uppermost Triassic
or Jura Trias.

Dromatherium,

Microconodon.

Uppermost Triassic
or Rhaetic.

Microlesies,

Triglyphus, ....

Upper Triassic,
Stormberg Beds,

S. Africa.

Tritylodon.

N. B. — The genera in adjoining columns and connected by dotted lines are closely related to each other.
Professor Cope now considers the Puerco as uppermost Cretaceous. Judging by the degrees of specialization
observed in the related American and British genera, the American Upper Jurassic beds are slightly older
than the Purbeck

TJIK STHUOTUBE AND CLASSIHCATIOX.

] M8

wl! " vtv'rarew'— !or»lK,w^ »f

times. \ en eaic somewhat unspecialized

r ^.n.rd to the excessive number of teeth. In the greatly extended field of ex-
Iltion we should have anticipated finding one or more types of dentrt.on wholly d.s-
!inct from those described by Professor Owen from the English Jurasmc but this has
not proved to he the ease. Fmm the very fact of their general zoological relationship, _
howlver, these newly-discovered genera from other countries are of “

their taring upon the structure and relationships of the English genera. It is not so
much then the form of the teeth as the presence of an excessive number of molars,
which f?ives a primitive character to the Jurassic fauna. In other respects it is, upon

Fioi-re 1. The types of the British rae.sozoic mammals, representing the natural size. 1. Amphilesles.
2. AmphUyltu. 3. PhuKColotheriuiii. 4. Triconodon mordcuc. 6. Peramns. 7. Spalacotherium. 8. PeraUstes. 9.
PmupcJax. \Q. LfjtUx'ladut. U. Amblolherium. 12. Phascolestes. 13. Achtjrodon. lA. Stylodon. 13. Athrodon.
10. liolodnn. 18. Plnyiaulax minor. 19. Stereognathus.

the wliolc, surprisin<rly modern. The various divisions of the dental series are almost
ns sharply defined as in modern genera. Another characteristic is the diminutive size
of tliis fauna. As shown in the accompanying series of life-size outlines of the man-
dibular and maxillary specimens, the genera vary from the size of the smallest
Ilodents to that of the smaller varieties of the Hedgehog.

Literature. Professor Owen gave in his Memoir a full list of the papers upon
the Mesozoic Mammalia which had appeared previously. The most valuable among
the.sc were his own contributions upon the Stonesfield Slate genera in the “ Transac-
tions of the (icological Society, 1835”, and Dr. Falconer’s Memoirs upon Plagiaulax
in the “ (Quarterly Journal of the Geological Society,” in 1857 and 1862. Professor
Owen s well known Memoir of 1871, embraced a very elaborate and able description
and discussion of all the Mesozoic genera which were then known. In 1878 Profes-
sor Marsh first discovered the American Jurassic mammals, and began a series of brief

OF THE MESOZOIC MAMMALIA.

189

papers in the American Journal of Science and Arts, which have since appeared fre-
quently. In 1878 Professor Cope discovered the Puerco Beds, in New Mexico, which
have subsequently yielded several genera closely allied to the mesozoic forms de-
scribed by him in the American Naturalist, in the “ Proceedings of the American Philo-
sophical Society,” and in his large memoir upon the “ Tertiary Vertebrata.” In 1883
Dr. Lemoine published his valuable memoir upon Neoplagiaulax. In 1884 Professor
Owen described the remarkable genus Tritylodon, which may prove to be the same as
Trifjlyplius previously described by Professor Fraas in his work “ Vor der Siindfluth,”
p. 215. In 1884 Professor Cope published a highly suggestive paper upon the Ter-
tiary Marsupialia, in which he described Meniscdessus from the Cretaceous, and pointed
out the ordinal relations of Tritylodon, Polymastodon and Playiaulax. The most
recent contribution to this subject is an important article by Professor Marsh on the
“American Jurassic Mammals,” which appeared in April, 1887.^ This marks a very
great advance in our knowledge of the Jurassic forms previously known, and adds many
new genera, together with a classification of the American and some of the British forms. ^
Preparation of the present memoir. — Through the kindness of the members of
the Geological Department of the British Museum, I was recently enabled to study
the fine collection of mesozoic mammals preserved there, which formed the principal
material for Professor Owen’s monograph. My original intention was simply to re-
view the types as described by him, but the discovery of new facts followed so rapidly
that the plan of a systematic revision of these forms gradually resulted. While
naturally confirming the greater part of Professor Owen’s observations, I was led to

* The MS.S. for the present memoir was nearly prepared when I received this article. The principal ser-
vice it afforded me, in connection with the British types, was in correcting my views of the supposed family
relationship of Stylodon and Athrodofi ; in showing the full pattern of the Stylodon type of molar, and in the
discovery of the maxillary dentition of Plagiaula.v, which widened the separation of this genus from Bolodon.
The transitional dentition of the genera Meiiacodon and Tinodon also first suggested to me the relationship of
Spalacotlierinm to Phascolotherium. The importance of this contribution arises not merely from the variety of
new forms described, but from the fact that the author has, in many cases, studied both faces of his specimens
by freeing them from the matrix entirely, whereas most of the British types are still partly imbedded in
the matrix.

2 Partial List of Memoirs and Shorter Articles;

Professor Richard Owen.

1. Monograph of the Fossil Mammalia of the Mesozoic Formations. Palaeontographical Society, London,
1871.

2. On the Skull and Dentition of a Triassic Mammal {Tritylodon longaevus, Owen) from South Africa.

“ Quarterly Journal of the Geological Society,” 1884.

Dr. Vidor Lemoine.

3. Etude sur le Neoplagiaulax de la Faune Eocene inf4rieur des Environs de Reims. Extrait du “ Bulletin
de le Soci6t4 G^ologique de France.” Fevrier, 1883.

Professor E. D. Cope.

4. The Tertiary Marsupialia. “ American Naturalist,” 1884, p. 687.

Professor 0. C- Marsh.

5. The American Jurassic Mammals. “American Journal of Science and Arts.” April, 1887.

6. On the structure and classification of the Mesozoic Mammalia. (Abstract of this memoir). Proc. Phila.
Acad., June, 1887,

190

ON THE STRUCTURE AND CLASSIFICATION

differ from him in some important respects, profiting in several cases by the ne^v ma-
terial which has been added to the collection since the publication of his memoir.
Every facility for this study was extended to me by my friends, Dr. Woodward, Mr.
Etheridge, Mr. Davies and Mr. Smith Woodward, to whom I wish to express my
sincere appreciation. I have also enjoyed much assistance in other collections. Dr.
Ix-moine, of Rheims, kindly allowed me to examine, Avith the rest of his materials, his
very interesting series of the Eocene Plagiaulax. Professor Cope generously placed
his'Puerco collection in my hands for study and comparison. Professor Marsh, hav-
ing a memoir ui>on the Mesozoic Mammalia in preparation, has kindly permitted me
to make a careful examination of the type specimens of his various genera, which
has been of great assistance. The American Triassic genera have also been studied
from the original specimens in the Williams College and Philadelphia Academy col-
lections. I did not have an opportunity of examining the types of Amphitherium,
Amphityhis anA AmpJiilestes, axid wca mvicYi indebted to Mr. Lydekker for the assist-
ance he has extended in connection with the study of these genera. Influenced by
these opportunities the purpose of the present memoir has gradually shaped itself as
follows :

1 . To present as clearly as the available material alloAvs, the characteristic features
of each of the Rritish mcsozoic genera, without especial regard to specific characters.

2. To present the principles upon which the mesozoic mammals, in general, may
Ik? cla.ssificd into larger and smaller zoological divisions and families, including a com-
plete generic synopsis. Also, to show their relationships to modern orders of mam-
mals.

3. To di.scuss the dentition of these genera in its bearing upon the origin and
succession of mammalian tooth forms.

I. THE BRITISH MESOZOIC MAMMALIA.

I he following description of the British genera is based upon study of the original
siK?cimens in the case of all except the lower Purbeck genera above mentioned ; also
StercogmithmaM some of the molars of the Rhaetic Microlestes and Hypdprymnopsis.

ith the aid of Mr. Lydekker, I have here largely relied upon Professor Owen’s draw-
ing and descriptions, and tluis have been able to place onlv one of these genera in the
senes of typical figures given upon plates VIII and IX. The notes upon these genera
are, therefore, somewhat less complete. In the course of studying the type specimens
winch, as seen m the accompanying figure (1), are often extremely minute and difficult
o gmsp, laAc learned to attach great importance to minor characters such, for ex-
ample, as the basal cusps of the premolars, which prove to have a very important
bearing uixin the problems of affinities and classification. These cusps present vari-
ous t egrees o ceAclopment and a variety of shapes, Avhich in every case have fixed

OF THE MESOZOIC MAMMALIA.

191

relations to the pattern of the molars, canines, incisors and to the shape of the man-
dible ; in other words to the kind of diet. In order to britrg out these minor char-
acters clearly, the drawings have been finished with the utmost care and made upon
a very large scale. ^ A second principle adopted in the drawings is that of composi-
tion, upon a system which is Mly explained in connection with the text of the plates.
AVhile open to some objections this has the effect of bringing all the known characters
of a species which can be legitimately placed together, before the eye at the same
time. In Professor Owen’s Memoirs, the majority of the specimens thus placed
together are figured separately. The numbers correspond with those affixed to the
specimens in the British Museum collection.

AMPHITHERIUM.

Since the publication of Professor Owen’s memoir, a portion of a small jaw from
the Stonesfield Slate has been added to the British Museum collection and referred to
Amphitherium (No. 36,822). The teeth preserved are the last premolar and five
molars, in all of which the cro^vns are perfect. A close examination of these crowns,
in comparison with the figures of A. Prevostii (Mes. Mamm., PL I, fig. 23), and of
A. Broderipii (PI. I, fig. 25), at first led me to believe that this specimen was wholly
distinct from Amphitherium, but subsequently these molars were found to correspond
closely to the somewhat mutilated molar crowns of the type specimen of A. Prevostii,
as figured in PI. I, figs. 21 and 22. Unfortunately I was unable to compare the ori-
ginal types, but from a study of all the drawings and descriptions available, this cor-
respondence has been confirmed, and the conclusion reached that among the speci-
mens heretofore referred to Amphitlierium, we have the types of three distinct genera.
The A. Broderipii has, in fact, already been separated with some qualification, by
Professor Owen,^ under the name AmpMlestes-, the third genus remains to be dis-
tinguished.

Let us begin with the type specimen of Amphitlierium,^ the first to be discovered
and described. All the numerous figures of this specimen which have been published^
agree as regards the pattern of the molar crowns. Observe especially m, nij, and m^.
“ In the fifth molar the middle external cusp is nearly entire to its sharp apex; part
of the anterior cusp and the base of the internal posterior cusp are preserved.” In
this description Professor Owen indirectly suggests that the summit of the posterior
cusp has been broken away. If we adopt this suggestion we must suppose that the

‘ Palaeontology has suffered much from the mistaken custom of making figures large or small in direct
proportion to the size of the object illustrated. A quarto plate will often be devoted to some very large object
in which perhaps the anatomical details are few and simple, while a row of small teeth, full of important
diagnostic characters, is crowded into such a small scale that it is impossible to make out the details.

^ Mes. Mamm., p. 16.

» De Blainville, Comptes Eendus. Aug. 20th, 1838.

* Prevost. Ann. des Sc. Nat., April, 1825, (PI. 18, fig. 2). Owen, Oeol. Transactions, Ser. 2, Vol. VI.,
1839. Also, Brit. Foss. Mamm., (fig. 16) ; and Mes. Mamm., (figs. 21 and 22).

ON THE STRUCTURE AND CLASSIFICATION

c„s,,s of all the .oolars are ako broken, whreh is ver, improbable. The faet is,
these eroivns of the molars eoiiskt of elevated anterior and median cusps, followed by a
low poMcrio,- hed, and with an internal cingulum rising into the low cusp on the inner
face of the ineilian cusp. When these mutilated crowns are comparetl, one by one,
with the iierfect crowns of the newly-actpiired jaw (No. 36,822) there can be no
doubt that they belong to the same pattern. If this be the case, the latter specimen
is of great interest, as it enables us for the first time to fully characterize the molar
dentition of Ainplntherium.

Tliese teeth deserve a somewheat detailed description, (fig. 2). They are seen upon
the outer surlace, which is devoid of a cingulum. The premolar, which is probably
closelv resembles pm,, of A. Prevostii (fig. 22, Mes. Mamm.). The crown is bifanged
and slightly rec■ur^•ed, with a low posterior heel, and a cusp upon the anterior slope,
which prohablv represents part of the internal cingulum. The molars, in general, dif-

Fiourf. 2.— .-V portion of the left mandible of the Amphilherium Prevostii, seen upon the outer surface,
approximately flve times the natural size, from a specimen in the British Museum collection.

fer from tlio.se of the .1. Prevont'd (fig. 23, Mes. Mamm.), first; in the repression of the
thinl, or jMi.stcrior cusp, wliicli is replaced by a low, sloping heel ; second, in the elevation
of the anterior cusp, wliicli rises nearly to the level of the middle cusp; they differ from
those of A. lirodcripd, lioth in the absence of the posterior cusp and of all tr<ace of a cin-
gulum ujKin the anterior and posterior slopes of the crown. The molars, as a series, are
snib-etpial, but the size of the anterior cusp and the width of the posterior heel varies
somewhat. These teeth, at first sight, approach those of Amhhihermm (PI. IX, fig. 11),
and l%iMct}lrfites (fig. 1 2), somewhat more closely than those of Amphilestes or Ainphi-
tf/hiM. 'fhey are, however, widely distinguished from the AmhJotherium molars by the
promimmee of the anterior lobe, the stout, erect and conical character of the middle
lolx*, the narrowne,ss of the heel, the strong internal cingulum, and by the sub-equal
size of the series as a whole. The same features distinguish them from the molars of
PhaftcoJfMejt, a genus which stands near Amhlotherium, but is distinguished by exter-
nal cusps.* The separation of this genus from the two following leaves the dental for-
mida of Amphitheriwn uncertain.

AMPHITYLUS.

Amphityi.cs Owexi, gen. et spec. nov.“

1 he accompanying cut shows how widely the molars just described differ from
those of the third specimen referred to AmpMthermm by Professor Owen, viz, the A.

* It is now probable that Phascolestes belongs to the Stylodon family.

’ See also abstract, Proc. Phila. Acad., June, 1887.

OF THE MESOZOIC MAMMALIA.

193

P)-evostii of the Buckland Collection (Mes. Mamm., fig. 23); also how the latter differ
from those of Amphilestes. It is clear that the two fossils, last named, resemble each
other much more closely than they do Arnphitherium, and in the discrepancy which
exists between the figures and descriptions of the A. Prevostii under discussion, it is
difficult to know what to accept and what to reject. All the available figures repre-
sent the molars of this specimen as follows; they have compactly placed crowns,
narrow at the base and bearing three cusps, the median cusp slightly the largest ;
there is perhaps a trace of an internal cingulum appearing upon the anterior and pos-
terior slope, but it does not overlap the base sufficiently to separate the crowns as in
Amphilestes. The crowns are described by Professor Owen as quinquecuspidate,
(Mes. Mamm., p. 14) and the formula is given I 3 C 1 pm. 6 m. 6. Mr. Lydekker
gives the formula as follows^ : I 4 C I pm. 4 in. 7. This is probably correct.

AMPHILESTES, Plate VIII, fig. 1.

The fourth specimen of AmpMtJieriim was originally designated by Pro-
fessor OweiP as A. Broderipii, but in his subsequent memoir, he tentatively pro-
posed the name Amphilestes^ which is undoubtedly valid, as distinguished from the
type of Amphitherium, the only doubt being whether the genus may not embrace Am-
phitylus. This genus also has but four premolars.^ The molar crowns, as viewed on
the inner surface, are well separated from each other by the fore and aft extension of
the basal cingula. “ Each molar presents a large middle cusp, with a smaller but
well developed and pointed cusp at the fore and back part of its base ; the ‘ cingulum,’
a part peculiar to mammalian teeth, plainly traverses the inner side of the crown,
Avhere it develops three small cusps, one at the base of the large external cusp, and
the other two forming the anterior and posterior extremities of the tooth.” (p. 16,
Mes. Mamm.). These molars approach those of Phascolotherium in pattern. So far
as preserved, the contour of the ramus of Amphilestes resembles that of Amphitherium.
In both genera the coronoid is broad and rather low, and the condyle is on a level
Avith or slightly below the molars. In Amphitylus, on the other hand, the condyle is
pedunculate and considerably raised above the molar level, while the coronoid is
narrower than in the above genus.

The three genera may be clearly distinguished as follows ;

Amphitherium.

Type. A. Prevostii, De Bl. ? pms j

m 5

Molars bicuspidate, with a pos-
terior heel : no cingulum between
the molars ; an internal cingulum ;
condyle on the molar level.

Amphitylus.

Type, A. Prevostii, Owen, i j c ^ pm

jm-

Molars tricuspidate, compactly
placed; cingulum faint or wanting
between the molars ; condyle ele-
vated and pedunculate.

Amphilestes.

Type, A. BroderipU, Owen, i j c i
pm jm^

Molars tricuspidate, separate,
cingulum strong forming anterior
and posterior basal cusps ; condyle
on the molar level.

* In a letter to me dated April 16th, 1887. See fig. 2a, Amphitylus upon a later page.
^ Geol. Transactions, 2nd Series. Vol. VI, pi. 6, fig. 1.

’ Mr. Lydekker (April 16th,) sends me the following formula ; I 4 C 1 pm. 4 M 7.

Iit4

OX THE STRUCTURE AND CLASSIFICATION

, 1 ns to the generic separation of Amplutylua from

formulas are the same, and the molars in each
AmphileMtes. Althou^n ^ specific

--- - - -- -

articular portion of the jaw.

PH.A,SCOLOTHERIUM. Plate VIII, fig. 3.

.Ithoimh the single specimen representing this genus has been long knoivn and
oftcm d s b^ed, a revi^v of its principal characters is necessary here. While .sepa-
tZ tZ AnyJuIestes and AmykltyU. by its mandibular characters -d the entire
absence of teeth of the premolar pattern, it is nevertheless clearly related to the line
of these genera and of Triconodon, by the character of the molar crowns

Tlie^-enus is known from a single, well-preserved, right mandibular ramus
from tlie Stonesfield Slate, the size and proportions of which indmate a strong animal.
Tlieaimle and condyle are confluent, the former presenting a widely inflected border
wliicli has been partly broken away. The condyle is on a level with the molars ; it
faces backwards and is rather broad transversely ; above this the border is deeply
notched and rises into the powerful, recurved coronoid process. The coronoid has a
decided anterior rim which sinks below the alveolar border. In the lower part of the
deep pterygoid fossa, thus bounded, is the dental foramen, and below this, the
myloliyoid groove stretches forward and sinks beneath the fifth molar. The in-
ferior border presents a single curvature from the condyle to the symphysis. The
svmplivsial surface is partly fractured. The incisor border is elevated and the molar

iKirder depressed.

Close to the fractured symphysis, the fang of h can be distinguished. The me-
dian incisor was apparently the largest, and the series decreased in size slightly
towards the canine. The incisors are semi-procumbent, with long, straight fangs, ex-
])anding very slightly at the summit into a flattened crown, distantly resembling those
of Amhlnfherimn and Phascolesies, but quite different from the Triconodon incisors.
The canine is erect, slightly recurved at the summit, and implanted by a stout cylin-
drical fang. The first molar is separated by a diastema from the canine and by a
narrower interval from m^. A close study of mi shows that it possesses, in miniature,
the characteristic features of the other molars, three cusps and a basal cingulum.
^^'c observe in other mammals of this period as many as six, seven and eight true mo-
lars ; tlierc is, therefore, no ground as regards number, either for describing the ante-
rior tcetli of this series of eight as premolars, or, for calling this genus “ typo dentate.”^
Tlie fact that there are seven teeth of uniform pattern, when considered with the
unusual ])rcscnce of a diastema behind the canine and the comparatively short space

* Mr. Lydekker in a letter to me, May, 1887.

* Mesozoic Mammalia, p. 115.

OF THE MESOZOIC MAMMALIA.-

195

between the coronoid border and the canine, suggests rather that premolars were pres-
ent in members of the ancestral line of Phascolotherium, and have disappeared in
this genus, the. true molars only having been retained. The diminutive size
of mi and suggests that a still further reduction of the series is in progress at each
end. The molar pattern consists of a prominent central cone with smaller anterior
and posterior cusps sub-equal in size, upon its slopes. There is a very pronounced
internal cingulum encircling the crown and rising into anterior, posterior and median
basal cusps as in ArnpMlestes} Faint vertical ridges may be observed upon the main
cusp. According to the writer’s observations the lateral cusps project partly from the
inner slopes of the main cusp, and are not precisely in line.

TRICONODON, Plate VIII, fig. 4.

This genus, from the Purbeck, is represented by numerous remains of both jaws,
and is therefore the best known of all the Mesozoic Mammalia. It is distinguished
by many “ recent ” characters, and forms an important link between three of the
Stonesfield Slate genera and some of the modern Marsupials.

As shown by Professor Owen, the mandibular rami vary in different species. In
T. ferox, which has been selected as the type in this memoir, the lower border has a
single downward curvature, slightly raised beneath In T. mordax the angle of

the jaw is slightly depressed below the condyle, but in T. ferox it is sharply and
widely inflected so as to partially obscure the condyle, recalling the Phascolotherium jaw.
The condyle is usually upon the molar level, or rather the level of the alveolar bor-
der; in some specimens, as in the T. mordax (Mes. Mamm., PL III, fig. 7), the strongly
convex articular face of the condyle is directed backward ; in another specimen, pro-
bably T. ferox, the condylar face was seen directed upwards (compare Mes. Mamm.
PI. Ill, fig. 2, B). The supracondylar notch in T. ferox is much deeper than in T. mor-
dax. The coronoid process is in all cases broad and powerful with rather shallow fossae
and a swollen anterior border. In the lower angle, on the inner face is the dental fora-
men, and from this the shallow mylohyoid groove extends forward near the lower
border. The inner face of the ramus is vertically convex, and indicates great strength;
the outer face is flat below the alveoli and bulges near the lower border. In some speci-
mens (Mes. Mamm., PL III, fig. 7,) a shallow groove extends forward from the crota-
phyte fossa ; below this fossa is a ridge extending backwards to the outer side of the
condyle. Below in T. mordax, the lower border bends sharply upwards to form
the stout chin ; this character is unique among the mammals of the period.

Mandibular dental senes in T. ferox. The incisors as preserved in this species
and in T. occisor are represented by 4 and 4 ; there are also traces of the alveolus of 4.

* The median basal cusps are slightly less prominent than in Amphilestes. They are omitted in the text
and drawings given by Professor Owen, who describes the molars as “quinquecuspid,” but may be seen in the
figures given by Buckland, Bridgewater Treatises, Geology and Mineralogy, Vol. II, Plate 2.

19(5 ON THE STRUCTURE AND CLASSIFICATION

, . .V, f fhP bases overlap ; when complete, the series of the

The incisors are closely set so a curves; the crowns are pointed and

sides prabably ‘"°el”nd imfibrmly con^x anterior slope. The canine

recurved witli a low postcn . . the base of the outer surface is slightly

is loa>^ ™ ^ double'fang on the inner snrfaee. The premolar,

grooved mt thei rs distinct diastema ; they have a uniform pattern; m

are rvulely set but there over pm, and pm,. The

;"fT,ri-v:i‘uhoC in r. occisor (Mes. Mamm., H. IV, hg. 2); it has a low
use centml cusp, with a distinct internal cingulum, and anterior and posterior bi^l
cl rrcb are sl^itlv raised above it. In pm, ( r. /crox), the central cusp is higher
lid the basal cusls more distinct. In pm. and pm, the central cusps are lofty fte
internal cingulum pronounced and erenate, and the basal cusps much more elevated.
The molar, have a prominent serrate or indented cingulum embracing the inner face
and the anterior and posterior slopes of the crown ; in m, and sometimes in m» the cm-
giilum forms a distinct cusp u,»n the posterior slope. The crown consists of thr«
Larly cmct lonical cusps, set in line and partially confluent at the base The
posterior surfaces of the two forward cusps, a and i, are slightly loss convex than the
anterior, and tlie central cusp is the most elevated.

The maxillary dental series of T ferox. A fragmentary maxilla (No. 47.788),
wliicli lisus been acquired since the publication of Professor Owen’s memoir, contains
the canine and three foremost premolars, and, excepting the upper incisors, completes
our knowledge of the dentition of Triconodmi, adding as an important character the
bifanged upper canine. This specimen agrees in size and minor details with those
which Profes,sor Owen has referred to T Ferox, but it is, of course, quite possible that
one and all of these specimens belong to other species, the principal ground of corre-
lation lieing similarity of size. The maxillary series have, in general, a uniform
stnicturc with the mandibular. They differ principally in the bifanged canine, in the
jiresence of a cingulum on both the inner and outer surfaces of the molars and pre-
molars, finally in the smaller relative size of 'pv'?. The canine is a powerful tooth,
imiilanted by two stout fangs ; the anterior border is convex and nearly vertically
])laced ; the jiosterior is concave. The premolars are known from three specimens ;
the first (No. 47,788), presents the inner view of the canine and the second

(No. 47,778) gives the outer view of prn^, also of the third (No. 47,779) gives

the inner view of jinv^, m^'^ and part of So far as these specimens overlap each
other they agree in all essential characters, and we are justified in superjiosing them
as in figure 4. In the inner cusp has a faint indication of the anterior basal
cusp, while the posterior basal cusp is much more prominent than in the loAver molars;
the prominent cingulum slightly overlaps the base anteriorly, and is produced into a
cingidum cusp posteriorly. repeats these characters on a larger scale, with a

greater distinctness of the anterior basal cusp. Pm^ is only slightly larger than

OF THE MESOZOIC MAMMALIA.

197

and differs from it in the greater distinctness of the anterior basal cusp; the cingulum
is well marked upon both the inner and outer surfaces (see also Mes. Mamm., PI. Ill,
hg. 18). In two specimens the anterior basal cusp of is wanting; in the third
(No. 24,778) it is faintly developed on the outer surface; this tooth is larger than
pm^, and has a pronounced and much indented cingulum. The molars resemble
those of the mandible inverted ; the central cusp is slightly the most prominent ; the
cingulum is bold and deeply indented. M^, in (No. 47,779), is very instructive, as
showing the manner of wear; the posterior surfaces of the cusps, a and h, are worn
slightly concave, probably by the anterior faces of the cusps, h and c, on the lower
molars. The external cingulum is also indented, and descends low upon the outer
face of the crowns.

Varieties of Triconodon. — It is probable that the numerous specimens of Trico-
nodon, as Professor Owen has suggested, represent several species. Besides the varia-
tions in the mandible which have already been described, we observe many differ-
ences in the forms of the teeth. In T. occisor the canine is nearly straight. The pre-
molars vary in the development of the anterior and posterior basal cusps. The molar
variations are still more marked ; the molar cusps are sometimes erect, subequal in
size and only partially confluent (Mes. Mamm., PI. Ill, fig. 9) ; in other specimens
they are retroverted (fig. 19) ; sometimes the middle cusp is much the highest (PI. IV,
fig. 2) ; the cingulum is in some cases smooth, in others it does not embrace the
anterior and posterior faces of the molars; this seems in a measure to be due to age.

Of still greater interest are the variations in the number and succession of the
molars, because they serve to connect the genus Triacanthodon with Triconodon, and
to show that in Triconodon we have, in all probability, the same relation of milk and
permanent dentition which we find in the modern marsupials.^ The evidence for this
hypothesis, which was suggested to the writer by Mr. Lydekker, is found in a com-
parison of a series of specimens beginning with Triacanthodon serrula. When these
are placed in line, as in the accompanying cut, we at once observe a constant increase
in size of the jaw taking place in direct proportion to the succession of the third and
fourth molars. In the smallest of the series, a, T serrula (Mes. Mamm., PL IV, figs.
7 and 8), behind three teeth of the premolar pattern are five teeth shaped like molars.
The foremost of these is somewhat undersized, the hindmost 9??4 is still in its forma-
tive capsule, and it is only owing to the fracture of the jaw that it is visible ; the pen-
ultimate molar, m^, is still partially covered by bone. The second of the series, h, is the
specimen described as T. occisor by Professor Owen (PI. IV, fig. 2) ; it is slightly
larger ; is only partially protruded as its third cusp is still covered by bone ; the tip

’ In describing the dentition of Triacanthodon (Mes. Mamm., p. 731, Professor Owen pointed out that the
fourth tooth, counting from the canine, may belong to the deciduous series. In discussing with Mr. Lyddekker
the question of uniting the above genera he suggested that the fully adult mandibular formula of Tricmodon
may be pm 4, m 4.

198

ON THE STKUCTUKE AND CLASSIFICATION

is just appearing above the alveolar border. The third of the series, e, is still
larger, T. ferox (PI. Ill, hg. 11), and we observe that is fully exposed and pn^ has
come fully into position. The fourth of the series, d, is T. mordax (Willett) it is
slightly smaller than the third, there are two premolars and four molars, fully exposed
in place. At the time this .specimen was described by Mr. Willett \ Professor Flower
suggested two hypotheses to account for the extra tooth of molar form : (1), That
the most anterior of these teeth represented the single deciduous premolar, d^,
which in the marsupials is molariform^; (2), That all the teeth preserved belong to
the permanent set, when the dental formula will be pm 3 m 4, and indicate the
most fully matured specimen as yet discovered. The writer adopts the second
with the exception of the formula of T. mordax, which he
believes to be pm 4 m 4, on the following grounds. It is
evident that in Tricoiiodon, as in the recent marsupial
Thylacinua^, the posterior molars are very late in coming
into place ; the first molar, in the specimen under consid-
eration, resembles the other molars much more closely

eration, resemoies tne otner molars muen more closely
anterior molariform tooth in T. serrula, and
is therefore probably a true molar ; in all the specimens
o of Triconodon thus far observed there are four premolars.

The following hypothesis seems to conform to all the
present evidence, viz.: the fully adult dental formula is
p>m 4, m 4; the single deciduous tooth is the fourth pre-
Kicii-RE3. A^erie8of Tricono- molar, d^, which is molariform ; the fourth molar is very
don mandibles, all drawn natural late in Coming in.

si*e, representing the (?rowth of the . j • rr, • , ,

mandible in relation to the succes- According to this the IViacantJiodon serrida, a, is an

Sion of the teeth, a Triacanihodon immature THconodoii with the formula pm 3 d 1 m 4 the

“ ::: The ?: s,

dax.K somewhat older individual. older, the formula being pm 4 m 3 (;«4 still in

d T. mordax (Mr. Willett’s type', its capsule). The T. ferox, c, is still older. The T. mor-
probably a fully mature individual, f^^y mature with m , in place.

1 Iterc is little- or no doubt that the most anterior tooth of molar form in
T. sernda is the fourth deciduous premolar, but we must admit that the balance of
evidence derived from the majority of specimens belonging to T. ferox and T. mordax

ir. WilUtt, Etq.

• ir. ir. Flmirr.

** the Development and Succession of. the Teeth in the Marsupialia

■ Flowr.
t>p. cit., p. 6.39.

OF THE MESOZOIC MAMMALIA.

19&

is that the fourth molar does not come into place at all ; in several of these specimens
the jaw is to all appearance fully mature. It may be that in some species is
more letaided than in others. While therefore the evidence as a whole favors the
above hypothesis, there remains the possibility that m , is wanting in Triconodon and
characterizes the allied genus Triacantliodon. In such case the T. mordax, Willett,
should be added to the latter genus.

AMBLOTHERIUM, Plate IX, fig. 11.

W hen the genera Amhlotherium, Achyrodon and Phascolesies are placed side by
side, as upon Plate IX, a striking general resemblance is at once observed. This is
extended when the dentition is carefully examined. The molars especially are
essentially similar in form and number and distantly recall those of Amphitherium.
Amhlotherium is the best preserved and most representative member of this little
group. It is known from two well-preserved mandibular rami which belong
to different species and enable us to determine all the characters of the lower jaw' as
seen upon the internal surface. The figure is taken ixom A. soricinum^, (No. 47,752.).
The condyle is raised above the molar level, upon a broad condylar process.
The angle is slender and slightly inflected at the tip, as in Amphitylus ; a ridge
extends from this to unite with the thick anterior border of the coronoid
and thus bounds the deep pterygoid fossa. In the angle thus formed is the dental
foramen from which the mylohyoid groove reaches forward to the symphysis. The
inferior border of the ramus has a double curvature and ascends anteriorly, tapering
to the symphysis. The symphysis is long and narrow and the incisor border is well
raised, while that of the premolars is depressed. There are four incisors, a canine, four
premolars, six molars wfith the impression of a seventh in sihi. The whole dentition
is rather 5veak, the incisor-canine series especially so. The incisors are widely sep-
arated, with slightly expanded sub-recurved crowns set upon slender fangs; they
decrea.se in -size from % to the latter being very small. The canine is a slender,
recurved tooth, with a single contracted fang. The premolars increase rapidly in size
from before backwards ; pm-^ is a minute tooth of the premolar pattern most prevalent
in the mesozoic mammals, i. e., a recurved crown, bifanged, with a low posterior heel
and a faint internal cingulum ; in pm 3 the heel is more prominent; prn^ has a high
crown and less distinct heel. A characteristic feature of the molars is the absence of
an internal cingulum. They increase in size from nii to m^ and then decrease ; they
are all bifanged and have a uniform pattern. The third molar is typical of the series;
the croivn supports a high central and two lateral cusps ; the central cusp is high,
pointed and slightly recurved ; the anterior cusp is directed obliquely forwards and
upwards, while the posterior has rather the character of a basal heel, which is over-

* There is little doubt that some of the specimens referred by Prof Owen to Amhlotherium, belong to Stylodon
or the Stylodontidx, with a styloid external cusp.

ON THE STKUCTURE AND CLASSIFICATION

lai.pe<l by the anterior cusp of the succeeding molar In old individuals (Mes.
Mamm id. II, fig. 2), tlie central cusp is worn nearly to the level of the anterior
misp, and the molars resemble tliose of Phascolestes.

PHASCOLESTES, Plate IX, fig. 12.

This genus is represented by the anterior portion of a left mandibular ramus
(No. 47,741). Professor Owen proposed the name with some doubt as to its value,
since he was inclined to associate the specimen with Peralestes, a genus repre-
sented only by an incomplete maxillary fragment (p. 35, Mes. Mamm.) Such an asso-
ciation seems to the writer unsafe and improbable on the follmving grounds, which
will be made clear bv a comparison of figs. 8 and 12 : (1)» There are six molars, and

possibly five premolars in the Peralestes maxilla, and eight molars and four premolars
in the Phascolestes mandible; (2), The Peralestes (upper) molars have separate
opposed i. e. internal and external cusps, the highest of which is internal, while in the
Phascolestes (lower) molars there is no indication of the presence of separate opposed
cusps; (3), We find in another genus, Peraspalax, a mandibular dentition of the very
character which we .should anticipate to find opposed to the Peralestes dentition.

There are some reasons for uniting Phascolestes with Amhlotherium. The worn
molar crowns of the Phascolestes mandible indicate a rather older individual than that
to which the A. soriciiium mandible belonged. The resemblances between the two
genera, as seen upon the internal face, are in the molar, premolar and incisor patterns,
and in the curvature of the alveolar border. The differences are still more important,
viz. : that wliile the matrix impressions of the Amhlotherium molars show no trace of
external cusps, the last three missing molars of Phascolestes have left impressions
of .styloid external cusps similar to those of Sti/loilxm, or “the impressions of
thret' successive long and slender cones,” as described by Professor Owen, (Mes.
Mamm., p. 35).

The principal chariicters of the Phascolestes mandible and dentition are the fol-
lowing : The symphysis is long and the incisor alveolus is elevated. The incisors are
cqtiidistant; is much the largest, the tip of the crown is wanting and the fang is faintly
grooved ; is a small tooth with a slender fang and expanded crown ; 4 is slightly
larger, and t, is nearly double the height of The canine is high, pointed and
rcciwved, with a broad fang, grooved upon the inner surface. The first premolar is
nu imcntary , has a double fang, a well-worn crown and a low posterior heel ;
pm^ ii so 1 ange , with a high recurved crown and prominent posterior heel like that
\ f f f ^ blunt conical crown, with a distinct cingulum

hi els cu" M ^ ”<1 >«. have a

hind the fir 7 “ anterior cusp and a posterior sloping heel. Be-

stvloid cxtental on ‘Vtl casts of the

Sty loid external cusps of three suceeeding molars.

OF THE MESOZOIC MAMMALIA.

201

ACHYRODON, Plate IX, fig. 13.

As was fully recognized by Professor Owen, the molars of the minute Aclixjrodon
are of the Amhlothermm type, but the genus is well distinguished by the acuteness
of the cusps and the elevation of the premolars. The specimens consist of portions
of four mandibular rami, the most perfect of which (No. 47,745) is represented in
the figure. This is A. nanus, (Owen). The ramus is mutilated at the extremi-
ties, but preserves two premolar casts followed by two premolars and eight mo-
lars in situ. The posterior half of the symphysis is preserved, and from this the
mylo-hyoid groove extends backwards to, and seems to perforate the border of the
pterygoid fossa. Judging by the portion preserved, this fossa was divided into an
upper and lower basin by a median ridge. Below the dental foramen is a lower ridge
which extended into the angle. The coronoid border rises abruptly behind the last
molar. The premolars are lofty and supported upon two fangs. The most anterior
in this specimen is probably pm^, it has a very high crown, with a convex anterior
and nearly vertical posterior slope, it has a pronounced cingulum, which slopes
obliquely backwards and encircles the crown ; the last premolar has an equally high
but more slender crown, rismg to double the height of ,• the cingulum is less decided
but embraces the base of the cro\vn as in^jmg. The coronal patterns of molars are
exactly similar ; there is no cingulum ; there is a high central cu.sp sloping forwards
with a waving contour, and produced to a sharp point ; from its base rises freely the
sharp and prominent anterior cusp and the low and comparatively blunt posterior
cusp, which is, however, more elevated than in Amhlotlierium. The molars overlap
each other. The first molar is relatively larger than in the allied genera ; the series
increases gradually in size from to m^. The last molar lacks the posterior cusp.

From the matrix impressions observed by Professor Owen in another specimen
(PI. II, fig. 8 ; p. 40, Mes. Mamm.), it is probable that there were three or four
incisors, a canine, four premolars and eight molars.

LEPTOCLADUS. Plate IX, fig. 10.

This Purbeck genus is represented by a single fragment of a left mandibular
ramus, with the outer surface exposed, and containing eight molars. Professor Owen
(p. 53, PI. Ill, figs. 4, 4®. Mes. Mamm.), placed it as incertce sedis near Styhdon,
remarking, however, that he considered this relationship somewhat doubtful. A very
careful examination of this specimen, the results of which are expressed in the figure,
shows that it is very remote from Stylodon; and, so far as known, represents an
entirely unique type of dentition. The molars are seen upon the outer surface, and it
is possible that a view of the inner surface would reveal the presence of internal cusps
similar to those of the Peraspalax molars. The main molar cusp of each suggests a
resemblance which is lessened by a close comparison of the molar pattern as a whole.
When the .dentition of Leptocladus is carefully compared with that of each of the

202

ON THE STKUCTURE AND CLASSIFICATION

mo»o»lc mammals, the nearest relationship suggested is to AmNoa^um. Uptocla.
,lu. approaches this genus in its dental formula (p».4 »6), and d, tiers from it and .ts
allies in the suppression of the anterior lobe of the molars which is replaced by a cm-
gulum cu.sp.

The ramus has a nearly straight lower border ; below the first premolar it curves
upwards rapidly. The outer surface is convex and shows two foramina beneath
p;»2 and m,. The alveolar border is depressed below the premolars and rises in the
middle of the molar series, this curvature resembling that in Phascolestes. Professor
Owen discovered traces of two incisor sockets; these teeth were probably small,
compactly placed, and not widely separated from the canine. Judging by the socket,
the canine was a large, erect tooth. The succeeding four teeth are evidently pre-
molars ; they increase rapidly from the first to the fourth ; there is a minute cusp
ui)on the anterior slope and a posterior heel which varies in width ; the absence of
an external cingulum separates them from the molars. The premolars of mesozoic
mammals invariably lack the external cingulum. There are probably six bifanged
molars, two of which filled the space between nii and the coronoid process. The
first molar has a conical, central cusp and a broad posterior heel ; on the anterior
8loi)e, the cingulum forms a basal cusp, and, disappearing below the main cusp,
reappears at the side of the posterior heel. In mg, m 3 and the main cusp is tall,
slender and slightly recurved, while the posterior heel is very broad and much worn.

PERAMUS. Plate VIII, fig. 6.

In Peramns and the genera which, although not closely affiliated, will be con-
sidered along with it, viz, Spalacotfierium, Peralestes and Peraspalax, all from the
I’urbcck, we meet a new principle in the construction of the molars. There are
still three cusps, but these cusps are not arranged in the same fore-and-aft line ;
owing eitlicr to the rotation inwards of one or more of the cusps, or to the elevation of
the internal cingulum. We find the crown of the tooth broadening to support
internal and external or opposed cusps.

1 lie chief materials for the determination of the characters of this genus consist
of portions of two mandibular rami. In the type specimen (No. 47,742, Brit. Mus.), the
])osterior half of the ramus is preserved; in the second specimen (No. 47,743) the anterior
half of the ramus is prc.served; both specimens preserve the first molar intact with
some of the adjoining teeth, and we are thus bnabled to place these halves together
and reconstruct the jaw, as seen in figure 6. Another mandibular fragment (No. 47,743),
preserving the canine and portions of the premolars and incisors, has been placed with
Peramus by Professor Owen (PI. II, fig. H), but in the absence of a molar tooth,
this determination is uncertain on the following grounds : the fifth and sixth pre-
molars of this specimen have conical crowns, with a narrow base, whereas in the type
specimen, pm 3, is bifanged with a very broad base and anterior and posterior basal

or THE MESOZOIC MAMMALIA.

20.1

cusps. A fomth specimen (fig. 13, Mes. Mamm.) may, however, be safely referred to
Peramm, but, unfortunately, it adds little to our knowledge of the dentition. The
jaw of Peramus is quite unique. The coronoid process is very high and tapers as it
ascends ; its summit is fractured, but a faint cast indicates a rounded contour ; its
anterior border descends in a ridge which extends along the outer face of the ramus
beneath the molars. The condyle is on the molar level and terminates a ridge.
Below this, the border descends into a triangular process which, according to Profes-
sor Owen, is sharply inflected and thus represents the angle. This observation
cannot now be confirmed as this process has been broken away. The ramus tapers
anteriorly but less so than in Stylodon. There is a foramen below the first and
second premolar. The fourth specimen seen upon the inner surface shows a mylo-
hyoid groove.

In the matrix of the anterior portion of the type specimen there can be distin-
guished a faint cast of the canine ; behind this are traces of nine teeth, six of which
are preniolars ; the paucity of molars is a unique feature not elsewhere observed
among the mesozoic mammalia of this type. The sixth tooth is counted among the
molars by Professor Owen, but it has a distinctively premolar pattern and lacks the
elevated anterior cusp of the true molars. The premolars increase from first to last ;
they all show the usual recurved crowns and low posterior heel, while have

anterior basal cusps indicating the presence of a strong internal cingulum. The
pattern of the three molars is substantially the same, being the typical tooth of
the series. It has a high central cusp with a strongly convex outer surface ; from
the base of its posterior slope rises a prominent heel, while from the upper internal
surface of its anterior slope rises a small cusp; this cusp, although rotated inwards, is
accessory to the main cusp and is not an independent inner coronal cusp, such as that
in the Peraspalax molar, as Professor Owen’s description (p. 41) and figure 10 c
(PI. II) would indicate; a minute cusp at the base of the anterior slope probably points
to an internal cingulum, and we may conjecture that the inner surface of this crown
was broad and shelf-like. M and are slightly smaller than m^, and the anterior
basal cusp, if present, is faint.

Since the above was written, much evidence has come to hand that the number
of premolars in all the mesozoic mammalia never exceeded four. This rule is so
universal that it seems unlikely that Peramus should form the single exception.

It is therefore possible that Avhen the inner faces of the teeth are discovered, those
determined as pm^ and pm^ will prove to be m^ and and the formula will stand
pm 4, m 5.

SPALACOTHERIUM. Plate VIII, fig. 7.

This genus, from the Purbeck, is represented ‘by numerous mandibular fragments
with well-preserved teeth. The two here chosen and combined for illustration as
types, are: first, the left ramus (No. 47,750, Brit. Mus,), figm-ed by Professor Owen

ON THE STRUCTURE AND CLASSIFICATION

, , fi T8 this has five molars with the somewhat doubtful topression
in I’l. I, ftg. vonvpsented by Professor Owen, in figure .34,

of u sixth : second, the ramus^^ premolars and one molar well

with two incisor imprcssioi . , „py„j.al succeeding molars. There are two

preserved, with the J^ese fragments together as represented

chief grounds to jus y _ They naturally involve the

in figure 1, the anteno e character of the premolars,

r,„estio„ofthem„hrrformu a.andjfJhe^^^^^

and need therefore o h f^J^ impressions of pw, and pm„

Professor Owen (fig- • )y besides impressions of four others mi,

, 'r fi„ o. and show conclusively: (a), that the premolars were
llralyT^re the molars’; (h), that there were six molars and four ^molars;
second the specimen figured in fig. 33 (Mes. Mamm.) confirms the above, as .
h.clud;s two Lisors, a canine and ten teeth behind it. This result differs from that

readied hv Professor Owen.* • ei ;

There were at least three moi«,r, (p. 26, Mes. Mamm.) ; two of them, and ,,,
are represented hv distinct impressions which indicate that they were compactly placed,
with |H.inte<l rci urved crowns. In figs. 33, 40, 41 (Mes. Mamm.) the lateral mcisor
is er(*et. 'I'hese teeth and the rather slender recurved canine resemble the correspond-
ing teeth in Trirnnnthm, rather than those in the AmhJotherium or StyMon series.
Tlie online is nitlicr slender, vertical, recurved at the summit, and apparently bifanged.
'fhe premohirH liave tlic typical number, four, and increa,se in size antero-postenorly.
'I'he crown is implanted by two fangs, with a convex anterior and concave posterior
8loiK>; tlie cingulum forms an anterior basal cusp, but extends slightly below
the jKisterior liasal lu'el, which is unusually prominent. The molars are very
unique in pattern : they present three cusps, the anterior and posterior cusps being
rotnteil inwards. The outer surface presents a high vertical and symmetrically
eonv<>x main cusp, with a faint cingulum near the base ; from its anterior and
posterior sloiies project tlie lateral sub-equal cusps which are confluent below with
the general ronvexity of the crown ; on the inner aspect these cusps are seen to be
rotated inwards and to spring in part from the shelf-like plane surface of the crown
a.s two cones with widely divergent apices. The shelf at the base of these cusps
may lie considered either as a broadened cingulum, or as a wide cusp-bearing
base, such as is seen in some primitive bunodont molars, e. g. Palceochoerus. The

• The prcinolars are correctly represented in figs. 35 and 36 ( Mes. Mamm., PI. I), and conform with my
drawing. In figs. 33 and 34 they are incorreatly drawn, as shown by comparing them with the impre-sions
of four recurved premolar tips in fig. 33 (No. 46019). Part of the figures thus give a false idea of the dentition
which Professor Owen’s description does not clearly remove, otz.' that the molar pattern is a development
of the premolar pattern, and that the premolar-molar dentition is homodont.

OF THE MESOZOIC MAMMALIA.

205

second and third molars are the largest ; behind these the teeth gradually decrease
in size.^

The ramxis of Spalaeotherium is very long and shallow, with a single main
curvature from the condyle to the symphysis. The most distinctive feature is the
remarkable elevation of the condyle and its confluence with the angle ; in the latter
respect this genus approaches Diconodon and Phascolotherhim, but the condyle is
much more elevated than in either of these forms. The condyle is broad transversely,
and from its inner face a somewhat fractured ridge, representing the angle, extends
forwards and downwards to the dental foramen. The pterygoid fossa is thus very
deep, but contracted vertically. The mylohyoid groove disappears beneath the fourth
molar. Another marked feature of the ramus is its contraction beneath the last molar.
The lower border extends forwards without bending upwards at the symphysis.

PERALESTES. Plate VIII, flg. 8.

This genus is represented by a portion of a right maxilla, seen on the outer face,
containing the last premolar, six molars and the alveoli of an incisor, the canine and
three premolars. The distinctive feature of the genus is the molar pattern, in which
we find a complete opposition of internal and external cusps, a further development
of the partial opposition observed in Perainus and Spalaeotherium.

The portions of the maxilla which remain are entirely uncharacteristic. In the
forward fragment we can distinguish a part of the premaxilla with the small alveolus
of the lateral incisor ; behind this a large alveolus belongs probably to the canine.
Then follow two pairs of sockets, in the second of which are traces of fangs ; here were
probably inserted and pm}. Behind this is a fractured interval with space for
two premolars of increasing size.^ A portion of the bony palate is preserved in the
specimen (PI. II, fig. 3, Mes. Mamm.), which shows that this interval has not been
greatly increased by fracture, so it seems possible that there were five premolars (see
Peraspalax). We may, however, provisionally regard the last premolar as pm*.
This tooth is much more elevated than mh- the crown is supported upon two widely
set fangs, with a broad base contracting above the cingulum in a pointed and nearly
vertical cone. Behind this are five molars, of nearly uniform pattern, followed by a
sixth of smaller size and rather obscure pattern. The crowns increase in height from
m* to m*, and then rapidly diminish. The marked feature of the crown is the lofty

» There is again a considerable discrepancy between the drawings accompanying Professor Owen’s Me-
moir, and those here given. So far as the writer's observations went the enlarged molars, (PI. I, figs. 32 B and
34 B) are decidedly incorrect. By a comparison of figure 7 with those in PI. I, No. 38, both from the same
specimen, the reader can observe the errors of the draughtsnjan in the latter. Figure 7, and the enlarged
molars in the text, do, however, approximately conform with the partly broken molars represented in fig. 36,
A 5 Mes. Mamm., and those in fig. 38. What is more important they corre.=pond with Profetsor Owen’s
description (p. 24),' which shows that he himself clearly understood the characters of these teeth.

’ These alveoli are mentioned in Professor Owen’s Memoir, p. 33, but not studied in detail. A very care-
ful examination of the maxilla; brings them out clearly as figured.

2Qg ON THE STRUCTURE AND CLASSIFICATION

• . 1 n.nln fusD c which is stout to the apex and slightly recurved; behind,

“nS'.Uv oxton.l t,. this,’ is the ,„stcto-ietomal cusp, I, tvhich is about one-third the
hl.ht of c ■ op,»site the antero-intemal ensp the crown ts very broad, while .t narrows
,o oLlmlf the breadth posteriorly; it is thus sub-triangular in honzontal seetton; the
main cusp c, has an outer concave slope leading to a longitudinal depression, beyond
which the crown rises into the low antero-external cusp, a : from a. the outer border
slopes ixisteriorly into the serrate margin, d, opposite the postero-mtemal cusp. The
position and height ol the antero-external cusp, a, varies iii to ■, it is quite

Tlie genus Peralestea is obviously related to Peraspalax, in which we find also, in
this case, in the lower molars, the complete opposition of cusps. After a description
of Peraspalax, the points of similarity and difference between these forms will be dis-
cus.sed.

PERASPALAX. Plate VIII, fie. 9.

'J'liis genus is also known from a single specimen, an incomplete mtindibular
ramus, with seven teeth m situ, and the impressions of three others. The portion of
of tlic ramus preserved, as seen on the inner surface, is stout and well rounded, and
lielow the canine is a partial impression of the chin which bends upwards, like that
of Triconodon, indicating that the incisors were nearly erect. These robust features
of the jaw, taken together with the structure of the molars, seem to place Peraspalax
in the line of the modem DasyuridcB.

Judging from the cast, the canine was stout and recurved, like that of Tricono-
don. At a short distance is tlie impression of a small premolar, which was probably
pj»2, as the interval is broad enough for a small pm^. The second premolar had a
low, recurved crown with a broad heel ; had the same pattern slightly enlarged ;
pwq is hifangcd with a high, conical crown, and strong internal cingulum ; this forms
an unU'rior ha.sal cusp, and posteriorly encircles the base of the posterior cusp. This
elevation of the posterior cusp of the last premolar above the cingulum is observed
in all tlie supposed carnivorous genera of the mesozoic period. Behind this pre-
molar is a narrow gap, which was probably filled by a true molar as there is barely
space enough for a ])remolar of the same proportions as pm^. The drawing (PL II,
fig. 9), accompanying Prof Owen’s memoir, gives an incorrect impression of these
molars. In the specimen a portion of the external cusp of is preserved, and
a ca.st of the same cusp in m^; this fact, taken with the fully preserved molars
and m-j, leaves no doubt that the molar pattern was uniform, and that the cusps seen
in and Wj are the internal cusps, the external cusps having been broken away.
The tyi)ical molar pattern is seen in ; there is a high, pointed, antero-verted exter-
nal cusp a, and directly opposite it, on the inner side of the crown, a low Conical cusp

‘ lor the details of the Vcralestes and Peraspalax molars, see the cut illustrating the typical molars of
meaozoic mammals, under heading Classification.

OF THE MESOZOIC MAMMALIA.

207

the anterioi and posterior borders of the basin between these cusps are raised into
prominent basal cusps c and cl; there is also a posterior cusp at the base of the crown e.
The internal cusps, 6, are broad in the anterior molars and become more pointed pos-
termrly ; the reverse order is true of the external cusps, a. A pecidiar feature of the
seiies is the overlapping of the posterior by the anterior cusps. These molars resemble
the third lower molar of Didelphys, but lack the external basal cusp of the latter.

The relations of Peralestes and Peraspalax. — The writer’s grounds for not fol-
lowing Prof Owen in referring the Phascolestes mandible to Peralestes, have already
been given (jvide Phascolestes). In the jaw of Peraspalax, however, are lower
molars which closely correspond to what we should expect to find in opposition to the
Peralestes upper molars. These genera are the only ones among the British mesozoic
mammals, as yet discovered, with fully opposed cuspsf Not only so, but the molar
crowns in both genera reverse the usual arrangement of the higher and lower cusps,
i. e., in the upper molars {Peralestes) the highest cusps are internal and retroA^erted ;
in the lower molars {Peraspcdax) the highest cusps are external and antero-verted.
It would appear from this that in each the arrangement of higher and lower cusps
is as in Didelphys and Sarcophilus. The type maxilla and mandible also agree
approximately in size. So far as the pattern of the molars and premolars is con-
cerned there is, therefore, every reason to believe that these specimens belong to the
same genus, but the number of the molars and premolars presents a difficulty. The
series are unfortunately incomplete in both specimens, and we have provisionally at-
tributed these formulae : pm 5, m 6, Peralestes, pm 4, 7; Peraspalax, the whole number

agreeing in each case, but the division differing. It is, hoAvever, possible that the
interval between pm^ and the last premolar in Peralestes has been widened by frac-
ture, and that but one premolar Avas present there; or, that the space behind in
Peraspalax, held a small premolar ; or that the upper and loAver formulm differed ;
either alternative Avould enable us to unite the,se genera Avithout further hesitation.
As the matter noAv stands the safer course is to keep them separate.

STYLODON, Plate IX, flg. 14.

The genus Stylodon is knoAvn from numerous mandibular fragments, undoubtedly
representing more than one species; of these L. pusillus {m. 47,757) is here selected
and figured as a type. In this genus Ave find a Avholly different type of dentition
from those Ave have been considering.

The JaAv is A^ery slender and tapers to the symphysis; there are tAvo mental
foramina beneath the anterior premolars and the canine. The contour of the coronoid
process, judging from a matrix impression, is Avide and high, and enough of the pos-
terior border and angle is preserved to shoAv that the condyle was beloAv the molar
level. The incisors in L. pusillus are very procumbent. The median incisor is much

* Leaving out of view, of course, Plagiaulax and Bolodon as belonging to a widely different phylum.

ON thp: structure and classification

the lamest- it continues the line of the lower border of the jaw; the crown broadens
towards the tin and is flattened upon the upper surface. The series dimimshes m
size towards the canine, while the inter-spaces increase, and, judging by the fang^
which is all that remains of this tooth was diminutive. The canine has a high,
strongly procumbent crown; its fang is slightly grooved (No. 47,767), and in another
specimen (No. 47,768) there are two distinct fangs. There are four bifanged premolars,
which increase rapidly in size posteriorly; are broken; pm^ has a high, re-

curved crown with a simple convex anterior slope, and a low posterior heel ; pm 4 has
a slightly stouter crown, and a broad posterior heel. The apparently single-fanged,
styloid molars suggested to Professor Owen the appropriate name of the genus ; there
are seven distinct molars, with the indications of an eighth, in one specimen, (Mes.

Mamm., p. 52, PI. II, fig- 18a).

External aspect of the molars. The first molar is low and obtuse, with a broad
ba.se, and is distinguished from the premolars principally by its single fang; the cin-
gulum rises anteriorly into a faint basal cusp. The second molar has a broad fang
and rather stout conical crown, with a distinct cingulum ; is nearer the typical
molar pattern, the cingidum rising anteriorly; 4 is a typical styloid molar, with a
rather narrow base, distinct cingulum and lofty tapering crown; and are
.slightly smaller, while m-, is a much smaller tooth.

In another sjjecimen, "(No. 47,758), the molars are still more slender and tapering.
Unfortunately none of the specimens present the inner surface of the ramus, but
much additional knowledge of the molars is derived from jaws in which the teeth are
partially rotated in their sockets. Thus in PI. II, fig. 18a, Mes. Mamm., we see that
the crown is not actually styloid but rather chisel-shaped, with its greatest diameter
tninsver.se and the wearing surface sloping obliquely inwards and downwards from the
outer tij). In fig. It), PI. II, an internal cusp upon is represented, and in fig. 15a,
the molars arc more compactly placed, and has an internal heel. In PI. Ill, fig. 2,
»«#, the molar is nearly in side view, and shows what may represent part of an inner
fang. 1 his accords with the conjecture of the writer, that these molars are not single-
fanged, but have two fangs placed transversely, as in the upper molars of Kurtodon.

Since the above was written Professor Marsh has discovered the full pattern of
the Stylodon type of molar, viz, a styloid external and tricuspid internal face,
which renders it probable that some of the specimens attributed to Amhlotlierium and
other genera, present the internal mandibular aspect of Stylodon, or an allied genus.

KURTODON, KQen. iVoiO^ Plate IX. Fig. 15.

I he type of this genus is the single maxilla (No. 47,755) tvhich was referred by
Professor Owen to Stylodon (Mes. Mamm. p. 48. PI. II, fig. 14.)

• The name Athrodon Was at first assigned to this
preoccupied by Sauvage (Bull. Soc. Geol. 1880, p. 630).

genus (Proc. Phila. Acad. June, 1887), but is found to be
Kurtodon was substituted later, (Am. Nat., Nov., 1887.)

OF THE MESOZOIC MAMMALIA.

209

Enough of the palate is preserved to show that the inner surface of the teeth is
the one exposed. The fragments of bone in front of canine cannot be recognized as
incisors. The canine is proportionally large, directed backwards and recurved, with
a faint median groove, which may indicate a double fang. Behind this is a small,
columnar premolar; a space which may have been occupied by or may represent
a diastema, follows; the premolar behind this is extremely small and functionless,
and from this we might infer thatjim^ was permanently missing; is slightly larger
and bifanged, (Mes. Mamm., p. 49); pm, maybe distinguished from the molars by the
absence of a cingulum, but it is most interesting to observe that it is apparently in
course of transformation into the molar pattern, the two fangs are not set in the line
of the ramus, but obliquely, and the long diameter of the crown is also slightly
rotated into a transverse position, with its apex internal. The seven molars are nearly
uniform in size and very similar in pattern. They slightly increase in size from the
first to the fourth and fifth, and then diminish ; there is a corresponding downward
curvature of the wearing surfaces. The inner line of the crowns is concave, and the
outer, convex; this curvature is shown to be
natural, and not the result of pressure, by the
wedge-shaped sections of the crowns (fig. 4) the
inner faces being much narrower than the outer,
and the proximal surfaces closely applied to each
other. The crown is supported upon two power-
ful fangs, placed transversely to the jaw; the
convex inner slope is marked by a faint cingu-
lum and rises to a narrow point, so that the
direct internal view resembles that of the Stylo-
don molar ; judging from the contour of the wearing surface, the outer slope is
divided by a vertical groove, g; the summit of the crown slants obliquely out-
wards from the internal tip, but the tooth is so obliquely placed in the maxilla
that the wearing surface is not far from the horizontal plane; this surface is
concave from side to side, and, under a close examination, reveals a complex
pattern: two enamel ridges, e, diverge from the inner apex of the wedge, along
the sides of the crown, becoming thinner and less prominent towards the outer
surface ; from the inner angle of the thus formed, a median ridge, e\ traverses the
crown, which is also less prominent as it extends outwards, dividing the surface into
two valleys opening outwards. The crown is thus divided into transverse ridges and
grooves like that of a rodent, but the resemblance is not complete since the median
ridge is not the result of an infolding of the side of the crown, but is apparently the
remnant of a folding of the enamel on the wearing surface, which will disappear in
course of further attrition, A partly worn Phascolomys molar presents a somewhat
similar appearance, (fig. 15, B e, e^). This description of the molar pattern differs widely

Figure 4. The inner surface of the left
maxilla of Kurtodon pusillus, enlarged 5i di-
ameters.

210

ON THE STRUCTURE AND CLASSIFICATION

from tliat given l)y Professor Owen (Mes. Mamm. p. 49). The additional details
discovered in these’ crowns are of great interest; they indicate that there was a regular
fore-and-aft or side to side grinding motion between the molars, such as is observed in
the Rodents or in PhaHcolomiis ; this inference is strengthened by the rudimentary
character of the premolars, the presence of a diastema, and the transformation of
pm* into a molar which is apparently in progress. Upper molars of this character are
invariably opposed by homologous lower molars with the pattern of the wearing sur-
face reversed. The mandibular series of S. ptisillus, the type specimen, present many
points of difference : there is no diaste ma ; the premolars are erect and functional ;
the molars are set in a straight line, they are slender and widely separate from each
other (fig. 14; see also Mes. Mamm., PI. II., fig. 18, A) ; the series are not subequal in
size, blit diminish in both directions from the middle molar. In ChrysocJiloris the
in.sectivore selected by Professer Owen as most nearly approaching the Stijlodon type,
the tricuspid upper molars are separate, they interlock with the tricuspid lower molars,
(the pattenis being reversed) and the motion of the jaw is vertical, but in Kurtodon
tliere arc, strictly speaking, no cusps, and the action of the jaws must have been
cliicfly horizontal. There is thus no real homology between the Kurtodon and Chry-
mrfdortM dentition. The separation of this genus from Stylodon ivas made before the
complete patterns of the Stylodon molar was known; now that it is fully known it is
clear tliat tlie two forms belong not only to distinct genera, but to distinct families.
.\mong the mandibular specimens which have been referred to the Stylodon, and thus
fignriHl by Profc.s.sor Owen, (for example, fig. 3, Plate III.), there may be some which
Indong to Kurtodon.

BOLODON, Plate IX, fig. 16.

Since the jmblication of Professor Owen’s memoir, another specimen, from the
Rvklcs collection, has been received in the British Museum, which supplements the
t\ i)c siwcimen (47,735), and gives us the complete upper dentition of this very inter-
esting genus. Through the kindness of Air. Davies and Mr. Smith Woodward, this
new siK'cimen, which the writer found partly covered with the matrix, was fully ex-
posed, and the important characters of the full series of true molars were brought out. •
linlodon IS thus known from portions of two right maxillm, one of which is com-
plete anteriorly, the other posteriorly. Fortunately they preserve the following parts
in common, as determined by the writer: the malar portion of the zygomatic arch;
the maxillo-preniaxillary suture, also the first, second and third premolars and first
molars; the.se parts agree in every particular, and justify our placing the two speci-
mens together, as is done in the figure. The question of the maxillary suture is natu-
ral l>iery important in its bearing upon the dentition of Bolodon. Professor Owen

h- ‘yPe speci-

,rZ. r ™ a strong light, no doubt remained as to the

too* P-'^e^ed. This result was eonfirmed
t an exammation of the second specimen, in which a fracture has taken place along

OF THE MESOZOIC MAMMALIA.

211

the same line and left a distinctly serrate, sutural edge. The two foremost teeth, it
follows, are in the premaxilla, while the diastema and the seven teeth behind it are in
the maxilla. The anterior border of the premaxilla is smooth and rounded, sloping
obliquely backwards; the outer face bulges around the fang of the large vertical
incisor. Above the diastema, the njaxilla is slightly concave, and then swells out
into the widely arching zygomatic process; the infraorbital foramen is above the third
premolar.

The foremost incisor lacks the tip of the crown ; it is strongly convex and vertically
placed, with a straight anterior edge and a small cusp upon the slightly oblique pos-
terior cusp. The second incisor has a comparatively low, simple, pointed crown with
anterior and posterior accessory cusps ; it apparently lacks the vertical surface grooves
which are so conspicuous on the premolars. Behind the suture is a wide, smooth
diastema with no apparent trace of an alveolus. The three teeth which follow are evi-
dently premolars, as they are well distinguished from the remainder of the maxillary
series. It is uncertain whether they possess
one or tAvo fangs. The crowns are oval in sec-
tion, wdth the short axis transverse; they are
compressed towards the tip and bear three
sub-equal cusps, equidistant, one anterior and
two posterior. The posterior cusps are oppo-
site, giving the tooth a bicuspid appearance in
outer and inner view^ (Mes. Mamm., PL III,
fig. 6B). There is an internal cingulum, but
no external cingulum was observed. The
sides of the crown are marked by grooves, maxilla of Bolodon, enlarged 4 diameters.
Avhich converge at the summit. In both specimens the third premolar is slightly
smaller than the first and second. The four molars have comparatively Ioav and elon-
gate croAvns. There is a prominent cingulum upon the outer face, which partly embraces
the anterior and posterior slopes of the croAvn. The croAvn supports a double longitu-
dinal roAv of small cusps. In the outer row of the first, second and third molars there
are three cusps ; in the fourth molar there are only tAvo outer cusps, which are some-
what more prominent. In the inner roAv of the first, second and fourth molars there
are three cusps, Avhile the third molar has four cusps in the inner row. Each of these
cusps is a minute cone, Avith faintly grooved sides. In the third and fourth molars
there is a Avell Avorn, longitudinal groove betAveen the inner and outer rows Avhich cuts
into the inner slopes of the cusps. In the first and second molars, on the other hand,
there is no trace of such a Avorn median groove, but the Avhole inner face of the tooth.

Figure 5. The outer surface of the right

1 Professor Owen was misled by this bicuspid appearance in a fragmentary specimen (fig. 6), and de-
scribed the two premolars as molars.

212

ON THE STliUCTlIRE AND CLASSIFICATION

us far as the tips of the inner roAV of cusps, is worn smooth ; in the second molar, in
liict, the inner row of cusps is neaidy obliterated.

This (fissimilar attrition of the crowns of the anterior and posterior pairs of molars
is a very puzzling fact. It would seem to indicate the presence of two kinds of lower
molars, the first pair of a trenchant character, the second pair of a pattern somewhat
similar to that in tr? and m^}

Notes upon the genera Microlestes, Plagiaulax and Slereognathus are given
under the next section.

II. THE CLASSIFICATION AND ZOOLOGICAL RELATIONSHIPS OF THE MESOZOIC
MAMMALIA.

Our materials for the purpose of classification are very limited. The greater
number of genera are represented merely by the mandibular dentition between the
canine and the coronoid proce.ss, the ends of the jaw being usually fractured or wanting.
Only four of the Ilritish genera are represented by maxillae, and only two bv both
the maxillary and mandibular dentition. In the American forms, however, several
upjM'r and lower jaws have been found by Professor Mar-sh. Limb bones are rare
and when found arc still more difficult to associate. It follows that the only present
available ba.sis for classification is the dentition.

^^'e first observe that the Mesozoic Mammalia divide into two large groups.
In the first group. A, one of the incisors is greatly developed at the expense of the
others, and of the canine, which usually disappears ; behind these teeth is a diastema
of varying width, followed by premolars which are subject to great variations in form
and numl)er, while the molars bear numerous tubercles. In the second group, 13, the
incisors arc small and numerous, the canine is always present, and well developed; the
teeth usually form a continuous series, and the molars bear cusps instead of tubercles.
These two divisions suggest those which obtain among the modern Marsupials, but are
in fact much more sharply defined and widely separated from each other. Professor
Flower^has shown the difficulties which arise from the Diprotodont and Polyprotodont
divisions of the recent Marsupials, upon the lines drawn by Professor Owen, owing to
the strong similarity in thestructure of the feet observed between families which upon
the basis of tooth structure fall into different divisions. Admittiiig the marsupial
re ationship, it is clear that the genera of the first group are closely related to each
other and widely .separated from the Diprotodonta by their dental structure which
Ls very dissimilar and indicates that they probably branched off from the stem of
the recent marsupials at a remote period, probably the Triassic, (see Appendix).

Atecte. E„eycl„p.Aia Brlitonlc, ninth edition, 1833, p ^6.

OF THE MESOZOIC MAMMALIA.

213

Therefore, selecting the tubercular character of the molars as a common character, we
may adopt for this group, with a modified definition, the Marsupial sub-order
Multituherculata which has been proposed by Professor Coped The second group is
characterized negatively by its wide separation from the first, rather than by the
presence of distinctive characters common to all its members, and for reasons Avhich
will be fully stated later, it does not appear to constitute a single well defined division.
The first group is much more primitive than the second ; it was apparently widely
spread in the upper Triassic and extended upwards, while the second group, with the
exception of two genera which are very distantly related to the others, appeared in the
lower Triassic, and was widely distributed in the upper Jurassic.

Figures. The molar tooth forms of the multituberculate marsupials. 1. Triglyphus, an upper molar
la, ditto, in side view, natural size. 2, 2a. Tntylodon, an upper molar, wearing surface and outside view
natural size. 3. Polymastodon, the second upper molar, natural size. 4. Bolodon, the third and fourth upper
molars, enlarged about 6 diameters. 5. Slereognathus, a lower molar enlarged about 2J diameters. 6. Chirox,
the upper molars enlarged 1 J diameters.

A. FIRST GROUP

SUB-ORDER MULTITUBERCULATA.— Cope.

An extinct sub-order of Marsupials in which the teeth are below the typical
number ; one incisor on each side is greatly developed ; the lower canines are
rudimentary or wanting; there is a broad diastema in front of the premolars and the
molars are provided with tubercles in two or three rows with longitudinal valleys
between them. Th(

1. Plagiaulacidse
A single lower incisor.

Premolars in both jaws
developed into flat cut-
ting blades. Lower mo-
lars with irregular tuber-
cles; in early forms a
vertical ; in later forms a
fore-and-aft grinding mo-
tion between the molars.

(Upper molars with three
parallel rows of tub-
ercles.)

1 “ Tertiary Marsupialia,” American Naturalist, 1884, p. 681. The order AUotheria was proposed by Pro-
fessor Marsh (Am. Journ. Sc. and Arts, Sept., 1880), to embrace Plagiaulax and Ctenacodon and other genera,
but without the statement of characters suflicient to distinguish it from the Marsupialia.

!re is no mylohyoid groove in the mandible.

3. Tritylodontidx

2. Bolodontidx
Two or three upper in-
cisors. Upper premolars
tubercular. Upper mo-
lars with two regular rows
of conical tubercles, adap-
ted toafore-and-aftgrind-
ing motion, separated by
longitudinal grooves or
valleys.

Two upper incisors.
Upper premolars tuber-
cular. Upper molars
with three parallel rows
of conical tubercles, ad-
apted to a fore-and-aft
motion, separated by
longitudinal grooves.

4. Polymastodontidx
A single lower incisor.
One simple premolar in
the lower jaw, no upper
premolars. Two molars
in each jaw. Three rows
ofpavement tubercleson
upper molars, two rows
on lower molars, adapted
to a fore-and-aft motion,
without wearing grooves.

ON THE STRUCTURE AND CLASSIFICATION

1 PLAGIAULACIDAD.* Marsh.

Tin, family Fobablv embraces the genera Mk.-ole.te., Gtenaeodok, Plagk^edatc,
miodm. K.o,,lmjti,ntar, Me,.i.coi.m. and perliaps also Ihylaeoho.

MIC'IiOLKSTES^ Plicninger, 1847.

In describing Plagiaulax,^ Ur. Falconer fully recognized the likeness of its molars to
those of Mk-rolestes. He gave an excellent figure of the molar of M^roJestes antiqmu^
obtained bv Sir Charles Lyell from the original in the Stuttgart Museum, fig. 7,
which is much more accurate than the figure copied by Owen, Giebel and others.
When these crowns are carefully compared with those of 31. 3Ioorei (British Museum
Collection), fig. 7, 2, and with the posterior molar of P. 3I%nor, (3, %a) the following
resemblances are apparent: the inner margin of the central sub-circular valley is in
each case raised into two tubercles ( % ) ; these are conjoined in 31. anhqmcs, and

31. 3Ioorei, and .separated in P. minor, but in each case the antero-internal tubercle is

Kioore 7. The molar tooth forms of the Plagiaulacidie. 1 Microlesles nnUrjuus (Stuttgart Collection'*), a
lower molar viewed from above; la, posterior face; 16, external face, greatly enlarged. 2 c Plagiaulax
Moorei, from above. 3 Plagiaulax minor, the lower molars viewed from above, 3 a. external face of .same
enlargi'd Oj diameters. 4 Ptilodm Trovemartianus, lower molars viewed from above, 4 a, external face of
same i internal tubercles, e e', external tubercles. Original.

the most elevated of the two as well as of all the coronal tubercles ; the outer margin
of the central valley is raised into numerous tubercles, which vary in distinctness
but are usually five in number, the antero-external being the most prominent. In
M. 3Ioorei we observe as an exception, a third small tubercle upon the inner margin.
On the other hand, the differences between these molars, are seen in the deeper cre-
nation of the outer margin of 3L antiquus, and the lateral compression of the crown,
which brings the margins nearer together and deepens the valley into a groove more
oiMJn at the ends than in the Plagiaulax molars.

' Proposed by Professor Dlarsh, Am, Jour. Sc., 1881, p. 511, to embrace Plagiaulax and Ctmacodon.

* “ Jahreahefte des Vercins fiir Vaterliindische Naturkunde in Wlirtemberg,” Band 11,1847, p. 164. taf i,

tigs. 3 and 4.

* liuarierly Journal of the Geological Society, August, 1857.

* Through the kindness of Dr. E. Fraas, of Stuttgart, I have recently procured this complete set of figures of
this type which fully confirm the drawings given by Lyell.

OF THE MESOZOIC MAMMALIA.

215

The result of this close comparison is first that, according to our present knowl-
edge, the generic separation of PJagiaulax from Microlestes (type) is not very wide,
and that the English species, M. Moorei, so far as known at present,^ cannot be sepa-
rated generically from Plagiaulax, as it stands nearer this genus than it does to Micro-
lestes. Second, we are justified in considering Microlestes as the earliest known
representative of the Plagiaulaucidoe.

PLAGIAULAX, Falconer, 1857.

Type : P. BecMesU. Dentition, i 7 c 7 pm. 777 m. 7 This genus is so well
known .through Owen’s and Falconer’s memoirs as to require no detailed description
here.^ The different species mark numerous variations in the number of premolars, in
the development of ridges upon their sides, and in the greater or less degree of
confluence of the angle with the condyle. The more primitive of the Jurassic forms
are those in which the premolars are four and faintly ridged, and the angle is en-
tirely distinct from the condyle. The most primitive is Ctenacodon, Marsh,
which may be considered a distinct genus,^ if we also subdivide the Purbeck
species of Plagiaulax into two genera.'^ In this American form the condyle is pedun-
culate, the angle is effected and inflected and the grooves upon the premolars are so
faint as to be scarcely distinguishable. In the specimen of P. minor, (Professor Owen’s
drawing, PI. lY. fig. 9, is more accurate than that in Falconer’s memoirs, A"ol. I. PI.
33), unfortunately, the angular portion of the jaw is wanting ; it was probably inter-
mediate between that of Ctenacodon and of P. medius ; there are two or three grooves
upon pms 2^, while- there are about seven grooves on pm^, extending half-way
across the crown. In P. medius the premolar grooves are much deeper and more
numerous.

The later dental evolution of the Plagiaidacidce is thus foreshadowed in the
changes Avhich are observed in progress in the Jurassic species, viz, the loss of the an-
terior premolars ; the growth and deepening of the ridges upon pm^ ; the elongation of

’ I judge from the specimen in the British Museum which seems to correspond closely to the figure of the
molars in other collections.

2 I may mention that I observed a faint cingulum upon the second molar of P. minor. Waterhouse observed
the same (Xat. Hist, of Mamm.,) as cited by Dr. Falconer, Memoirs, p. 426.

’Compare Marsh “Jurassic Mammals,” April, 1887. p, 332. The characters here assigned to distinguish
Ctenacodon are: )“ four premolars instead of three.” In Falconer's type P. BecMesii there are but three pre-
molars, but in the closely related P- medius (Owen), there is a socket for pm’, and in P. minor pm’ is well
developed. (2) “ The summits of the teeth only are notched and the sides.smooth.” In a close examination of
the premolars in C?e?iocodon very faint grooves can be observed on the sides. (3) “ The condyle has a distinct
neck, see also Plagiaidax medius 'Fa\c. “ Memoirs,” p, 424, and Plate 34, Vol. II. (4). “ The outer margin is
eflfiected ” see Owen, Mes. Mamm. p, 88. The constant presence of four premolars can be adopted as the
generic distinction of Ctenacodon, which should naturally embrace P. medius and P. minor.

* Professor Cope makes the P. minor of Falconer the type of a new genus, PUoprion, characterized by 4
premolars ridged and serrate. Such a definition would also include P. medius, Owen, aud introduce further con-
fusion, since P. medius is very close to P. Becklesii.

210

ON THE STEUCTURE AND CLASSIFICATION

tlie molars, accompanied by a multiplication of the tubercles into two thickly studded
rows, separated by a groove. In the Jurassic species, the molar crowns form a sub-
circular basin which shows no signs of fore-and-aft wear, the marginal tubercles being
mere crenations ; in the later forms, the basin is converted into a groove by the ap-
proximation of the sides, the tubercles become distinct, and the groove shows fore-and-

Figi'ke 8. a, Ivcft lower jaw of Ctenacodon saralus, Marsh, inner view, three times natural size:
b. Right upper jaw of C. polem, inner view x4. c. The same seen from below, a. First premolar, b, fourth
preiiiolar as interpreted by Professor Marsh. After Marsh.

aft wear as in the Bolodon molars. These stages, already partly described in the
valuable memoirs of Cope and Lemoine, may here be presented synoptically :

Jlihdus, ' Cope.

» T pm I j

The first and second premolars
entirely wanting; the third is
rtidinienlary ; the fourth has
about l.'i obli(|UC grooves. The
first molar is narrow and elongate
with three internal and five exter-
nal tulicrcles. The second molar
has two tubercles on the inner
row and four upon the outer.
There is a well-worn groove be-
tween the rows of tubercles.

Neoplagiaulax, Lemoine.

The condyle is elevated above
the angle and transversely ex-
tended. The fourth premolar
alone remains and is marked by
fourteen deep oblique grooves.
The molars are very elongate in
TOj, there are six tubercles in
the inner, and nine in the outer
row. In m2 there are 3 or 4 in
the inner, and 5 in the outer row.

Thylacoleo, Owen.

The fourth (?) lower preraolar
only is preserved, with smooth
sides and well marked grooves at
its base. (Falc. Pal. Mem. Plate
34, fig 9).

N. B. The position of 'Ihylacoleo
in this series is very doubtful.

The structure of the upper molars has an
I j"* “f Phgiaulax and Bolodm. Dr. Lemoine'' in

: “T"* ‘wo molars with a triple row

01 ulmrclcs, 1 ut otlierw.se so closely resembling those belonging to the ma^ible
that he conjectured they belonged to the maxillary series. In the maxillary s^S

‘American Naturalist, 1884, p, 370.

‘ f.tude sur le Neoplagiaulax, etc., PI. VI, fig. 17.

OF THE MESOZOIC MAMMALIA.

217

mens of Cte^iacodon discovered by Professor Marsh, the true molars are unfortunately
missing, although the premolar series is complete, (fig. 8, 6, c). The five teeth pres-
ent increase from before backward. The first and second are of the Bolodon type, i. e.,
with a subcircular crown supporting three conic tubercles; the third is sub-trenchant;
the fourth and fifth are trenchant with deeply indented borders. Behind the fifth is
a space for two molars, (p, 333 Am. Jur. Mamm.^)

Is there a family relationship between Bolodon and Plagiaulax ? In comparing
this series with the corresponding teeth of Bolodon, we observe that the Bolodon pre-
molars decrease rapidly in size from the first to the third ; secondly, that the succeed-
ing teeth increase rapidly from the fourth to the seventh ; third, that the third tooth
behind the diastema in the Gtenacodon maxilla is large and trenchant while, in Bolo-
don it is tritiibercular and very small; the fourth tooth behind the diastema in Gten-
acodon is high, trenchant and has an indented upper border, while the similar tooth
in Bolodon is a lo w crown bearing six conical tubercles. Dr. Lemoine’s discovery
renders it probable that the upper molars of Plagiaulax had three rows of cusps, but
111 default of positive evidence upon this point, we must compare the Bolodon maxil-
lary molars with those of the Plagiaulax mandible. They are very widely distin-
guished from each other (a) by the presence in the former of a strong cingulum which
embraces three fourths of the crown; (b), by the double row of distinct conical
tubercles with striate sides, arranged in parallel lines, and separated by a well worn
median groove. These cannot be mistaken for the crenate margin of the basin-
shaped molars of the Jurassic Plagiaulax; they belong rather to the Tritylodon type
of molar with two rows instead of three. I had previously supposed that the edges
of lower premolars of the Plagiaulax type might fit in these grooves, but this hypo-
thesis is disproved by the above discovery. The two anterior premolars of G. potens
are, it is true, similar to those of Bolodon, but beyond this there is no homology in
the maxillary dentition of these genera. The dentition of Bolodon suggests a fore-
and-aft grinding motion ; that of Plagiaulax a vertical motion of the mandible.
The determination of the dental formulte in these genera, at the present time, is
largely an arbitrary matter. Judging from the natural division of the tooth structure
the formula of Gtenacodon is i} eg pt m|, differing from the Bolodcm formula as given
below. The wide separation indicated by these numerous diverse characters over-
weighs the affinity suggested by the likeness of the two premolars and makes it
necessary to place Bolodon in a distinct family.

MENISCOESSUS, Cope, 1884.

This genus, from the American Cretaceous, is much larger than the Mesozoic or
Eocene Plagiaidax. It is represented by a single molar and premolar tooth probably
belonging to the maxillary series. The molar tubercles are arranged in three rows.

* Professor Marsh places Allodon in the Plagiaulacidse.

^ ON THE STRUCTURE AND CLASSIFICATION

21o

r • 1 fiibpirles of the median row are crescentic, and those of the

l' The premote show four notches on one-half of the

lateral rows are semi-crescen . J^^^onaing portion of the outer face; the

»- i. .h. m..

latter surmou ^ representing the

cingulum.

The median crescentic and lateral semi-cre-
scentic tubercles of this genus suggest the molar
pattern of Stereognathus, in which the tubercles
Fiat'RE 9. Maiiscfjisgus. — u. Probably an similarly shaped and disposed, but less

upi>er molar viewed upon the wearing sur- , vniep n rlnnbl

fai, enlarged two diameters ; b, probably numerous (Text. fig. 6, 5 ) and raise a doubt

the inner face of an upper premolar; c, ^y^ether the type molar really belongs to the max-
outer face of the same ; rf, anterior face of , . rpv 1 u

the same. Cope Collection. Original. illary or mandibular series. The premolar, how-

ever, resembles that of tlie maxilla of P. potens. Marsh, more closely than any of the
known lower premolars. There is thus little doubt that Professor Cope has correctly
placed this genus among the Plagiauladdce.

2. BOLODONTID/E, Osborn h 1887.

This family embraces Bolodon^ the closely allied genus Allodon and possibly
Chirox.

BOLODON. Owen, 1871.

iPndlion, iM c" pm® m^. The second upper incisor is large, caniniform,
sepamtc from its opposite fellow. The median incisor small or wantitig. The second
incisor small, with a bicuspid crown, followed by a diastema. Premolars single
fanged with faintly grooved sides and tricuspid crowns. The tubercles upon the
molars conical, varying from two to four in each row.

ALLOOON, Marsh, 2 1881.

Dentition, i? c? pmf m^. This genus is separated from the foregoing merely
by the presence of the small median incisor which has not as yet been observed in

lim-RKlO. \iew8 of the maxilla of Allodon laticepa, Marsh; a, seen from below x 4. Allodon fortish,
rremaxilla from the outer side, x3. c. The same from the inner side, s. Suture; o, Alveolus of lateral
incisor or canine. A Uer Marsh.

liolodon. 1 he diastema is narrower and it is possible that a weak canine is present. In
all other respects, oven to the number of tubercles upon the molars, the genera are alike.

I’roc. bhila. Acad., June, 1887.

Am. Journ. Sc. and Arts, 1881, p. 511.

OF THE MESOZOIC MAMMALIA.

219

liofessor Marsh in view of the supposed close relationship of this genus to
Plagiaulax places but two of the upper teeth in the molar series, giving the post-incisor
ormula as pm ^ ml This can hardly be correct since the three premolars are very
sharply separated from the molars by many details of structure such as the number of
tubercles, the internal cingulum etc.. The first and second molars of AUodon have
their crowns somewhat flattened on the inner sides but not worn as in Bolodon. This
further increases the uncertainty as to the character of the lower dentition in this
family.

CHIEOX, Cope L 1888.

Dentition, il cl pm! m!. The number of premolars is somewhat uncertain.
This genus may be provisionally placed in the same family, sabject possibly to re-
moval later when its dentition is more fully known. It is represented by a maxilla
with three premolars and two premolars in situ. The most anterior premolar is the
largest, the series decreasing posteriorly ; it has but three tubercles while the succeed-

« b

Figdre 12. Chiro.v pUcaltis, Cope, one and a halftimes natural size ; a, viewed from below, palate with den-
tition, three premolars and two molars in snfu; b, viewed from the outer side. After Cope.

ing smaller premolars have four. The tubercles are conic, compressed and faintly
grooved as in Bolodon.. The molars have each two complete and one half-row of
tubercles. The first molar has two conic tubercles in the outer half-row, six in the
mid-row and seven in the inner row. The tubercles are conic and separated by valleys,
not by grooves; the inner face of the crown is smooth The second molar has the half-
row on the inner side ; the mid and outer rows, have eight tubercles each, separated
by grooves apparently indicating fore-and-aft wear.

Several interesting resemblances will be noted between this and the Bolodon
series. Chirox seems to be transitional in the structure of its molars, between the two
and three row type, the additional half-row appearing to arise from the cingulum, but
the premolars both ■ in form and number are very similar to those of Bolodon, with

’ Proc. Amer. Phil. Society, p. 321, 1883. Also, Amer. Naturalist, June, 1887, p. 566. Professor Cope places
this in a new family, the Chirogidx, but I tbink it may for the present be retained in the Bolodontida;.

.,20 ON THK structure AND CLASSIFICATION

,he ox, q, lion Of the additional tubercle upon the two posterior. In both genera
the pron'okrs decrease in size nntero-posteriorly. The first molar o CAnm has un-
won' valleys between the tubercles and a smooth inner face as in m and m of liolodon-,
while the .second molar resembles and m' of BoMou in the signs of antero-posterior
wear between the tutarclcs. For these reasons I am inclined to regard C7, urn as a
successor of liolodon, or as having a relation somewhat similar to that which may have
obtained between Polymadodon and Tritylodon.

3. TRITYLODONTIILF, Cope >, 1884.
TRITYLODON, Oweu*,1884.

Dentition, i ? c ° pm and m !!. One large median vertical incisor is followed
by a small incisor and this by a wide diastema. Behind this are two teeth with
broken crowns, the foremost or both of which may represent premolars. Behind these
are four quadrate molars with three parallel rows of conical tubercles, separated by

well worn grooves. In m'’ to m'^
inclusive there are three tubercles in
the inner row, four in the middle
row and two in the outer row. In
the sixth molar the tubercles are
less numerous. The face is elongate.
The frontals do not join the pre-
maxillaries. The parietals diverge
anteriorly into a wide depresson.^

Fiai’KK 13. Tritylodon lonaaviis, anterior portion of the rni in i ii i i j

-knli viewed u,»on the left face, two thirds natural size, ^he lachrymals are well developed
.\nert)wen. upon the face, and the foramen is

intra-orbital. The anterior nares are terminal. The posterior nares are between the
fifih and sixth molars.

TRIGLYPHUS. Fraas 1868.

1 his genus is represented by a single molar which closely resembles in the num-
l)er and disjiosition of its tubercles the molars 3 — 5 of Tritylodon, as pointed out by
NeumayrV AVhen these teeth are closely compared (fig. 6, i and 2), they will
jirobably prove to belong to the same genus, in which case Prof. Fraas’ genus has the

l)riority.

' .American Naturalist, loc., cit.

• Quart. Joiirn. of the Geological Society. Dr. George Baur kindly investigated this skull at my request
and reports that there is no trace of a foramen here.

• Discovereti in the Rha-tic Beds near Stuttgart and described by Prof. Fraas in his work, “ Vor der Sund-
fluth/* page 215.

‘NeuesJahrbuch.f. Min., Geol., und Pal.. 1884., p. 279.

OF THE MESOZOIC MAMMALIA.

221

The accompanying figures represent two views of the crown of a small tooth
from the supposed Rhaetic Bone Bed near Hohenheim, not far from Stuttgart. It
has been preserved for many years in the Mineralogical Cabinet of the Akademie
Hohenheim, and was forwarded to the writer by Prof Dr. F. Nies, through the
kindness of Dr. Baiu'. It has not been heretofore described. It con-
sists of a low quadrate crown supporting four smooth, conic tubercles
“ at the corners, which are very slightly worn ; the fangs are wanting ;

the history of the specimen is somewhat uncertain. If it is actually
^ from the Rhaetic Beds, it probably represents a premolar of Trigly-
phus or one of the allied Tritylodonts.

POLYMASTODONTID^, Cope, 1884.

Fig. 14. Pre-
molar of Trigly-
phus (?) a, Upper
view ; h, side view.

f natural size. embraces the single genus Polymastodon (Cope) which

has several known species. The dentition is i ^ c ^ pm f m |. The family char-
acter as stated by Professor Cope, is that the fourth premolars are more simple than
the first true molars. This is a rather uncertain distinction from Tritylodon in which
the crowns of the premolars are not known. The dentition is much reduced. As
there are no worn grooves between "the rows of tubercles, the upper tubercles
simply oppose the lower, without alternating with them. No other family
character is at present to be found, although it seems as clear that Polymastodon
and Tritylodon belong to separate families as it is that they belong to the same
sub-order.

The incisors resemble those of the Plagiaidacidoe. The molars have three rows
of numerous tubercles in the maxilla, and two rows in the mandible ; these tubercles
are flattened into a tesselated pattern, lacking the longitudinal grooves. Various por-
tions of the skeleton are described by Prof Cope.

Incertje sedis

STEREOGNATHUS, Charleswortli.t, 1854.

The lower molars support six cusps arranged in three antero-posterior rows of
two cusps each. From the tip of each cusp of the middle pair two low ridges diverge,
forming a V, opening forwards. The lateral pair of cusps have similar ridges ex-
tending from the median side of the cusp only, towards the centre of the crown
(fig. 6,5).

It is doubtful whether Stereognathas belongs to this sub-order, or to the follow-
ing group. It cannot be placed in any of the foregoing families, since the lower
molars have three rows of cusps instead of two. At the same time it is even more
remote from any of the genera of the second group. The nearest likeness to its molar
pattern is seen in the meniscdessus superior molar.

* Report Brit. Assoc., 1854, p. 80; also Owen, Quart. Jour. Geol. Soc., 1857, p. 1.

222

ON THE STRUCTURE AND CLASSIFICATION

B. SECOND GROUP.

triassic period.

While the American juraasic fauna is closely related to the British, the American
.riassic fauna is widely separate from both, so far as we can judge from the scanty
material which has been obtained from the North Carolina Beds. In the jurass.c
forms of tall, countries the crowns of the molars are well distinguished Irom the
fangs, and the latter are distinctly paired or multiple, ex-
cept in cases where they are undergoing a secondary union
{Kurtodan). In the two triassic genera known at present,
the crowns are continuous with the fangs, and the only
evidence that the fang is divided is a shallow median de-
^ pression at the base which opens downwards. A similar

Fit;. 8,— a. Inner aspect of division of the base of the croivn has been observed by
Professor Cope, in Dtmetrodon, one of the Tlu,romorpl,
ofthefang.i, Section of another j-eptiles of the Permian. This character is, therefore, of
S^‘‘p.HpTivfty‘‘‘®(5‘,r'^Ue? great interest and importance, and necessitates the ordinal
tion. orifrinal. • separation of these genera from those of the Jurassic period.

ORDER PROTODONTA.— Osborn.

Primitive lieterodont mammals in which the fangs of the molars and premolars
were unpaired and not well distinguished from the crowns, the incipient division of
tlie fang Iieing reprc.sented by a lateral groove on the base of the crown.

DROMOTIIERIIDiE, Gill, 1874.

'I'his family was proposed by GilP and adopted by Marsh% without definition, to
inchule Dromotherium. It may now be defined to embrace also ^Rcroconodon, as
follows: A wide diaeiema behind the canine. Premolars styloid and without a distinct
heel. Molars with the main csisp and the lateral cusps in the same fore and aft line.

DROMOTHERIUM, Emmons,^ 1857.

Dentition — ijC^pm^m^. The incisors are caniniform, recurved and separate.
1 he canine is large and recurved, followed by a wide diastema. The premolars are
styloid and semi-procumbent with ungrooved fangs. The last premolar crown has a
deep iK)sterior groove. The molars have imperfectly divided fangs. There is a lofty
main cusp and irregularly disposed anterior and posterior cusps, sometimes multiple.

By the AiUhor'!'"*®"''' ^dromotherium and Microconodon,” Proc. Am. Phil. Society, April, 1887.

• “ Arrangement of the Families of Mammals, &c.,” Smithson. Misc. Coll., 1874, p. 27.

• Am. Journ. Sc. and Arte, April, 1887. p. 344.

• American Geology, Part VI, pp. 93 and 94. 1867.

OF THE MESOZOIC MAMMALIA.

223

upon the anterior and posterior slopes. The molars have perhaps a faint posterior,
but no internal cingulum. The mandible is very stout with a lofty coronoid process.
The condyle is probably midway between the angle and coronoid. There is a deep
mylohyoid groove terminating beneath the molars. The symphysial surface is
indistinct.

MICEOCONODON, Osborn,' 1886.

There is a wide diastema behind the

Dentition. — I ? c pm^, m., or pm^,
canine. The premolars are erect and sub-
conical, with a faint posterior cingulum,
and the third possesses a slight lateral
groove in the fang. The molars have a
shallow grooved division of the fang.

There is a large median cusp and regular
anterior and posterior cusps, in no case Figum a. Microconodm tenuirostris, outer face of
1 rpi . T right mandibular ramus ; four times natural size.

P e. ihere is a distinct cingulum Dotted contours of molars conjectural. Coll. Phila.
posteriorly, which may represent the ex- Academy. Original.

tension of an internal cingulum. The mandible is slender, the coronoid low; the
condyle is probably low, and the angle is represented by a curvature of the lower
border as in Peramns.

JUEASSIC PERIOD.

The Jurassic genera of the Second Group, like the triassic, possess a mylohyoid
groove upon the inner surface of the mandibular ramus. They differ from the
known triassic genera, first, in the complete division of the molar fangs; second,
the premolars are not separated from the canine by a diastema, except in cases where
they have evidently suffered numerical reduction. They are generally further dis-
tinguished by the following characters: The incisors vary from four to three in
number. The canines are invariably present, usually well developed and frequently
bifanged. "With a few exceptions there are four premolars, well distinguished in
pattern from the molars ; in other words the dentition is distinctly heterodont.' The
molars vary from four to eight, generally exceeding the former figure, and present a
variety of patterns of the cusped, but not of the tubercidar order. These features

' “ Observations upon the Upper Triassic Mammals Dromotherium and Microconodon.” Proc. Phila.
Acad. Jfat. Sc., 1886, p. 359.

* Phascolotherium forms an apparent but not real exception, since the premolars have probably disap-
peared. In Diplocynodon (Marsh, loc. cit. Plate X), the premolars when viewed upon the inner surface
are very distinct from the molars, although the outer aspect of the series is uniform. Professor Marsh,
however, gives the imperfect differentiation of the premolars and molars as one of the characters of the
“ Pantotheria,” an order proposed for the reception of this group.

224

OX THE STKUCTUEE AND CLASSIFICATION

distinguish the mammals of this period, so far as known, very clearly from the
Mulfituberculaia and P)-otoclonta.

In this, as in the former divisions, the molar pattern forms an advantageous
starting ^wint for classification. The entire dentition is in fact distinctly, although
not highly, specialized ; in carefully studying the details of the numerous members of
this group we invariably find a certain form of premolar, canine and incisor accom-
panying a certain molar pattern and an equally fixed relation existing between the
dentition and the characters of the mandible. In some cases where the molars are
apparently rather diverse, the structure of the remaining teeth and of the mandible
brings us back to the conclusion that there is some affiliation. As the genera fall
into smaller groups we at once observe that these groups shoAv a more or less clearly
marked specialization for a certain kind of diet, which is usually manifested most
clearly in one genus, which we may therefore speak of as typical of the group. The
allied genera diverge more or less widely from this type, which, it must be understood, is
not selected as the most primitive or the most central but as showing the most clearly
defined functional adaptation. While some genera are thus functionally typical others
are traimtioruil, that is, they show a divergence from the central type towards a different
kind of adaptation. Still other genera are isolated ; they do not approach other known
tyixjs but stand apart by themselves, either because few specimens have been found and
wc are less familiar with their structure, or their molar pattern does not conform with
that of any other known genus, or represent a distinct type. Our first object then is,
where i)o.ssible, to group the genera into families; secondly, to unite these families
into what we may call sul)-groups, indicating their general adaptation to a certain
diet. Ihe sub-groups naturally have less permanent taxonomic value than the
families, and still less than the genera. The families are thus grouped where they
seem to show evidence of being in early stages of differentiation along certain lines of
ftmctional adaptation. These lines are not sharply defined, but by a comparison of
the typical forms of each of these sub-groups with the most nearly allied recent genera
we may divide them into carnivorous, omnivorous, herbivorous and insectivorous series,
as indicating, in most cases, an initial rather than an advanced stage of specialization.

♦ 1 e! ; "lost part, clearly distinguished from each other, but

the is the only fully defined family, in which numerous genera, with

ZuM n ZZT 'r“‘‘ 'i^UHonofboth jaws known, ase

VO ™ •» boundaries when

"r f” example, that the

I'nconodonUdiv will embrace a larger number of genera

OF THE MESOZOIC MAMMALIA. 225

alternatives are to place them in three families or in one. I have finally adopted the
latter^ upon grounds which are more fully stated later.

In describing the teeth a distinction has been made between a “heel” or sloping
extension at the base of the crown, a “ basal cusp” and a “ cingulum cusp,” which
is simply a prominent portion of the cingulum. These distinctions also enter into
the classification frequently, especially in connection with the premolars.

The chief molar types of this group are shown in the accompanying figure.

Figure 10. The principal molar tooth forms of the Mesozoic Mammals of the Second Group. The
anterior face of the molars throughout is to the left, and the posterior face to the right. A, Dromothe-
rium, the second lower molar, inner face X 7. B, Microconodon, the fourth lower molar, outer face X 7-
1, AmphiUstes, the second lower molar, inner face. 3, Phascolotherium, the fifth lower molar, inner face
4, Triconodon, the second lower molar, inner face. 6, Peramus, the fourth lower molar, outer face. 7, Spala-
colherium, the third lower molar, inner face ; a, outer face. 8, Peralestes, third upper molar, inner face.
9, Peraspalax, third lower molar, inner face. 10, Leptocladus, third lower molar, outer face. 11, Phascolestes,
third lower molar, inner face. 13, Achyrodon, fourth lower molar, outer face. 12, Dryoleates, lower molar,
inner face ; a, outer face ; b, wearing surface. 15, Kurtodon, upper molar; a, wearing surface. Original.

In the first type there are three cusps in the same fore-and-aft line (figs. 1, 3, 4, 11,
13). In the second the cusps are placed upon opposite sides of the crown and
separated by a median valley (figs. 8 and 9) . In the third the cusps are placed upon
opposite sides of the crown, but connected by transverse ridges (figs. 12, 12a and b).
In the fourth the crown is columnar, there are no cusps, and the fangs are placed
transversely (figs. 15 and 15a). Transitional types are seen in figs. 6 and 7. Fig. 10
represents an isolated type. The next figure shows the form of the premolars
which accompany these types, the numbers corresponding to the above. A compari-

^ In the preliminary abstract of this -paper Amphilestes was embraced in the Triconodontidx, and Phas-
colotherium and Spalacotherium made the types of other families.

226

ON THP] STRUCTURE AND CLASSIFICATION

son of these teeth with the corresponding mandibles, gives us an outline of the
correlation which is the basis of classification.

Vtk & ^ ^ Hi &

A a 16 7 // /i /i

FKiURE 11. The premolar tooth forms of the mammals of the Second Group. The premolar repre-
eented is invariably the most posterior of the series ; the anterior face is to the left. The reference numbers
are the same as those given above for the molars, and correspond to those upon Plates VIII and IX. Nos. A,
4, 0, 11, 12 are seen upon the inner surface, the remainder upon the outer surface. Original.

Incitort.

Caninet-

Premolars. Molars.

Mandible.

Tb/pical genus

1. Erect.

Large and erect.

With distinct ba- W ith three stout
sal cusps. cusps and cingu-

lum.

Stout, with a
broad coronoid
and low condyle.

Triconodon.

(4)

2. Erect.

Large and erect.

With distinct ba- With opposed
sal cusps. cusps. Uncon-

nected.

Stout.

Peralestes.

(Peraspcdax.)

(9)

3. Unknown.

Large.*

Small, or transi- With no cusps,
tional to molars. Columnar. No
cingulum.

Unknown.

Kurtodon.

(16)

4. Prorumbent.

Small and semi-
procumbent.

With a “heel” With three slen-
or cingulum der cusi>s. No
cusps. cingulum.

Slender, with a
narrow coronoid
and high con-
dyle.

Ambloiherium.

(11)

5. rrocnnibcnt.

Small and semi-
procumbent.

AVith a “heel” With opposed
cusps. Con-
nected.

Slender, with a
narrow coronoid
and high con-
dyle.

Stylacodon.

(12)

Tliese genera are typical not only of families but in a less degree of Sub-Groups.
As remarked before, the same degree of functional specialization for insectivorous,
carnivorous or otlier diet is not by any means observed in all the allied genera, yet
we maj broadly attribute this specialization to the entire sub-group as a general
characteristic. The sub-groups were the Insectivora, Carnivora, etc., of the mesozoic
l>eriod ; not in the recent sense of these terms, but in relation to their feeding habits.

SUB-ORDER PRODIDELPHIA.— Haeckel.2

Primitive Marsupials, generally distinguished from the recent forms by the
fn.<jucnt ,,ro«„ce of four premolars arrd numerous molars. Molars with distinct
multiple fangs ; molar crowns not fiUly tritubercular or tubercular-arctorial.

( .tRNiyonous and Omnivorous SuB.GRonp._The mammals which are included
m tta sulugroup have many points of mutual resemblance, although upon the first
exam matmn they appear to differ widely. They sub-divide into two series

era ail J,le r'^’ ^ includes all the largest gen-

em and some of intermediate sire, and is distinguished by the primitively sectorial

* Thw tooth 18 imssibly an incisor.

pof- ithout definition in the History of Creation,” and provisionally defined and adopted here.

OF THE MESOZOIC MAMMALIA.

227

character of the molars. This is the Caknivorous series, and may be distinguished
as follows : the molars have three stout, erect cusps in the same fore-and-aft line, or
with the lateral pair rotated inwards, without an internal heel but showing an
internal cingulum. The premolars, when present, have prominent “cingulum” or
“ basal ” cusps. The canines are erect. The incisors are semi-procumbent to erect.
The mandible is usually stout, with a broad coronoid process, and in two cases a
transversely extended condyle on or below the molar level and often on the plane of
the angle. The most highly specialized genus is Triconodon, in which the incisors,
canines and premolars are well adapted to a carnivorous diet ; the molar cusps are
sub-trenchant, the upper being worn sharp by the lower. (Plate VIII, ftg. I). The
closest modern ally is Th;/lacinus.

(2) The second, or Omnivorous series, embraces a number of families which are
closely inter-related both as regards their dentition and probable form of diet. The
molars are characterized by a more or less complete opposition of cusps upon the
crown, i. e., the cusps are placed transversely, but do not .show the sectorial disposi-
tion. In the typical forms, such as Peralestes, tlie upper and lower molars oppose
eacli other somewhat as in PidelpJii/s, but not with cutting edges. The internal
cingulum, invariably present in the first sub-group, is here replaced in the lower
molars by a more or less prominent series of cusps. The posterior basal cusps of the
premolars, if present, are somewhat less prominent than in the first group ; anterior
basal cusps are always wanting. The canines are stout, erect and often recurved.
The condyle is rounded and upon the molar level. The mandible is moderately
stout and rounded at the symphysis, indicating an erect position of the inci.sors. The
coronoid is narrower than in the first group. The angle is always separate and well
defined.

1. Carnivorous Series.

1. TKICONODONTID.E,! jpir.^h, 1887.

The Triconodemtidev. may be defined as follows : Upper and lower molars tcith
three stout, erect cusps and strong internal cingidtim, not opposed. Opposition of
dipper and lower molars sub-trenchant. Canines stout and erect, often hifanged.
Incisors semi-procumbent or erect. Premolars loith prominent basal cusps. Condyle
low, articidar face sometimes broad. Coronoid process broad. Angle sometimes
inflected.

This family embraces numerous genera which are apparently upon divergent
lines of descent, but are not sufficiently distinct to be placed in three separate
families, so that we may conveniently, and with more probability of rightly expressing
their relations, divide them into three sub-families. Amphilestes, from the lower
Jurassic, is the most central genus, as it has the full complement of teeth and the

1 “Am. Journ. Sc.,” April, p. 341.

ON TIIK STRUCTITKP] AND CLASSIPNCATION

•22«

molars arc of an iiitermoiiiate form. Arnphitylus, from tlie same strata, stands near it
(althougli not very fully known and presenting some features exceptional in this sub-
group); while Triconodon, from the Upper Jurassic, is much modernized. Phascolo-
therium, of the second sub-family, from the Lower .Jurassic, apparently lacks preraolari-
form teeth, but is linked with the other Triconodontidoi by Tinodon (Upper Jurassic)
which has premolars. The molars in each of the latter genera are intermediate
between those of Amphilestes and Spalacotherium, which, in turn, is the type of the
third sub-family. The primitive genera have four incisors, but the lateral incisors,
disappear in their successors.

a. AMPHU.ESTISM}

.Molar cusps in same fore-and-aft line; little or no reduction of the premolar
series ; angle distinct.

AMPHILESTES, Owen,^ 1871.

Dentition — i^, c., pnij, m,. The posterior basal cusps of the premolars, if
pre.sent, are not fully distinct from the cingulum. The anterior basal cusps belong to
the cingulum. The middle cusps of the molars are much more prominent than the
anterior and posterior. The molars are separated, the internal cingulum projecting
beyond the anterior and posterior slopes of the crown. The condyle is distinct from
the angle and on the molar level.

AMPHITYLUS, Osborn,’ 1887.

Dentition — i,^^ c^, pm^, m^. The premolars ^
resemble those in the last genus. The molars
have three blunt, compressed cusps, and are
compactly placed. The cingulum is less promi-
nent and does not embrace the anterior and po.s-
terior slopes of the crown. The condyle is lofty
and pedunculate.

TRICONODON, Owen,'* I860.

Syn. IVku-anthodon, Owen,® 1871.

Dentition— 1 1 c 1, pm 4, m i or 4. As shown upon page 196 of this memoir, the
fourth molar comes into place only in old individuals or is developed as a specific
chamcU-r. In young individuals the fourth premolar, d,, is molariform and is shed
early, riie premolars have prominent posterior and sometimes anterior basal cusps.
rho molars have three sub-equal trenchant cusps. The canines are stout and re-

' Sub. fain. nov.

rr

Fiouhk 10b. Amphitylu* Oweni, after Owen
(.1. 1‘rfrotiii), two and one eighth times
nalnntl eiie, from the Bnckland collection.

’"Meeoioic Mammalia,” p. 16.

Encyclop. Bnt.. Vol. 17, 1859. Art. Paleontology (fide Owen).
Mceotoic Mammalia/' p. 72.

OF THE MESOZOIC MAMMALIA.

22!)

curved sometimes bifanged. The incisors are compactly placed and recurved. There
IS no diastema. The angle and condyle are upon the same level.

PRIACODON, Marsh/ 1887.

This formula is somewhat uncertain, as the

Syn. Tinodon ferox, Marsh.^

Dentition~i cj, pnii, m^.
type may be immature There is
a diastema behind the canine, fol-
lowed by three premolariform teeth.

The fourth tooth is molariform but
may represent a milk molar, in which
case this genus is a synonym of Tri-
conodon. The dentition, as given by n- ,

•W- X . - - X , ” ^ Figuke loa. Right lower jaw of Priacodon (Tnconodon)

iViarsn, is pm^, m^, but may prove to ferox, inner view; three times natural size. After Marsh.

be pmi, di = mp ’ The first molar lacks the full sized cusps which characterize Wi
in tlie adult Th-iconodon, and resembles the milk molar of T. serrula, Owen.

’ b. PHASCOLOTHKRJINM:'

Lateral molar cusps upon inner slopes of central cusps. Extensive reduction of
premolar series, or, premolars and molars alike. Angle confluent with lower border
of mandible.

PHASCOLOTHERIUM, Owen/ 1839.

Dentition — ij, ci, pnio, m^. The incisors are styloid and separate. There is a
wide diastema behind the canine. Premolariform teeth are wanting. The molars
have a stout central cusp hearing the smaller anterior and posterior cusps somewhat
upon its inner face. The angle is represented by the inflected lower border.

TINODON, Marsh,' 1879.

This genus is distinguished from Phascolotherkim by the presence of eight or
more teeth behind the canine {fide Marsh), and
by the inward rotation of the lateral cusps. So
far as known at present it is closely similar in all
other respects.

c. SPA LA CO THERIINAE.

Lateral cusps of lower molars strongly ro-
tated inwards. Preniolars full or not greatly re-
duced in number, and unlike molars. Angle and condyle confluent with lower
border of mandible.

Figure Right lower jaw of Tinodon
bellus, inner view ; three times natural size.
After Marsh.

’ Loc. cit., p. 341.

= “Am. Journ. Sc.,” 1880, p. 236.'

’ Sub. fam. nova.

* “ Geological Transactions,” second series, 'Vol. 6, p. 58.
' “Am. Journ. Sc.,” 'Vol. 18, p. 216.

;i:«)

OX THE STRUCrUIiE AND CLASSIFICATION

SrALACOTHERIUM, Owen,' 1854.

, nm- mr The incisors are compactly placed, pointed and

,ecur :: Tr»;:ine'i: Jhev;,e„aer.e.ect and necnn-ed. The pre.nohn, have
„.erior '“ cingulum cusps” and prominent posterior “ basal cj. The mam cusp
7{ the molarsl continuous upon its outer face with the rn cmal y placed antpor and
,M»lerior cusps. The Internal cingulum forms a broad shelf. The angle and condyle
are both elevated.

I.eft lower jaw of Memicodon rarus, outer and inner view ; three tunes natural size. After

MENACODON, Marsh, " 1887.

DcntUion—iZ, cj, pin:,, m',. The canine is small and directed well forward.
'Die premolars resemble those of Spalacotherium. The anterior and posterior cusps
of the molars are not so fully rotated inwards as in the foregoing genus and are more
separate u|)on the outer face. The median cusp is less lofty, 'fhe mylohyoid groove
is less distinct.

Noth. — An\}»hiti/hit< is placed in the Triconodontidce upon the Imsis of its molar
structure, although the position of its condyle is exceptional and considered alone
would nunovc it from this group. The position of the condyle in Amphilestes is
inferred from Owen’s description and earlier figures (see Plate VIII, fig. 1). It will
Ik* * observed that Juioiloti, in its molar structure and the shape of the jaw, aftbrds
such a clear transition between the Amphilestincn and Spalacotheriinm, that there is
no pr(‘.s('nt ground for a wider separation of these genera than that here adopted,
although such ground may be subsequently discovered.* If the number of the
premolars and molars be allowed great weight in classification it is clear that the
almve genera must Ik; divided into four families.

2. Omnivohous Skkiks.

AMI'IIITHPAtllDA:, Owen/ 184().

Upper molars irith one main external cusp and two lateral cusps, and one main

' "tjuart. Jour. (ieol. Soc.,” London, vol. 10, p. 426.

• “Am. Jour. S<'. and Arts,” April, p, 340. I follow Professor Marsh’s description, although 1 think it
not improbable that four premolars and five molars will be found in a more complete specimen.

It is so easy to overlook the distinctions between the premolar and molar patterns in these minute
jaws (sec .Marsh, Tincxtnn, p. 340, “Am. Jur. Mamm.”), that until the post-canine dentition of Tinodon is fully
deerribed and ligureil I may be pardoned for questioning the statement that “the premolars of this genus
have the same general form as the molars.” This statement is also made in regard to Mesacodon, in which the
premolars arc very distinct in pattern from the molars (p. 340).

‘ “ Rritisb Fossil.Mammals and Birds,” 1846, p. 29.

OF THE MESOZOIC MAMMALIA.

231

internal none with a small posterior heel {Diplocynodon)} Lower molars with hvo
lofty external cusps and a posterior heel, connected with a. broad crenate internal
cingrdum. Opposition of upper and loroer molars not trenchant. Premolars with dis-
tinct ''cingulum’’ and basal” cusps. Canine bifanged. Incisors erect. Condyle
low. rounded and tipon molar level. Coronoid process elevated, but not very broad.
Angle short, anteriorly placed, not inflected, always distinct from lower border and
from condyle. The molars have two fangs placed in line?'

Although this family belongs in this sub-group as now defined, its members .
present a more primitive dentition than the following family. The molar pattern is
a good example of the “ transitional ” type, in which the internal cingulum is giving
rise to a complete row of internal cusps and to the “ opposition ” pattern. The
writer has found it very difficult to assign Amphitherium, from the English lower
Jurassic, its proper position. Its wide distinction from Amphilestes, with which it
was at first placed by Professor Owen, is shown by the absence of the third cusp ; it
is thus upon an entirely different line of descent. As observed by Professor Marsh, the
molar pattern of Diplocynodon, and the allied Jurassic genera, distantly approaches that
of Amphitherium ; in both genera the molar is bicuspid with a posterior heel which
extends upon the postero-internal face of the croAvn into a broad crenate cingulum.
The Amphitherium molar then differs from the Diplocynodon molar in the greater
development of the anterior cusp — a difference of degree only. The mandibular
characters of these genera are very similar. This anterior or second cusp is wanting
in the molars of Peralestes ; the Amphitheriidai may thus be sharply distinguished
from the Triconodontidce, and less widely from the Peralestidoe as above.

AMPHITHERIUM, De Blainville,’’ 1838.

Dentition — 1 i ;, c j, pm j, m g. This formula is somewhat uncertain, being derived
from a study of Prevost’s and Owen’s drawings, and from the description given by the
latter. The premolars have posterior “ basal ” and anterior “ cingulum ” cusps. The
molars have two main cusps and a posterior heel, and an internal cingulum bearing a
prominent cingulum cusp.

DIPLOCYNODON, Marsh,* * 1880.

Dentition — ii, c J, pm j, mi. The jaw is elongate and gently curved below.
The mylohyoid groove is parallel with the lower border of the ramus. The coronoid
is large and elevated. The condyle is nearly upon a line with the teeth. The

* Marsh “ Am. Jur. Mamm.,” p. 338, 1887. The writer has not examined the upper molars of this genus.
2 This family is equivalent to the Diplocynodonticlx, Marsh, 1887.

« Comptes Rendus, Aug. 20th. “ Doutes sur le prdtendu Didelphe fossile de Stonesfield.” Unfortunately
I have been unable to procure good figures of the internal aspect of the teeth of this genus.

* “ Am. Jour. Sc. and Arts,” 1880, p. 235. Diplocynodon is preoccupied by Pomel. (See Appendix).

' “Am. Jour. Sc. and .\rts,” 1881, p. 512.

* “ Am. Jur. Mamm.,” p. 339.

• “ Meoozoic Mammalia,” p. 41.

2;{2

ON THK STIiUCrrUKE AND (.CLASSIFICATION

'interri-posterior faces of the upper and lower molars are deeply excavated and
grooved. 'I'he second premolar is smaller than the first. Tlie premolars have dis-
“ tinct external cingula.

DOCODdN, Marsh,* * 1881.

Dentition. — i 3, c j, pm 4, ni 7. This
genus is closely similar to the prece-
ding, but lacks the eighth molar.

ENNEODON, Marsh,* 1887.

Fkii'kk 22. Uigiit lower jaw of Diplocynodon victor,
outer view, twice natural si/e. Dentition i C j, pm 3, m 3. The

canine is very large. The surface of the premolars is grooved or striate. The
antero-external cusps of the molars are less distinct than in Diploetjnodon. The
second premolar is apparently missing.

PERAMUS, Owen,* 1871.

Dentititm — i c 7, pm and m 7. This genus may be provisionally embraced in the

Ampldtheriidm as aboije defined. In En-
neodon we observe that the antero-exter-
nal cusps of the molars are slightly rotated
inwards upon the inner face of the crown,
as in Peramim (see Marsh, “ Am. Jur.
Mamm.,” Plate X, fig. 2, m3). The arti-
Fiochk 23.— iiinht lower jaw of Docodon utriatiis ; cular portion of the jaw in Perannis is es-
inner view, twice natural 8l/e. After Marsh. sentially similar to that in DildoetpiOilon,

although the coronoid is slightly narrower. The condyle has the same level. The
angle in Ixith is short and obtuse.

'fhe formula assigned to Peramns, pm6,m7, upon page 202 of this memoir, was in

view of the fact that only the three posterior
molars possess antero-external cusps. But
the presence of six premolars is so excep-
tional a feature that it is probable that
when seen upon the internal face (the outer
face only is known at present) the formula
would resolve itself into pm7 mj^. As thus
divided, the jiremolars appear to lack posterior basal cusps, and have no external
cingulum ; wlule upon the above hypothetical formula the anterior molars have no
antero-external cusps. The main molar cusps are ‘ erect, and there is an anterior

233;

OF THE MESOZOIC MAMMALIA.

basal cusp, not observed in Diplocijnodon.
Peramus in this family somewhat doubtful.

These features render the position of

PERALESTID.E, Osborn,* * 1887.

Uxyper molars loitJi lofty internal and several low external Cusps transversely
opposed ^ e., separated by a Imgitudvnal valley {Peralestes) . Lower molars with a
^ngle lofty external and several internal cusps {Peraspalax and Paurodon). Oppo-
sition of upper and lower molars not trenchant. Molar fangs, two in lime. Premolars
with basal cusps, variable, usually strong. % Canines single fanged.

PERALESTES, Owen,^ :871.

‘ Dentitiou^i-, cl, pmfH, m«. The fourth premolar has an elevated external
cingulum and a lofty crown rising above the molar level. There are two internal
cusps upon the molars; the antero-internal is the main one and is slightly retroverted •
the postero-internal cusp is much lower. The outer side of the crown is a ridge
supporting an antero-external cusp and two or three tubercles behind this.

PERASPALAX, Owen,* 1871.

(Syn. of Peralestes, X) Dentition— cj, pmj, m 7. The premolars have
elevated conical crowns and a strong internal cingulum, rising to the anterior cingu-
lum cusps and to the posterior basal cusps. The molars have a single external
antero-verted cusp. The internal cusps consist of a high medial and low anterior and
posterior cusps at the ends of the crown.

PAURODON, Marsh,* 1887.

Dentitionr—ii,, cl, pmi, m;.® The canine is large, erect and single fanged.

b

Phcunp. 2.i. Left lower jaw of Paurodon valens, inner and outer view; three times natural size, g, mylo-
hyoid groove, .\fter Marsh

Behind this is a diastema followed by a small, first premolar. The second premolar

*Proc. .\cad., Phila., June, 1887. This is probably equivalent to the Paurodonfids:, Marsh. I have
substituted Peraleslidte, because the above family name implies a deficient number of teeth which is the
case only in Paurodon; secondly, the family definition, as given by Professor Marsh, would exclude the
less modified British genera.

* “ Mesozoic Mammalia,” p. 33.

* “ Mesozoic Mammalia,” p. 40.

* “Am. Jour. Sc. and Arts,” April, 1887, p. 342.

^ It is probable that additional material will modify the formula, given above, to pm j, m y,as there is a
considerable space between m j and the anterior rim of the coronoid process. (Plate X, fig. 8).

ON THK STIlUCTUKE AND CLASS fF'ICATION

2;J4

has a single main cusp and a posterior heel apparently supporting a low basal cusp,
as in Peraspnlax. The molars have a single main, external cone, which is very
slightly antero-verted, and has a distinct cingulum upon the outer face. The inter-
nal face supports a median cusp which rises to about half the height of the main
cusp, a slightly lower anterior cusp and a heel-like process posteriorly. The lower
jaw is short and massive, with a deep mylohyoid groove reaching the symphysis.

Note. — The molars of this genus resemble those of Peraspalax so closely as to
leave little doubt of the family relationship between these genera, although
Panrodon has but six, or at the most seven, post-canine teeth. The opposition of the
Peralestes and Peraspalax cusps (see fig. 16 text) is probably such that the tip of the
external cusp of a lower molar fits into the valley separating the cusps of an upper
molar, and vice versa.

Herbivorous Sub-Group. — The single family embraced in this sub-group is
widely stjparated from those which we have been considering, by the unique character
of the dentition. The inner aspect of the crowns is very similar to that of the Stylodon
molars and the single specimen which represents this family was referred to this genus
by Professor Owen. But the wearing surface of the crown is essentially different
from that of Stylodon as it is wholly devoid of cusps and without any degree of
trenchant function. The fangs are distihet and placed transversely and are in a line
of modification which ends in growth from persistent pulps. The wearing pattern of
<lentinc, traversed by ridges of enamel, resembles distantly that of the Rodents and
more nearly that of the PhascolornyidcB, and we may infer that Kurtodem represents a
class of animals which fed upon roots and other vegetable substances. The large size
of the foremost tooth is, however, somewhat against this conjecture, unless it should
prove to l>e not the canine but one of the lateral incisors.

IV VJ i\ 1 1 xUJjliy

.yfolars wit/ioiU cusps, with compactly placed trihedral columnar crotons. Wearing
surMee flattened, with enamel ridges, indicating horizontal wearing action, as distin-

gutsh^ from vertical. Two or three fangs set transversely. Premolars rudimentart,
or sub-molariform.

at present the single genns Kurlodon, of which only the
mnx.llary dentition is known. It may be defined as above.

usDorn,-

AOO/.

the cTnite Ind 'll 1 'a ’’"‘nV” " is small, placed closely behind

canine and styloid. Behind this is a diastema followed by the rudimentary

> Proc. Acad.. Phila., .Tune.
•Proo. Acad., Phila., June.

Athrodontidx, Syn.
Aihrodony Syn.

OF THE MESOZOIC MAMMALIA.

235

second prcmolai-. The third premolar is larger with a sub-conical crown. The
fourth premolar has two fangs which are partly rotated into a transverse position.
The inner face of the crown is more lofty but otherwise resembles that of the first
molar. The wearing surface of the molars presents an enamel V upon the anterior
and posterior faces of the crown, diverging from the inner face, and bisected by a
faint median ridge, apparently of enamel, which disappears, as it extends outwards.

SUB-ORDER INSECTIVORA PRIMITIVA.i
An extinct sub-order which is probably on the line of the primitive Placentalia,.
with tritubercular molars, forming alternating series in the upper and lower jaws..
The nearest affinities in dentition are to some of the recent Insectivora.

. Insectivorous Sub-Group. — This embraces the families AnMotherikicB and Sty-
lacodontidoB. The types of the former family are known by the inner surface of the
mandibular rami only ; and as this is in many respects similar to the corresponding sur-
face of the Stylacodon types, the separation of these families is not fully established.
The genera vary from an extremely small to middle size. The smaller genera embrace
the typical insectivorous forms, in which the incisors are procumbent and spatulate,
and the canines are very small. In the larger genera the incisors and canines are more
pointed and erect. In the entire sub-group the premolars lack anterior basal cusps, the
series inci'eases rapidly in size, the last premolar being lofty and rising much above the
anterior molar level as in many recent Insectivora. The molars have no internal cin-
gulum ; the internal face being smooth and tricuspidate. The condyle is very high and
the coronoid is slender. The angle is slender and produced to a tip posteriorly. The
mandible is shallow and tapers towards the symphysis. The dental formula departs
little from the typical pm mg, in the various genera. The adaptation to an insec-
tivorous diet is very evident in the procumbent incisor-canine series of Stylacodon,
which indicates the presence of a protrusible tongue. The molars of Dryolestes show
a striking resemblance to those of the GhrysocMondod'} Another marked feature in
this sub-group is the retention of four incisors, while in the carnivorous and omnivor-
ous groups the lateral incisors are wanting in the upper Jurassic genera. It follows,
that this sub-group is sharply defined from the preceding ones.

AMBLOTHERIIDA:,'’ Osbom, 1887.

Molars loith two slender cmps in line and a posterior heel with an external cingu-
lum, forming an overlapping series ; no opposed, cusps (so far as known). Premolars

* Provisional ; see Appendix.

^ St. George Mivart, “ On the Osteology of the Insectivora.” Jour, of Anat. and Phys., vol. II, p. 161.
It appears from, Mr. Mivart’s description that the lower molars of CalcocJdoris, “with a marked posterior pro-
cess,” resemble those of Dryolestes even more closely than do tlmse of Chrysochloris.

= Proc. .'lead., Phila., June.

ON THE STUUCTUKE AND CLASSIFICATION

2nc

with a prominent ringuhm and sometimes distinct basal cusps. Median innsors
elongate, diminishing laterally. Condyle lofty. Goronoid slender. Angle distinct,
ftosteriorly placed, not inflected.

'J’lje fiimilv embraces Amhlotherium and Achyrodon, which are among the smallest
genera of the Purbeck group. The mandibular symphysis is shallow and the mylo-
iiyoid groove extends forward to it. As the inner surfaces only of the jaws are
known there is considerable doubt as to the full structure of the teeth and of the true
relationships of these genera. It is probable that some of the specimens which have
been referred to Amhlotherium are, in fact, portions of Stylacodon. A suspicion as to
the identity of these genera is raised by the mere fact that all specimens of Amhlo-
therium present inner surfaces, while all the Stylacodon specimens present outer
surfaces. Tlie proportions of the mandible are very similar but the incisor teeth are
widely different. The determination of the systematic position of these genera
tlepends ui)on the presence or absence of external cusps. The molars have a super-
ficial resemblance to those of Amphitherium, but the distinction is very clear when
the inner faces are compared, the Amhlothermm molars lacking the internal cingulum
and conspicuous cingulum cusp. The family may be defined as above.

AMBLOTHERIUM, Owen,i 1871.

Dentition. — i c pm j, m The incisors are widely separate and semi-pro-
cuml>ent. The canine has a single fang. The central molar cusps are rounded and
rc'trovertcil at the tip. The premolars are slightly recurved and rise to the level of
the middle molars.

ACHYRODON, Owen,= 1871.

Dentition i ., c ,, pm m g. The third and fourth premolars rise much above
the molar level. The central molar cusps are sharply pointed and turned forwards.

I he anterior cusps are also acute and the posterior cusps are more elevated than in
the allied genus.

STYLACODONTIDiE, Marsh,* 1879.

Upjwr molars with a single styloid internal cusp connected by divergent transverse
ridges with a pair of external cusps, which are followed by a lower posteiior cusp or
hed. Juicer molars reversing this pattern. Molars with two or three fangs set trans-
oereely, xoithout internal cingulum. Incisors diminishing laterally, spatulate in typical

’ “ Mesozoic Maniinalia,” p. 37.

■lour. lif r”"' M“»«<>embrace»,fo*«.™d

O«l.,opod. (inda, '■ '•I for . gep... of

family name. •i;i,i8 is further preferable to "n ^ be substituted as the

taUhed l>oth frol i’.a I doubtfully distin-

OF THE MESOZOIC MAMMAI4A.

237

generof. Coronoid slender. Condyle elevated. Angle small and separate, extending
posteriorly vntliout infieetion.

This family embraces the closely allied genera Stylacodon, Phascolestes, Dryolestes,
Aesthenodon and Laodon. While possibly embracing also the Amblotheriidoe, it is readily
distinguished from the Triconodontidce, Peralestidce and Amphitheriidoe by the pat-
tern of the molars, which consists of two or three internal cusps, the anterior pair
of which are connected by transverse ridges with a single styloid external cusp,
the upper molars reversing this arrangement. The definition is as above.

STYLACODON, Owen.i 1866.

Dentition. — i c pm j, m The incisors have very much elongated spatu-

late crowns and are compactly placed. The canine is long and semi-procumbent.

The premolars have pointed, recurved crowns,

and are slightly separate. The inner face of

the molars shows three internal cusps (Marsh).

The species S. gracilis (Marsh) has a distinct

„ T ft 1 " 1 j eighth molar, which is represented by a fang

Figure 26. Left lower jaw of Stylacodon gra- _ ° ^ °

cUis, Marsh; outer view, three times natural some of the English specicS,^ showing that

this tooth is probably late in coming into place.
'I'he jaw is very slender with a nearly straight, lower border, and very elevated condyle.

PHASCOLESTES, Owen,' 1871.

Syn. (probable), Dryolestes, Marsh, 1878.

Dentition — i c j, pm m The incisors are separate with the crown ex-
panding at the tip. The median is the largest, the second is the smallest, the third
and fourth increasing in size. The canine is lofty and recurved. Behind this is a

deep depression of the alveolar border,
with two rudimentary premolars. The
third and fourth premolars are very
large. The first molar is very small.
The matrix shows the impression of
the external styloid cusps of to m^.
The jaw is massive with a rounded
lower border. The Dryolestes vorax.
Figure 27. Leftlower jaw of Marsh; outer Marsh (Am. Jur. Mamm., Plate IX,

and inner views, three times natural size. fig. 4), is very similar to PJiascolestes,

and it is probable that these genera will prove to be the same upon further evidence.

^Stylodon, Geological Magazine, or Monthly Journal of Geology, May, 1866, p. 199. Syn. Stylacodon,
Marsh. “ Am. Jour. Sc.,” 1879, p. 60.

See “ Mesozoic Mammalia,” p. 61. Also Plate II, fig. 18 a.

> Doubtfully separated from Peralestes, by Professor Owen, p. 35.

2.18

ON TIIK STliUCTlTRE AND CLASSIFICATION

Dentition — i

DRYOLESTES, Marsh, 1 1878.

The angle of the jaw is slightly intlected. The
lower jaw is massive and has a rounded
lower border and elevated incisor al-
veolar border, as in the last genus.
The condyle is concave transversely
and slightly above the level of the
teeth. The middle internal cusp of
Fioukk 28. Lea lower jaw of Dryolesteg pmcua, inner molars is as high as or higher than
view • three times natural size, a, canine ; a, symphysis. rpi . •

AoTr’ Marsh. ^he Outer mam cone. The canine is

bifanged. The incisors are sub-erect and expand at the tip.

ASTHENODON, Marsh, ^ 1887.

Dentition— I „ c,, pm„ m,. The median incisor is very large, the series being
semi-procumbent and decreasing towards, the canine. The canine is rather small.

A B

Kiqubk 21>. a, right lower jaw of Aalhenodon aegnia, inner view; d, angle. B, anterior portion of same
outer view ; tliria- times natural size, o, canine. After Marsh.

The molars resemble those of Dn/olestes, but lack the third postero-internal cusp;
they are more uniform in size behind the first premolar which is rudimentary.

LAODON, Marsh,® 1887.

Dentition — i f, c j, pm fj, m^. The molars in this genus have the outer main

cone high and pointed, but the inner opposite
cusps are greatly reduced in size. The canine
is bifanged. The lower jaw is intermediate
I'lUDKK 30. U'tt lower jaw of ikioiton cenu«tus, in form between Dryolestes and Stylacodon.
M.r,h. inner view ; four times natural size. backwards

and is not inflected.

.INCERT./E SEDIS.

Ihc genus I^ptocladus is isolated from the remainder of the jurassic group and
yet is not sufficiently characteristic, or well known, to be placed in a distinct family.

* Am. Joiirn. Sc. and Arts,” 1878, p. 459. These three genera are chiefly described from the figures and
text of Professor Marsh’s article, and in part from his previous papers. It seems rather improbable that
/O on had live prcmolars, as it would in such case form an exception to the entire sub-group.

•'‘.\m. .lur. Mamm.,” pp. 3.36 and 337.

••'Am. ,Tur. Mamm.,” pp. 336 and 337.

OF THE MESOZOIC MAMMALIA.

239'

LEPTOCLADUS, Owen,i 1871.

Dentition pm m The lower premolars have a recurved main cusp with a
faint cingulum upon the anterior slope and a posterior basal heel. The molars have
a faint external cingulum and two fangs. The main cusp is elevated, and recurved.
The second cusp forms a wide, low posterior heel, which is barely distinct from the
cingulum, extending around the outer face of the crown.

III. THE ORIGIN AND SUCCESSION OF THE TEETH IN THE MESOZOIC MAM-
MALIA.

The tooth forms have been so fully discussed in the preceding section, in their
bearing upon classification, that it remains here first to briefly recapitulate the differ-
ent types ; second, to point out their probable origin and succession.

B. — Second Group.

Incisors and Canines. — In its entire dentition Dromotherium is separated from-
the whole Jurassic group. The incisors are caniniform and widely separate, increasing
rapidly from the median incisor to the canine. In the Stonesfield Slate genera, the
earliest of the English Jurassic, Amphitijlus and PhascolotJierium, the incisors differ
widely ; they are styloid and separate, while in the later Triconodontidm they become
close set, recurved and prehensile. Other degrees of specialization have been pointed
out in the Sti/Iacodontidce. The frequency of the bifanged canine, in all the sub-
groups, reverts to an earlier, homodont condition in which the canine was less
differentiated from the premolars. In Pliascolestes the median incisor also has
a grooved fang. In Amphitijlus the canine is apparently premolariform. In the
Stonesfield Slate genera, the canine is usually small, and resembles a large premo-
lar, but it assumes large proportions in the upper Jurassic genera.

Premolars and Molars. — The premolars of Dromotherium are very unique.
They are tall and styloid and single fanged; the last premolar has a vertical groove
upon the posterior face. In 2Iicroconodon, which belongs to a somewhat more recent
type, the premolars have a faint posterior heel and the last shows the trace of a double
fang. In all the Jurassic genera the premolars, where fully functional, are bifanged,,
and possess a convex anterior face and concave posterior slope terminating frequently
in a heel. As in the molars, the cingulum plays an important part in connection
with the basal cusps. It is present upon the internal face of the premolars of all the

1 “ Mesozoic Mammalia,” p. 53. Leptoeladus dubius.

240

ON THE STRUCTURE AND CLASSIFICATION

iurassic f?euera except Kurtodoa, and is observed upon the onter surface in DqAory.
nodon It thus in many cases enables us to draw the line between premolars and
molars, as in both the PeraleatidiP- and in the genera of the Insectivorous Sub-group
the inner faces of the molars are smooth. The cingulum generally embraces the
entire inner face of the crown, forming anterior and posterior cingulum cusps or cin.
(fidesd which are characteristic of the insectivorous forms, while in the supposed car-
nivorous and omnivorous forms, distinct basal cusps rise posteriorly and sometimes
anteriorly {Triconoflon) above the cingulum. As in the latter genera the cingu-
lum is present with the basal cusps, it probably precedes them in evolution,
but there is no direct ei idence of the conversion of cingules into true basal cusps,
such as we find in the molars. A review of the premolars of all the genera shows
that they are sharply distinguished from the incisors and from the molars and less
distinctly from the canines in many instances. In several genera they have un-
dergone considerable specialization, as in the production into lofty cones of pm^
of Achyrodon or the apparently incipient assumption of the molar pattern in
Kurtodon.

Molars. If DromotJierium is a mammal, as there may be some question, it is the
most reptilian in type of dentition in several respects : first, there is no internal cin-
giduin upon cither premolars or molars. Second, the premolars have single fangs, w hich
nniy, by the way, indicate that the division of the fangs in the premolar-molar series
extended from behind forwards ; third, the division of the molar fangs is incomplete,
the molars are, strictly speaking, single fanged so far as they are exposed to view; fourth,
tlie incisors are more reptilian than mammalian in appearance, resembling tho.se of
uome piscivorous reptiles, or the homodont series of some of the Delpldnklai ; finally
the molar crowns, although tri- or polycuspid, plainly revert to the monocu.spid con-
dition. The lateral cusps of the main cone are irregular in size and development
and appear to present an experimental stage which is transitional between the single
reptilian cone and the tricuspid, or parent mammalian molar crown, as seen in Micro-
conodon.

In the Theromorph reptiles, among which Professor Cope has found many mam-
malian characteristics, although it is improbable that the mammalia can be derived di-
rect y from them (Baui-), as already observed upon page 222, we find the teeth im-
planted in distinct sockets with the bases deeply grooved upon the inner and outer
aces, {Dimetrodon). The crown is a single cone with a flattened section and serrate
e( ge, wi 1 no tiace of lateral cones ; from this condition Ave must infer that the pri-
and nft * u^^ lesulted from some mechanical cause other than the fore

aft rocking following the production of lateral cones. In other w^ords the division

{1876, ^112.)"^ introduced by Harrison Allen. “ Studies in the Facial Region.” Dental Cosmos,

Ueber die Abstammung der Amnioten Wirbelthiere.” Munich, March 8th, 1887.

OF THE MESOZOIC MAMMALIA.

241

of the fang preceded the division of the crown.' Starting then with the assumption, ^
which the Dromotherium dentition seems to support, that the primitive mammals had
monocuspid molars with incompletely divided fangs, we observe four distinct lines of
modification in progress in these pre-cretaceous mammals ; these are partly in
the nature of progression from the reptilian condition and partly in the
acquisition of changes of form leading directly towards the modern mammalian type
of molar. 1 The division of the fang, followed in some cases by a rotation of one of the
fangs fiom a fore and aft to a transverse position with relation to the other and a
further subdivision. 2° The development of the internal cingulum. 3° a The growth
of anterior and posterior cusps upon the faces of the primitive cusp, h, the rotation in-
wards of the lateral cusps to form a triangular crown. 4° and 5° The growth of in-
ternal cusps from the internal cingulum to form a crown with transversely opposed cusps.

1. ° The first stage of the evolution of the fang is seen in the Triassic genera.
The second stage, in which the fangs are entirely distinct and in the same fore and aft
line, is seen in all the lower Jurassic (Stonesfield slate) genera. The upper Jurassic gen-
era present three types of modification of the molar fangs. In the Triconodontidce
and AmpJiitheriidcB the fangs are in the same fore and aft line, conforming to the sim-
ple condition of the crowns. In the Kurtodontidce, so far as it is possible to deter-
mine their relations, the fangs are placed opposite each other, i. e., transversely, and are
somewhat connate ; possibly the crown is passing into a prismatic condition, with a
single pulp cavity ; but this inference must be taken with reservation. In the Sty-
lacodontid CP. the fangs are also opposite ; in the lower molars there is but a single fang
seen upon the outer face beneath the protocone ; on the inner face, however, there are
two fangs visible beneath the para and metacones ; it is a question, whether one of the
latter may be connate with the outer fang^ ; if not, these molars are three-fanged, and
have in this respect already acquired the higher mammalian condition.

2. ° The internal cingidum, as already observed, is wanting upon the Droinothe-
rkim molars, but is, possibly, present in Microconodon. As a general law, the inter-
nal cingulum is present upon the molars of all the Jurassic genera in which the cusps
are not transversely opposed, and absent in molars in which the cusps are thus opposed.
Examples of these two types are seen among the Triconodontidce, in which the cingu-
lum is most strongly developed, and the Stylacodontidw. This law, which may find

' This point ha.® been ably discussed by Wortman, “ Comp. Anat. of the Teeth of the Vertebrata.” Am.
Sys. of Dentistry, 1886, p. 420.

2 Oldfield Thomas, “On the Homologies and Succession of the Teeth in the Dasyuridse,” Phil. Trans.
1887, p. 456, is inclined to adopt the Baume hypothesis, that in their first stage, mammalian teeth are simple
cones, rootless for part if not the whole of the animal’s life.

SI have not been able to examine these fangs very minutely. Marsh describes these molars as bifanged :

“ Seen from the outside, these teeth appear to be inserted by a single fang, but, in most cases, each has two
roots, although these are nearly or quite connate.” Amer. ,Tour. Sc., April, 1887, p. 335. Several of the speci-
mens' seem to present two well-separated internal fangs. If either is connate with the external fang, it is prob-
ably the most anterior, since the posterior would probably be developed beneath the third cusp, or heel.

212

ON THE STRUCTURE AND CLASSIFICATION

7 • 1 nni-iLfs also to the Per alest idee, and lends support to

an exception in internal cusps of the Peredestes type are pro-

the theory, discussed j^^,,pjatheriideB the crown spreads at the base into the

duets of the cingulu . Diplocynoelon, or has a median elevation,

"d as a cusp,^ as in A.yddt,er,.. The internal
whicn 1 roiessor nremolars of the Jurassic genera, is thus

or, rven developed and in course of transformatron rate a row of rntema c„ap .»

3 U, If as now seems probable, the derivation of the mammalian molar from the
sin.de reptilian cone can be demonstrated by the comparison of a series oOrans.tional
stages between tire single cone and the three-cone type, and from the alter to the
central tritnbercular type, the separate history of each cone can certainly be traced
tlironglioiit the series in its various degrees of modification, development, and depner-
ntion The remarkable part played by the tritubercular molar has been unfolded by
the discoveries and writings of Cope. It is undoubtedly the ancestral molar type of
the Priniatcs, the Carnivora, the Ungulata, the Cheiroptera, the Insectivora, and of sev-
eral, if not all, of the Marsupialia. For example, we can trace back the quadrituber-
eiiln'r linnodont, or parent inigulatc type, to the IriUAermlar ■, this to the type with
three cones in line, which we may call the triconodont type, and this in turn to the hap-
lodont* reptilian crown. A nomenclature may be suggested for these cones, with reference
to their order of development and primitive position, to keep clearly before the mind
their liomologies during secondary changes of form and position. The primitive
cone inay lie called the protocone ; upon the anterior and posterior slopes of which
apjK'ar, resjKJCtively, the paracone and meiacone. After the tritubercular crown is
prcMluced, by the rotation of the lateral cones, inwards in the lower jaw and out-
wards in tlie uppt'r jaw, the hypocone, or heel, is developed, giving us the tubercular-
sectorial molar. Exclusive ^ of the Midtituhercidata and of Stereognathus, this is the
most advanced stage of molar development thus far found in the mesozoic period.

The protocone of Dromotherium (Plate IX, fig. 17) is prominent and constant

' Lydckker ha-v" observed a minute inner cusp to the blade of the hinder lower true molars of Amblolhe-
num, in some cases : (.4 sonciiiuin). Cat. of Foss. Mamm. Part V, p. 274. This apparently is an exception to
the nilc.

• " Mcsorxiic Mammalia, p. 14.

* Wortman (“ Dental Anatomy,” p.418,) writes : “The various steps in this process of dental evolution I
conceive to have l>ecn as follows; (1) Additions to the anterior and posterior edges of the cone and formation
of a cingulum. (2) Division of the single root into two. (8) Addition of basal cusps from the cingulum. Long
continueil vertical pressure, I believe to be an adequate cause for the appearance of the wrinkle or fold of the
enamel covering at the base of the tooth, which is designated as the cingulum.” These stages, which in part
had been pointed out by Cope and Allen, coincide remarkably with the actual condition of the molars in
the Mesozoic Mammalia.

‘See Cope: ‘‘The homologies and origin of the types of molar teeth of the Mammalia Educabilia.”

Jour. Phila. Acail., 1874.

OF THE MESOZOIC MAMMALIA.

243

thiough the molar series while the para and metacones are irregular in size and
position, always close to the main cone and in several teeth either splitting into two
needle-like cusplets or bifid at the tip. Altogether, they are in what appears to he
an experimental stage of development. Microconodon, however, from the same strata,
has uell defined para and metacones which are Avidely separated from the main cone,
the ciown presenting the pure triconodont type. This reoccurs in Ampliilestes, of the
lower Jurassic, and Triconodon of the upper Jurassic. In this series we are struck by
the gradual increase of size and prominence of the lateral cones until they are upon
the level of the main cone and sub-equal to it, this increase being accompanied by a
marked elongation of the crown so that the three molars of Triconodon occupy a
greater proportion of the jaw than is taken by the seven molars of Dromotlierium.
This unmodified triconodont type is very rare in the more recent mammalia. It per-
sists in the lower jarv, at least, of Dissacus from the Puerco, and in the lower molars
of Thyktcmus, the upper molars presenting an internal heel.

b. In his paper upon the Creodonta^ Cope observed that the Spalacotlierium molars
represent a stage of transition between the triconodont and tritubercular molars.
There can be no doubt that the cusps seen upon the inner face of the inferior molars
of this genus are homologous with the para and metacones and there are several facts
which support Cope’s hypothesis that they represent a stage of inward rotation of
cusps Avhicli were at an earlier stage in the same fore and aft line with the main cusp.
These are, that in Phascolotherhim the lateral cones are seen to he slightly internal to
the main cone so that their median slopes descend upon the inner face ; in Tinodon,
of a later geological period, this disposition is slightly more pronounced ; in Menaco-
don it is still more marked but less so than in Spalacotherium. These genera, al-
though evidently in two different lines of descent, afford the desired transition stages.
The Spalacotherium molar as seen from above^ has a striking resemblance to the an-
terior sectorial triangle of the Stypolophus or Didymictis molar of the Puerco. It is
in fact sub-triangular, the superior molars probably having the lateral cones rotated
outwards, so that the upper and lower, molars form an alternating series, the ridges
connecting the main and lateral cones acting as sectorial blades.

The question now arises whether the Stylacodon molar represents the next
higher stage of development, viz. the tubercular-sectorial molar in which the anterior
triangle is followed by a low heel. And if so has the Stylacodon type passed through
the stages of iiiAvard rotation of the lateral cusps'? The superior aspect of the Styla-
codon molar presents an anterior triangle Avith the long styloid cone forming the apex
and connected by divergent ridges Avith the anterior pair of cusps ; behind these is a
third cusp not connected by a ridge Avith the styloid cone. In the upper jaAv the
three cusps are external and the single cone internal, these relations are reversed in

> “The Creodonta,” American Naturalist, 1884, p. 259.
* Owen. “ The Mesozoic Mammalia.” Plate I, flg. 32c.

ON- THE KTKUCTUKE AND CLASSIFICATION

, ■ , We cannot well avoid the infeieuce that the SylaoodoA lower molar

the lower jaw . that the styloid external cusp, which until

J. a si-ialired

Marsh's internal cusps represent the paracone and meta-

protocone while • , the hvDOcone or heel. This is further confirmed

cone followed J f Spalaeotlierium type seen in the molars of Adkeiwdon

cot while the remainder of the crown is closely

Itr lo that of St.la^on. The internal cusps present many degrees of develop-
nicnt in different members of the StuUKoMda, ; in Laodo«. toy are much less
Ziinent than in Z>rj,o/c.<«, the heel being also inconspicuous While the relations
of the four cones composing the Stylacodont crown strongly suggest the tuber-
cula, -sectorial molar there is one matter of doubt in the way of the derivation
of this tooth from the Spatacolliermm type; that is, the position of the fangs.
In SjHihicothennm and Menacodon the fangs are paired and placed beneath the
pam and metacones. In the Stylacodonts the external fang is directly beneath the
protorone; the question is does this represent the anterior or posterior, or an addi-
tional fangl .

4.° The molars which have been considered thus far show directly or indirectly

the triconodont type, i. e., the presence at some stage of their evolution of the central
and two lateral cones. In the Amphitheriidee it is clear that the main cone and the

lc8.scr one, upon its anterior slope, represent the protocone and paracone but it is un-
certain whether the basal cusp, seen for example upon the external face of the Diplo-
cyuodon molar, is homologous with the metacone or hypocone. The latter alterna-
tive excludes the development of the metacone or the passage of these genera through a
triconodont stage and implies a considerable separation of the Avipliitheriida; from the
stem of the two families already considered. The former involves the supposition that
the metneone has metamorphosed into a heel. The most primitive molar in this fam-
ily is seen in Etmeodon^ The crown has an obtuse recurved protocone, more like
that of a preniolar ; ujion the anterior slope is a rudimentary paracone which affords
the only means of distinguishing the molars from the premolars. The posterior slope
terminates in a low extended heel. This molar pattern largely confirms the second of
the above alternatives, viz, that this heel is to be compared to the hypocone of the
tubercular-sectorial crown. Further confirmation is seen in the fact that this heel
is not above the level of the internal cingulum, as in the metacone of all the
triconodonts, but is continuous with the broad shelf-like projection of the internal
cingulum, which is well represented in the internal aspect of the DipJocynodon
molars. The concave internal slope of the protocone descends into this shelf and
the cingulum rises at the margin into numerous crenations, which cannot properly

• Marsh, “.Vmeric.an Jurassic Mammals.” Am. Jour. Sc., April 1887. PI. X, fig. 4.

OF THE MESOZOIC MAMMALIA.

245

be called cusps. The Diplocynodon molar presents a decided advance upon that
of Enneodon in the development of the paracone, which is much more pro-
minent. In Ami)liithenum (text, fig.2), the paracone is subequal to the pro-
tocone in several of the molars, and the heel is on the level of the internal
cingulum, from which, according to Owen, there arise one or two small cusps.^
Internal cusps which develop in this manner are from the first separated from
the external cusps by a longitudinal valley instead of being united with it by
divergent ridges, and cannot therefore at any stage possess a sectorial blade,
such as is more or less distinctly developed in the Spalacotherium and Slylacodon
molar.

5°. It follows also that the triangle of cusps presented by the Peraspalax molar
cannot, with probability, be considered as representing a tritubercular stage and that
the AmpliitlieriidcB furnish the key to the mode of derivation of the internal cusps of
the molars of the Peralestidce. The inferior molars of Perasp)alax and Paurodon are
apparently very similar (see PL VIII, fig. 9, m^, and fig. 9, text), consisting of a
prominent external cone, and two internal cusps followed by a third cusp at the end
of the crown. As pointed out in the synopsis of molar types, this internal surface
strongly suggests the Dryolesies pattern, but may be clearly distinguished by the ab-
sence of transverse ridges and the presence of a longitudinal valley between the cusps
instead of a transverse valley opening inwards. The internal cusps have probably,
therefore, arisen from the internal cingulum^ but these molars do not seem
to be a later development of the Ampliitherium type because both the paracone
and metacone are wanting, the main cone showing no trace of the lateral cusps
upon its slopes. The superior molars of Peralestes, however, when viewed
from above (Plate VIII, fig. 8), present one large internal and two smaller
external cusps disposed in a triangle opening outwards, and as this is the
general disposition of superior cusps of the tritubercular type, we must admit
the possibility that the smaller cusps do represent the para and metacones in a
stage of inward rotation not accompanied by the production of the sectorial
blades, for this is by no means an essential feature of the tritubercular molar.
The history of the derivation of the molars of the Peralestido} must, therefore,
be left in some doubt; while the balance of evidence points to a line of development
similar to that in progi'ess in the Amphitheriid(B, although the line of descent
appears to be different.

1 A8 previously stated, the writer has not personally examined the internal surfaces of the molars of

this genus.

»Nui
important i
of the post
Allen, op. c
molars are

ON THE STUUOTUKE AND CLASSIFICATION
246

• .V,- .,,,1, of the molars the following are the principal deductions ;

Hcvicwing this study ol th , y „oup presents one mam cusp

(.) The molars of all the 1 may be considered homologous with

Ihich is either so central or so prom.nent that . t may

e,.e single reptilia., upm' Jre rterior and^posterior slopes of

cusi>s, the para and me . ’ PP frequently repeated stage of evolution. It

H.e protocone. Th.s .s a “tloplnt ; in L first, the para- and meta-

gives rise to two lines persistent triconodont type,

conesareretaiued n the^fo- and^aft ^ ^

but increase grea y in . , In a second line of genera the

hcrciilar type, which ^ y jijg protocone but the metacone is not

or HypLone which .tends Inwards to
form °lm intema”l cusp, (d) In a fourth line of genera neither the pp- nor me^-
concs are developed upon the sides of the protocone, but they are replaced by. basal
cusps derived from the cingulum.

Reduction and Succession of the Teeth.

The homologies of the molar cusps naturally have an intimate bearing upon the
pliylogcnctic problems, i. e., of the relations of these families of mammals to each
otlier and to a common primitive stock. It must be constantly kept in mind, how-
ever, tlint like meclmnical or functional forces produce like effects, so that we may
nlmo.st as.sunie that the triconodont and tritubercular type has appeared independently
iu widely different phyla. To counteract errors which may arise from this law of
development, valuable data are afforded by a comparison of the dental series as a
whole, in the genera embraced in the different mesozoic families, with respect to
the retardation, atrophy, suppression, acceleration^ and hypertrophy of the teeth.
These terms arc here employed to express, first, the relatively late time of ap-
pearance of a tooth in its adult position; second, the relative decrease in size
of a tooth as (compared with its fellows of the same series ; third, the loss or absence
of a tooth ; fourtli, the relatively early time of appearance ; finally, the increase
of size from excess of nutrition. Thus retardation and acceleration, atrophy and

' Coi)« has employed ‘‘acceleration” in a larger sense as expressing an increase or addition of parts as
well ns an increase of rate of growth (Proc. Phila. Acad., 1876, p. 16). But in the dental series, as lately
observeil l>y Oldflehl Thomas (loc. cit., pp. 452-3), an increase of size is frequently preceded by a relative
decrease or retardation in the rate of growth ; the term must be here used in the more restricted sense.
Kowalevsky has employed •' reduction ” in all his memoirs to express the process of loss of one of a series of
teeth or limb members, and this term has now come into universal use. We may describe a dental series as
reilnccd. i. e., from the typical complement of the teeth, in which one or more teeth have been suppressed.
Atrophy is frequently used as equivalent to “ suppression,” but may better retain its original significance. As
all changes result from a transfer of nutrition they may be described as metatrophic.

OF THE MESOZOIC MAMMALIA. 247

Sertiol''’'’ condilioM, ullimatel; re™ll either in snppreerion or

Photodonta.

Dromotheriidie.

Dromotherium.

Microconodon.

Phodidelpiiia.

1. Triconodoniidie.

a. Amphilestes.
Aniphitylus.
Triconodon.
Priacodon.*

b. Pliascolotherium.
Tiiiodoii.

c. Spalacotherium.
Menacodon.*

2. Amphitheriidte.

Amphltherium.

Diplocynodon.

Docodon.*

Enneodon.

Perainui-.

3. Peralestidar.

Peralestes.

Peraspalax.

Paurodon.

4. Kurtodrmlidx.

Kurtodon.

I.NSECTIVORA PkIMITIVA.

5. Amblolheriidic.

Amblotherium.

Achyrodon.

C. Stylacodmitidn-.
Stylacodon.
Laodon.
Plia^colestes.
Drvolfstes.
Astlienodon.

7. Leptocljjdus.

From this table it is seen that the prevailing or typical dental formula in these
mammals is i c x, p t, ni s- The incisors in no case exceed four. The premolars in
the large majority of genera are either four or have recently been reduced to three ;
in two cases in which the determination of the teeth is somewhat uncertain, five pre-
molars have been observed ; the only other exceptions are in the Dromotheriidce, in
which the premolars number three only. The molars are less constant, varying from,
8-7 in all the more ancient genera to 4-3 in some of the more recent.

The mode of reduction is by no means uniform in the different families but
varies little within the limits of the families themselves and certainly tends to
strengthen rather than, impair the family boundaries adopted in this memoir.

In the T)'iconodo.ntid(e there are four incisors in the earlier genera which are
reduced to three in the later forms, probably by the loss of The reduction of the
premolar series seems to have been at the expense of for this is the smallest tootli

Mandibular Dentition.

Total

-j

i.

c.

p-

m.

p.&m

Dentition

Estimated

1 Reduction &c. of Dental Series.

3

1

3

7

56

?3

?7

4

1

4

7

64

4

1

4

7

64

3

4

1

1

1

4

?3

4-3

4-8

7

48

i4 suppressed. 104 retarded or suppressed.

Pi suppressed “ “ “

premolar series extremely reduced or suppressed.

1

?8

?3

.

■

56

reduced.

?3

i4 suppressed.

Pi suppressed.

?4

4

6

60

3

3

1

4

8

64

P2 atrophied, atrophied.

3

6

60

‘ “ m, suppressed.

9

52

Pa suppressed, ni,_8 suppressed.

1

4-5

6

1

4

7

1

2

5

Pi- 3 suppressed, suppressed?

?1

4

‘

Pi_s atrophied, P4 hypertrophied.

4

1

4

4

7

8

64

Pi atrophied, P4 hypertrophied, m, atrophied.
P3-4

4

1

1

4

?5

7-8

8

68

m, atrophied.

4

4

1

1

4

4

8

8

68

68

Pi atrophied, m, atrophied.

4

1

3

8

64

Pi suppressed, “ “

4

6

_ 1

248

ON

the structure and classification

, • 1 Prwoodmi by a diastema behind the canine,

where it is present an is lep ac . ^^known. In the Spalacotheriince

In the PWIoftmin* the mode of reduction is unknotv 1

it is •uraiii the «rst premolar which has been suppressed. The mode lediiction ol
, m* in this family is not certainly known but probably took place from behind
LLs. This is cerLiy in process in TiWon m winch n, is very much

retardd in some species, if not actually suppressed. ■ nm

In the AmfhUheriidm, the mode of incisor reduction is unknoira. e find the
preniolars reduced at the expense of ft, which is atrophied in D^locyrnd^ and
Lwon and suppressed in Smeodon. The reduction of the molars ,s obviously
from behind forwards, Diflayymxh,, having the typical number and EnrKxion falling

two short of it. . p i j-

In the PeralestidcB the dental formulae are uncertain. Judging from the diastema
behind the canine, it would appear that the premolar series of Paurodon has been
reduced by the loss of pi_2.

In Kurtodon the typical number of premolars is present but the atrophy of the
three most anterior, pi_3, is in marked contrast with the hypertrophy of pi-

General characteristics of the Insectivora Primitiva are the apparently constant
atrophy of the anterior pair of premolars and hypertrophy of the posterior pair, and
the reduction in size of the molars at both ends of the series, accompanied by a re-
tention of all the incisors, and the typical number of molars.

In the AmhlatheriidcB the first premolar is extremely small and the molar series
increases regularly in size from before backwards. In the Stylacodontidoe the incisors
are unreduced, but a slight hypertrophy of the median incisor is almost a constant
feature, ivith a corresponding atrophy either of the second or fourth incisor. The
first premolar is atrophied in three genera, so that there is little doubt that this is the
tooth which is suppressed in Astlienodon, in which there are but three, premolars.
The second premolar is also small. Adjoining the hypertrophied posterior pair of
premolars is usually found a very small first molar; the last molar is retarded in
development and is generally small, so that although there is no case in which either
of these teeth has been suppressed, we may assume that the molars are in course of
reduction at both ends of the series.

These observations are subject to be modified by the discovery of new material
but are certainly of very great interest in their present shape. The diverse modes of
extreme reduction in the different families are summarized as follows : The Tricono-
dcmtidcB^ lose the lateral (1) incisor and first premolar and the reduction in the molar
series is from behind forwards. The AmphitheriidcB lose the fourth (1) incisor, the
second pmmolar is suppressed and the reduction in the molars is from behind forward.
The suffer atrophy of the foremost three premolars. The Slylaeodonti-

* Excepting the Phascolotheriinse.

OF THE MESOZOIC MAMMALIA.

249

dee retain four inciaon*. the first and second premokrs are atrophied, or the first sup-
pressed, and the atrophy of the molars is at both ends of the series.

The only instance in which a vertical replacement of the teeth has been observed
IS in the genus T,-iconodon, fully described upon page 198 of this memoir, which suc-
cession IS confined to the last premolar, precisely as in the modern marsupials. Pria-
codon may prove to present a similar mode of succession.

General Conclusions.

1. The primitive mammalia, ancestral to the known Jurassic mammals, were
heterodont. The teeth were without diastema and divided into three series, incisors,
premolars and molars. The incisors were separate and inserted by a single fang.
The premolars had single or grooved fangs and simple conical crowns ; the addition
of cusps took place at the base of the crown in connection with the internal cingu-
lum ; first, by the addition of a heel and its elevation into a posterior cusp ; second,
by the addition of an anterior basal cusp. The molars had grooved fangs and simple
conical crowns ; the additional cusps were found upon the anterior and posterior
slopes of the crown above the base, or upon a heel from which secondary cusps arose
as in the premolars ; or the development of secondary cusps was wholly at the base of
the crown. Canines were difi’erentiated from the first member of the premolar series,
and at first were distinguished by their larger size from the first true premolar, sub-
sequently by the coalescence of the paired into single fangs.

2. Tlie complication of the molar crowns increased from before backwards, and con-
versely the ju'imary division of the fangs probably took place from behind forwards, first
in the molars, then in the premolars but not extending to the incisors. Rotation of one
of the fangs inwards and triple division of the fangs, accompanied the development of
internal molar cusps.

3. Tlie typical dental formula was i4, cl, p4, m8. Reduction of this formula
was effected by the loss of the lateral incisors, resulting possibly from the hypertrophy
of the adjoining canine; the premolars were reduced by regular antero-posterior
suppression {P/iasr.olotherium'l), or by the loss of the first or second member of the
series ; molars were reduced either by antero-posterior or by postero-anterior reduction
or by simultaneous reduction of both ends of the series.

4. ’ The complication of the molar crowns and specialization of the dental series
into the four sharply defined groups, incisors, canines, premolars and molars took
place independently of reduction, i. e., some of the genera in which the dental groups
were most sharply defined, retained the typical formula. The specialization of the
incisors and canines for different functions, in different genera, proceeded with com-
parative rapidity. The premolars were the most conservative members of the series,
retaining longest the primitive common pattern. The molar differentiation proceeded

ON THK STJIUCTUKE AND CLASSIFICATION

rapidly alon, diverse lines as eonditioned by the mode of addition of seeondary

cusps to the crowns can now be to be the single

cone b„ our present evidence does not support the hypothesis that there was but one
of addition of cusps to this cone. On the other hand as descri ed in detail in
the foregoing sections, we 4nd evidence of three or more modes of addit on.

u In one series, to which the larger number of genera belong, lateral cusps
were added upon tbe anterior and posterior faces of the protocone forming the tricouo-
donl fvpc. This tvpe persisted in one line of genera (Tncarmlori), with a gradual
increase of the lateral cusps or para- and metacones. In another line of genera the
imru-and metacones were rotated inwards to form the <,*,4crc«?ur type (Syiuluco-
rtcmmi, AMmclon). In a third line of genera, this process was probably completed
liefore the upper Jurassic period, together with the addition of a heel, forming the
tnlyercuhir sectorial type i^Stylacodoii).

h. In a second series, only tlie anterior cusp or paracone was developed upon the
protocone, tlie metacone being replaced by a heel which became continuous with the
internal cingulum, and the latter gave rise to internal cusps {AmpMthenum) .

c. In a third series, neither the paracone nor metacone were developed upon the
protocone but the crown was reinforced by the development of cusps from the posterior
heel and from the internal cingulum. Or, the postero-internal basal cusp represented
the metacone and the antero-internal the paracone {Peralestes) .

<1. In a fourth series, represented by the single genus Leptocladus, there was
simply an clongjite heel behind the rnain cone, the molars having the same general

|>atteni as the premolars.

e. The mode of development of the prismatic columnar crown of the genus
Kurlodon, is unknown. It may have sprung from the tritubercular type, in which a
complete union of the internal cusps has left a record of the transverse valley in the
line of enamel extending across the crown.

The following is an hypothetical scheme of the mutual relations of the Mesozoic
families and genera, founded upon the homologies and reduction of the teeth, as con-
sidered most probable in the above analysis. It is iirtended, not to show the actual
line of succession, for our paheontological record is far too imperfect for such an
attempt, but as an outline of a possible line of succession in which the genera are
taken merely as types representing certain stages of development of the molars. At
the sjime time, the diagram does express the author’s present views of the degree of
separation of the families from each other. There is, for example, little doubt that
the Stylw'odonhdiv have diverged from the common stem at an earlv period, since they
present the most modem type of molar known at this period, excepting perhaps the
Kurtodontidw. * The central line is through the Tricemodontidee. The Spalacotherii-
foe and Pliascolotheriince may have branched from this. The position of the Arnplii-

OF THE MESOZOIC MAMMALIA.

251

theriidce and Peralestidce depends entirely upon the homologies of the cusps. The
position of the Amhlotheriidce is also uncertain, since their molar structure is not fully

**HypotheticaL

known. The Dromotheriidae, the only representatives of the Protodonta, are consid-
ered somewhat aberrant because of the wide diastema behind the canine and
the presence of but three premolars.

A. — First Group.

We have at present but little insight into the derivation of the multi tuberculate
dentition. In the oldest known genera the dental series has already undergone con-
siderable reduction and a much higher degree of specialization than is attained by
any of the mammals of the recent group. The most prominent features of the denti-
tion are the hypertrophy of a pair of incisors in each jaw, the atrophy of the remain-
ing incisors and the canines, the reduction of the premolar series, the longitudinal
rows of tubercles upon the molars and the wide diastemata.

Incisors. — Among the genera in which the mode of reduction has left any record
we find the second incisor, or rather one of the lateral incisors hypertrophied. In the
Bolodontidm, as demonstrated by Marsh in his observations upon Allodon, the median
incisor is atrophied and the second incisor hypertrophied. In Bolodon the median
incisor is apparently suppressed, and the third is much smaller than the second. Of
the two incisors in Tritylodcm, the outermost is close to the maxillary suture, the
hypertrophied incisor is close in front of this and widely separate from its opposite

252 OX THE STKUCTUEE AND CLASSIFICATION

. ,■ •• ,1 , ;(■ this »t*nus is descended from a form with three or four

fellow, J °Bolodm renders probable, it is again the median in-

incisors, ns a p ^ evidence bearing upon this point,

w nt rimlZnee to ascertain whi^i of the incisors is hypertrophied in Pla^
^nufax. The lower incisors in PohjmaMon and Plag^a^la^ are reduced to a single

‘’"'The conine. if present in the previous history of this group, have been entirely
suppressed in the known forms, with the possible exception of Plag,aidax.

Premdan. It is interesting to find in the early PkujmuM,.. the typical nura-
lier of four premolars. There are three premolars in Bolodon, Allodon and Olarox,
probably two in Trilglodci, and one in Pdymmtodon. There was undoubtedly a
regular antero-posterior reduction of this series, accompanied in Plagmulax only, by
the liypertrophy of p,. The tritubercular crowns of in Bolodon are replaced m
Chirox by three tubercles upon and four upon A hint as to the possible

derivation’ of the trenchant preinolars of Plagiaulax from tubercular forms, is obtained
by a study of tlie superior premolars of Ctenacodon serratus (Fig. 8), and comparison
of the same with the first pair of molars of Bolodon (Plate IX., fig. 16). In the
former, the trenchant margin is composed of four distinct tubercles; in the latter,
the internal row of tubercles is partially obliterated by vertical wear of the inferior
teeth.

Molars. 'I'he structure of the molars is associated with that of the incisors.
An almost universal characteristic is the fore and aft grinding motion between the
upi^r and lower rows of tubercles. Professor Marsh recently called the writer’s
attention to the wearing of the posterior face of the large upper incisor of Allodon
hv tlie tip of the lower tooth. The same relation obtains in nearly all the other
genera, and causes au interference which forces the jaw backwards as it ascends, by a
mechanism similar to that in the rodents, as demonstrated by Professor Cope.^^ This
fore and aft grinding motion was found in the Tritylodontidae, Eolodontidae and, later
Plagiaulacida* ; it is observed in a transition stage from a fore and aft to a circular
grinding motion in the Polymastodontidte. The most primitive molar crown known
is that of Microlestes. In this the tubercles are not very numerous and one is much
more prominent than the remainder (p. 214) ; this inequality is also observed in the
primitive Plagiaulax niiiior molar, with four tubercles and trace of a cingulum, but
in tlie more recent genera the tubercles are subequal, the crown is elongate, tuber-
cles being added posteriorly. In the Tritylodontidae and Bolodontidae the tuber-
cles are conical. In the Polymastodontidae they are flattened. The transition from

Ly.lekkcr mentions (Cat. of Foss. Mamin., Part V., p. 195, footnote), that Lemoine describes two upper
inciaon. and a canine in Xeoplagiaulcu:. I have not met with this description as yet.

•••The Mechanical Causes of the Origin of the Dentition of the Rodentia.” American Naturalist,

January, 1888, p. 12.

OF THE MESOZOIC MAMMALIA.

253

the two to three row types is beautifully shown in Ghirox (p. 219). The molars of
Stereognathus, which has provisionally been placed in this group, show an antero-
posterior crescentic disposition, very similar to that observed in the transverse cres-
cents of the primitive Selenodont Artiodactyle molars. The same is true of the
Meniscotissus molars. The former is the only genus in which three rows of tubercles
are found in the lower jaw.

AVe can form no adequate conjecture as to the origin of the multitubercular
molars. If the quadritubercular type, in other lines of descent, sprang from the
single cone, there is no reason why the same should not have been the case here.
There is some ground for this surmise, in the evolution of the multitubercular from
the quadritubercular molars among the Plagiaulacidse, and the transition from the
tri tubercular to quadritubercular premolars of the Bolodontidm.

The reduction of the molars was evidently postero-anterior. The typical or
stem dentition was probably i 3, cl, p 4, m 6. The hypothetical relationships of
these families may be expressed in this diagram. The Plagiaulacidse and Bolodonti-
dce seem to have diverged at an early period from one stem and the Tritylodontidae
and Polymastodontidse from another. It is possible that the last two families were
upon the same line.

1^

P

3 oi

CO S.

Neoplagiaulax

^Hypothetical.

254

(4N THE STRUCTUKE AND CLASSIFICATION
IV— the zoological position of the MESOZOIC MAMMALIA.

A. FIRST GROUP.

While the Multituberculata are widely separated from the mammals of the
second group, they are so closely related to each other by the unique structural and
functional adaptations of the dentition, that the discovery in one genus of a single
ta.xonomic character, which is distinctive, will probably determine their position either
with the Monotremata or Marsupialia or in an independent order ; no character of
such importance is known at present. Their relation to the Marmpialia was proposed
by Falconer*, accepted by Owen^ Cope® and Marshy and in fact has not been ques-
tioned until Poulton’s® recent discovery of multitubercular teeth in Ornithorhyn-
chtUy which has led Cope to suggest their reference to the Monotremata.®

Falconer and Owen referred Plagiaulax to the Diprotodontia, principally on the
following grounds: the similarity of the premolars and incisors to those of Hypsiprym-
niM, and the slight inflection of the lower inner margin of the ramus. Cope sepa-
mtcd the MultitulKTculata as a sub-order from the Diprotodontia, but gave additional
grounds for their reference to the Marsupialia, from his observations upon the skele-
ton of Pofyma«fo(lon, as follows: the inflection of the angle of the jaw and the
jiosition of the dental foramen at the apex of the masseteric fossa; the astragalus is
without trochlea and bears a large facet for the cuboid bone, with a narrow hLd and
navicular face convex in a vertical direction only, a form much like that of Ilahna-
inrm. The condyle of the humerus has a double articular facet, and a stron<^ and
tliick inlcrtrocl.lonr ridge in front. The distal end of the humerus of
.lK|.lnp the some cimracters. In the skull of D-ili/lodon, we observe the marsupial
nffimties ,n the terminal imsition of the anterior nares, in the junction of malars and
lachrymals and the exclusion of the premaxillaries from the frontals

-Ote writer has provisionally adopted Cope’s sub-order in this memoir.’ Ly-
deseribedthis group as primitive Diprotodoni;.
nnW r n "I ’ / -evidence for general mar-

suldv or e 1 Iv" -cond,?hat a close

special ml«tiortL'thrnrp“r''' their supposed

M rv, Plagiaulax, &c.’>

MomoirB. \ ol. II, p. 43i».

Mfsotoic Mammalia,” p. S8.

Maraupialia,” Am. Nat., 1884, p. 688.

‘ “American JuraPsic Mammals,” loc. cit., p. 345.

^ ^y. .Soc. Pr<K'6e<linpi, Febniary, 1888.

‘American Naturalist.” March, 1888, p. 259.

I nhil&« Acft<I .TiinA iftQ7 A I A

• Cat. Foes. .Mamm.,’ Part V, p. iog Naturalist, March, 1888, p. 232. This Memoir p. 213.

Quart. Journ. Geol. Soc., August. 1857. Palseontol,
Also, “Tertiary Vertebrata,” Hayden’s Surv., 1884,

OF THE MESOZOIC MAMMALIA.

255

The longitudinal arrangement of the conical tubercles in two or more rows upon
the molars has no parallel among the Diprotodonts. The only approach to it is in
Myrmecohius. The most striking dental feature of both these groups is the hyper-
trophy of a pair of incisors in each jaw ; but so far as a close comparison of these
incisors in the fossil and recent forms is possible, it shows that these teeth in the two
groups are neither homologous nor homodynamous, although they bear a superficial
analogy. As regards homology ; in all the quaternary and recent Diprotodonts it is
the median incisor which is hypertrophied, whereas in the mesozoic genera, upon
grounds given above, the second incisor, or rather one of the lateral incisors was hyper-
trophied, while the median incisor was atrophied or suppressed. As regards homo-
dynamy ; the nearly universal characteristic among the multituberculates of a fore
and aft grinding motion between the alternating rows of tubercles, was associated with
the rapid reduction of the upper and lower incisors to one pair. In contrast with this
disposition, the recent Diprotodonts present, for the most part, three upper incisors ;
while the extreme reduction and fore and aft grinding motion, are confined to a
single family, the PhascolomyidcB, in which alone the incisor function is like that in
the Kodents.

The relationship to the Monotremes is possible. As observed by Cope, Poulton’s
description ' of the true teeth in the young Ornithorhynchus paradoxus at once reminds
us of the dentition of Plagiaulax. “ The anterior tooth of the upper jaw was long,
narrow and simple as compared with the others ; it was very fully developed, contain-
ing completely formed dentine and enamel, and its apex was nearly in contact with
the lower surface of the oral epthelium. All the other teeth were broad and large,
those of the upper jaw possessing two chief cusps on the inner side of the crown, and
three or four small cusps on the outer side, while this arrangement was reversed in
the lower jaw.” According to this, the two chief cusps are upon the outer side of the
lower jaw, whereas in the Plagiaulax series (fig. 7, text) they are invariably upon
the inner side ; this fact lessens the degree of resemblance, but there is little question
that these teeth are of the rare multituberculate type, and this discovery has an impor-
tant bearing upon the problem. The humerus of Ornithorhynchus and Echidna pre-
sents a single convexity for the radius and ulna, the proximal face of the radius being
placed immediately in front of the ulna. The multituberculate humerus {PoJymasio-
don, 3Ienisco^sus) presented a double convexity; the ulna and radius were placed
transversely. In some Ornithorhynchus specimens there is a stout intertrochlear
ridge, as in the above multituberculates.

Such comparisons leave no certain result. The separation of these genera from
the Diprotodonts, justifies the prediction, as a result of future discovery, that the
Multituberculata will prove to be the last representatives of a very ancient phylum

I Proc. Roy. Society, Feb. 9th, 1888, p. 353. Abstract in Nature, Feb. 16th, 1888, p. 383. See Appendix.

ox the structure and classification

Whifli miched too great a degree of specialization and dental reductioiD at the close
of the Cr<-taceous to survive or leave descendants in the recent period. Whether they
are to be considered as a branch of the monotreme or of the marsupial stock is an
juisettled (piestion.

B. Second Group.

As we have seen upon pages 212 and 223, the mammals of this group are so dis-
tinct from the Multituberculata that their zoological position must be considered sei>
arately, and, unlike this order, they conform so little to a common type that when the
approximate systematic position of one genus or family has been determined, it by no
mean.s settles the que.stion in regard to the remainder. Do they belong to a distinct
order? .\re they exclu.sively Marsupials or Insectivores, or do they stand in ancestral
lines leading to each of these orders ? These are the three forms of the problem, which
are conilitioned by the wider question whether the Placentalia have ever passed
through the marsupial stage, with a peculiar yolk-sac placenta^ and restricted milk
<lpntition.

In the conclusion of his memoir (page 113), Professor Owen expressed his views
ns follows: “Among these initial forms of Marsiqnalia we may see in Amithitherium
the prototyi)eof Myrm€(x>bim ; Slylodoii has its analogue in ClirysocMoi'k ; Peralestes
ha.s culminated in Surcoji/nlm; Triconodon in Thylacinus; Plagiaidax is to Thrjla-
.«/« what tlic wea.sel is to the lion.” On page 111, he suggested that we found here
also among those genera, in which marsupial characters were less clear, early forms
of m«Klcm Insectivorn, but gave no specific grounds for this view. The prevail-
ing opinion among paheontologists that the jurassic mammalia are all to be classed
with the Marsupials, has been recently adopted by Lydekker.^ In reference to the
lK>lyprot(^ont genera l.e writes : “The majority of which appear so nearly related to
existing Marsupials that it has been a question whether some of them should not be
...rludcl m ,l,a families.” In proposing the order PanWierin, Marsh in

ISSO mul „p.,n 1887,* expre,sscd the diver* opinion that the mesozoic mammalia

rannot 1» ^fslnctor, y pined in any of the recent orders: ” With a few exceptions
Inv IZr host preservd are manifestly low generalized forms, without

dl^ .T r P“”‘ ">”<=

transfer them ti***^V*H^^^*' evidence based on specimens alone would
transfer them to the latter group if they are to be retained in any modern order.”

lion.

v„,x..o Placenta in Didelphys.”

• Cmt. Fom. M.njin.,'PaH V, p. ix.

Mm. Jour. .Sp., Vol. XX, p. 239, 1880
•■im Jour. Sr.. Vol. XXXIII, p. 344, 1887.

Journ

OF THE MESOZOIC MAMMALIA.

257

The grouping of all these genera in one distinct order is, however, impracticable ;
first, because the members of at least one family present distinctively marsupial char-
acters ; second, it is impossible, with our present knowledge, to assign a single
character of ordinal value which is universal ; third, as to the minor question of sys-
tematic arrangement, there is no precedent for including in one order, such types as
Kurtodon, Stylacodon and Triconodon, in which the teeth are as diverse as in the
recent Rodentia, Insectivora and Carnivora. If distinct from the Marsupialia, the
mesozoic mammals certainly represent an equivalent subdivision of the Metatheria.
Of the nine characters assigned to the Pantotlieria by Marsh, only two rest upon
actual observation through the entire series, viz. : the mylohyoid groove and the unan-
kylosed symphysis. The latter is not distinctive. The mylohyoid groove, is shown
by data collected in the Appendix, to have little taxonomic value. The character, (1)
“ cerebral hemispheres smooth,” was undoubtedly true of all mammals of this period,
and can be actually observed in one of the unique Yale College specimens. Each of
the remaining characters excludes one and, in some cases, several genera : (2) Teeth
exceeding, or equaling, the normal number, 44. (3) Premolars and molars imper-

fectly differentiated. (4) Canine teeth with bifid or grooved fangs. (7) Angle of lower
jaw without distinct inflection. (8) Angle of jaw near or below horizon of teeth.
(9) Condyle vertical or round, not transverse.^

The supposition that all these mammals can be placed in the Marsupialia is
equally untenable, or, at least, it may be said to rest upon no foundation whatever.
It has' been the fate of numerous primitive mammals, at the period of their discovery,
to be placed without much reason or question in this order. The Greodonta is a con-
spicuous instance. This tendency is a remnant of the old doctrine that all primitive
mammals were Marsupials, which is opposed on numerous grounds by the more
recent view that the Marsupials and Placentals were branches from a common steal ^ ;
in fact the peculiar reduction and succession of the teeth® and mode of placentation
exclude the derivation of the Placentals from the Marsupials, and we now have
abundant evidence that these eccentricities of the marsupial dentition were fully
developed as early as the later Mesozoic period. Does this not indicate that the
separation of these two stocks had already taken place 1 Where are we to look for

1 (2) Excludes Paurodon. (3) In all the genera known to the writer, the premolars, where present, are
well differentiated from the molars. (4) Excludes Phascolotlierium and Amblotherium. (7) Excludes Triconodon
in some of its species, T. ferox. (8) Excludes Amblotherium, Stylodon and Amphitylus. (9) Excludes Phasco-
lotherium and Triconodon.

* See Huxley, “ On the Arrangement of the Mammalia,” Proc. Zool. Soc., Dec. 14, 1880, p. 649. The
systematic portion of this valuable article was partly anticipated by Gill, in his “ Arrangement of the Fami-
lies and Sub-Families of Mammals,” Smithson. Contrib.. Vol. XI, 1874. Following Gill’s line of suggestion,
Huxley proposed the term Prototheria for the representatives of this stem stage.

3 Oldfield Thomas, in his recent memoir, shows that the consideration of the reduction and succession
of the teeth alone forces us to the same conclusion.

258

()\ THK STllUCTURE AND CLASSIUCATION

tlie ancestors of the rich fauna of placentals found in the Puerco, if not in the kno^vn
Jurassic and as yet unknown Cretaceous mammals] The probable features of the
dentition of the stem type have already been outlined from a comparison of the
Mesozoic genera, on page 247. The jaw had an unankylosed symphysis, a mylo-
hyoid groove and a distinct coronoid, angle and condyle.

^^'e may now consider the limited evidence we have which bears upon the
zoological relations of these mammals. The Protodonta are considered as a distinct
order and are not included in this discussion because nothing is known of their con-
temporary or succeeding fauna.

Rel.\tions to the Marsupialia.

The only distinctive features of the modern marsupial mandible and dentition
arc the inflection of the angle and the peculiar reduction and succession of the teeth.
But we find the angle is not inflected in Tardpes nor in some species of Pera-
thermm,' showing that this is not an essential marsupial character. The condyle and
angle var\' in jwsition and relation directly according to the function of the jaw.
'I'hey arc low and confluent in the carnivorous forms, lofty and separate in the
insectivorous forms. A mylohyoid groove is occasionally developed ; it was described
by Owen in Mi/rmecoldus,^ which is also multidentate, the teeth numbering 54, (i 1,
c 1, pm I, m I). There are in most genera four molars and never more than three
premolars. Oldfield 'fhomas has recently confirmed Flower’s hypothesis that the
Marsupials have lost one premolar, enabling us to homologize this with the placental
•series. The canine is bifanged in Chceropiis and occasionally in Perameles. Four
lower incisors are sometimes developed, e. g., Didelphys, although the typical number
is three.

I'nmisUikable marsupial characteristics are found among the Tricatiodontuke
and Aniphitherilda-. The mylohyoid groove is always present. The angle unfortu-
nately is rarely preserved ; so far as known, it is not inflected in the latter family. It
is distinctly inflecteil and shelf-like in Phascolotherium. and Spalacotherium, and fully
marsupial in Tricotiodon. The primitive number of incisors is four, but, as shown
upon i>age 248 is reduced to three in the carnivorous series, by the loss of i 4. The
canines arc bifanged in the greater number of genera. The premolars are almost
coi„tantly four in number, and their mode of reduction and succession is strikingly
mnniupinl. As slioun U|>on page 247 the Amphitheriidm lose the second premolar,
rvluch .s by no means a common mode of reduction, yet it corresijonds with what has

• ThI. oWrvMion ,pp„„ to h.ve boon a mi.toie, s,e Append!,.

OF THE MESOZOIC MAMMALIA.

259

probably occurred in the ancestors of the Dasyuridce} In the Triconodontidce, on the
other hand, jj i was apparently suppressed. In each case the reduction resulted in the
typical marsupial number. The mode of premolar milk succession in Triconodon was,
so far as observed, typically marsupial.

We thus find in these two families several characters which are shared by one or
other of the Marsupials, and others which are exclusively Marsupial, leaving no
reasonable doubt as to their relationship. The evidence in the case of the Tricono-
dontidcB is, however, much the strongest, and, as Professor Owen pointed out, they
bear further a family likeness to the Dasyuridce. Triconodon resembles Tliyladnus
in the shape of the mandible, in the triconodont type of inferior molars, in the very
late appearance of the fourth true molar, but lacks the internal heel of the superior
molars. The position of the Peralestidcs is doubtful, turning largely upon our inter-
pretation of the homologies of the molar cusps. The molars of Peraspalax are very
similar to those of Didelphys, as seen upon the inner surface, but lack the apparent
derivation from the tritubercular type. As observed above, in discussing the Multi-
tuberculata, we must distinguish carefully between real and superficial resemblances.
I'his obtains also in the following comparison.

The discovery of the Kurtodon molar pattern apparently adds another mesozoic
marsupial prototvpo in its likeness to that of Phascolomys (Plate IX, fig. 15.) In
the mesozoic genus the premolars are rudimentary and separate ; in the recent genus
all but one have disappeared. In both genera the upper molars are compactly placed
and present an outward curvature. The Phascolomys molar resembles two Kurtodon
molars placed side by side, as the columnar crowns present an external groove g, and
two outward opening V s instead of one ; the enamel e at the sides of the \ is raised,
and the intervening valley of dentine d is bisected by a faint ridge e' which appar-
ently is the bottom of a superficial fold of enamel. In both genera the last premolar
is molariform. The remaining premolars are small in Kurtodon, and have disappeared
in Phascolomys. An important difference is the large canine ^ in Kurtodon vs. the
rodent-like median incisor of the recent genus, which seems to show that these genera
do not belong upon the same line.

To conclude, the Triccmodmitidai were undoubtedly in the marsupial line ; the
Amphitheriidce were probably Marsupials and the Kurtodoniidce, were possibly so;
while there is no means of deciding in regard to the Peralestidcs. No definite
subordinal character can be assigned, but in view of the retention of several primitive

1 See Oldfield Thomas, “ On the Homologies and Succession of the Teeth in the Dasyurid®, etc.,” Phil.
Trans., April 28th, 1887, p. 443. In this valuable memoir, the author reaches the conclusion that pm^,
was probably the tooth which was suppressed in all the Polyprotodonts, and i 4 of the incisor series. The gen-
eralized marsupial formula is given as i 5 p 4 m 4. The apparent reduction of p, in the ariconodoMa;, does
not support the author’s hypothesis thatp^ was uniformly suppressed in the Marsupials.

» It is possible that this tooth although caniniform may prove to be an incisor.

ox tiik structure and classification

ft.atures and of their ancestral position, these mammals may be distinguished from
the recent Marsuihals as tlie sul>order Prodidelphia.

Relations to the Insectivora.

It has been shown that the Stylacodontidm have the dentition and jaw peculiarly
adapted to an insectivorous diet (p. 235). They apparently present the tnhercuJar.
sectorial molar pattern, a much more recent type than that attained in any other
family. The nearest point of contact of this pattern is with Spalaeothenum, a genus
widely separated from this family by its functional adaptation. The reduction of the
prennilars and molars differs from that observed in other families (p. 248). The
dentition is unifpie in combining the rapid progression of the molar pattern with the
conservative retention of the primitive formula. All these facts go to support the
a-ssumption that this family is on a distinct line of descent and that it separated from
the line of the Trk-otiodontidcB, the only family to which in its molar pattern it is in
any degree allied, at a very distant period. This is in the nature of demonstration
that the marsupial affinity of Triconodon does not necessarily affect the position of the
Styhu-odontUla;. Again, omitting the tubercular-sectorial molar which leads into
both the marsupial and placental series, there is not a single marsupial characteristic
in the dentition or mandible of this fuiiiily. Nor does any fossil or recent Marsupial
prewmt tritulicrcular molars of the Stylacodon type.

'I'he rc.scarches of 1 luxlcy,* Parker,^ Cope and others all point to the early origin
and centnd {wsition of the Insectivora. We have abundant anatomical and embryo-
logical evidence for the hypothesis of a primitive point of contact of this order with
the Marsupials, to which additional palaeontological evidence can now be brought
forward.

-\mong the Insectivora we find traces of the primitive mammalian dentition in
the retention of the simple tritubercular type and frequent occurrence of the bifanged
c’anine, as in Ceatetes, Talpa and Oymnura. Some of the specializations of this den-
tition have been enumerated recently in Schlosser’s exhaustive memoir.® These are, the
chis<d-shaped incisors and elongation of the central pair; the occasional metamorphosis
of the amine into an incisor as seen in Talpa ; the enlargement and complication of the
posterior preraolars, beginning with the last and extending forwards; the reduction of

* Op. cit., p. (167.

‘he Skull in the Mammalia, Part III, Insectivora.” Phil,
knowledira of iho Htr, ( ’ \ *i ‘he pre.<ent fragmentary

(ype arc immo,iiaUOrarvr "tlie mIX'^'i? aX^thlt Th '

modifications of what is characteristic oT the Marsupwt > I«®ee‘ivora are more or less transformed

OF THE MESOZOIC MAMMALIA.

261

the first premolar and frequent atrophy, of the occasional prismatic elongation of
the molars, {Ghrysochloris).

All the above peculiarities are observed in different members of the Stylacodon-
tidcB, some of which approach the typical insectivorous structure much more closely
than others. The peculiar feature of some genera is the separation and pris-
matic elevation of the crowns in a triangular section, as in Ghrysochloris, so that
when the upper and lower series are brought together they form alternating trian-
gles, with the bases turned outwards in the upper and inwards in the lower molars
{AstJienodon) . The styliform elongation of the molar crowns is very extreme in some
of the British Museum specimens of Stylacodon (No. 47,758) . The procumbent incisi-
form canines and chisel-shaped incisors are seen in Owen’s type of Stylodon. The
postero-internal cusp of Dryolestes is also found in Gahochloris. Altogether, while
admitting the risk of systematic determination upon the basis of such analogies, we
cannot deny that there is far more ground at present for placing the StylacodontidcB
in or near the line of the Insectivora,^ than in any other order.

No distinctive characters can be assigned at present to the Imectivora primitiva
except the primitive formula, to distinguish them from the recent Insectivora, and the
tritubercular molars, to distinguish them from the other J urassic groups.

The above general phylogenetic conclusions may be summarized as follows :

I. That the Jurassic members of the Second Group, although not forming a single
distinct order, bear marks of comparatively recent origin from a common stem.

II. They subdivide into at least two larger series, including six or more families,
which respectively lead to the Marsupialia and to the Placentalia,, possibly to some of
the existing families of the same.

III. These series, as found at this period, have considerably diverged from each
other and have assumed structural modifications which are at present peculiar to
the Marsupialia and Insectivora.

In addition to the acknowledgments made in the introduction, I wish in closing
to express my indebtedness to Professor W. H. Plower, for his friendly aid extended
to me while working in the British Museum ; to Professor S. F. Clarke, of Williams
CoUege, for the loan of material ; to Professor O. C. Marsh, for the supply of cliches
of his woodcuts. All the text illustrations, with the exception of these cuts, are the
work of Mr. Rudolph Weber. I may call attention to the fact that since my first
studies and sketches of the English types were made, I have been unable to re-examine

^ Schlosser (op. cit., p. 137) leaves the phylogenetic position of the Chrysochloriida; in some doubt. Their
limited distribution, unique dentition and anatomy, possibly denote that they represent a low persistent type.

According to Peters, the mammary glands of the Cape mole {Chrysochloris) are without teats. Monats.
Akad. Wiss. Berlin, 1865.

2^2 OS THE STRUCTURE AND CLASSIFICATION

this material, and have tlms been obliged to leave several mooted points in doubt.
There are some discrepancies between the earlier and later pages of this memoir,
owing to its having occupied nearly nine months in passing through the press. This
has been in spite of the kind efforts of Dr. Edward J. Nolan, Secretary of the
Academy, to hurry the matter forward. The delay has, however, given me the
benefit, in the latter portion of the work, of the valuable recent contributions of
Lvdekkcr, Oldfield Thomas, Schlosser and Cope upon this and related subjects.
J'Bixarri>s, July. 1S88.

APPENDIX.

1. Tiik .MynoiiYoii) (troove in the Mesozoic and Recent Mammalia. Professor
Owcm descrilied and figured a mylohyoid groove in Myrmecohim and, as it is univer-
sally present in the Mesozoic mammals of the Second Group, much stress has been
laid upon it in classification. Ur. Otto Meyer recently called the writer’s attention
to the fact that the groove in the Myrmecohim jaw is not similar to that in the
Mesozoic mammals, and in any case questioned its homology and taxonomic im-
IMirtance. 'I'his led me to examine the lower jaws of all the marsupials and
primates in the collections of Princeton, the Philadelphia Academy and Yale College,
with the following results: 1° A groove similar to the mylohyoid of the human
jaw is Irecpicntly, but not con.stantly, present among the primates ; in Gorilla,
strongly developeil ; IVoglodytes, wanting ; Simla, faintly developed ; Gynocephulm,
very distinct. It varies with age and somewhat within the species. 2° Among the
Marsupials this groove is even more variable, never very distinct, constantly subject
to individual variation : Myrmecohim, wanting in the two specimens in the Yale
Mu«-um, also in the numerous specimens in the British Museum, as kindly observed
for me bj .Mr. Oldfield Thomas ; Phascolomys, present in only one-half the specimens
e.xamine<l : faintly seen in some specimens of DidelpJiys and Dasypm ; Dasyurus,
nylacmw and Itetiongia, absent in all the specimens examined. 3° In all the above
rases this groove extends obliquely downwards and forwards from the orifice of the
^tal < anal . there is thus little doubt that it lodges the mylohyoid nerve or artery,
which brancii from the dental pair at this orifice. 4° In all the Mesozoic mammals,
m wJuch the groove has been observed, it invariably extends from near the dental
toramen for a greater or less distance along the inner face of the ramus, sometimes
n-m h border {PlLmcohtlterium) , sometimes reaching the

/, A . ' "^‘01 termm). hrom its constant relation to the dental canal and varia-

ner,-e lr T' T the mylohyoid

“y “aer supposition. 6» oino-

. . le anterior liorder of the pterygoid fossa is not clearly defined as in

OF THE MESOZOIC MAMMALIA.

263

all the Jurassic genera, but gradually closes into a long, narrowing groove, which sud-
denly terminates in the middle of the ramus in a foramen beneath the last premolari-
form tooth. It appears as if the inferior dental artery may have lodged in this groove
and entered the jaw at this anterior point. From these data, I see no reason for alter-
ing Professor Owen’s designation of this as the “mylohyoid groove,” but strong rea-
sons for not attaching great taxonomic value to its presence or absence.

2. Synonymy.

For Diplocynodon read Dicrocynodm,. Professor Marsh in a letter to myself,
dated April, 1888, has substituted the latter name, Mr. Lydekker having called
attention to the fact that the former is preoccupied by Pomel. Bui. Soc. Geol.,
1846, t. Ill, p. 372.

For Athrodon read Kurtodon ; see page 208 footnote.

For Stylodon read Stylacodon ; see page 236 footnote. It is possible that a new
generic name may be required for the English type of Stylodon, if the American
types prove distinct from it.

For TriglypTius read Tritylodon. Mr. Lydekker (op. cit., p. 201) notes that the
former name is preoccupied for a genus of Diptera. The supposed premolar, described
upon page 221, probably belongs to the species T. fraasii, Lydekker.

Errata.

For Dromatheriu7n read Droinotheriujii throughout.

Page 191, 18th line, read “ Amphitherium."

Page 194, 3rd line, for “ genera ” read “ genus.”

Page 213, 10th line, for “ lower Triassic,” read “lower Jurassic.”

Page 214, 1st line and footnote, for “ Plagiaulacidcep Marsh,” read '■'•Plagianlacidm, 'Gill.’'
“’Smithson. Misc. Coll., 1874, p. 27.”

Page 219, 13th line, 6th word, for “premolars ” read “molars.”

Page 220, 10th line, for “ median ” read “ intermediate.”

ox THE STKUCTUKE AND CLASSIFICATION

2(0

EXPLANATION OF PLATES VIII AND IX.

Illu.4trating Dr. Henry Fairfield Osborn’s Memoir upon The Structure and Classificatiox
OK THE Mrisozmc Mammalia; —

The figures were drawn by the author with the aid of a camera,’ in.suring their accuracy of
proi>ortion and outline. They are enlarged in some cases to seven diameters, and often reversed,
to bring out clearly the comparative structural details. The enlargement is not proportional to
actual size. Figures 1, 3, 5, S, 9, 10, 11, 13, 14, 15 are from single specimens ; the remaining
seven are comf>osites} Composition figures are adopted in cases where two specimens of one indi-
vidual fall in reversed slabs; or where two sj^ecimens, from different individuals, agree in size
and contain two or more similar teeth in common. For example, in Bolodon, figure 16, parts of
two maxilla- were thus united, both of which showed the maxillary suture and four similar teeth
behind it. In most cases, the numbers attached to the original specimens in the British Museum
collection are r(!Corded, in order to enable other investigators to confirm or disprove the compo-
sition. In preparing the drawings, some parts were naturally more fully known and certainly
r«-lnt*tl to each other than others. These degrees of probability are expressed in the draw-
ings in the following manner: (1) In cases w-here there is positively no reasonable doubt as to
the relation of two composite specimens (as in the Bolodon maxilla) the parts of each are fully
shndeil, ns if they belonged U) one individual. (2) Where the outline of the teeth or jaw is
ascertained from impressions left in the matrix, or where a specimen has fallen into two slabs
one showing the inner, the other the outer surface, plain contour lines arc used. (3) Where the
evidence is not from one of the comi>osites, but from another specimen belonging to the same
g«-nus or sjH-cies, or where the presence of a tooth is somewhat conjectural, dotted lines are em-
ploy,•<!. Thi-se ml, -8 an- all illustrated in the figure of Spalacotherium and are adhered to in all
tlie ,lrawing» unless it is otherwi.se distinctly stated.

Abhrex'uUwns. a, angle, r, condyle, d, dental foramen. /, infraorbital foramen. ///, mylo-
hyoid groom, mf, mental foramen, r, mandibular symphysis, ms, maxiUo-premaxillary
suture. /, (, p, m, dcntid series.

I HE BRITISH MESOZOIC MAMMALS.

-landibukr ramus, enlarged 4

, T. ' frofesBor Owen', memoir, «Geo4ic.I

1 ransaclions, &er. 2, Vol. VT Ploic irr >> -n • >6

•nolars, m, was omitted. " ’ ^

““"dibulnr ramus, enlarged

Plate II.” ■ ’ “nt'gewaler Treatises, Geology and Mineralogy,

•lout, t.o„,e„l„rge«^meler,. The main portion of the mandible and
».n, for “Z";" 1:,";:;;:::;^^ ■„ i...iu.bi. iae,n,.
k the re«,u of the “mbZZTMwtlZmZrtlch r’”’*' ‘ Tie former

OF THE MESOZOIC MAMMALIA.

265

lower dentition is from No. 47,775 in the British Museum collection ; che tij)S of the first and
second premolars are restored from a specimen of T. occisor ; the canine is from a matrix
impression, and the incisors from another specimen of T. ferox (Mes. Mamm., PI. IV.,
fig. 1). The angle and condyle are drawn from another specimen of T. ferox. The max-
illary dentition, also viewed upon the inner surface, is from Nos, 47,788 and 47,779, which
have the third premolar in common.

Figure 5. Triaca7tthodon (Triconodon) serrula. The outer surface of the left mandibular
ramus. Drawn from the original specimen. No. 47,763. Enlarged 31 diameters.

Figure 6. Peramus tenuirosfris. The outer surface of the left mandibular ramus, enlarged 4J
diameters. The main portion of the ramus with three molars and the last premolar is
drawn from No. 47,742; the premolar crowns and symphysial portion of the ramus is
from No. 47,744; these specimens have and w, in common.

Figure 7. Spalacotherium triciispidens. The inner surface of the left mandibular ramus, re-
versed. Enlarged 31 diameters. The ramus and dentition as far forwards as is from
No. 47,750; the remainder of the figure is from the outer view of the forward portion
of the same specimen in the counterpart block of matrix. The incisors are from other
specimens.

Figure 8. Peralestes longirostris. The outer surface of the right maxilla, enlarged 3i diame-
ters. Drawn from a single specimen. ("Mes. Mamm., Plate II., fig. 3).

Figure 9. Peraspalax talpoides. The inner surface of the left mandibular ramus, enlarged 31
diameters. Drawn from a single specimen. No 47,738. The canine and anterior premo-
lars are shown in the matrix impressions.

Figure 10. Leptocladus dubius. The outer surface of the left mandibular ramus, enlarged 6
diameters. Drawn from a single specimen. No. 47,739.

Figure 11. Amblotherium soridnutn. The right mandibular ramus, seen upon the inner surface,
and enlarged 51 diameters. This was drawn from a single specimen, No, 47,752.

Figure 12. Phascolestes dubius. A portion of the left mandibular ramus, seen upon the inner
surface, and enlarged 4 diameters. Drawn from a single specimen, No. 47,741.

Figure 13. Achyrodon nanus. A portion of the right mandibular ramus, seen upon the inner
surface, and enlarged 5 diameters. Drawn from a single specimen. No. 47,745.

Figure 14. Stylacodon pusillus. The outer surface of the left mandibular ramus, enlarged 41
diameters. The main portion is from No. 47,757. The coronoid and angle are from an-
other specimen. (See Owen, Mes. Mamm., PI. II., fig. 15).

Figure 15. Kuriodott pusillus. The inner surface of the left maxilla, enlarged 4 diameters.
Drawn from a single specimen. No. 47,755. 15a represents the wearing surface of the
molar crowns; e, the enamel encircling the crown; /, the enamel ridge traversing the
crown; g, the external groove. 15b. represents the wearing surface of a left upper molar
of Phascolomys urshms; letters e, e’ and g as above ; d, dentine between the median enamel
ridge and the surface enamel.

Figure 16. Bolodon crassidens. The outer surface of the right maxilla, enlarged 31 diameters.
The anterior portion is from No. 47,735; the posterior portion is from another specimen.
The specimens have four teeth behind the maxillo-premaxillary suture in common.
16a wearing surface of the molar premolar-series.

American Triassic.

Figure 17. Dromotherium sylvestre. The inner surface of the left mandibular ramus, enlarged
41 diameters. Drawn from a single specimen in the Museum of Williams College.

PL. 5,

1^

MESONYX OBTUSIDENS

JOURN ACAD NAT SCI PH I LAD. SER.yOL.IX

PL .6

1, ME S ONYX, 2.HYiENODON

JOURN ACAD NAT SCI PHILAD 2’^‘i SERyOL.IX

PL. 7

1-3.MESONYX. 4-6.HYiS.NODON.

1 . AMPHILE STE S . 3 . PHAS C OLOTHERIUM - 4. TRIG ONODON . 5 .TRIACANTHOD ON . 6 .PERAMLIS .
7, SPALACOTHERIUM. S.PERALjESTBS . 9 PERASPANAX ,

JOURN.ACAD.NAT.SCI.PHiLAO 2-^d 3^;^^ yoL ,IX

.lOUHN. ACAD. NAT. oCl . PH ILAIj . SERyOL.lX

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10 , LEPTOCLADUS . 11. AMBLiOTHERIUM . 12 PHASCOLE STBS . 13. ACHYRODON . 14.STYLODON .
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CONTENTS

•AHT. I,— t)n jioiiM! Sew ninl Little-known Creodonts. 'By W. B. Scott. (Plates V,

VI, VII.) . 155

•AHT. V.— On till? .‘structure and Classification of the Mesozoic Mammalia. (Plates

VIII, IX... • 186

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•Extra ropini printed In advance for the Author. July 25, 1888,

‘Hi): ‘

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JOURNAL

OF

THE ACADEMY OE NATURAL SCIENCES

[207]

A MEMOIR UPON THE GENUS PAL.EOSYOPS LEIDY, AND ITS ALEIES.

By Charles Eaki.e.

The following memoir is the result of my studies upon the collections of speci-
mens belonging to the Palisosyops in the Museum of the Aciidemy of Natural

Sciences of Philadelphia, in the E. M. Museum of Geology and Archmology of
Pi-inceton College, in the collection of Professor E. D. Cope, and upon some of the
specimens in the A" ale College Museum.

The association of the renovYiied name of the late Dr. Joseph Leidy with this
genus has made these investigations appear of especial interest at the present time.
I am greatly indelited to the authorities of the Academy for their liberality in plac-
ing in my hands the large and very valnahle collection of Palmosyops material which
is deposited in the Museum of that historic institution. This collection is especially
valualile as it contains many of the original type specimens of Palceosyops, from
which Leidy first gave to the scientific world the knowledge of the existence of these
animals, and which later, in 1873, he fully described in his “ Extmct Vertebrate
Fauna of the West. ”

Since Leidy in 1870 described the genus Palceosyops from a few scattered frag-
ments of teeth which were found at Church Buttes, Wyoming, a great advance has
been made in the palamntological history of this and allied genera.

During the whole course of this investigation, 1 was fortunate enough to be sit-
uated in Princeton, and through the kindness of Professors Scott and Osliom, 1 had
access to the large collections of Pala^osyops material which had been made by their
M'estern expeditions. Among the numerous exploring parties that have visited the
Bridger Beds, none ^Yere more successful than those sent out by Princeton College,
under the leadership of Professors Scott and Osliorn. Four parties in all have been
sent out by Princeton to these beds, with the result that the collection in the
Princeton Museum of material referalde to the genera Palcsosyops, Limnohyops and
Telmatotherium is one of the most complete in this country. It is to this collection
that I am chief!}- indebted.

Like all palaamtological investigators, I have felt the want of more complete
individual material to corroborate some of my identifications. In a fev- cases the
parts were found Avidely scattered. In some cases I have placed parts of the skele-
ton under a certain genus, Avhere the boiies Avere not associated Avith any teeth, and
consequentlA' the reference Avas partly conjectural. This applies particularly to my

36 JOURN. A. N. S. PHILA., VOI . IX.

A MKMOlIv UPON THE (JENUS

I- .. <lw. .ronim Limnohyops, the skeleton ol‘ wliichiias l>een so little
jl,-teniniiat.oiis u>>' ‘ r ' ^ .something to the morphology of this

I*""" M 1 , nv i,l<.nlWioa,i,.„. will, I tl.ink, atan,!. Tl.crc. ia no.doal,,

.un.'..r.l,c. .vi. »,aa.k.a. 1 .ofer t„ tl,e line akelcton «f Pal.o.yops

paludosus, with ti-.-th. fonn.l in the Prineeton Collection. .

With sneh limitations it is clearly impossible to write a final memoir upon tins
p-n.iH Mv ol.ji-et has In-en rather to break the way, to clear up the synonyms, to
,listingui.«h'tl.e'.lifreivnt tyiies. and to throw as niiich light as possible upon the mor-
phologv and the variations in dental and skeletal structure.

'I’i.e ivmler will find the phylogenetic part of this work rather crude. Owing
to the pivsmit lack of material, I am unable to fill in the gap.s, and offer the scheme
at till* eml of this memoir as a preliminary basis for further observations.

It is with the givatest .satisfaction and pleasure that 1 take this opportunity to
tliaiik mv friend Dr. Henry K. Osborn, now of Columbia College, who, upon my re-
turn fnaii Ceniiaiiy in the fall of 1889, invited me to come to Princeton, and sug-
gest«*d lay taking iip this investigation. His kindly advice and many valuable sug-
g«>stions iiavi- Isam a constant stimulus to me throughout the course of my work.
I am also imlebted to I’rof. Scott for having given me the aid of his valuable criti-
«-isni in many cas<-s. .Mr. Hndolph Weber has prepared the drawings for this
memoir, and thev an* np to his usual fine standard of Avork. In conclusion 1 Avisli
to thank Dr. Edw. .1, Nolan of the Academy of Natural Sciences of Philadelphia fiir
tlie tnadde he has taken in connection with this memoir.

IXTHODI'CTION.

Prei’ious Lileralure. — 'I'Ik* literature on the sul>family Falceosyopince is very
limited, comparatively few authors having Avorked upon this group of fossil animals.
.\inong tin- .Vineriean palannitologists Avho IniA'e AA'orked upon Palceosyops, Ave must
first mention Piufessor la'idy. He states in the preface to his Avork ” The Ex-
tinct \ ertebnite Eannaofthe M'estern Territories,” that his time had been so much
taken up with pn)ft>s.siomd engagements, that he had not been able to study the
material descrilM'd In the alsiAe mentioned AAork as thoroughly as it should IniAe been,
ami conchule.s that the msnlts aiv not as complete as he aa ouIiI like to IniA e had them.
I find on candidly studying his original material and comjiaring the same Avitli
Ills de.s4-riptions. that then* is .some confusion in his Avork, and a number of slips in
n'ganl to th<' s|H‘cific ndations of the forms described.

Nomenclnhire and Synonyms. — In my preliminary paper I attem])ted to clear up
the iiomenclatnn* and the s|H'cific relations of the sjAecies included in this subfamily',
and I shall include this jKirtioii of my former paper in this for reference.

< o|H>, in his “ I ertiary \ ertebrata,” has shoAvn the relation of the nomenclature of
PaJteosyops and Limnohyus proposed by Marsh and Leidy, and there is no question
as to I/cidy s priority. Eeidy de.scribed the genus Palceosyops three months before
ars I pn »Iisln*d his iindiminary notice, in Avhich he describes his Palceosyops laticeps.

PAL.EOSYOPS LEIDY, AND TTS ALLIED.

269

Cc)])e tlid not atteiiipt to determine Leidy’s original types, irom Avliicli the genus
and species Palceosyops paludosus were first indicated. After studying Leidy’s orig-
inal specimens, no^r in the National Museum, which he described,' and which later
he figured^ I am convinced that they belong to the large species of Palaosyops ;
that wliich Leidy subsequently named P. major. Second, that tlie smaller forms
later referred by Leidy to P. paludosiis were quite distinct li'om his types of this
species. Therefore, as the original specimens were called P. paludosus, and as they
were identical with a form which he later called P. major, the hitter name is a
synonym and must drop out. As Leidy’s name P. major was I'ery convenient in
designating the relative size of the two species, we pro])ose to call the smaller form
Palceosyops minor— \\\q, P. paludosus, according to the later use of Leidy and others.

I imiy also add that Cope’s P. Icevidens is a different form from this smaller
species of Leidy, so that Cope’s specific name cannot be used for it.

Cope^ accepts Marsh’s statement that the original specimens figured by Leidy
belong to Limnohyus. This is, I think, an erroi’, as the teeth are much larger and
correspond in every resjiect with Leidy’s P. major. Marsh’s statement that the teeth
of his P. laticeps have the same general structure as those of Leidy’s smaller species —
namely his P. paludosus, is also incorrect. I have examined both types, and I shall
show later that the two forms are quite distinct — one approaching the Telmatotherium
form of molar, the other type being more like the typical molar found in P. paludosus.
INIarsh’s type of his genus Telmatotherium'^ agrees in all particnlars with the type ot
Scott and O.shorn’s Lezirocephalus,^ so that the latter genus must become a synonym
of Telmatotherium. I retain Scott and Osborn’s species T. (Z.) cultridens, as a good
species, and it has very interesting characters Avhich place it rather lower in the
scale than the T. validus of Marsh. The skull figured by Scott and Osborn in their
report for 1877 as P. paludosus, should be referred to Marsh’s genus Limtiohyops.
Its general form is very different from Palceosyops, as will be shown later. After
carefully considering the matter of uniting the various genera into one, 1 am of the
opinion that Telmatotherium may be retained, and that Lymtiohyus, or as it is now
called, Lymnohyops, should not have a generic value equal to that of Telmatotherium.

The type specimen of the genus Limnohyops is very closely related to that of
Palceosyops in the teeth structure, and we have good reasons for supposing that the
presence of the hypocone on the last superior molar is a transition character, which
is not a\-ailable for generic definition. The j)resence of a rudimentary hypocone on
the last superior imdar of Palceosyops paludosus is not an uncommon occurrence.
The premaxillary regions of Limnohyops and Palceosyops are identical, although the
skull contours are very dillei’ent. The generic reference of Leidy’s smaller species

'Proc. Acad. Xat. Sci. Phil. 1870, !>. 113.

2U. S. Geol. Survey of the Ter., Yol. 1, 1873, Plate V, fig. '5, and PI. XXIII, figs. 3-6.
^Tertiary Vertehrata, i). 698.

*Ain. Jour. Science and Arts, Yol. lY, pub. July 22nd, 1872.

^E. M. Museum Bulletin. Xo. 1, Eeport Princeton Scientific Expedition, Sept. 7th, 1878.

270

A .MK.MOIK ri’ON THE (iENUS

of /‘.i/ifosyops, .)ur P. minor, in m.ccTtaiii, very little being known of the skull
or ..r tl.e linil> l.<.neH. 'I'lie eliaraeters of the molars (see his PI. IV, figs. 8-G)
arerlo.-*-lv similar to tliose of Telmatolherium ; they have the square form observed in

that j'eiiiis.

We an- imiehteil to Professor Marsh f()r having deserihed Litnnohyops laticeps,
althongii at the tiim- of its <lescnption he created great confusion in the nomencla-
tim- l«v totally igmn-ing la-idy’s |irevions description oi' Pai^eosyops. It was one of inj
first diith-s in taking up tliis investigation to unravel the work done by Marsh, and
att4-nipt t4i phn-e it in its true relation to that done by Leidy. Marsh at the time of
«les<-rihing liis genus Telmatolherium did not appreciate its true relationship in Dipla-
(odon and lat«-r in his " Inti-fslnction and Succession of Vertebrate Life,” jdaces the
genus Paheosyops ia-.\t t<t that of Diplacodou in its evolution. This is an error. As
I shall show in tia-ating of Telmatotherium. this genus was probably the direct
fon-nnnn-r in tin- Hriilg«*r of the I'inta genus Diplacodori and I Ix-lieve Telmatolher-
tum to lie tin- tninsition fiirin la-tween Palceosyops and Diplacodou. Also the state-
nn-nt made by Marsh that I.imuohyops{=Limnohyus) is found lower in its geologi-
«-al horixon than Pal(rosyop.<! incorrect. They both occur in the JJridger proper,
ainl tin-n- is no iveonl n[' I Jmuohyops from the Wind River.

Pnifi-s.siir ('o|M-’s collection of Pahv-osyops material is a small one; but owing to
its iinii|iie cbaracler he has la-en enabled to describe a number of very interesting
in-w s|M-<-ies. wbicli I find on «-omparison with other tin’ins to Ik- quite distinct. We
an- hnlebt«-d t«i ('o|k- fbr having descrik-d the earliest known species from the Wind
River l-sK-i-in- of Wyoming, namely, P. borealis-, and from this fbrmation he also de-

s«-rilH-d the g4-nns Lambdolherium which he con.siders as the direct ance.stor of the
Palasis\ops-I)qda<-<Mlon line. We consider that Lambdolherium may have been the
aneoslor of Pahrosyops. but certain characters of its dentition— fbr exam])le, the loss
of inf.pin. I— iHiints to its k-ing a side line, and not leading directly to Palceosyops.

Pn.f.-ssiir ( ’o|H-’s <-olh-«-tion tains only one skull referal)le to the genus Limnohyops,

naniely. Ins /,. fonHualis, and in 'relmatotherium material his collection is very
liinit.-d A\e shall not detain the reader with a long de.scription of the original
inat.-nal iqH.n which k-i.iy based his de.scriiitioms, but merelv add that the type
siHvnm-n of P. paludosus is now in the Smithsonian Institution at AVashington.
His Iat4-r niat4-rial of PaUrosyops, which was fully described in his report for 1873,
.s now n, tin- Aca.Iemy of Natural S-iences of Philadelphia. Profes.sor Marsh’s
* II • . <^tyeps .IS well as his L. robuslus and Telmatolherium validus

‘ , Have,,. I ,v„K v..n- R,rl„nat, i„ teing

' . V ", ,V|H. tlu,..k. t„' l,i. Tl.e

inul'l ”tl"' *1 a kVl-*- -veix' ilescribud is all in his private col-

■11- .•.Iiu";i,, : , 7""" Archa.„logy a, Princetoa College.

osvophur. ' known material referable to the Pales-

271

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

Geological Succession and Distribution of Species. — It is hardly necessary in this
memoir to dwell upon the geology and subdivisions ol the Bridger Eocene, as Prof.
II. F. Osborn, in his memoir on Loxolopltodon, gwci'A a long descri})tion of the geology
of the Bridger, and the tannal relations of the mammals found in this formation,
lie comes to the conclusion that thei’e is abundant evidence to show that the
Washakie is a later formation than the Bridger proper. He further shows
that the nature of the rocks in the tAvo subregions is difl'erent, and that the
Washakie contains none of the higher genera of the Ungulates which are so
characteristic of the Bridger, for example the genera Loxolophodon, Amynodon,
Triplopiis, Achcenodon. Professor ScotP, in his paper on the “Eocene Lacus-
trine Formations of the West,” says that the Washakie is characterized by
“ a great reduction of the Creodonts, and Lemuroids, in the difl'erent type of the
Dinocerata, in the presence of Amynodon, and in the fact that very few species are
common to the two basins. ” Professor Scott,^ in a later paper, lurther supports-
the above AueAV and goes into a long discussion endeavoring to show that the Bridgei
and Washakie are separate formations having been deposited successively, the
Bri<lger having as a \Adiole an older fauna than the Washakie. My own studies
upon the species of Palceosyops from these two formations, support the above
views and indicate that the Bridger is characterized ly many species of Palceosyops
and allied genera Avhich are not known to occur at all in the Washakie basin. I
think it Avill be interesting to enumerate the difl'erent species that characterize the
tAVO sulidivisions of the Bridger, as tliey furnish important evidence as to the distinc-
tiveness of these two formations. We^ have already stated that Palceosyops borealis
is the only species of this genus that is found in W ind Riv'er Eocene. Both the
species of Limnohyops are confined to the Bridger. In the genus Palceosyops there
are three species which are peculiar to the Bridger proper, namely, P. Icevidens, P.
minor, and P. longirostris. Telmatolherium has only one peculiar species confined
to the Bridger, namely, T. cultridens. The MLishakic has fcAver peculiar species than
the Bridger proper, but one of these belongs to the most specialized species of the genus,
and leads almost directly to Diplacodon. These are P. hyognathus, the type Avith the
much elongated juAv, and P. vallidens which is really a doubtful species and is
intermediate between P. paludosus, and Telmatolherium. The species that are
common to both formations are three in number, namely, P. paludosus, P. megar-
hinus, and T. validus. MY see from the above enumeration that the less s])ecialized
member of the group, Limnohyops, is confined to the Bridger proper, whereas
the most specialized genus of this subfamily occurs in both formations, it is true,
but the most progressive species ol' the genus, T. hyognathus, has been only
recorded from the Washakie. The above consideration will give support to the view
that the WLashakie has as a whole a more highly developed fauna as regards P alce-
osyops than the Bridger, and should be placed higher in its geological horizon than

'The Eocene Lacustrine Formations of the AA'est. Proc. Am. Ass. Adv. Sci., 1887, page 277.-

2The Alammalia of tlie I’inta Formation, p. 464.

\ MK-MOlli Ul’ON THE GENUS

. will sl.ow the .lixtrllmtioll of the .pecies in this

'ul.f'.ii.ilv’. A» lilt a» poanihle it has heeii arranged phylogenetically, ami itartially
rlin>i»)l(t}rifall\ . ^ —

».W»UKil<'AI. U1.-T1£I»ITK)X OF
SI-KClK-s.

KOCKNE.

TiiaixHlKTiuiii
(llaiiUnHloti)
l»i|*l»niiloii rinliu*
T<-liiuiU>iiiiTiiiiii liyiv'iii'liiit*
Ti-liiuil<>lli<'riiini vmIuIiik
T<-liiuiii>tliiTitiiii mllridfiif
l.liiiiioliyoi* fiuiiiiuilix
IJmimliy<>|* Inli'vini
|*B|jr<Myu|w liiiiitinwlrii*'
l*nlir<«yo|ai minor
|‘nUt'<«yo|a< vnlli<l<'m>
l‘■li«'■«yo|l)■ iiHtnirliiiiiix
I'lilAafaiyoiiii lii-viil<-iiK

l‘HlMaiaiyo|Bi |ialll<l< xll*
l*iilM'<»iyo|w iMinitliN
IdUiilHloilirrium |Mi|H<i)(ifiiiii
laimiMloilKTiiim’'

Bridger

MIOCENE.

CL.\SSI FI CATION.

I li*> «liiMM»v«*rv hy M. Filliol ol the relations of Chalicothermm to Macrotherium
liax iiiade an «'ntin* muTaiifreiiient ol this family necessary, so that a new family
name must U- applied to the frrouj) including the genus Palccosyops ‘aw^S. allied genera.
I»n.r.-ss<.r ('o|H'' has taken this op|M)rtunity toprojiose that Chalicotherium he placed
in a new order entitled the Ancylopoda, and has likewise instituted a new family
name Ihr PaUosyops and allied genera— namely, the Lambdotheriidcr this is derived-
In.m Ins g,.„ns Lambdothcrium,^ which was described a long time after Paiteosyops^
nil I MS n In Is*id\. I accoiilinglj- cannot accept Cope’s jiroposed name for this
lanniy. as the family name of a gi-oup must, according to the rules of nomenclature,
iM. . erivisl In.m the oldest generic name, that is to say from Pcdceosyops, which
would give ns the name Palccosyopidcc for this fomily. I find in looking over
n>is.n>r o|H s ^alious pa{K‘i-s from 1879-87, upon the arrangement of the fiimi-

'Ain. Xni., Mnn’li IKSft, p. 152.

•Am. Xnl., l.SSO. 7ia.

•lUydenV. P„.|im. Up,, of Gih,I. .s„rv. of Montana, 1872, p. 358.

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

273

lies of the Perissodactyla, that in his first paper upon this snljject' he did not sub-
divide the family Menodontidce from the ChalicotheriidcB . lie included the genera
Pal(eosyops and Menodus 0.11 under the fiunily Chalicotheriida:, and he follows this
arrangement in his second paper upon the classification of the Perissodactyla.^ In
his third paper upon this subject Professor Cope, for the first time, separated the
Menodontidce from the Chalicolheriidce, basing the differential characters of the two
families ni)on the simplicity or complexity of the jjremolar series respective!}’. Both
Schlosser and Osborn® have noticed the close affinity between Palceosyops, Diplacodon
and Titanotherium, and consider that on account of the transition characters of the
preraolars t)f Diplacodon, the three genera in question should be united into one
family. Lydekker,^ in his Manual of Palasoutology, follows Cope in the arrangement
of this family, including in it the genera Palceosyops and Titanothermm, and placing
Chalicotheriurn in a distant family of the Perissodactyla. I should also add that
Lydekker jjlaces Palceosyops in the family Lambdotlieriidce proposed by Cope. Stein-
maiin and Dfoderlein'^ form three suljfamilies for the genera Palceosyops, Titanother-
ium {—Bronlotheriiim), and Ckalicotheriuni Ye\i\iQQXivii\y , condjining these all in the
family Chalicotheriidce. After considering the question of the union of these genera into
one family, I quite agree with Osborn and Schlosser, and see no real line of family
di.stinctiou between them. I think that Palceosyops and allied genera, Diplacodon
and lastly Titanothermm, should be placed in the family Titanotheriidce, proposed
by Osborn."

It appears to me that the arrangement proposed by Doederlein, of placing the
genera of this family into subfamilies, is a very good one, and I shall accordingly
follow it. ^ . '

General Characters of the family Titanotheriidce. — The family Titanotheriidce
may be defined as follows : Skull elongated, with zygomatic fossa prolonged beyond pos-
terior limit of molars. OiLit small and not separated from temporal fossa behind.
Nasals elongated and reaching at least as far as premaxillary symphysis. Lateral
nasal notch deep. Nasals with or without horns. Auditory processes Avell developed.
Postglenoid process large. Occiput broad with prominent descending paroccipital
2)rocesses. Alisjjhenoid canal much elongated. Foramen ovale distinct and widely
separated from the for. lacerum medium. Tympanic bone not coossified with petrous.
Superior molars of the buno-selenodont type, with symmeti’ically developed external
A^’s, separated by a prominent median buttress. Internal cones of molars separated
from external lobes. Intermediate tubercles generally well developed. Lower
molars of the lopho-selenodont type, consisting of double V’s, with the posterior crest

■Bull. r. S. Geol. Surv., 1879, p. 228.

“Am. Xat. April, 1881, p. 340.

“Uinta Mammalia, p. 141, Aug. 20, 1889, (Trans. Am. Phil. Soc. Vol. 16).
^Manual of Pateontology, Xicholson and Lydekker, 1889.

“Elemente der Palaeoiitologie, 2 Band, p. 776.

“Loc cit.

A MK.'IOlli rroN THE (iKNU.S

.J7I

ol tlu- ..iit.-rioi- an.l til.- aut.-ri.ir <-ivst of tlio posterior V in contiimitv internally,
p t.-rior tiilK-r.-l.- of last inferior molar always iiresent. Manns of the paraxonic

iZ- with four funetional .li/'t*^- nt'^rly

M.l-smal i.ia.m.im ami nn.-if..nn fiieets. ami eonse.piently scaphoid widely separated

MilMspial iiiafriiiiiii

from iim-iforiii. Mafriuiin small. _

,.„|..„m-al faeols jr.-m-rally widely separated. A large astragal.Kiuboid contact. Fils

IVs with three wide .spreading digits. Astragal.s

<-alcam-ai im-.-is s' • • i in, i .

ul.M-al.-am-al facet pivs«-nt. Navicular hroad and l(jw. Metatarsals of the alternat-

*\s aln-a<l\ |)ropo.se«l. the family Titanolheriicice maybe divided into two sub-
fainilies with the foll.iwiiig defiiiitioii.s.

A. Nom-ofthe pi-emolai-s molariforin, Pal.ko.syoplv.e.

H. Sane of the pi-.-molars molariforin, Titaxotheriix.e.

C.euentl Chatackrs of the Palcrosyopinee. — Dentition.— i.| c.{, pin.J, ni.i
The siihfamily l\il<eosyopht<c is distingnished above all from that of the Jitan-
otheriitur by the simplicity of the premolar.s, and in none of the genera are any of
ihcM- l.s-lli as e.aiiple.x in their structure as the true molars. Only in the highest
genus of this sulifainily. namely Telmatotherium, do we find any signs of the
pn-iiiolars taking .ai the .-haraeters of the molars. Then again in this sub-
family. all its im-udM-rs as liir as known have a full complement of both upper and
lower im-is4irs. and al.so the canines are very much developed, much more so com-
pansl with the size of the animal than in the other subfamily. The first superior
pn-iiiolar is a double faiigi-d t.Kith. with or without heels; the .se.-ond tooth of the
M-ries alM»\e may havi- its iuternal cone rudimentary. The last two upper premolars
an* alwa\s Irieouate in struct iir.-. As a rule the bust sujierior preniolar is much
smaller than tin- first su|M-rior imdar. This rule applies especially to the more prim-
itive tueiiilH-rs of this subtiuuily. 'I'he variation in the details of the molars in the
iliflen-ut gi-u.-ra is eoiisideralde ; and when we comjiare the undiflerentiated molars of
/^imbitoihenuni \\\\\\ those of 7'e/>naiothe)'jum,\\ {i can appreciate the great specializa-
tion of the one gi-iius ov.-r the other. This ajiplies e.specially to the develop-
im-nl of the external V’.s, ami the crowns of the teeth. In Lambdotherium the V’s
an- shallow ami the external cusps of the .same show strongly their original bunodont
ehanieter. I he eniw ns ol the molars in this genus are very low. On the other
haml. in l\tt<rosyops the.st* characters become more .specialized and progressive;
w hen-as in 7'etiuotothenum the characters of its molars approach more nearly those
of I'ttonolheriuni. and an- intermediate in character between the latter genus and
/ okrosyops. In tin- lower genera the external cingulum of the true molars is
"anting. In /'ehnatothenmn the external cingulum is a verv conspicuous character
ol the inolai-s. I he intermediate tubercles are variable in this .subfamily, and we
«an taifely .sav- that a.s a whole the less sjiecialized genera, such as Lambdotherium
nm^ akrosyops. have thegn-atest development of the intermediates. This is specially
noti«-<a ill in Lombdothcnunt when* the development of the protoconules has gone

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

275

BO far as to form a true transverse crest ; thei’e are also signs of a posterior crest in this
genus. The development of transverse crests is the great exception in this suh-
family ; hut there are signs of these in L. laiiceps and in P. borealis. The first and
second superior molars are always provided with two well developed internal cones
in all the genera of this family; but the variations in the number of internal
cones of the last xipper molar are considerable. In Limnohyops this molar has
two internal cones, whereas in Palceosyops and TelmatotIieriu7n the hj’pocone of the
last upper molar Ijecomes rndimentarv, although all stages of the degeneration of
the hvpocone may be observed within the genera alreadj'^ mentioned. The Amria-
tion in the form of the last inferior molar rvitli its tubercles Avill he considered
later. Diastemas may he present in the dental series of some species, and the inter-
vals increase as we approach the higher forms, although a reversion to the primitive
form takes place in Titanotherium, which genus is Avithout a diastema in its
dentition.

Skull. — The general form of the skull in the two subdivisions of this family is
A'ery diftereut. All the members of the PalcBOsyopince have small skulls compared
Avith those of the Titanotheriince ; and, moreover, in the former the fixcial region is
much longer in comparison Avith the cranial portion than in the latter subfamily.
The marking off of the orbit by postorbital processes from the temporal fossa is a Avell
marked character of Palceosyops. The coalescence of the temporal ridges to form a
sagittal crest is characteristic of the Palceosyopinte, Avhereas in Tiianotherium no
such crest is found, the roof of the cranium Ixeing very broad, flat and limited
Laterally by the strongly developed temporal ridges. The nasal bones in Palt^osyops
are more slender and elongated as compared to those of Titanotherium ; they do not
jxroject beyond the j)remaxillary symphysis, and the lateral nasal notches are smaller
than in the last named genus. The nasals never bear any horns, nor does any
other part of the skull iii the Palceosyopmce. The auditory jjrocesses are large, and
the postglenoid and posttympanic i-emain separated. In the loAver jaA\' the anterior
extension of the symplyysis beyond the preniolars is much greater than in the Titan-
otheriince. In the latter group the anterior portion of the syunphysis is A^ery much
abbreA'iated and there is, consequently, a crowding together of the teeth in this
region. The brain is less coinmluted, and the forebrain is more Avidely separated
from the hind brain than in the Titanotheriince.

Carpus. — In the carjxus the lunar diameters are more nearly equal than
in Ti(anoikeriu??i, Avhere the transverse diameter of the former is much greater
than the A'ertical. The distal fixcets of the lunar are more unequally divided,
the lunar-magnum facet being nearly vertically placed in some genera. As
a consequence of this the distal portion of the lunar forms a beak-like process,
Avhich in one genus {Lininohyops) ma}' nearly diAude the second roAV of carpals
as far as their distal face. The scaphoid and uncifonn are more displaced in
the Paleeosyopince than in the Tilanotheriince . The articulation of metacarpal III,

37 JOCKS. .A. S. S. PHIL.A., VOL. IX.

A MK.MOJll UPON THE GENUS

aii.i tl.r mH-iform in v.-rv larKt*. T\w tninsverso extent of the magnum is less,
.•4.in|.arati\.-l\-, llnm in the Titayiolheriime. As a Avhole the carpus in Palceosyops is
more eloiigaite, its transverse axis )x‘ing less in proportion to its vertical. This also
ajiplies to the elements of the tarsus.

Tarsus. — '1'Ih> tai-sns of Palceosyops is jn-oportionally higher and narrower
tiiaii that of Titanotherium, al.so the metapodial region is much less spreading,
'Fla* astragahM-alcaneal liu-ets aif ncjt as widely separated as in the Titano-
Ihcriiiue ; ami. in fact, in some of the smaller species of Woi Palceosyopince
teiitaeiilar ami iiiferi(*r may Ih‘ continuous. In Palceosyops the smstentaculum is
verv largely develo|)«*d, wliei-eas in Titanotherium this facet is .small. The astra-
pilixmls»id hu-*'t is much smaller than that of Titanotherium, and con.sequently the
navicular is less nslneed tlnin in the latter genus. A small contfict takes place
Ijetwixm the cnlMii«l and inetatansal III. The cuboid is rather narrow and high.
.\ small lihnlcM-alcaneal facet is developed in Palceosyops, but there is no tibio-calca-
neal conta<-t. 'I’he gap Is^tweeii the a.stragalus and calcaneum is very small in the
Pahrosyopitue, and the astragalar ti*ochlea are deeper than in the Titanotheriince.

sVXO|>SIS OF TIIK (iK.XKK.V OF THE PAL.EOSYOPIX.E.

I. .Ml thns* inci.‘<ors pres<*nt in each jaw.

.\. External hiU's of snp. molars very oblique and

shallow.

1. L.\MBr)OTnERIU.M.

M. External IoIh*s of sup. molars straight and deep.

a. premaxillary symphysis short and round,
last snp. molar with two internal cones
last Slip, molar with one internal cone

2. Limnoiiyops.

3. Palaiosyops.

h. premaxillary .symphysis elongate and
narrow

4 . Tp:iAr ATOTIIERIU.M .
0. HaPLAC0D0X.(3)

Ml. Only two ineism-s pi-es<*nt in each jaw .

The aliove analytical table of the genera of the Palceosyopince differs radically
fnaii the hist table of the propo.sed by Professor Cope'; of course this

.hflereiiee is due to the di.s<-overy of the i«xsition of Chalicoiherium.

PAL.EOSYOPS LEIDY, AND- ITS ALLIES.

277

PAL,E08Y0PS.

Syn. {Liiiiiioliijits — JIaxtili.)

The dentition of Pala:osyops lias been partially described bj^ Leidy, althongh
liis descriptions are faulty in not indicating distinctly the sjiecific difference betAveen
the species. lie Aras either not familiar AAutb the genus Telmato thorium, or con-
sidered it the same as Palceosyops, for in the material described liy him there
are no teeth AAdiich can be referred to Telmalotherium. Leidy, in giA'ing the
dental character of his tiim species of Palceosyops, seems often uncertain under AA^hich
.species he should place ncAV material, and is constantly doubting their specific dis-
tinction. He has given us a tolerably full account of the dentition of P. minor,
but he compares the dentition of P. paludosus with that of the former species, and
speaks of their A^ery close similarity in dentition ; liut ho does not point out fully
the specific characters of each s^iecies. Tlie following generic characters are mainly
derived from the typical species — auz : P. paludosus.

Generic Characters : — Dentition : — The incisors in this genus form a closed
series, their croAvns being short and triangular in outline. The posterior face of the
incisors is not deeply excaA'ated as in Telmatolherium, and there is no prominent
basal ridge as in the latter genus. The diastemas betAveen the canines and incisors
may be large, but the posterior canine diastema is generallj^ Amry small.

The canines are A’ery large, bear-like tusks, aud round in section. The croAAUAS
of the upper premolars are loAver than those of Tehnatotherium, and their external
lobes are less acute. The first premolar is much simpler than that of TelmatotJier-
lum. The second has a aa'cII dcAmloped internal lobe. In the last tooth of this series
the external lobes are generally separated by a median buttress, which is Avanting in
Telmatotherium. In the less specialized mendjer of the genus the transAmrse diam-
eter of pm. 4 and m. 1 is considerable. The intermediate conules of the premolars
are generally Avantiug. In the inferior premolar series the first tooth is quite
simple in structure, having no prominent licels. The second has no rudimentary
internal cone as in some species of Lambdotlm'him, and its anterior cone is larger than
the posterior. The fourth inferior premolar diflers from that of Telmatotherium in
being simpler in structure. The superior true molars have low croAvns and their
transverse axes exceed the antero-posterior. The external V’s in this genus are
round and narroAV ; their anterior buttress is very prominent and the median buttress
is not strongly constricted off. Prominent ribs may lie present in . some of the
species of this genus on the external face of the superior molars. In contrast to
Linmohyops oulj' the protoconules are developed on the true molars, the presence
of a metaconnle being a A'ery rare occurrence in this genus. The internal cones of
the molars are round, blunt, and the hypocone of m. 1 and m. 2 is more strongly de-
A^eloped than in Telmatotherium. The last superior molar has only one internal
cone, but traces of a hypocone may be present on this tooth. As a rule nearly
-all the species in this genus have, the external cingulum Avanting. The inferior

A MK.MOIK ri’ON THE GENUS

inular,. Imv.- iiin.-l. and less specialized crowns than in Telmatotheriim.

'Fids applies rs|H-.-ially to the \'’s, where crests are less developed than in the former
>r.-iiiis. 'I'll.- last iidVrior molar is short, broad and its tubercle may be highly

f>|M‘4-iali/e«l.

'I'll.* skull may under>ro various moditicatioiis as to form in this genus. It is
griiendh much eloiipitml, with the facial portion short and the zygomatic fossa
cloiipitisl, thus hriugiiig tjie orhit well forward over the molars. The premaxillaries
an- highly «-hani<-teristie, Is-iug short, coinpres.sed and with a small round median
sMiiphvsis. The ua.snis aiv shorter and broader than in Limnohyops, but not so
Mnaigl\' an-he«l lat«-rall\- as iu Telmatotheriiitu. The occipital crests are well de-
velo|M-«l and the zygomatic arches may undergo considerable variation as to develop-
ment. Till- auditory pna-e.^^es are distinct, the post-glenoid Ixdng generally
(-loiigaUti. The jaw symphysis is short and not horizontally placed. The inferior
Imnler of the jaw is stnuigly iueurved.

The liraiii is of a low type, with the subdivisions well separated. The
rrn-l»niiu is small, hut convoluted. The mid-brain was probably partially ex-
|s*Msl. 'rill- ecn-lM-lluiu is very broad transver.sely, being as broad as the hemis-
phen-s. 'I’lie olfa<-tory 1oIh-s weiv very large and extended considerably in front
of the c«-n-l»rum. 'flu* characters of the axial skeleton re.semble closelv those of
tin- Tapir, although the zyga|M)physes (»f the posterior dor.sal region are involute in
fonii. 'I'he iiiaiius is short and hn)a<l. The distal facets of the lunar are subequal.
Tin- magnum is broad and not high. The metapodials are short and broad. In the
tarsus the astragaliM-ah-aueum fa<-ets are generally widely separated, but consider-
able variation may Is- pres«-ut iu this re.sjx*ct. There is a large astragalar cuboid con-
tact. I In- contact l)etw«H-u the culsad and metatar.sal III i.s, as a rule, wanting.

I he |M-lvis was short and broad. The ilia^ were not subdivided, being Eh ino-
•H-nitie ill fonii.

svNofsis OF TiiK .si-kcif:s of the genus paueosyofs.

A.

Am-eiidiiig ramus of mandible short.

1. Na.sals not expanded distally.

a. !siz«* largi*.

liilerior molars stout and broad, posterior tubercle a cone. P. paludosiis.
Interior molai-s high and long, posterior tubercle a cone. F. vallidens.

b. Siz** iiieilium.

Su|H-rior pn-molar 2 with one external lobe
Su|H-rior pn-molar 2 with two external lobes

c. .<ize small.

Su|H-rior pn-molar 4 with a protoconule
Na.sals expanded distally.
n. Size medium

P. laevidens.
P. minor.

P. borealis.

. P. megarhinus.

PAL^EOSYOPS LEIDY, AND ITS ALLIED.

279

B. Ascending ranms of mandible very long,
a. Size inedinin.

Inf. molars stout and broad, posterior tubercle a lobe. P. longirostris.

PALaCOSYOPS PALUDOSUS.

(P. major Leidy) (Limnohyud robushis Marsh.)

The description of some scattered molars of this species by Leidy' in 1870 is the
fii’st indication we have of the existence of this subfamily. Later, in his “ Extinct
Vertebra ta of the West, ” he added largely to his above preliminary notices, and
compared the teeth of this species to his P. minor, but did not give a full descrip-
tion of tlie dentition. Leidy’s later material Achicli he referred to this species,
largely consisted of lower molars,” the material for the superior dentition being
rejjresented by scattered molars oidy. Scott and Osborn^ in their report de-
sci’ibed the canines and incisors, and referred to Leidy lor further particulars as to
the dentition in this species. Cope also follows the above authors and refers to
Leidy’s description. As this, in some respects, is the most important species of this
sul:)family, and a large collection of the teeth being in the Princeton Museum,
I shall give the descriptions of its dentition in detail and point out especially its
specific character ; I shall also dwell largely upon the variable characters of the denti-
tion exhibited by this species.

General Description of Dentition. — There are two very fine specimens of
portions of skulls of this species in the collection ; one containing both the upper
and lower series of molars (No. 10.009). The other specimen is a part of the facial
region of oJie side complete (No. 10,282 b), A\diich has the incisors and molars
in a very good state of preservation. These two skulls are very interesting, as after
a close study of their characters I can find no specific ditference between them ; bnt
they exhibit certain variations in their dentition, especially in relation to the size of
the teeth and the unAvrinkled condition of the enamel. These differences I consider
as a sexual variation, and in describing the dentition of this species, I shall refer
to the variation shown by the male and female respectively. An attempt to de-
scribe the dentition in both sexes of a fossil animal is, I think, quite a novelty, as
the investigator in this branch of science sees very little mentioned about sexual dif-
ferences..'* I imagine in a great many cases we may have different species described
under the same genus, whereas really they may be only sexual differences of the
same species.

The superior incisors in this species are arranged in a semi-circle, the in-
crease in size being from Avithin ontAA'ards. The external incisor is separated from
the canine by a diastema. The incisors in this species differ from those of Telmato-

iProc. Acad, of Xat. Scien. Phil., 1870, page 113.

^Extinct Vertebrate Fauna, etc., plate 24, figs. 1 and 2.

®E. M. Museum Bulletin of Princeton College, 1877, page 28.

^Marsh’s Monograph of the Dinocerata.

A MEMOli; UPON THE GENUS

2.HII

iherinm in that l^.tli tliair anterior and posterior siirtaces are convex, and there is
no pniinineiit hasal riflge so eharaeteristic of tJie incisors of Telmatotherhim.

'riie incisors of the male (No. 10,282 h) are larger and more massive than
ihos*- of tin- female (No. 10, <109). In tlie male the external incisor is a very power-
ful tisith, with a very thick and wide sj)reading crowm. The diastema separaP
in^' this t<s>th fn*m the canine is larger in the male than in the female. The canine
4if the male is a huge Is-ar-like tnsk. It is round in section, its posterior face exhibit-
ing a slight longitudinal ridge. The diameter of the canine in the male is much
great«-r than in the female, and its section is rounder. The post canine diastema
in ls»th s4-.\es is als»ut equal. The total measurements of the superior molar series
<»f /'. fHiluiiosus show a gn-at range of variation, and the accompanying table will
ilhistnite this j>oint. We ma\ consider the extreme forms of this species as varieties.

'I’vm.K OK MK.VSrnKMKXTS SnoWI.VfJ THE VAKIATIOX IX THE HEXTITIOX OF
PaI.-KO.SYOI’S i’ALUlXISUS.

Kiilirp inoUr

I j-iiBlh of iimiiolno ....
l»-iii{iti of ini)' niitlnrH

, ( initiM.

iiioUr ;t ■

( ■llt.-lHWl.

^ . f in«nii ....

niular 1 •

( niil.-IHixt.

iirrmotiir 4-1011111
-'Up po'niuliu- l-lnnin.

K.iaitr molar M-rics (Inf.)
l‘o'mi>Ur . (“)

Tmo HMilar lirri*-*! (“)

^ ( Imiia.

I atil.-|Mif>i. .
mip. canino
Sop. po'-oininc illai't.

.-op |,w| "

l•••t. lolion-lc inf. inolnr .T f

( nnl.-iKJut.

Inf molar 3 1

No. 10.27(!.

Lekly’s fig.
of skull.

No. 10,009.

No. 10,282 b.

No. 10,118.

•1.5S

•162

•172

•178

(Hi.)

•070

•074

•0!».")

•100

•102

•105

•(Ml

•043

•044

•046

•0.TS

•040

•039

•042

•o:tl

•031

•03.5

■o;!0

•032

•032

•02(i

•025

•027

•00.S

015

. - _

■

•I'H)

•187

!

•082

_

,

■112

•107

■ _ -

•105

•025

•024

•020

•051

■047

•048

—

•020

•025

•010

•013

■Oil

•010

•012

.015

•013 J

•013

gn-ater than in tin. i 1'/^^ '^anation in the size of the molar series is

shows .a,n«i<lcrahle ilifll-micr’ premolars also

.av./iAa4. y,t. JJUTlXiUiai I

-the first superior premolar in the female is very

111..I0 tlii, i, voIt I"*'

•liaiiii-l<.r i, v>.r.) ,-i,.„tcJiu|,,uvd to' * oomc®! in fonn its transverse
i.H 1-4.11 vex. the inner one Ix-ino- slier] +1^ ^ ^“^i^idual of this siiecies; its outer face
'xmg slightly concave. The premolar 1 is placed close to

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

281

the second, there Ijeing no interval between the teeth in the superior series. The
second preniolar is a triloliate tooth, its external lobes being eqnal, as is generally the
case in all the superior preniolars of this species.

The third preinolar differs from the foregoing in being larger ; its crown is
higher, and an anterior buttress appears for the first time. The external lobes
in this tooth show no signs of separation. The fourth premolar is an enlarged
representative of the preceding tooth with fhe addition of an enlarged anterior
buttress, and the separation of the external lobes by a well marked median
fold. The anterior border of this tooth is nearly straight. In the preceding jjre-
molar it is very oblique. In all the premolars of this species the internal
lobes are conical, shoAv little signs of becoming concave externally, and
have sharp lateral crests, as is seen in Tehnatotherium. The intermediate con-
ales are absent on the premolars of this species. In the male the preniolars
have the same general characters as already given for the female, but the trans-
verse diameter of the third preinolar is much less than that of jiremolar 4. Its
form is much more nearly square than that of No. 10,009. The last premolar in
this indi\adual is a larger tooth than in the female; although, as is always the case
with this species, the transverse diameter of the last premolar is less than that of
the first true molar. This tooth in the male has its form more nearly rectangular
than that of the female. In Professor Cope’s collection there is a series of superior
molars of this species in which the premohars have much higher crowns than in the
Ih’inceton examjjles; the external lobes are sharper and in the last premolar
they are not separated -by a median buttress. All these characters point to the
genus Telmatotherium, and we may consider this specimen as intermediate in char-
acter between the typical examples of P. paludosus and Tebnatotheriiim.

Another character of Cope’s specimen is that the superior jjremolars 2 and 3
have complete basal internal cingula. In all the premolars of this species that I
have examined the basal cingula are incomplete. This only proves what a variable
character a complete or incomjilete cingidum is, and that it cannot be used for specific
definition. We may add that in a species of Hyrachyus which I have examined, the
same jnemolar of opposite sides had on one side a complete cingulum and on the
other side the cingulnm was inconqilete.

The superior molars (Plate XII, fig. 17) in this species are large, with veiy
low crowns and their tran.sverse diameter exceeds their antero-posterior. They
differ in this respect from those of Telmatotherium in wdiich the form of the
molar is nearly sc^uare. In the latter genus the crowns of the teeth are very high.
In this species the external V’s are very strongly developed, although they are
much narrower and more concave than in Tehnatothermni. In some molars a
median fold is present on the anterior V, although this is a variable and a primi-
tive character. The buttresses of the external faces of the molars are very large ;
the anterior is widely jJi’olonged beyond the posterior limit of the one in front ; the
median buttress is low and jiromiuent, but not constricted off so much from the

A MK.MOIK Ul’ON THE GENUS

ill TehnaloUieriiini and tlu- smaller species oi Paiceosyops. The chacraters
oftla- rvtiTiial Inls-s and Imtlivsses in tliis species offer a sure means of distinguish-
i„g it Inmi tl...s.- of the s|H-cies of Tehnatothermm.

'riie pn-s«-nce of tlie intermediate conules is very characteristic of this species,
and ii|H.n earli iipia-r true molar a protocoiiule is always present. This lohiile in
Palteosyops piiltuhsus is ver\- larga- and prominent, especially on superior molars 1 and
*J. In tin- last iipia-r molar the protocoiiule is much smaller, it being largest on
molar I and d«*<-i-easing |M)steriorly in size. There is no metaconule on molars 1 and
•J. although this roiinle may Ik- jnv.sent on molar 3. In the collection of the Prince-
ton .Miih-iiiii there is a very inteivsting hmt upper molar, (Plate 12, fig. 18), which
ha.H Isith the intermediate coiinles strongly developed, especially the protocoiiule,

whieh is with the anterior cingulum by a prominent prolongation. In

this molar the ext«-rnal Vs are rather irregular in form, the anterior one having
a iiroiiiineiit iiH-«lian fold. 'I'liese characters are more primitive than those found in
a tvpieal molar of this siK-cies and point to Lambdol/ierium, where the external
lols-s «if tin- molars an- not as highly differentiated as in Palceosyops. The external
fare of tin- true molars is totally devoid of a cingulum, a character which readily dis-
tinguishes this s|H-eies from P. minor.

'Pile pn-senee of ail (-xteriial cingulum is a prominent character in the denti-
tion «if /*. minor. 'Pin- anterior (-ingulum is very strongly developed in this species;
it t’orius a v»-ry pnimiiient transverse ridge, distinct from the protocoiiule of the
molar. Is-lng eontiuinais ant«-riorly and e.xternally Avith the large anterior buttress
so cliaracteristie «»f this s|H*eies. The internal cingulum of the true molars is only
very slightly develo|M-d. 'Phe internal cones of the molars are large and rather
sharp : t In-n- an- no signs 4>f (-onnectiiig ridges betiveen them and the external lobes
of the luolars.

I In- h\ |MK‘<ines 4»f nndars 1 and 2 are rather large and not placed tio far
iN-liiinl and to the inside as in Pelmatotheritu}!. The jiresence of a small rudimeiit-
nrv 4-ouule (h \ |MK-one?) n|Nni the last ujijier molar of this species is not uncomnion.
W V hav4> such an (-.\aui]de in the Princeton collection on No. 10,276. The fine
series ot up|M*r molars ol this sjH-eies in Professor Cope’s collection also show a small
hy|NN-one u|Min the last molar. The di.scussion of this character and its relation to
the t\viM-«>ne«l h»nu «»f molar occurring in Limnohyops will be considered under the
In-a.l ..r I hat g4-nus. I may ineivly add here that Marsh’s L. laticeps is very closely
n-lat4Ml in its .h-ntal characters to P. pahidosus. The two series of molars
that hav«- Ikvii (le.scrilK-d under this species as belonging to the male and female
n-s|H-«-ti\.-ly .iffer no other iK-culiar characters in the conformation of their lobes,
hut III the condition of the enamel they present a striking difference, in the fact
that 111 the sup|M).m-,l male the enamel is strongly Avrinkled, Avhereas in specimen
No. HMHi't (HupiMised female) the surface of the enamel is perfectly smooth. This
ra< t< r is an iin]M)itant one as Cope', in his simcific table of this family,
'Torliary jiagt- aw.

rAL.EOSYOPS LEIDY, AND ITS ALLIES.

283

considers the condition ottlie enamel as a specific character. From the aljiindance
of material of P. pahidosiis in the Princeton collection, I can positively state that
wrinkled or nnwrinkled enamel will not hold as one of the specific characters of this
species, as we have teeth showing all grades of wriidding in the same species. The
larger molars with strongly rugose enamel, 1 believe very probably belong to the
male, whereas the smaller and smoother enameled molars probably pertain to the
females.

I should add also that the wrinkled condition of the molars in this species is
not dependant upon age, as the two series of molars show about the same stage of
abrasion.

Fiocek ]. Second suipcrior niolur; 1. Pahv()«yop-t pnliuliixus. 2. LiiiiiuihyapK Iriluyps. 3. Paheogy/rps
minor. 4- Trbnatntherinm rnUriden.'t. Two-thirds natural size-

j(a.=paracone, nie.=metacone. pr.=protocone, hy.=hypoeone, pl.=protoconulc, nd.=inetacomile.

Inferior Dentition. — The lower incisors tire tritingular in form, and are without
the internal basal ridge wliicli is so charticteristic of these teeth in Telmatotherium.
Their position in the jaAV is al.'<o much less procumbent than in the latter genus.
There was probablj^ no precanine diastema in the lower jaw of this species. The
lower canine is very large, and less divergent than in Telmatotherium. The canine
is ititernally flattened, the external surface being convex Avith prominent anterior
and posterior cutting edges. The first premolar is placed close to the canine ; it is
a single fanged tooth Avith a conical croAvn, the posterior portion of the same shoAV-
ing a slightly enlarged heel. A considerable diastema intervenes betAveen premolar’s
1 and 2 in this specimen (No. 10, 009), although this appears to be a A^ariable
character, as in the Cope collection there is a mandible of this species in Avhich
there is no Avell marked diastema in the lower jaAv. In premolars 2 and
3 the protoconid is much larger than the hypoconid, although the protoconid
of the second premolar seldom reaches the large size that it does in Telmatotherhim,
Avhere the tAVO cones of tliis tootli show a much greater difference in size. In the
last premolar the metaconid is Avell developed, and also the anterior crest of the
V is Avell shoAvn and joins internally a small paraconid. In P. paludostis the last
premolar is a less highly developed tooth than in Telmatotherium, as in the latter
genus both V’s of the last premolar are Avell expressed, the jAosterior crest of the
posterior V being Avell differentiated in T. cidtridens, Avhereas in P. pahidosus this is
not the case ; in other Avords, the last inferior preniolar in Telmatotherium has almost
assumed the form of a true molar, but the entoconid is still Avanting to form the
double symmetrical V’s of the true molars. Both the internal and external face of

38 .TOUB. A. N. S. I’lIILA., VOL. IX.

A MK.MOIli UPON THE GENUS

tl... i.n-iiiolurH aiv without i-ingula. The crowns of the inferior molars of P. pdu-
iiosusxxn' low aii.l very l.road, they differ in this respect from tliose of Telmatothe-
num, when* the form Id' the molar is very hish and elongated. The valleys between
the IoIm-m in this sis-eies ai-e shallow and the molar cusps do not project so much
ulsive them as in those of Tehnatotheriuni. The crests of the V’s are weakly
ileveloiMtl and «lo not present such sharp cutting edges as seen in the last mentioned
genus. We have in the last inferior molar a very characteristic tooth in this
sjH-ei.*s. ami one which readily di.stinguishes it from P. ininar and the differ-
«*nt s|H*«-i«-s of Telniatotheriuiu. In the typical form this molar is unusually broad and
heavv ; its en»wn is very low comi)ared w'ith that of Tebnatotherium. The posterior
tuU-n-le of the last inferior molar is simply a small cone placed in the middle axis
of the tiM>th, ami is connected with the entoconid of the molar b\' a feebly marked
rn‘st. A lower jaw of another individual of this species, No. 10,118, shows consider-
able variation in the characters of the last molar. In this specimen the crown of
the t<M)th is much narrower, and the diameter of its posterior tubercle is nearly as
gnait us that of a whole t«s)th. In this variety the posterior tubercle is still a cone.

I have ex'uinined at least si.\ jaws of this species, and they all correspond in the
linaid form of the molars and small .size of the tubercle of the last molar.

'Fkkth .Mk.vsi-kkmk.n't.s ok Pal^osyops and Limnoiiyops.

l*|l|HT JbW.

P. puludustw

L. laticeps.

j P. Isevidens.

P. raegarhinu

j| P. minor.

Knllrp iiMilar PBritw

•172

•155

•140

•148 ~

1 -153

of tnip uioIbth

102

•095

•085

•085

' -085

•070

•064

•056

•066

• -066

, . i •™ms- •

■024

•026

•022

•021

( an(. |Minl.

•021

•020

•019

—

•018

M-OBrll'""”

1 -(KIO

•031

•029

•023

(■III. IHWI.

j -osi

•030

•026

•025

%i • of irniui ....

Molar .I 1

( 044

•045

■036

•039

•035

1 ant. |Kwl.

■o;m

•041

■039

■037

■036

ir/mr Jaw.

Knliir inntar M'rirw

•187

•157

la>ninli of pn'molars

•082

•063

l.t'nfftli of Inis iiiolarH .

•107

•100

VI ■ of •rsns

M<4ar .It

•024

•020

( ant. iMmt.

•047

•040

Molar 3 tula-rrln |

•012

■010

( ant. ixwt.

Jaw

•013

--

--

•010

Total lonxtii of Jaw

•364

•300

•068

.060

Ivptli twlow last molar

ls<n«lh of symplimia

ilnwith of symphysis below Ist

•075

•085

premolar ....

•067 1

1

--

PAL^EOSYOPS LEIDY, AND ITS ALLIES.

285

Tlie variety last described, No. 10,118, we may consider as an extreme form of
this species, aiid we shall hereafter see when treating of P. vallidens, that in the
latter species we have intermediate dental characters ])ointing to the species nnder
consideration.

The Skull. — (PI. 10, fig. l.)The skull figured is a composition of the two very
fine specimens in the museum of the Academy of Natural Sciences of Phila-
delphia, figured by Leidy in his work ; they are an occipital region and a facial por-
tion of a skull from another individual. The restoration of the lower jaw is
derived from the fine mandible in the Princeton collection No. 10,000. Leidy'
has already given us a restoration of the skull of this s])ecies in his report, but in
some respects it is rather exaggerated ; for example, the occipital region, in com-
parison with the facial, is too high ; the anterior portion of the temporal fossa is
too much excavated, and the curvature and form of the zygomatic arch is incor-
rect. The general dimensions of the skull of this species as compared with that
of the Tapir are very much broader and heavier, although their anterior and pos-
terior dimensions are about equal. The facial axis of the skull was probably
slightly bent upon the cranial. In the Tapir on the other hand, these axes are in
the same straight line. The form of the facial region is very different from that of
any living Perissodactyle, as on account of the long and overhanging nasals it gives
this portion of the skull a different aspect from that of the Tapir, where the
nasal bones are much abbreviated and reduced.

The facial region of the skull is rather compressed, with a convex supe-
rior surface Avhich gradually rises to the interorbital region. The latter
portion is very much expanded and is depressed between the orbits, which
form an abrupt concavity, from which posteriorly the froutals rise suddenly
to form the much enlarged forehead so clniracteristic of this species. The gen-
eral form of the cranium in P. paludosus in many respects resembles that of
the Tapir ; that is to say, the frontal region is higher than the occipital, and
forms a high and flat forehead traaisversely, being strongly convex from
before backwards. The post orbital processes of the frontal are largely developed
in this species, and the anterior temple ridges rising from them are very prominent.
The surface of the skull between the temple ridges is very broad and slightly con-
vex. From the interorbital region the tem])le ridges converge, but do not meet
to form a sagittal crest until near the junction of the latter with the occipital
border. The lambdoidal crest is well-developed in this species, and extends later-
ally as far as the exoccipital region, but it is not nearly so much developed as in
Limnohyops where it is very heavy. The occiput of P. paludosus is much
broader than high, the portion above the foramen magnum being directed forwards.
The superior portion of the occiput is concave and overhung by the lambdoidal
crest. Viewed from the side, the skull shows nearly the same position of the

’See Report U. S. Geol. Surv. of Terri, for ]873-Pl. xxxi.

A MKMOlli UI'OX TJIE GENUS.

orbit tlo- 'I’apir’H HkuH. 'I'lu- orbit is sitiuited slightly in advance of the
middle of the skull, its anterior termination being above the middle of the second
umh'ir. In the 'Ihipir the orbit has a slightly more anterior jiosition, its anterior
limit IsMiig alsive the first true molai.

'I'he orlut in this s)K*eies is small and bear-like; it looks more forward and
outwanl than in the 'fapir’s skull, and is separated from the temporal fossa by
nstn.uglv iiiarktHl inistorbital priM-ess. The antero-posterior extent of the tem-
|s.nd ro.«su is very gn-at, and its height at the middle is very much greater than in
that of tlie 'rapir: the external surface is deeply concave, its middle por-
tion at the fnmtal .sipiaino.sal sutinv being slightly convex. Comparing this
n-giou with that of the Tapir’s skull we see how' much more reduced the cerebral
volume must have Is-eii than in the Tapir. Superiorly and anteriorly the
tem|s.ral ridges overhang the temiMiral fossa very prominently. Comparing the
si-Ai* ami form <d* the tmu|s)ral fossa in this species Avith that of the living Cami-
vop's, wv find that the lateral convexity of the w'alls and the reduction of the crest
ill the hitt«-r are much less than in Palceosyops pahic/osus, and it is not until we go
lnM-k to the FxH-eiie CnsHloiits, that we .see a like reduction of the brain, and a con-
('omitaiit diH'|H-uiug of the lateral cranial region of the skull. In the form and
weight of its zygomatic arch this species differs wn'dely from recent Perissodactyles,
mid iippniaches the Caruivoi'es, although we have yet to see one of the Felids
ill which the zygomas an* as strongly developed as in P. paludosus. The zygomatic
arch ill this s|M*«'ies is very strongly compressed, its posterior portion is Avidely set
off from the t<'m|Hiral n*giou of the skull, and in this character approaches that seen
ill the Ik'iirs. 'file middle |M>rtion of the arch first de.scends, and then gradually
iiMiMiils to tin* strongly compn*ssed and plate like malar portion.

The palate iii this s|K*cies is flat and broad, and its roof is not so coua'CX as in
that of Tclniatotheriiini. 'I'he posterior extension of the palate is to the posterior
lionler of the s4><*oiid molar. 'I’he basioccipital region of the skull is very broad;
mid this is »*s|K*eially marked betAveen the jiostglenoids, Avhere this region is nearly
twice ns broad as in the 'I’apir’s skull. Like that of recent Peri.ssodactyles the
Interal |Mirtiou of this region is proA’ided AA'itli large A’acuities Avhich lead into the
ermiial cavity .

Prenutxtllartes. — 'I'he pivniaxillaries in this species are shoid, rounded and
stnmgly depn's.sed. ^ icAviul fnmi the front these bones are coiiA'ex and shoAV no median
k€*i*l, the pp'simce of Avhich is .so characteristic of megarhinus. The outline of the
pp'iiiaxiliaries fnmi Isdow is round; posteriorly they^ send ofi’ tAA'o horizontal max-
illary pr«K*e.ss«-s including IndAveen them, and upon each side, the .separated incisive
foramina. this n>gion of the skull in Palceosyops paludosus strongly' resembles
that of the (’ariiivoivs in form; it is broad and short as in the latter order. In
the skull of the Ikmr the premaxillaries are prolonged farther upon the palate than
III t u skull of f . paludosus •, in the latter they are A'ery short and do not extend
farther u|kui the jialate than a line drawn between the anterior border of the

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

287

canines. The premaxillary symphysis is round and short in this species ; its fyrm
is in strong contrast to that found in the allied genus Telmatotherium, where the
symj)hysis is much elongated and narrow. The premaxillo-maxillary suture is
situated about midway between the outer incisor and the canine ; its superior
termination is on a line with the posterior border of the latter. The nasal notches
in this species are moderately deep and their upper and lower margins are less
sinuous than in P. megarhinus. Above, the broad plate-like nasals form the roof
of the nasal cavity, being prolonged anteriorly as far as the premaxillary suture.
The premaxillaries form the lower half of the nasal notch, the latter terminating
above the anterior border of the third premolar. Tlie portion of the skull between
the superior termination of the nasal notches and the orbit is elongated and
broad. In the Tapir, owing to the great reduction of the nasals and con-
sequent posterior prolongation of the anterior nares, the lamina between the orbit
and nasal cavity becomes very narrow and is bordered internally by a long ascend-
ing 2)rocess of the maxillary, which, in the skull of Palceosyops paludosus, is very
short.

Nasa/s. — The nasals are very broad in comparison with their length in this
species. They were not coosified, and not nearly so strongly arched laterally as in
Telmatotherium. Their superior surface is convex and their external border in
front is curved in outline, terminating at the • free extremities in rather pointed
and rounded borders. The posterior portion of the nasals is very broad and flat.
The posterior terminations of the same Avere probably on a line with the anterior
l)ortion of the orbit, although in the skull under description the facial sutures are
badly damaged.

Frontals. — The frontals have a more anterior extent than in the Tapir.
Their anterior prolongation is probably as far as the anterior orbital region.
There Avas probably no articulation betAveen the frontals and the ascending pro-
cesses of the premaxillaries, as seen in tlie Carnivores. The frontals send doAvn
very large postorbital processes, but they do not meet the ascending process from
the malar. It is impossible to determine the relation of the frontals to the bones
of the lateral sphenoidal regions OAving to the damaged condition of the skull.
Posteriorly the frontals extend on a vertical line with the posterior inferior mar-
gin of the temporal fossa. The extension of the frontals posteriorly is the same
as in the Tapir skull, and differs from the frontals of recent CamAores where they
extend to the middle of the temporal region.

Parietals. — The parietals form the largest part of the temporal fossa, but do not
extend so for beloAA" as in the Tapir. Their surface is deeply concave and at the
posterior part of the parieto-squamosal suture a number of postparietal I'oramina
are present. In the Tapir’s skull the parietals are preAmnted from articulating Avith
the alisphenoids by the articulation of the squamosals Avith the frontals. The con-
dition of the skull under consideration does not allow us to determine this point.
At the posterior superior angle of the temporal fossa the edges of the parietals

A MK.MOJK UPON THE GENUS

Uiiiti* to ron.i tl.f v.TV pn.iiiiiH-nt sagittal crest wliicli medially contains a deep
unM.ve 'I'he sagittal m-st only extends about one-tliird the length of the parietal
ns.f iM-fore it diverges int<. the anterior temporal ridges already ^pferred to.

The 8upra4K-cipital region is triangular in outline, and bordered by
the proiiiin.-nt lateral crests. Its surlace above the foramen magnum is very promi-
ii.-iit, ami hn-iiis lati-rally strong ridges on each side for muscular attachments. Supe-
riorly this n-gi'‘» iH-comes concave ami is not widely overhung by the lambdoidal crest.
The'most sniM-rior and isisterior part of the temporal fossa is formed by a portion
of thesupnuH-eipital. 'I'his is a character common to the Tapir’s skull but is absent
fn.m the skull of the Uarnivoivs, {Ursus). The lateral extension of the exocci-
pitals is verv gnmt in this species, owing to the extreme width of this part of the
ts-eipiit. 'rite lateral jiart of the exoccipitals is bent slightly forward fbnning an
angle with the imalian jHirtion of the same. At the posterior inferior angle of the
«K-eipiit tlu> large pans-cijiital proce.sses are given off. These proce.sses in this
s|Ka-ies an- cpiiti- diflen-nt in form from those of recent Perissodactyles, and they ap-
pn»a«-h thos«- of Rhinoceros in form more nearly than tho.se of the Tapir. The
pans-eipitals an- very hmail and heavy and they terminate below in a styloid process
which pndtulily «lid not extend iM-yond the condyles. The external borders of these
pnK-«-ss4-s «-«»im- in contact with the |«)st-tympanics of the squamosal. At the upper
part of the jnm-tion of the panK-cipitals and post-ta mpan ics there is present in this
skull a Iarg4- foratnen leailing into the cranial cavity (parama.rtoid). TJie presence
4if this foraim-ii is a constant character in the skull of the Tapir and Khinoceros
In litfnns this foramen, if pn-.sent, is not well expressed. In the Dinocerata the
|uininnistoid foraim-n is pn-s(-nt and is placed in nearly the same position as in
I'ttl<rosyof>s.

Tin ndyh*s in this s|H*cies, as in all the other species of this genus, have a

gn-at tmnsv«-rs«- ext4-nt ; viewe<l from the side they project much farther behind
than in tin- 'I'apir’s skull.

The |Mirtion of the (K-cipnt la-aring the condyles is, as it were, much constricted
from tin- iN-eipnt. thus pHslucing the very prominent aspect of this part of the
skull. I In- anterior and inferi»n' ends of the condyles are separated by a longitudinal
imteh ; hut on *-aeh side a tongue-shaped process from the condyle extends a short
(listain-4- n|Mni tin- basicK-cipital. The foramen magnum is oval in outline and
very long transvei-st-Iy. In the skull figured by Leidy, the foramen magnum has a'
inneh gn-at4-r transver.s4- extent than in that of the Tapir. The general form of
this forann-n n-.st-inhles clo.st-ly that of the Carnivores, being squarer in outline
than in Jo/nrus, with its sujx-rior lM)rder deeply incised and bordered upon each side
hy fw«i pniininent convex pnK-esses abutting against the continuations of the' ex-
•Htdpitals. I he basioccipital with the basisphenoid forms a broad triangular basal
axis to the skull and their junction is on a line with the glenoid facets. The basi-
•K-tipital is \erv hroad po.steriorly, the anterior portion having a very prominent

289

PALyEOSYOPS LEIDY, AND ITS ALLIES.

median keel, bordered anteriorly and laterally by prominent rugosities. Laterally
the surface of the bone is deeply excavated in a longitudinal direction. The lateral
extension of this region is much greater than in the Tapir’s skull. The basisjihen-
oid is much narrower than the basioccipital and terminates on a line with the pos-
terior opening of the alisphenoid canal. The posterior wing of the basisphenoid does
not extend as far behind as in the Tapir’s skull, and the portion of the alisphenoid
between the glenoid and the alisphenoid canal is broader than in the latter.

iiGURE 2. — Comparative view of the skulls of Palxosyops and Limnohyops- 1. Limnohyops laticepa.
S. Palxo-vjops megarhinus. S. Palseosyopspaliidosus^ 4‘ Pol^osyopslxvidens. One-sixth natural size.

Foramina — The condyloid foramen is distinct, and situated about an inch anter-
ior to the condyles. It is placed at the most anterior portion of the bridge of bone
connecting the basioccipitals. The anterior border of this foi-amen is very thin and
easily broken through to the lateral vacuity. The large lateral vacuity upon each
side of the basal region of the skull so characteristic of the Perissodactyles is very
largely developed in this species. It is divided by the petrous bone, but
the latter does not unite with the basioccipital, and consequently there is a
communication between the fr. lacerum posterius and fr. lac. medium. A
short distance in front of the vacuity and on a line with the glenoid cavity
is situated the separate and distinct foramen ovale. This foramen in Equus
and Tapiriis has fused with the fr. lac. medium, although in some species of Rhi-
noceros the anterior portion of the lateral vacuity is separated by a deeply situated
ridge of bone, dividing the foramen ovale from the fr. lac. medium. Just in front
of and below the foramen ovale is placed the large posterior opening of the alis-
phenoid canal, but owing to the damaged condition of the specimen we must leave the
description of this canal for another species.

290

A MEMOIR UPON THE GENUS

■ ThP nart of the squamosal bone forming tlm lower half of the
e .^q _ squamoso-parietal

kmipoi-al fossa is aigei . temporal fossa. In F. paludostts the suture is

s„turc. i, beWw . Ue “f" are .„ueh ferreted. The course of

i-oss.. T,.e

Ti.er,,,„u,tic,,r„ee.„ft,,e
0 losalis ver; strong aud placed rvidely out l.-o.n tl.e a.dc ol tl.e skull, umc ,
II sotbau any .eecut Perissodactyle. TW- portion of the r.ygoma tetweeu its
origin and bend is deeply concave and looks forward ; the posterior face ot it i Ha
aiiJ looks backwarf and dowuwanl. The external faee 0 the zygoma , p a d
obliquely and its surface is flat. The superior inlerior extent of tins part ol the
arch is viy large, and it develops a large surface for the origin oi the niasseter ninscic.
The articulation of the zygonnatic process and malar ,s very ohliqne and gradual.
The postglenoid pi-oces., is nii.cli elongated, with a distal rounded and rugose
extremity. It is bent slightly backward .and turned ontwani on its axis. ho
relation of the glenoid facet to the postglenoid process is very diflerent in this
species from that in the Tapir’s skull. In 7h/<r»,t the |K)stglenoKl is strongly com-
pressed and placed very ohllip.ely to the glenoid facet. The latter is narrow and
elongated. From the oblique position of these elements in the Tapir s skull, a deep
triangular space is left between them ; this space looks outward and backward.

In Palceosyops paludosns, owing to the more nearly ])arallel position of the
glenoid and its process, this space is largely obliterated. In the Uarnivores, where
the postglenoid process borders the glenoid facet along its whole extent, this
is still further the case. The glenoid facet in P. paludosus has very iiiiich the same
form as in the Tapir, although it is more transversely elongated and shows no anter-
iorly directed portion. There is no sign of an internal glenoid process in the skull
of this species. The post-tympanic process is much heavier than in the lapir;
its middle portion is compressed and distally it forms a club shaped extremity. 1 he
postglenoid and post-tympanic may nearly touch each other, although there is some
variation in the relation of these two processes. The periotic is placed deep within
the recess of the lateral space, its mastoid portion does not appear on the surface ol
the cranium, and its tympanic part was not ossified to the petrous portion.

Malar. — The form of the malar in this species is very characteristic, and it
readily distinguishes it from Telmatotherium.

At the junction of the malar with the zygomatic process of the sijnamosal, it is
strongly compressed and forms a broad lateral plate, strongly arched outward ami
slightly receding. The origin of the malar from the cheek is very gradual and not
abrupt, as in some species of Tchnatotherimn. The form of the inalar in this
species differs from that of P. megarhinus in having no broad and shell-like enlarge-
ment ; its inferior margin is sharp, rough and slightly incurved. The margin of the

PAL/EOSYOPS LEIDY, AND ITS ALLIES.

291

malar forming the inferior rim of the orbit is thick and rounded. At the posterior
inferior angle of the latter the malar is produced upward in a well marked post-
oi’bital process.

Maxillary. — The form of the vertical plate of the maxilhuy in this species is
more like that of the Carnivores than that of the recent Perissodactyles. This
portion of the cheek is elongated, being longer than high. The portion between the
malar insertion and the canine is flat and nearly vertical ; its interior margin, form-
ing the alveolar border, is only slightly rai,sed above the teeth. The superior part
articulates largely with the nasals, which send down broad maxillary processes.

Idle articulation of the maxillary externally with the frontals in front of the
orbit is ])rohahly very small. Anteriorly the vertical plates terminate in a very
prominent portion, forming the canine alveolus. The superior internal border of the
maxillary i'orms the upper half of the nasal notch. This margin is rounded and
slightly conciive, bordered above by the ascending nasal process of the maxillar}-.
The situation of the infraorbital foramen is just in front of the malar insertion ; it
is large and not exposed, and corresponds in position with tlie anterior border of the
first true molar.

The ])ortion of the maxillary forming the door of the orbit is short and broad ;
compared with that of Telmatotherium it is much less in its antero-posterior extent.
In the I'ccent Tapir the extension posteriorly of the alveolar portion ot the max-
ilhiry is verv great, but in Rhinoceros it is much less, and it is in about the same con-
dition in the latter form as in P. paludosus. In the most specialized Artiodactyles
where the oiLit is placed far behind, the roof of the alveolar portion of the maxd-
lary forms a small floor to the orbit, the large part of the orbit being opened widely

below.

In Palceosyops paludosus, owing to the very short premaxillary region and con-
seipient non-separation of the anterior premolars by a long diastema as in the Tapir,
there has lieen no i-reat drawing out of the alveolar region; and thus the roof of the
alveolar iiortion of the maxillary is short, whereas in the Tapir, owing to the extreme
length of the dental series, the alveolar border has been prolonged widdy posteriorly.

The /IiAiA’.— The form of the palate in this species is very bear-like. It differs
considerably from that of recent Perissodactyles, where the palatine region is
strongly prolonged forwards and compressed. As in the Carnivores, the hunt of the
palate is liordered by teeth all around its circumference, there being no considera-
ble interval in the dental series of P . paludosus.

In an example of a young specimen of this species in the collection, the palatal
region is not codsified, and the two horizontal plates of the maxillary form a
slight kool-like suture. As the pulate is preserved as far as the pesterior bonier ot
the Hrst true molar, .and it shows no signs of a transverse suture in its whole extent,
we can solely conclude that the horizontal plates of the palatines fonned only a
very small portion of the palate, resembling in this respect the palate of the Rhmo-

39 .rollR. A. X. S. PIIILA., VOL. I.V.

\ mkmoir upon the genus

wlu-n- llu. palulin™ , a, ly foi nUhe extreme posterior border of ^

l/W/zi/^— The lorni of the lower jaw of P. pahidosus belongs to the less
H.M^-iali«Ml tviH-of nmn.lihle limi.d .so generally distributed among Eocene forms;
that is the TsTtion Ix-aring the te-eth is more elongated than in recent forms, and the
Mirfac-e of the angular iHirtion of the jaw is correspondingly enlarged for muscular
attachment 'I'he external face of the mandible is nearly flat, becoming slightly
„„.ndar at the anterior Is.rder of the masseteric fossa. The inferior border of the
jaw is slightly a.scending fi-oni below the la,st molar. This portion is convex, becom-
ing .-oncave |K.steriorIv, and then suddenly expanding into the Avide and thin angle.
Tin- fonn of the inferior Isirder ol’ the jaw is very characteristic, and is quite differ-
ent fn.in that of Tclmalolhcrinm where the jaiv is straigliter, Avith a much more
..|..ngated symphvsial jM.rtion. The iiostm-ior half of the loAver margin of the jaw is
stn.ngly intlei-ti-cf; its inUwnal lime Ixdow the alveolar border is strongly convex, and
the loAviT isirtion of this liice thins out very niiich more than the upper part. The por-
tion of the jaw inferior to the last molar is very large and its angle is strongly everted.
'I’lie ina.-s«-t**ric fossa is not stnuigly marked, and the internal pterygoid fossa is less
develo|M-d than in the jaw of the I'apir. The middle portion of the ascending ramus
is very much hn)ader than in the Tapir’s juAV, and the condyle is placed farther pos-
ti-rioriv from tin* coronoiil priM*esst*s than in the latter. The coronoid process is
quite sle'nder. elongated and si*parated from the condyles by a long, slender
notcli. 'I’lie condyles an* much hniader transversely and heavier than those of the
'I’apir; they liave also not the ohlicjuc position as in the latter form. The angular
ridp* limiting the inass«*h*ric fossa anteriorly and becoming continuous Avith the
mronoid pna-ess alsive is very strongly dcA'eloped in this mandible, much more so
than ill the 'I'lipir's jaw. 'I’he a.scending ramus of the jaAV is much broader in propor-
tion to its height than in the 'I'apir.

Till* syniphysial jMirtion of the mandible is broad and short; it differs consider-
ably ill form fmiii that of the 'I’apir’s juAv. The inferior margin beloAv the premolars
slo|M*s gradually up to tin* incisor Ixmler, and presents no abrupt angle as seen in
Suillim*s. 'I’ln* syniphvsis lH*tween the second and third premolars is not prolonged
far lM*yoiid the caniin*s for the insertion of the incisors. Thus this species dift’ers very
niiirli from I'clttutMhcrtum in the characters of its symphysis, Avhich in the latter
p*mis is nion* Stiilline and moit* horizontally placed than in P. paludosus. The
mental fommen is situat4*d lx*low the second pi'emolar and a smaller posterior one
may U* |in*s«*nt.

CompiinsoH u>i(h the lapir's Skid/. — From the foregoing description Ave may
sum up tin* affinities and diff’emices of the skull of P. pahidosus as compared AAUth
that of laptrus. 1. — In the nasal region there is little similarity betAA^een the Iaao
skulls, as the extivniely highly six*oialized nasal region of the Tapir for the insertion
of Its larp* pmlKMH-is is entin*ly wanting in Palceosyops pahidosus. We may add
lu*n* that from the charactei-s of the nasals of P. pahidosus Ave may conclude that it
pmimhiy had no prols>s«>is, or if any, an extremely rudimentary one. 2.— The

PAL.^OSYOPS LEIDY, AND ITS ALLIES.

293

occipital region of the skull in both forms is closely similar, although the auditory
processes and glenoid articulation are different. 3. — The elongated zygomatic fossa
and the position of the orbit is similar in both forms. 4. — The orbital processes are
moi’e developed iu Palceosyops than in Tapirus. 5. — The facial region of this
species is quite different from that of the Tapir. 6. — The zygomatic arch is
much stronger and more bear-like than in the Tapir’sskull. 7. — The separation
of the foramen ovale from the foramen lacerum medium is different from that of the
Tapir in which these two foramina are fused into one.

Skull Measukements.

P. paludosus-

M. •

P. megarhinus

M.

L. laticeps

M.

P. Isevidens.

M.

T. cultridens.

Basal length of cranium

Length from premaxillary to ant.

■420

•355

■420

border of orbit

Vertical height of skull at ant.

•170

•125

•142

•125

•165

border of orbit

Length from i)remaxillary suture

•084

•095

•082

•110

•105

to postglenoid

•345

•285

•370

■310

Length of na.sals ....

•125

•100

Length of nasal notch • . . ‘ .

•115

■084

•112

•110

■125

Length of orbit

•035

■045

•050

0-45

•055

Length of floor of orbit at middle

•056

•064

•054

•070

Length of temporal fossa

Vertical height of temporal fossa

•200

•210

•225

at middle ....

Anterior border of orbit to end of

•115

•100

•110

postglenoid process

Greatest distance of z3'goma from

■220

■ 160

—

skull (one side)

•140

•092

■145

■090

Height of occiput

Width of occiput between post-

■133

■105

•140

—

tympanies ....

■165

•140

•210

Total width of condyles

■098

•098

•100

•092

Width of fi>ramen magnum

•043

•037

■030

Length of palate ....

•180

•165

■180

•180

•220

Width of palate between canines
Breadth of skull between post-

•050

■045

■050

—

■052

orbital processes

Length of premaxillaries along |

•1,35 •

•150

palate

Length of sui^erior border of pre- i

•084 1

■025

•042

•053

maxillaries . . . . !

•080 i

•065 j

■OtiS

•095

AXIAL SKELETON.

Getteral Characters. — The collection of Princeton College contains a series of
eleven vertebrm, which belong to this species. Of these there are three cervicals,
six dorsals from the same individual, another dorsal from the posterior limit of this

A MK.MOIII UrON THE GENUS

beautifully preserved, and shows interesting
,vgio„. and j recent Tapirid^e Rhinocerohdce . There is

,-harai-t.-i> quite diileivni ^ probably belongs to tins species. As

aUia fuu- HiHTimen of ^ " wanting, it will be impossible to give the

most of the dormds am nm )< ‘ there are enough of the vertebra'

...act nn.nU.r of tlu’ ^ eblracterize each. The vertebne are un-
of tliesuUlivisioiis of t . skeleton, and their dimensions approach

l..•»v,v than tliosc of the Tapir. The verhljral centra

! ''7| ’ a ortneas aiul great elepth compared to those of Mmoccr^s.

; 7 '7;,. ;,'!!;ive,-se. iTocesaes is striking. The lumbars on the
I he gr.-i.t lm-a.lth „f Kkhwceros have deeper ceiitras with ratlier

- aisiti.'.* r. sire .tf the articular pr^esses in some legions

:Mh.'.'''ve' t' -hr,,l .a.h u.n is .p.iU- .liflerent from that of recent Perissoihictyles.

- 1.. ver .-ll- of /' M-a-erttr tvm-tnhlc those of tlie lihinoceros as closc-lj- as tliose
' , r " • .ot in tin- characters of the atlas, and as the vertebra' approach

m.,'m ,,I.X'in si»- 'I"’'- ‘

lIM Xm, ligH. -iS-dl.) The bodies of the cervicals are very deep
„ml shor'.. showing that tl.is species had a short and thick lu.k. Their arches are not
.. muci, expanded as in Rhinoceros. In Diplacodon the deepening o the cervical
is carrhsl still fartlier, and with it a great compression of the body inakmg
i, very thin antens,H,st4'riorly. In Titanothcrium a greatc'r breadth and tliickness
of the eervieal eentra is to la ol).served than in Diplacodon.

\U„s —The atlas is very hroad and heavy, much more so than in Tapirns.
ItM transvers,. pnaesses «,v C-ery wide and broadly extended, the articular cavities
are extn-inelv wide and very ileep, Ix'ing wider than this region is in Rhinoceros-,
hut in eontni.-*! with tlie latter, the articular surfaces for the axis are much narrower,
just n-versing tin* diim'nsions of these two articular surfaces in Rhinoceros. Like
tliat of the 'Pajiir tlie atlas of P. paliidosus exhibits two foramina for the first cervi-
eal nerve; the lower one. for the inferior branch of this nerve, being connected with
the iipisT hy a grisive. In Rhinoceros the lower foramen is merely represented b}
a disqi notch, hut it is not enclosed as in this species. The transverse process of the
atlas is iHTfonitisl at its ha.st‘ by a large vertebrarterial canal, resembling in this re-
s|HS't the atlas of the 'I'apir. The floor of the neural arch shows a prominent tuber-
osity. 'File under surface of the atlas is smooth and rounded.

The . Ixis. — The gi'iieral form of the axis, specimen No. 10,279, resembles
chwdy that of the Hhims'enis. Its neural arch is very high and the spine is broad,
high ami ihx'p. Tlie neural spine is much higher than in the lihinoceros; it pro-
jivts nion* |»osterinrly tlian in that form, but its antt'rior extension is not as great.
I he ]M>st7.yga|N)ph vs<'s an* largi*r and more nearly vertical than in Rhinoceros.
The surfiux* of the vertebra Ix'tween the latter articulations is deeply exca-
vnt«sl. fonning a longitudinal gixxive which extends upon the surface ol the

PALiEOSYOPS LEIDY, AND ITS ALLIES.

295

si)iiie. The centnun of the axis is very short ; its posterior siirfiice is slightly con-
cave and very deep from above downwards. The under surface of the centrum is
provided with a prominent keel, its surfiice being deeply excavated on each side of the
latter. The keel is much longer and more prominent than in Rhinoceros. The ante-
rior ai'ticular surface of the axis resembles closely that of the Khinoceros. The
odontoid process is very long and conical, much longer than in the Tapir. The articu-
lar surfaces for the atlas ai-e much more oblique to each other than in the Rhinoceros.
They are triangular in outline, their extenial portion being very broad, becoming
nai-row as they approach the middle of the vertebra. The neural canal of this ver-
tebra has the same height as that of the Rhinoceros, but it is narrower, and the floor
of the same has anteriorly a very conspicuous longitudinal tubercle. The axis of
this species agrees with that of the Rhinoceros in not having interspinous foramina
for the spinal nerves, which in Tapirus as in Eqnus come ofl‘ from the spinal cord
through a special foramen in the axis. The form of the transverse process of the
axis is. peculiar ; it is placed higher than in Rhinoceros, its vertebrarterial canal being
on a line with the upper surface of the body, and instead of the transverse process
arising from the middle of the canal, it is placed above it. so that its inferior root is
nearly vertical. This is certainly a very jjeculiar character of the vertebra.

Fourth cervical. — This is the only cervical vertebra posterior to the atlas which
is preserved in the collection. Its most striking character is its high centrum, and
this is apparently out of all proportion to the size of the arch. Compared with that
of the cervical of the Rhinoceros the body is very much shorter ; its height is about
the same, but the breadth of the centrum is very much greater. This vertebra is
slightly opisthocoelous, the anterior convexity being much less than in that of
the Rhinoceros.

The anterior convexity, moreover, is marked by a transverse depression. The
neural opening is slightly smaller than in Rhinoceros. The basal portion of the
transverse processes pierced by a large vertebrarterial canal, and the diapophysis is
much thinner and shorter than the parapophysis. The neural arch of this cervical
is low and broad. The prezygapophyses are very large, and oblique and their in-
ferior ends do not become concave as in those of the Rhinoceros. The peduncular
portion of this cervical is lower than in that of the Rhinoceros. The postzyga-
j)ophysis has been damaged in this vertebra. There is also in the collection a
seventh cervical belonging to a smaller species than P. paludosus. This has the
general form of the vertebra already described, its centrum is more opisthocoelous
tlian the latter. The diapophysis only is present. The vertebrarterial canal is, as
usnal, wanting in this vertebra.

Dorsals, (No. 10,282.) PL XIII, flgs. 32-35. There are six dorsal vertebrm in
the collection in^nldition to the cervical last described, all belonging to the same indi-
^ndual. The most striking differences between this series of dorsals and the same
vertebra} in Rhinoceros, are the dimensions of the centra and the great extension of

\ MEMOIR UPON THE GEISUS

‘m

'I'lie centra of these vertebrai are nearly as convex aiiter-
bu. tl,eir surface is less concave,

Mkasukkmknts of Vertebrae of P. paludosl-s.

M.

AiIom. _ -220

T'Mrnl width of a>hu> 112

Width of •nt.mrllc imK-cmw 100

Width oflKWt-wrtic.pniccHt^^ at middle . ■ • . . . 067

lacnitthatl«« oftmnK

IHawetor of iifural canal • • ' ... -070

|k-|tth of alhu* at middle • • J J ^

.i™.

laPlieth of B«i»

KIrvation of »|.ine a«»ove floor of eimfrum
Ungth ant i—t. along lamina
Total hrwMith of ant. artic. aurfaciii

41I, (Wrimt.
larngth of laxly
llrighl I total)

llmallh of arrh at ant artic prooewa
Height erf neural canal

lx>ngth of iMxliea of xix cervicala

■077

•093

•063

•106

•044

•047

•082

•022

•250

'rite rirst tlnrsiil is lower and Hatter than that of Rhinoceros;, the pedicles are
Ittwcr, anti the heijfht t>f its anterior articular processes above the centrum is not as
Ifreat. 'rite traiisverm* process is longer and thicker from above downward than in
RhiHoceros. ’rite faet'ts for the ribs look more anteriorly, whereas in the Rhinoceros,
they l«s»k tlownwaitl. The transverse diameter between the postzygapophyses is
not as great in this sjsfies as in Rhinoceros, and the latter approach more nearly
a liorizonttd than the latter form. The posterior capitular facets are more oblique
t«> the plane of the centrum than in the Khinoceros.

'Flu* ii«*teln*s for the spinal nerves are deep and open as in the vertebne of the Rhi-
nix^'nw, then* ls*ing no |K*rft)ration of the pedicles as in that of Tapirus. The char-
wters of the wH'oml dorsal arc about the same as those of Rhinoceros, \\z : a de-
cn*n.*w* in height in the ix*diele8 and change in slope of the prezygapophyses. The
spine of this vert«*hni is very long and heavyq although shorter than that of the
satne vert«*hni in the Khinoceros. It is deeply grooved in front.

I h«* tuls'rrular facet is horizontal in Rhinoceros and it looks more outward
than in J\il<rosyops. 'I'lie is>stzygapophyses are more oblique than in the first dorsal.
In the thinl dorsal the transverse pn)cesses are finally preserved, they are broader
ami heavit'r than thost* of the Rhinweros. The position of the tubercular facets is
diflen*nt. fniiu thos«* of Rhinoceros. The lamina of this vertebra is quite short.

PAL^.OSYOPS LEIDY, AND ITS ALLIES.

297

The intervertelu'al notches are mucli smaller than in Rhinoceros, the same being
the case in all of the dorsals. The centrum of this vertebra has a ^^rominent keel,
the lateral surfaces on each side of the same being deeply excavated. The spine
of the fonrth dorsal is very oblique and elongated ; its anterior edge is flat and
grooved.

The width of the transverse process has diminished very much and it has
become raised. These changes are likewise observed in the vertebrm of the Rhi-
noceros. In contrast with the latter fonn the tubercular facet far exceeds in size
the capitular. It is deeply concave and looks downward and forward instead
of outward as in Rhinoceros.

In the fifth dorsal the transverse processes are exceedingly short and have
become very much raised. The tubercular facet has become flattened and looks
more outward and downward. In this vertebra the two facets for the rib nearly
approach each other in size ; the body and pedicles have become higher as is
nsnally the case. The post-zygapophyses are more elongated and horizontal than
in the Rhinoceros.

In Rhinoceros bicoi'nis in the 6-8 dorsal vertebrm the differentiation of the meta-
pophysis from the diapophysis begins to appear. In Palceosyops paludos^ls this
change is not well shown in the sixth dorsal, this being -the last vertebra of this
series preserved. The transverse process of the sixth dorsal is veiy short and heavy
distally ; its lamina is strongly triangulai’ and raised. The anterior capitular
and tubercular flrcets of this vertebra have nearly coalesced.

Posterior dorsal and anterior lumbar regions. — There are two vertebras in the
collection which belong to the jwsterior axial region. Their size agrees very closely
Avith those already described as belonging to P. paludosus, and for that reason I shall
refer them to this sjAecies. The characters of these vertebrm are highly interesting,
as they depart Avidely in some respects from those of the recent Tapir and Rhi-
noceros, approaching more nearly those of Equus.

The most important difference is found in the pre- and postzygapophyses, and in
the region of the lamina of the neural arch. The accessory processes are also more
largely developed than in Tapirus.

Posterior dorsal. — This vertebi'a, No. 10,286, probably belongs to nearly one of
the last of the dorsal series, as the position of its articular processes indicates. The
peculiarities of this vertebra as compared Avith that of Tapirus and Rhinoceros pertain
especially to the postzygapophyses, Avhich in this species are much elongated and
placed nearly vertical. In Tapirus and Rhinoceros the processes of the posterior
dorsal region are obliquely placed and look doAvuAvard and backAvard ; it is only in
the lumbar region that the postzygapophyses show a tendency to approach the ver-
tical, but they never reach the position found in Palceosyops. In Eqtms, on the
other hand, the posterior dorsal region has the posterior articular processes nearly
vertical, but these processes in the ' lumbar region are not placed as vertically as in
the dorsal region. Cuvier figures in a lumbar vertebra of Palceotherium magnum
the same peculiarities in its postzygapophyses as in those of P. pahidosus. The

A MKMOIll UPON THE GENUS

. r vertcO,ni in the former genus is very high i*nd narrow ; its
,K-.hmeiihir ivgion ol tin obli(luely placed tuhereiilar facet. Tlio

tmiiMV4TS4- |.nK-.-ssesaivs lo • ‘ i^jveloped and connected with the trails-

m /f" T

v.-rw- P«^'<‘‘‘'*^’'* tlieir external margin being slightly raised and
the pn-7.yga|H.phys<-s '“y oblicpie and with the surface plane

l«.nli-n-a liv ■ . ■ |- articular proceases />. departs

'“del/" ,M, --..0 sa,-, a. e„ar„c.er approaches the

■''■'"'nlell.Tdrun, .d this vertel.ra is la, -go a„d opisthoccelous.

> i ,e l-n,e el,'„„elers of the hiliibar vei tebra, are veiy mteia-stmg and are
Liim/iar. Hhinoecros, and, like those of the

■ ; U K, nh.e. The eonfun. is elongated and

til' '-..g^ligUly foncave. Theh.dy is

k.l:.|.il l..h.tv and slmnglv l,iang„b,r in ontline. The netn-al arch ,s very high,
nainnv and inneh elongated; more so in pro,,ortlon to its size than that of Efmis.

are hiaiken olV, hilt their bases are ol good size. 1 hose procesres

iven- linihahrv stniight and rather narrmv. The piezygapophyres are ivide, l«„g
Iiiiieh a ider and iniieh less laineave than those of the dorsals. I he superior |K.rt«,„
of lliii* pnK-..m< 4-\hilMt.s no .sign of convexity, as m the Artiodactylcs vherc tl.i
upiHT ami l.nv.T articulations are convex and concave respectively. The prcvyga-
iH.i)hvs.-s an- ls.nl«-n-«l l>v the verv prominent metapophyses, which are very large.
!.o,nim.ss.-4l and .-xti-mled half way across the surface of the lamina. They ternn-
i.nte in a rugom- incurvi-il .-xtivmity. The metapophyses m /\ pa/udosus are very
tmu-li larger than in any of the ivcent Perissodact/es. In the Tapir and Kl.i-
ms-4-n»s they an- «|iiit«- .sniull. The neural spine is different in forin and ciirvatiire
fnan that <»f A7//«errr<v and approaclies in form that of Jtqtnis. I he torni of t le
l»oi*l/.vga|M»phys«-s in the Ininhar n*gion is different froni that of the dorsal just
ih-m-rilMsI. Tln-.-s- pnM-«-s.s(‘s an- placed more nearly horizontal. In this vertebra
\v»- have a true int«-rhK-king of the articular surfaces, resemhling that of the
.\rli<Hlaetyh-s hut not as highly developed.

In eontnist with the latti-r group the lower portion of the involute is ver\
largi- ami stnaigly c«>nvex. when-as the upper part joining the spine is \ei_\
small ami rudiim-iitary. In the lumbars the basal portion of the episphen is
ileveh»|M-4l. In eoinjiarisim with the postzygapophysis of the last dorsal just
ih-srriln-«l. we find tin- articular surface of this vertebra more complex; that is, the
hnnluir |s»st/.yga|Hiphyses an- moiv highly developed than those of the doi*sal region.
In this n-sja-t-t /’. pa/ndosus ivseinbles tlie Artiodactyles where the lumbar region
n-nches tin- highi-st i-omplexity in its vertebral processes. The articular pre-
. rt-sses ami tin- fitriu of the neural arch of the dorsal and lumliar vertebral just
descriU*<l difl'er so widely fnnn tho.se of the Tapir and Khinoceros that it may bo
«»f int«-n-st to n-view the characters of these processes in recent and fossil Perissodac-

299

PAL^OSYOPS LEIDY, AND ITS ALLIES.

tyles. Palcsosyx)ps shows its close affinity to Diplacodon in the characters of its
lumbar vertebrm, in the latter form the neural arch and postzygapophysis having
the same form as in the posterior dorsal region of P. paludosus. We have seen that
at the posterior part the axial skeleton in this species departs widely from that of
Tafnrus and Rhinoceros-, that it has strong Equine characters in the form of its
articular processes, and also in the character of the neural arch. Cope mentions the
fact that the pre- and postzygapophyses in Plyrachyus embrace each other as in the
Equidce, and the vertebrae are elongated and high as in Palceosyops. PalaotJierium
also agrees with Palceosyops in the form of its lumbar vertebrae, as in the former
genus the articular processes are placed vertically. Pdyracothernmi approaches
Eqtms ill the form of the lumbar processes, as is shown in the following descrqi-
tion by Cope : — "

“ The remaining parts of the column (including dorsal and lumbar) show decided
indications of Equine rather than Tapiroid affinity in two points ; these are, first,
the absence of isolated interspinous foramina, and second, the narrow form and more
revolute articular surfaces of the postzygapophyses. ”

The large size of the metapojihysis is a peculiarity of Palceosyops as compared to
recent Perissodactyles, as in Equus these processes are larger in the posterior dorsal
than in the lumbar region. In the Tapir and Rhinoceros on the other hand they
reach their greatest size in the lumbar region, but they are very small comparatively.

Sacrtim, No. 10,245. — The sacrum in this species is very long and narrow com-
pared with that of Rhinoceros. It is made up of four coalesced vertebrm. The
diapophyses are very short and compressed, those of the second being the largest
and offering a large fiat iliac surface. The diapophysis of the third sacral vertebra
is also much flattened, so that the pelvis probably articulates with this vertebra.
The intervertebral foramina are large.

The first sacral vertebra shows a much raised prezygapophysis, and in fact the
vertical height of this part of the sacrum is greater than that of the Rhinoceros.
The sacral diapophyses in this species have no articular surfaces for the lumbar
vertebra} as they have in the Rhinoceros and TajDir. The extremely small size of
the posterior face of the last sacral vertebra indicates that the tail was very short in
this species, much more so than in Rhinoceros, where the body of the last sacral
vertebra is quite large and broad.

The Ribs. — There are a number of 2}ortions of ribs in the collection. No. 10,281,
all from the same individual, and as they are associated with the series of dorsal
vertebrre which we have already described, I shall refer them to this species. The
ribs are proj)ortionately longer and narrower than in the Rhinoceros, and the width
of their shafts is intermediate between those of the Rhinoceros and the Tapir. The
shaft is characterized Ijy its comparative thickness, and also by its external face being

^Tertiary V6rtGbrata. Page 627.
40 JOUR. A. X. S. PHILA., VOU. IX.

v MEMOlIi UPON THE GENUS
JiOO -v • *

.. . i for nuiscular attacliment ; this is particularly true of the portion

fXrutaliiiKly naig i ^ „u,ich is covered with a strong rugose prominence for
of thi- shaft in the collection are from the anterior thoracic

1 lit 1 ,vhich is one of the most anterior of the series, the

-'•P';”' : '.'T::';;'! , ■ .ea lie tuberculum. The facete of the head are

, a ^ "hlilcly placed to one another ae in RMuocero. The
uillTuir rl-t i. very large and forms a perfect semi-eirde equally placed on both
s i., ..r .he e.,.l ..f the -halt. In Rhinocerm th.s facet is limited more near y to
le side Tivo „l her iiroxiiiial portions of ribs in the collection, winch are probably
Ilie fourth ..r tilth, show .... appro..ch of their proximal facets and, coiTespondmg

,|.,plv ex.-avat.al taeet .... the transverse process of the dorsal, the tuber-

eular f..<-e. i. very large, ciuvex and placed nearly alright angles to the axis of the
Hhalt In tli.‘ HhiiuK-oros on the other hand, the tubercular facet is perfectly flat
,„h1 xvrv ohli.iuely placed. As witli the more anterior ribs the fourth and fifth
l.ave th’e faeots of tlie head in continuity. The total length of the shaft of the 5tli
rib was from ■lO-'lo cm.

.MK.vsruKMKNTS OK VkktebRs^: of P. paludosus — Conttfmed.

Ihirmtit.

l,g-nKtll of InuIv of litl ilontfll
llrltflil of ImhIv of IkI tlorital
Wltlili of ifniutviw imM-twi*.

M.

•040

•047

•170

Kli-viilioii of of .‘Inl tlomil

WhIiIi imiut itrofjt. ofllrtl ilomil
WhIiIi of |H»tfri<ir artiniUr |inK». of muiie
l,/'n4tiii of itplno ofAlh tlomil ii1m>vp IxhIv
Isrnulli of ImniiVrnH' |irtK-o»*xtH

•l.iO

•1.10

•052

•115

•104

.Vo to^w.

larnjfth of Uxl y ........... "047

To««l wltlth of mil. «rtic. jirtHiwiw ... ..... •037

lartittlli ■I'tnit laniiiin .......... 'OOS

VrTllr»l hi'iitlil of ix»l- artlc. pnioiwH'* 023

.Vo. lO;f7S.

larnitllt «if Ixwly ........... 051

Isrnitlli of lamina inrluditiK nrtic. pmcx. ........ •Oil

lioitflil of iMwi. artic. |>nic alxive IkxIv ........ ^035

Tttlal wiillli of anterior artio. procf). . ^042

of ml•ta)•o|■ll^•am .......... -032

Strrum .Vo /0^4S.

Ttaal Irnmli ............ 150

iinmlrat wiilih anloriorly .......... -112

WMth of cl’ntniiii in front ..... -045

WMih of cvntnuii lioliinti ..... 015

(imunil Vfiiii^l hfiKht • . . . .070

301

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

Appendicular Skeleton.

Scapula. (PL XIII, figs. .37, .38). — There are a number of fragments of
scapulm in the collection, the best example being No. 10,277, which I refer to this
species. Only the lower half of the scapula is well preserved, the suprascapular
region being wanting. The part preserved is characterized by its breadth and
massiveness. The glenoid cavity is deeply concave from before backward and anter-
iorly it is limited by the hook-like projection of the anterior border. Viewed from
below, the outline of the glenoid is very different from that of Tapirus and more
closely resembles that of Rhitioceros. In the latter form tlie outline of the glenoid
is a broad oval, being about erpial at both ends. In Tapirus Indictis the middle
dimension of the glenoid is the greatest, whereas in P. paludosus it forms an elon-
gated oval. The coracoid jirocess in this species is rather short, stout and strongly
recurved ; internally it is separated from the glenoid border by a deep notch. The
form of this part of the scapula is very different from that of recent Perissodac-
tyles, where the coracoid is not separated from the glenoid border by an interval
as in the Rhinoceros, but rises directly from it. In recent Perissodactyles the cora-
coid is sejiarated from the glenoid border by quite a long interval ; in the Tapir
and Rhinoceros this process is short, and is not incurved.

Eqmis has a small and incurved coracoid process. The anterior border of the scap-
ula in P. paludosus is thin and concave above this process ; then it becomes strongly
convex, its superior border having been probably rounded and convex as in Rhi-
noceros. The anterior border is not divided by a coraco-scapnlar notch as in the
Tajiir and some sjiecies of Rhinoceros. The posterior border is slightly concave and
probably formed a rounded angle with the suprascapula border.

At the lower part of the posterior border, and separated from the glenoid by a
slight notch, is a large rugose tuberosity. This is oval in outline and forms a prom-
inent character in the scapula of this species. In the Tapir and Rhinoceros this
tuberosity is wanting. The neck of the scapula is only slightly marked off, and is
concave on each side below the origin of the spine. The spine arises on a line with
the upper end of the tuberosity ; at its origin it is very broad and heavy. The
spine forms a right angle with the glenoid cavity.

From the scapula of a form closely allied to Palceosyops, in which the spine is
provided with a recurved process, I conclude that in this species the scapula sjiine
was also thus pu'ovided. The internal face of the scapula is nearly smooth, showing
only a slight longitudinal convexity. In comparison with that of the Tapir the
whole plane of the scapula is strongly incurved.

Htmierus, No. 10,373. — There is in the collection only a distal part of a humerus
which I can refer to this species. This humerus was not associated with the
rest of the skeleton of P. paludosus, but was found in the same locality. The
distal portion represents probably about one-half of its entire length. The shaft
of the bone is unusually heavy compared with that of the allied genus Limno-
hyops. The upper portion show's the distal prolongation of the deltoid ridge.

;m)2

A MKMOIH upon the genus

• V,.rv thick, heavy and strongly bent outwards,
whicli in this HiK-cnnen is > tbe deltoid ridge

The ,M>sterior fa.-e oi tlie shaf ’being very massive. The supinator ridge

it spn-adrt .mt wuhdy, its <iis i n„ttened iust above the trochlear, but aljove

• I imiiieiit. The external coml>le IS luiuLc

mill U-h.w it thins out of the external trochlear

'riie upia-r pna-ess ^^rface itself is very broad and heavy, its

iH esiHvially Umnohyops. The internal division of the troch-

p.iienil lonn resembling , nroiecting process than in Limnohyops. The

lear is limited by a imjre i j‘„„„Sed' than in the latter genus, with the median
..xteriial tnx-hlear is a sc ^ between the two trochlears is wider and

ktad not so sharj)!} dt ■ gupra-trochlear and anconeal fossa> are large,

a,..ei„g in this re.,„ec. with the humerus „( i.

inaking the articular surface apiKuir unusually wide ; the d.sta portion ,s hil y one-
bair wider than in Lhntohyops. The portion ot the shatt presemHl is also
wide and heavy, showing that it Ixdonged to a very heavy formmn.
cf the- artieuhir surfa.-e olVei-s no very striking peculiarity. The scaphoid poition
cftliis artieuhir surface takes up a considerable space posteriorly. It is mm e pi o-
IcmgcMl vc-rtieallv on the shatt of the radius tlian in allied lorms, thus giving the
fon-ann nion- f/.n- and alt play than in the more lightly constructed arm oi Limuo-

^ ^ The Maims, (PI. XIV, tig. 4')).— The carpus of this species, which is figured
is a eoiniHx.ition. and is .lerived fnim a well preserved lunar, which was associated
with otlier parts of skeleton. No. 10,282. The renmining elements of the carpus
wen- not found as.-sx-iatc-d with this skeleton. The carpus is characterized by being
very hnaid and hi-avy ; its transverse axis is about twice that of the vertical, difl’ei-
ing in this n-s|H*c-t fnun Tapirus and Hyrachyiis, in which the height of the carpus
inon- nearly coincides with its breadth.

'Phe liflli nietaearpal in P. paludosns is large and not as much reduced as in the
Tapir. Owing to tlie largi* size of metacarpal V the mesa.xial line of the carpus
|Ni.-^>s iH-twiH-n inetaearpals III and IV, presenting the arrangement found in Txtan-
otherium (Paraxouia). In the Tapir, on the other hand, metacarpal HI is ver\
inueh hirgi-r than the otlier metapodials and consequently the axial line of the
nianus |ias.-H>s through that digit.

The meta|MMlials of P. paludosus are heavy and wide spreading, being short in
roinparison to their hn-adth. The carpal elements are broad, short and their rela-
tions to each other an- quite dift’erent fi'oin those of recent forms, diftering radically
fnaii the 'Papir an«l ajipniaching moi-e nearly the character of Titanotherium, but

PAL^OSYOPS LEIDY, AND ITS ALLIES.

303

also showing some Rhinocerotic affinities. The shape of the lunar and unciform,
with their facets, is very characteristic of this species. The division of the carpal
elements equally by the inferior process of the lunar is not so strongly marked as in
some other genus of the family, [Limnohyops.)

Scaphoid. — The scaphoid is a very broad and exceedingly heavy bone. Its
superior facet is plane, very large and not boi’dered by prominent processes as seen
in tliat of the Rhinoceros. The inferior facets of the scaphoid are very oblique to
each other. The scapho-magnum facet occupies all the superior face of the magnum.
The scapho-trapezoid facet is very long from before backward, deeply excavated,
and its anterior portion rises upon the anterior face of the bone. There is a very
small facet for the trapezium in this specimen. The beak of the scaphoid is not so
widely prolonged ectally as in Rhinoceros, being in about the same progress of dis-
placement as in Tapirus.

Ltinar. — The form of the lunar is very characteristic in this species. It is
remarkable for its massiveness and breadth as compared with that of Limnohyops.
The posterior jorolongation of the lunar between the magnum and unciform is not
as great as in the latter genus, but rather more so than in Titanothernim. Its
transverse diameter along the superior surface is nearly equal to its vertical. From
before backward the lunar in this species is deep and is not provided with a pos-
terior hook-like process. The superior facet of the lunar is separated medially by
a deep concavity dividing the face into an anterior and posterior portion ; the latter
is high and convex and slopes abruptly backward as in Tapirus and Rhinoceros.
The inferior facets of the lunar are unequal in size, the lunar unciform taking up
about two-thirds of this face. This facet is deeply concave from before backward,
and is separated from the lunar-cuneiform facet by a slight ridge. The lunar mag-
num facet is very characteristic of this species, its plane of articulation, as it were,
ha^’ing been rotated anteriorly, thus exposing it to view when looked at from the front.
It is very oblique to the facet of the opposite side, and it ciu'ves upwaa’d and back-
ward to become continuous with the lunar-scaphoid facet. In form and general
relations the lunar in this species approaches more closely to that of Titanotherium
than to the lunars of other forms studied by the author. The lunar of P.
paludosus is easily distinguished from that of Hyrachyus, in which its form is very
hio-h and narrow with the lunar magnum facet placed widely to the outside and
nearly vertical. ,

Cuneiform. — The cuneiform is quadrangular in form, being very broad and
low. Its shape differs very much from the cuneiform of Tapirus and Hyrachyus
where this bone is high, narrow and slopes abruptly away from its radial angle.
Owing to its form the cuneiform in P. paludosus offers a very long superior facet for
the ulna. This facet is very extensive transversely and shallow from before back-
ward. The cuneiform-pisiform facet is placed high up and posteriorly, the pisi-
form not appearing upon the anterior aspect of the carpus. In Tapirus the cunei-
form-pisiform articulation is seen conspicuously upon viewing the carpus from the

304

A MEMOIR UPON THE GENUS

The cuneiform-unciform facet is triangular in outline, the widest portion

Magnum —The anterior face of the magnum m P. pahidosus is pentagonal m
outline being very broad transversely. The form of this bone differs radically from
that of Umnohyops, in which it is much higher and narrower than m this species,
thus resembling Hyrachyus which has also a high, narrow magnum. The magnum
in P. paludosus resembles closely that of Titanothernim, as its general form and
arrangement of the fiicets are nearly the same as in that genus.

The relations of the magnum to the other bones of the carpus in Hus species
are very different from those of recent forms, and when we compare its position
in the carpus of Tapirus with its place in Palceosyops, the striking difference in its
size and plane of articulation is apparent. The plane of the magnum-scaphoid facet
is very oblique, being broad in front and narrowing posteriorly as it ascends upon
the pivot of the bone ; it is taken up entirely by the scaphoid, ofiering no articula-
tion for the lunar. The external face of the magnum forms a right angle with its
superior face. The anterior part of the external face is perfectly plane, and is sub-
divided equally for the lunar and unciform. Thus the magnum and unciform
have quite a broad surface of contact anteriorly, which is very nmeh reduced in
Limnohyops. In Titanotheriiim we find about the same relations between these
three carpal elements as in this species. In Tapirus on the contrary, the external
facet of the magnum is wholly taken up by the unciform ; and the lunar being
crowded out, as it were, from this articulation presents a nearly plane surface of
contact for the magnum and unciform. The articulation ol the magnum-metacar-
pal III facet in this species is triangular in outline. This articulation is placed
rather obliquely and internally and is produced by the large facet developed
on metacarpal III for the unciform. The magnum-metacarpal II facet is nariw
and produced far posteriorly. It forms an angle with that for the trapezoid. The
pivot of the magnum is very strongly developed in this species and rises lugh above
the plane of the anterior face.

Unciform. — The unciform is another characteristic bone in the carpus of this
species. It is very heavy, with a long transverse diameter. Its vertical axis is
equal to about one-half the transverse. The shape of the unciform differs very
much from that of Tapirus and Rhinoceros.^ as in these forms the transverse

PALiEOSYOPS LEIDY, AND ITS ALLIES.

305

axis is rotated more to coincide with the vei’tical than in P. pahidosus, thus produc-
ing a wide unciform-magnum surface for articulation.

The extensive transverse breadth of the unciform prolongs its articulation
with the magnum nearly to the median axis of metacarpal III.

The superior facet of the unciform is obliquely placed and concave from side
to side ; it is I’ather shallow from behind forward and limited by the posterior tuber-
osity of the bone. This tuberosity is placed externally and curves outward instead
of downward as in the Rhinoceros. The unciform-lunar facet is large, very
oblique, and forms a wide angle with the superior facet for the cuneiform. The
unciform-magnum facet is small, only allowing about one-third of the interual sur-
face of the bone to articulate with the magnum. This contact in P. paludosus is
much larger than in Li7}tnohyops. Comparing this facet with that of the Tapir and
the Rhinoceros we remark their great difference. In the latter form the unciform
has a large and more nearly vertical facet for the magnum which is very
extensive and extends all across the articular face of the bone. The facet
for metacarpal 111 is large, more so in proportion than in the Tapir, and nearer hori-
zontal. The inferior surface of the unciform is deeply concave from before back-
ward, and is subdivided slightly for the two lateral digits of the mauus. Owing to
the large transverse extent of the unciform, the facet for metacarpal V is large, and
this digit is not placed so fin- to the side and behind as in the Tapir, in which the
fifth metacarpal is smaller than in P. paludosus.

The inferior face of the unciform is not prolonged heyond the magnum like
that of Tapirtis Imt is nearly on the same horizontal line with it. In fact a hori-
zontal line drawn beneath the magnum would limit the carpus distally.

Pelvis, No. 10,232. — The pelvis in P. paludosus is short and broad and its
general proportions approach very nearly those of Rhinoceros. It agrees with the
latter form in having the iliac portion longer than the ischial, although in this
species the ischia are longer proportionately to the ilia than in the Rhinoceros.
The total length of the os innominata compared with the expansion of the ilia is
greater in this sjjecies than in the Rhinoceros.

Diplacodon differs from Palceosyops in having a pelvis much longer and nar-
rower in comj^arison to its breadth. The external border in Diplacodon is shorter
and the plane of the gluteal surface is thrown more outward than in Palceosyops.

Ilium. — The ilia are flat and thin with their external angles inverted. The
supra-iliac border is not interrupted by a depression as in the pelvis of the Tapir
but forms a strongly convex border pointing forward and outward. The ischial
border tapers gradually below and then becomes strongly convex superiorly, where
it joins the supra-iliac border to form the sacral jjortion, the latter being much like
that of Rhhwceros in form. The external or acetabular border is rather long and
deeply concave ; it forms with the supra-iliac border a sharp angle. The pedun-
cular portion of this border is rounded and terminates at the rim of the acetabulum
in a prominent triangular tuberosity for the rectus muscle.

306

A MEMOIR UPON THE GENUS

The proximal portion of the pubic border is very prominent, producing in this
portion of the pelvis a strongly triangular section. At the distal part of the neck
this border disappears. The neck is long and very broad compared with the other
pelvic dimensions. It is longer and rises more gradually from the acetabulum than
in the Rhinoceros ; its section is triangular, being flat externally and subdivided
internally by the pubic border.

Above and below the neck is thin, with the basal portion of the same very
heavy, owing to the presence of the large rectus tuberosity. The acetabulum is
much longer than high ; its anterior and superior rim is very prominent, being
limited anteriorly by a well defined anterior border. The depression for the ligamen-
tum teres is very long and narrow and penetrates half way across the surface
of the acetabulum. The acetabulum of this species difiers in form from that
of the Rhinoceros. In the latter it is very high and narrow with only a slight
depression for the ligament.

Figure 3. — Pelvis of Palseosyops paludosus ; one-
sixth natural size. Si, ih, oh, borders of the ilium ;
a, acetabulum ; il, ilium.

Ischium. — The ischial division of the pelvis is short ; its border above the aceta-
bulum exhibits a slight spine roughened at its basal portion. There is no decided
ischial notch as in the Rhinoceros. In the latter this tuberosity is very prominent
and triangular in outline. The middle part of the ischium is triangular in section.
The neck tapers gradually to the ischial tuberosity, which is very difi'erent in form
from that of the Rhinoceros. This portion of the ischium in P. paludosus forms a
broad plate, rounded at the extremity, with the tuberosity not constricted off as in
the Rhinoceros. The ischial plate becomes thin as it approaches the symphysis,
and is limited behind by a strongly convex border. The lower portion of the ischium
and also all of the pubis are wanting in this specimen. The broken extremitv of
the ischium is very small, and probably the ischim formed but a small
part of the symphysis. The obturator foramen in this species is oval
in outline, being larger and not as broad as the same foramen in the

PALil^OSYOPS LEIDY, AND ITS ALLIES.

307

Kliinoceros. The angle formed by the inferior elements of the pelvis was
probably more acnte than in the Rhinoceros, as in P. paludosus the ischial
part of the pelvis is longer. We see from the above description that the
pelvis of Palceosyops paludostis is very different in outline fr(jm that of the recent
Tapir which is elongated, with a triradiate iliac portion. The dimensions of
the ischia are very long compared with those of the ilia in this species and approach
more nearly those of Titanotherium. We should hardly expect to find the pelvis so
elongated in an intermediate form like that of Diplacodon, but we have seen that
the diameter of the tarsus of the latter is also elongated and higher than in
Palceosyops.

Measukp^ments of Pelvis No. 10,232 — P. fai.udosus

Total leiifitli of innominate bone .......... -415

Length of ilium from middle of acetabulum . . ...... -270

Width of crest of ilium ........... -265

Width of peduncle ............ -060

Length of if=cliium frf)m middle of acetabulum . . . . . . . . -loo

V'idth of iscliium behind ........... .090

Length of acetabulum ^ ^ ^ ^ ^ ^ ^ ^ ^ . . -063

Femur, No. 10,282. — There is in the collection of Princeton College a posterior
extremity of P. pabidosus, including a femur, tibia and the jiroximal portion of the
tarsus, all belonging to the same individual. The femur is very much crushed and
consequently abnormally elongated, and we shall therefoi’e take our descrqition
largely from other portions of femora belonging to the same species. Leidy has
timired a femur' which he refers to the smaller species of Palceosyops. This speci-
men is in the Museum of the Academy of Natural Sciences of Philadelphia and it
is unusually well preserved. After having studied this femur and taken compara-
tive measurements of it, I believe that it was incorrectly referred by Leidy to P.
minor. It should have been refeiTcd to the species under consideration. The
femur of this species is very much like that of the Tapir in its general characters,
but its proportions are altogether longer and broader. The head is round and
placed well to the side as in the Tapir. The depression for the ligamentum
teres is placed nearer the centre of the head than in the latter animal. A slightly
constricted neck separates the head from the shaft. The region between the head
and the trochanter is very broad and heavy, and is compressed and narrow.

The great trochanter is very large and extends from before backward for
some distance ; its posterior process is strongly recurved and rises somewhat above
the head of the bone. The distance between the anterior and posterior tuberosities
of the great trochanter is considerable. This ^portion is strongly concave and is bor-
dered externally by a prominent crest. The anterior tuberositj’ of the same is very
prominent and strongly rugose. The form of the great trochanter in Palceosyops is
very different from that of the Tapir where the posterior tuberosity is much higher

'Extinct Vertebrata, etc. Plate xxix, Fig. 5.

41 JOl'E. A. N. S. PiriLA., VOL. IX.

308

A MEMOIR UPON THE GENUS

tlian the head, and the anterior one is ninch reduced. The fossa between the
two divisions of the trocRanter is absent in Tapirus. An exaggerated form of the
.rreat trochanter of P. paludosus is seen in Eqims, but in the latter form the posterior
hook-like process is placed nearer the head than in P. paludosus. The trochanteric
fossa is deep, broad, and bordered externally by the prominent rim of the great
trochanter.

The anterior surface of the shaft below the head is strongly triangular in out-
line, becoming deeply concave at each side and above the lesser and third trochan-
ters! The anterior surface of the shaft below the trochanters is strongly convex
and its surface narrows below the third trochanter. The lesser^ trochanter is
proniiiient, compressed and very much elongated ; it extends posteriorly to a hori-
zontal line cutting the third trochanter near its middle. The third trochanter in
its large size is in strong contrast to that of the Tapir, where it is very much smaller
than in Palceosyops. The third trochanter is placed at about one-third the
length of the shaft from the head ; it is long, Hat and not as prominent as in the
smaller species of the genus; its position in the Tapir is nearer the middle of the
shaft. In Rhinoceros we see a wide variation from the above form in the position
of this trochanter, which is placed at about the middle of the shaft.

The distal extremity of the femur in this species is iiniisiially heavy and broad,
very much more so than in that of the Tapir. The trochlear surface is narrow and
long. The internal ridge of the trochlear is more elongate and i)roniinent than the
external. Posteriorly the trochlear surface becomes continuous with the condyles,
the latter being heavy and extending some distance backward. The intercon-
dylar notch is long and very deep. The tuberosities are prominent ; the surface
between them and the trochlear is convex instead of concave as in Tapirus.

The posterior face of the shaft presents a number of differences distin-
guishing it from that of the Tapir; the lower portion is very broad and flat
and resembles in this respect the shaft of the femur in the Rhinoceros. In the
Tapir and in the Equine series the posterior external border of the shaft of the
femur presents a deep fossa for the flexor perforatus muscle. In Palceosyops this
fossa is entirely absent, and as in Rhinoceros, the surface for the origin of
this muscle is flat and slightly rugose, somewhat more so tlian in the latter.

Patella, No. 10,282. — The patella is narrower and much more elongated
than in the Tapir. Superiorly it is rounded and shows no projecting processes ;
the inferior end is pointed. The anterior enlargement of the patella is slightly
curved outward. Its internal articular surface is long and narrow, with the
external articular portion broader than the internal.

Tibia, No. 10,282. — The tibia of this species is more slender and rather longer
than in Rhinoceros bicornis. The femur on the other hand in Rhinoceros is longer
than the same bone in P. paludosus. The upper articular surface of the tibia is
much broader transversely in comparison to the antero-posterior diameter, whereas
in the Rliinoceros these diameters more nearly approach each other.

The superior external facet is also long proportionately, the internal fiicet
being much shorter and rounder. The crest of the tibia is very prominent and

PAL^OSYOPS LEIDY, AND ITS ALLIES.

309

heavy ; its tuberosity is Ijroad, bevelled oft' and shows no subdivision like that of
the Rhinoceros and Tapir. Tlie superior external border of the tibia is not incised
as in the Tapir for the transmission of the tendon of the anterior extensor. This
notch is only slightly marked in Rhinoceros. In the Equine series the notch
for the extensor tendon is very strongly marked, especially so in the recent Horse.
The longitudinal fossa? of the upper portion of the shaft are sti'ongly developed and
deep. The middle section of the shaft is flattened, thus reducing the diameter of
the internal border of the bone. The distal extremity of the tibia is broad and
flattened. The trochlea? ai'e shallow, the external border of the outer being deeply
excavated for the fibula. The posterior trochlear tuberosity is short and not promi-
nent. The superior contact of the fibula and tibia forms quite a deep depression,
and the tibia shows a distinct flat facet for articulation with the fibula. In the
Rhinoceros this facet for the fibula is absent.

Tarsus. (PI. XIV, figs. 46-49). — There is an abundance of material in the
collection pertaining to the pes of this species, and, moreover, an astragalus
and a calcaneum are associated with the posterior extremity already referred
to, so there is no doubt as to the correct identification of the tarsus. The figure
of the foot is a composition, the tarsal elements, other than the astragalus and
calcaneum, not having been found with the extremity aliove mentioned. The foot
of P. pahidosus as compared with that of P. 7ninor and Liimiohyops is very much
heavier, being broader and longer. The form and arrangement of the tarsal’ facets
are quite different from those of the related species and approach more nearly the
conditi(?n found in Diplacodon, although in the latter genus some of the facets
are the reverse in size of those of P. pahidosus. Compared with the recent Per-
issodactyles, such as the Tapir, we notice a great change in the size and arrange-
ment of the tarsal elements, and in order to make the description clearer, 1 shall
enumerate some of the most important variations in the tarsus of this species as
compared with that of Tapirus. The most striking difterence between the two
tarsi 2)ertain to the ectocuneifbrm and its facets. In P. pahidosus tins bone is very
high and narrow and the jiroximal portion of metatarsal IV is likewise narrowed,
conse(|uently there is no articulation between the latter and the ectocuneifonn ;
in other words, the reverse type of tarso-rnetatarsal articulation does riot occur in
this species as it does in Tapirus indicus. The cuboid moreover, has a slight con-
tact with metatarsal III. The astragalo-cuboid facet is very large. The articular
faces of the tarsal bones are flatter than in the tarsus of the Tapir. And lastly
there is not so decided a difference in size between metatarsal III and the lateral
metatarsals as in the Tapir.

Calcaneiwt. — The calcaneum in this species is short and broad. Its articular
portion is particularly massive. The tuber is short, the distal part of the same
being club-shaped and very rugose. The neck of the calcaneum is slightly com-
pressed, with a considerable depth. All the fiicets of the calcaneum are widely
separated. The ectal facet is very large, convex, and sends a narrow tongue-shaped

310

A MEMOIR UPON THE GENUS

portion anteriorly. The ectal fixcet may articulate posteriorly with the tibia,
although this is a marked exception to the rule, as generally the astragalus extends
too far\ehind for such an articulation, (tarsus No. 10,282 shows a slight exposure
of the ectal facet of the calcanemu for the tibia.) A fibido-calcaneum fiicet may
be present, although in some specimens it is not well shown.

Three out of five calcauea of this species in the collection exhibit a
fibular facet. The sustentacnlar facet is very large. It is oval in form and
slightly bent toward the cuboid side. This facet is widely separated from the in-
ferior. ^ The size of the sustentacular facet may vary considerably, being in some
cases short and broad, or it may be more elongate than usual. The inferior facet
of the calcaneum is well marked. It is rather elongate and narrow. It extends
about half way across the anterior border of the bone and is not separated by a
ridge from the cuboid fiicet. The position of the inferior facet is very ohliipie.
The calcaneo-cuboid fiicet is large and deeply concave from above downward.
Its middle portion transversely is nearly plane. This facet is bordered externally
by a rounded margin and internally by a straight border which terminates above
in a prominent process. A longitudinal fossa separates the sustentacnlar from the
ectal facet of the calcaneum and corresponds with the depression upon the astra-
galus, whereby along, narrow opening is produced when the two bones are in juxta-
position. This fossa is very large in Titanotherium.

Astragahis. — The astragalus is relatively short and broad ; its trochlear sur-
face is broad and low. The external trocldear is bordered by a prominent, incurved,
flat process, Avhich is a continuation of its anterior margin. Posterior to the inser-
tion of this process upon the internal side of the trochlear there is a deep fi)ssa.
The antero-posterior diameter of the twm troehlem are generally equal, l)ut in some
specimens the external may be excavated behind to allow of the contact lietween
the tibia and calcaneum. The facets of the inferior surface of the astragalus are
separated, the inferior especially being widely isolated from the sustentacular.

The ectal facet is very large and deep, and it sends a narrow portion anter-
iorly. The antero-posterior diameter of this facet is much greater than the
transverse. The sustentacular facet is large and extends to the anterior
face of the astragalus ; it there abuts against tlie cuboid facet, being separ-
ated from the latter by a slight ridge. The inferior facet of the astragalus is
characteristic, as it is small and widely separated from the sustentacu-
lum. The inferior facet only takes up about one-third of the whole culjoid
border of the bone. We shall see later that in the forms related to P. palitdosiis
the inferior facet is much larger, as is the case with Diplacodon, where the susten-
taculum is reduced and the inferior fiicet larger than in P. paludosus. The section
of the anterior face of the astragalus is triangular, the apex of the triangle being
formed by a narrowing of the bone at the junction of the snstentacular witli the
cnboidal facet. The latter fiicet forms an angle with the navicular face gi’eater
than 90 degrees. In PdyracJiyiis and the smaller species of Palceosyops the cuboid

PAL.5<]0SY0PS LEIDY, AND ITS ALLIES. 811

facet is more sharply separated from the navicular than in P. paludosiis. The
cuboid facet ot the astragalus is large and takes up nearly one-third of the
anterior lace ot the bone. Strange to say, in Diplacodon, where we should expect
to find tliis facet still larger, such is not the case, the astragalus of this genus
figured Scott and Osborn in their Uinta Mammalia being really not as large com-
pared with the breadth of the whole face of the bone as in P. paludosus.

Whole face.

Cuboid facet.

M.

M.

Diplacodon-

.060

.015-

P. paludosus—

.050

.015-

Navtailar. — The navicidar in P. pahidosus resembles very closely that of the
Tapir. It is a flat and very low bone and rather deep; its proximal surface is
bordered externally by a prominent raised process as in Tapiriis. The distal artic-
ular face of the navicular is subdivided differently from that of the Tapir. Owing
to the small size of the ectocuneiform, the facet for this bone upon the navicular
is not much larger than that for the mesocuneiform, although the facet for the
latter is not as deep as that for the ectocuneiform.

Ectocimeiform. — The ectocuneiform in this species is a much narrower and
higher bone than that of the Tapir. In Plyrachyus we see the breadth in compari-
son to the height still more reduced than in P. paludosus. The narrowness and
great depth are the most important characters of this bone in P. pahidosus. * Both
articular foces are nearly plane, the upper one being slightly concave. On the
external side the ectocuneiform shows a single large facet for the cuboid and, inter-
nally, two separated facets for metatarsal II. The articulation of metatarsal II
aud the ectocuneiform is quite different from that in Tapirus. In P. pahidosus this
metapodial oveiliangs, as it were, the upper surface of metatarsal III, aud thus the
ectocuneiform does not pass beyond the articulating surface of this metatarsal as it
does ill the tarsus of the Tapir.

Mesocuneiform. — This cuneiform is much larger in P. paludosus than in the
Tapir, and consequently there is not as great a difference in size between the two
internal cuneiforms as in the tarsus of the Tapir. This bone is triangular in outline,
being broad in front and narrow behind ; its external side presents an oblique sur-
face oiitAvard, and internally there is apparently no facet for the entocuneiform,
although this facet is displayed by the navicular.

Cuboid, No. 10,288. — The cuboid is compressed and very deep ; its external
surfiice is concave, being bordered anteriorly and posteriorly by the prominent raised
edges of the bone. The inferior surface of the cuboid is provided with a deep,
narroAv and very prominent tuberosity which is median in position. The form of
the cuboid is quite unlike that of P. minor. In the latter species this bone
has nearly a square form with very much less depth than in P. paludosus. The
in the articular surfaces of the cuboid in the smaller species are also much flatter than
latter. The tuberosity of the cuboid in P. minor is not so narrow and elongated

312

A MEMOIR UPON THE GENUS

as in the larger species. The subdivisions of the proximal face of the cuboid in P.
'paludosus are not well marked. The calcaneal porticm is very deep and slightly
convex from side to side ; the astragalar facet is elongate and narrow, larger above
than below and concave from above downward. The facets for the navicular and
ectocuneiform are short and deep ; they are qxiite different in form from those of the
smaller species. The cuboid-ectocnneiform facet is much larger than the facet for
the navicular. The distal face of the cuboid in P. pahidostis is much deeper than
broad ; its posterior portion is narrower than the anterior. The surface of this facet
is plane and slightly oblicpie. The inferior internal angle of this cuboid exhibits a
small truncated facet for metatarsal III. Another cuboid in the collection does
not show any facet for this metapodial (No. 10,282).

Metatarsals. — The metatarsal region of P. paludos2is is short, with the digits
wide-spreading. The metatarsal 111 is slightly larger and broader than the lateral
metapodials, but does not show the difference in size that is seen in the foot of Palce-
othermm.^ for example. The proximal portion of metatarsal II is broad, with
the external side abruptly truncated. A peculiarity of this metatarsal is that
it shows no facet for the entocuneiform such as occurs in Limnohyops. Its
articular face for the ectocuneiform exhibits two round separated facets. The distal
extremity of this metatarsal is heavy, with prominent tuberosities Ijordering the
articular surfaces.- The upper part of metatarsal III is very narrow compared with
its distal portion. The surface for the ectocuneiform is nearly flat and obliquely
placed ; its cuboidal sides show two facets for metatarsal IV. The distal part of
metatarsal III is extremely heavy and its articular surface is wide and subdivided
posteriorly by a prominent keel.

Metatarsal IV is strongly concave on its external side and its shaft is much
heavier than that of metatarsal II ; its superior face is unusually Hat, being
bread and shallow. The metatarsals in P. pahidosus resemble closely those of the
smaller species of the genus, the difference being largely in their heaviness and the
size of their articulating surfaces.

Summary or the Characters and Affinities of the Skeleton of Pal.eosvops

PALUDOSUS.

In the foregoing chapters I have described the bones of the skeleton of this
animal and compared them with those of recent and fossil Perissodactyles, and 1
now propose, as briefly as possible, to sum up the ^irincipal characters of the skeleton,
and to compare its peculiarities with those of allied forms.

Certain characters are found in the vertebral column which depart widely
from those of the Tapir. These are the form and position of the articular pro-
cesses of the posterior axial region. It was also observed that among recent forms
the Horse ajiproaches PalcBosyops more nearly than any other existing Perissodac-
tyle in the position of its lumbar processes.

313

PAL.EOSYOrS LEIDY, AND ITS ALLIES.

PaUeosyops shows its closer affinity to Tapirus than to Rhinoceros in the fora-
mina ol its atlas. 1 he large size of the vertebral centra is observed as a striking
characteristic in the axial skeleton, and one which is carried still farther
in Diplacodon. The long and narrow form of the sacrum departs widely from
the characters of this bone in recent forms ; and lastly, the very short caudal
region is different from that of Rhinoceros. The characters of the appendicular
skeleton are interesting, and differ considerably from those of recent I’erissodactyles.
The shortness and breadth of the scapula, the large size of the ccjracoid process, the
presence of the scapular tuberosity and the want of any coraco-scapular notch
are of interest as characters of this bone. The difference in shape and
subdivisions ol the trochleae of the humerus in this species is very striking when
compared with those of the Tapir or Rhinoceros. The form of the bones
of the lower arm is found to be closely similar to those of the Tapir, although
the ulna, in its relation to the carpus, is somewhat different. In the carpus is
found many striking characters very different from those of the Tapir. The follow-
ing are some of the most important : the mesaxial line of the manus passes
nearer through the ectal side of the metacarpal III than it does in the Tapir, and
there is not the same disparity in the size of the metapodials in Palceosyops as com-
pared with those of the Tapir; in other words the metacarpal III approaches nearer
the size of metacarpal IV than in Tapirus. It was also found that metacarpal V
was not as much reduced as in the latter form. The penetration of the distal face
of the lunar betAveen the magnum and unciform, is a character not found in the
Tapir. The more vertical lunar-magnum articulation is also a peculiarity of this
carpus, this character being greatly augmented in the allied genus Limnohyops. The
form of the unciform is very different from that of the Tapir and its large contact
with the lunar is striking.

The square form of the cuneiform and the shutting out of the pisiform from
the anterior aspect of the carpus distinguishes this species from Tapirus. In its
short and Avide-spreading metapodials P. paludosus differs Avidely from recent forms.
In its rather short and broad pelvis it approaches the Rhinoceros, but differs very
much from the Tapir in the Avant of a triradiate ilium, this bone in P. paludosus
being undiAuded. Most of the characters of the femur are found to be closely
related to those of the Tapir, but in the flatness of the lower portion of the shaft
and especially of its 23osterior face it differs from the latter. The fact that the
femur of P. paludosus lacks a fossa for the flexor perforatus distinguishes it also
from that of the Tapir. The form of the great trochanter of the femur is
found to be intennediate betAveen that of Tapirtis and Eqtms. The large size of
the lesser trochanter is also a conspicuous feature of the femur of P. paludosus. In
the shape of its tibial tuberosity and the want of an incision for the extensor muscle
of the tibia it differs from the femur of Tapirus. The Avide separation of the facets
of the calcaneum and astragalus and the large contact betAveen the latter and the
cuboid are found to be different from the condition of the parts in the Tapir. In

314

A MEMOIR UPON THE GENUS

the tarsus also, the middle metapodial is not much larger than the laterals. The
ectocuneiform articulates, moreover, with only one metapodial, viz : metatarsal II,
the reverse type of tarsal articulation being wanting.

RkSTO RATION.

The restoration of Palceosyops paludosus is derived from material in the collec-
tions of the Academy of Natural Sciences of Philadelphia and of the Princeton
Museum. The restoration of the skull is from the fine specimens in the Academy.
The axial skeleton is restored from the material in the Princeton collection.

Paheomjops paludomx Lcidy.— Ee.storation. About one-twelfth actual size.

This drawing is nearly all derived from material in the Princeton collection; the skull having been
drawn from two specimens in the Academy of Natural Sciences of Philadelphia. The drawing wa.s prepared
under the direction of Prof. 11. F. Osborn.

The hind limb is restored from the finely jireserved sjiecimen of this extremity
in the Princeton Musetim. It is associated with parts of an anterior limb and also
a right maxillary portion ol the skull containing the teeth, so there is no doubt as to
its correct identification. Lastly, the parts of the anterior limb that are wanting
in the specimen above referred to, are restored from the closely allied genus Lbmto-
hyops. I believe that this restoration is nearly accurate in all its details, as there is
such an abundance of materifil of Palceosyops in the Princeton collection that nearly
every part can be accurately restored. The figure' is drawn in perspective with the

•l am under obligations to Prof. Osborn for having loaned me the figure of the re.storation, and also for
some of the drawings for the plates.

315

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

animal jjlaced obliquelj in relation to the plane of the paper. Our study of Palcs-
osyops ^ leads to the conclusion that P. pa/udosus, in tlie cliaracter and form of its
skull, is more closely related to the Tapir than to any other living animal, although in
regard to size Palceosyops departs considerably from the Tapir and is interme-
diate between Tapirus iudicus and Rhinoceros bicornis. The accompanying meas-
urements will show the intermediate position of this animal with regard to size.
The inci eased length and heaviness of all the bones of the skeleton demonstrate
conclusively that this species was not only heavier than the Tapir, but that the
total length of the animal was greater.

Length of head and neck
Total length of body
Height at i^houliler
Height at thigh
Depth of thorax at 4-.5 rib

*Not including Vertebral Spines.

Comparative Measuremekts.

E. bicornis.

P. paludosus.

T. iudicus.

M.

M.

M.

•88

•74

•65

2-13

2-00

T80

*1-09

*•94

*•88

1-16

1-00

•87

•52

•45

•35

The measurements of the limbs prove that P. paludosus was raised higher from
the ground than Tapirus. The length of the head and neck as compared with that of
the fore limbs is slightly less (.03cm) in P. paltcdosus than in the Tapir.

The fonn of the skull differs considerably in this species from that of the
Tapir and this applies especially to the muzzle, which was much shorter and more
obtuse than the Tapir’s and Avas not provided with a proboscis. In its short and
heavy facial region P. paludosus resembles the Bear, and this resemblance is more
strongly marked by the presence of its huge canine teeth.

The great hreadth of the temporal region Avith its large deA-elopment of zygomas
is more like that of the Bears than of Tapirus. The position of the small eye and
the general form of the cranium proper are very like those characters in the Tapir.
The peculiar modification of the zygapopliyses of the lumbar vertebrm points to the
fact that this animal maA' have been more agile in its movements than the Tapir in
Avhich the vertebral processes are flat. The articular surfaces of the limb bones
resemble more closely those of the Tapir, and the position of the limbs Avas proba-
bly the same as in that animal. The manus and pes are broader and heavier than
those of the Tapir; the metapodials especially are stouter. The tail is A^ery
short. As the palseobotany of the Bridger eocene closely resembles that of the sul>
tropical regions of the present day, Ave may conclude that the food of Palceosyops
paludosus Avas much like that of the present Tapii’, and as the remains of this
animal are ahvays found in the Tertiary Lake basins, it is probable that the
habits of P. paludosus Avere like those of the Tapir, that is to say, it led a partially
aquatic life.

42 JOUR. A. N. .S. PHILA., VOL. XI.

316

A MEMOIR UPON THE GENUS

Pal;eosyops valudens.

This species has been described by Prof. Cope' from a lower jaw which was
discovered in the Washakie Eocene. He also described a series of superior molars
under the same name, but was doubtful whether they should be assigned to this
species or not. I have shown elsewhere" that the latter specimens should be
referred to Telmatotherium mlidus Marsh. I am uncertain whether P. vallidens
should really hold a specific rank, as the characters of its molars are so closely
related to those of Telmatotherium that it is difficult to separate it from the latter
genus. At any rate it is one of the most interesting varieties or species of this sub-
family that I have studied and is a true connecting form between Paleeosyops and
Telmatothei'ium, thus showing how closely these two genera are related to each
other.

The diagnostic characters of this species are the posi-
tion and form of the posterior tubercle of the last lower
molar, which in this variety assumes the character of this
lobe in P. paludostis ; but in other respects all the charac-
ters of the teeth are really those of Telmatothermm.

Dentition. — The teeth have high and elongated
crowns such as we find in the genus Telniatother-
mm. Their lobes and crests are very prominent, with
sharp cutting surfaces. The molars are totally without
external cingula. In the premolar series there is no well-
marked diastema in the jaw under consideration, which
would distinguish this species from T. hyognathus, although
ithe total measurements of the molar series are about
^ equal.

The fii’st premolar is wanting in this jaw; the second
has a very high protoconid, which exhibits the same differ-
ence in size to the posterior cone that is seen in Tclniatother-
'' hmi. The V’s of the last jjremolar are apparently not as highly
developed as in the la.st named genus. The lobes of the two
anterior true molars are very much abraided. The last infer-
ior molar (fig. 4) is a very high crowned tooth, much elon-
gated, with the valleys deeply bordered by prominent crests ;
its posterior tubercle, instead of being a functional lobe as in
Telmatotherm7n, is only a cone, without a median valley or
lateral crests. In this respect this molar resembles that of
P. paludos7is but difters from the latter in its posterior
tubercle having a transverse diameter as great as the whole
width of the tooth in front. Then again the last molar of this species shows its
'Pal. Bull. No. 7, p. 1, Aug. 22nd, 1872.

'Prelim. Obs. upon Palajosyops and allied genera. Proc. Acad. Nat. Sei. Phil., Jan., 18i)l.

PAgukk 4.— a series of last
inferior molars to sliow
the form of the posterior
tubercle. 1. Palico.<ti/op.‘t pal-
•udoma. 2. Pal!cosyop.f pal-
udoKHis, variety. S. Palico-
syopn vallidens. 4. Telmato-
thrrimn cuUridens. Two
thirds natural size.

PALJ^OSYOPS LEIDY, AND ITS ALLIES. . 317

close affinity to that of Telmatotheriimi in its high form, whereas in P. paludosus
this tooth is generally very hroad and low, although we have one jaw oi P. palu-
dosus in the collection in which it is quite elongated and narrow. I have con-
sidered the latter variety as a transition form between P. paludosus and the species
under consideration.

d . vallidens is surely the direct transition form to Pelniatotherium ; so we have
in the three species, viz : P. paludosus with its varieties, P. vallidens with its transi-
tion form of molar, and lastly in T. mltridens, the final differentiation of the pos-
terior tubercle, which in the latter species has assumed the form of a true lobe,
with a ^rell-marked valley and crests. The open form of tubercle in Telmato-
thertuni must be considered a case of reversion.

Lower Jaw. — The shape of the jaw in this species is very much like that of
Telniatotim'ium ; it is much elongated and very deep. The anterior portion of the
horizontal ramus narrows more abruptly than does that of P. paludosus.

The body of the jaw is thinner than in P. paludosus and its j)osterior
border is nearly straight and does not show the middle convexity and pos-
terior concavity so characteristic of the mandible in the latter. The posterior
inferior portion of the jaw is not strongly inflected as in the last named species.
The angle of the jaw in this specimen is wanting. The coronoid 23rocess is
high and slender — much higher than the condyle. The region of the sym-
physis is more procumbent than in P. paludosus. The dental foramen is
large, ])laced anterior to the median line of the ascending ramus and on a line
with the molars. The mental foramen is large and placed below the second
premolar. From the consideration of the characters of this jaw we see that
this species was more closely, related to Telmatotherium validus than to P. paludostis.

PALiKOSYOPS L.EVinEXS.

(Not 1\ paluihmi.H Leidj’.)

Prof Cope' has established this species upon the characters of a fine skull in
his collection. He considers this species probably equal to Leidy’s smaller form — our
P. minor ; but in this identification I cannot agree. I shall point out later the dif-
ferences in the dental characters of these two species. In some respects the
characters of the skull of P. leevidens, like those of the teeth, approach closely
those of L. laticcps.

Dentition. — The dentition is interesting as it is very closely related to that of
Limnohyops laticcps, and I consider the molar characters of P. Icevidens much inore
closely related to that sjsecies than to P. minor.

The fact that the second superior premolar has only one external lobe is unique,
and upon this character Coj^e has established the species. In the dimensions of its
teeth P. Icevidcns a2:)25roaches more closely P. minor. The characters of the
incisors are tyjjical of the genus, viz : rounded cones without cingular bases. Both
the pre- and postcanine diastemas are very small. All the preniolars except the

'Annual Keport tJ. S. Geol. Surv. Terr., 1872 (1873) p. 591.

318

A MEMOIR UPON THE GENUS

first have well-marked internal lobes (although in Cope’s figure of this species the
internal lobe of superior premolar 2 is omitted), and their internal basal cingula are
incomplete. The last premolar is considerably smaller transversely than molar
1. In this character it differs from P. minor where these two teeth are more
nearly of the same dimensions. The measurements of the molar series are
mucli less than in P. pahidosus or L. laticeps. The crowns of the molars are low,
without external cingula; the buttresses are well developed, the anterior is pro-
longed, the median buttress being of the typical Palmosyops form ; that is to say, not
widely constricted ofli

In its molar characters P. Icevidens differs very much fi'om P. minor, in which
the crowns of the molars are high, with prominent external cingula. The interme-
diate collides are reduced. As Cope' says “ The anterior median small tubercle of
the first true molar is wanting”. This is a character very different from that of
P. paludosus where the protoconules of the superior molars are always very large.
The internal cones of the molars are low, and in the last superior molar the posterior
internal angle has quite a large basal enlargement. This portion of the tooth is
damaged, but I think it points to the fact that we are here dealing with another
species in which a rudimentary hypocone is present on the last ujiper molar.

Prof Cope“ figures another series of molars which he supposes to belong to this
species. Their dimensions are intermediate between those of P. Icevidens and P.
paludosus. These teeth ai'e no smaller than some molars which we have referred
to P. paludosus in the Princeton collection, so 1 think they should be referred to
that species. The last preniolar of the above mentioned series has its external lobes
without a trace of a median buttress. This is a character which is variable in P.
paludosus, but is generally present. The intermediate conules in the above men-
tioned molars are well developed, and the last preniolar is smaller than the first tiaie
molar transversely. In both series of molars described by Cope as belonging to this
species the enamel is smooth.

Shdl (Fig. 2, p. 289). — The facial region of the skull of this species in Prof
Cope’s collection is very finely preserved ; it is rather short and, when compared
with this region in the skull of P. paludosus, is much higher and more compressed.
This is especially noticeable in the height of the roof of the skull above the pre-
molars. The nasals are much elongated, narrow and not expanded distally.

The characters of the nasals are nearly the same of those of L. laticeps.
The nasal notch is deep; its superior border slopes gradually downward, but
the inferior, instead of being nearly parallel with the superior, diverges widely
from it and thus makes the anterior narial opening very large. The iireniaxillaries
are much elongated from above downward, and sliort antero-posteriorlj-. Their
symphysis is filled up by a matrix in this skull, although Prof Cope considers that
there was no union between these bones. This would be an exception to the rule

'Tertiary Vertebrata, page 703.

^Tertiary Vertebrata, PL L, fig. 3.

319

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

in this subfamily of having no median junction of the premaxillaries while in all
other species these bones have a broad symphysial attachment.

rile anterior border of the orbit is placed over the posterior third of the first
molar. The floor of the orbit is rather elongated and the orbital process of the
frontal is large. The zj^gomatic arch is very heavy, and its scpiamosal division
presents a broad external fiice. The arch is strongly descending, and the zygo-
matic portion has a very long horizontal connection with the malar. The malar
arises abrujitly from the cheek, jiresenting outwardly a sharp external ridge, and
inferiorly a broad horizontal surface. The malar insertion resembles very closely
that of L. laticeps. The infraorbital foramen is large and not exposed. Most of the
cranial portion of this skull is wanting, but enough remains of the auditory region
to show that the postglenoid was short and heavy, being more like the form of this
process in P. inegai'himis.

Pal,t:osyoi>s- bore.vlis.

This species has been described by Prof. Cope' from a portion of a right maxil-
lary bone containing the last three true molars and also one premolar. Other por-
tions of the skeleton have also been described by him i]i his “ Tertiary Vertebrata ”.
As this is the earliest species of the genus in its geological horizon and as it is asso-
ciated with such forms as Lambdotherium popoagicum, both from the Wind River
Eocene of W3u)ming, we should expect to find some interesting primitive characters
more closely connecting it with Lambdotherumi than with the higher .species of
Palceosyops. In my opinion, however, such is not the case, and I find in the
molars of P. borealis advanced dental characters which relate it much more closely
to Palceosyops than to Lambdotherium. Perhaps this may indicate that Lanibdo-
therium is not the direct ancestor of the Palseosyops line, and that we must look to
an earlier geological period for the common ancestor of both Lambdotherium and
Palceosyops.

Dentition. — The last sujjerior premolar, the only one of this series pre-
served, is smaller transversely than the first true molar. Its external face is straight
and shows no median buttress. Its anterior lobe is provided with a slightly marked
vertical fold. The paracone is larger than the metacone. Its internal lobe is
large, low and blunt, and the tooth is provided with a Avell developed protoconnle.
In Lambdotherium a large protoconnle is present upon the last superior premolar,
and this conule is much larger than that of P. borealis. The absence of this conule
from the premolar series of the higher genera of this subfamily is to be remarked ; so
that this character in P. borealis must be considered a primitive one. The last
superior premolar of P. borealis is provided with an incomplete basal cingulum, and
its anterior and posterior cingula are very conspicuous.

In the true molars we have much more highly differentiated teeth than in
Lambdotherium, the external Y’s being more strongly expressed than in that genus.
The external lobes of the molars have not those Cbnspicuous vertical folds between

'American Xaturalist, 1880, page 746.

A MEMOIR UPON THE GENUS

320

the buttresses which are so characteristic of the external V’s in Lambdotherimn.
The form of tlie molar in P. borealis approaches more closely that of Telmatother-
ium than of Paleeosyops, being of a nearly square form without very prominent ex-
ternal buttresses. The external lobes of the molars are moderately high, and traces
of an external cingulum are present. The protoconule of all the three superior
molars is large, especially that of molars 2 and 3. There is no metaconule upon
molar 1. The second and third molars in this specimen are so badly damaged that
it is impossible to determine the presence of this conule.

Slight traces of transverse ridges are to be seen in the molars of P. borealis.
In the first molar these ridges are only slightly developed, whereas in the last
molar the anterior ridge connecting the paracone with the protoconule is plainly to
be seen. The last named conule is largely developed. Compared with those of
Lambdotherium the protoconules and transverse ridges of P. borealis are not
nearly so strongly developed. The smaller size and the peculiar oblique form of
the external face of the true molars in Lambdotherium Avill also readily distinguish
the teeth of that genus from P. borealis.

The Skeleton. — The parts of the skeleton associated with the dentition of this
species are very interesting, and the characters of the well preserved lunar
strongly remind one of those of Limnohyops. This lunar is high and narrow, like
that of L. laticeps ; its distal part is prolonged, with the lunar-magnum facet nearly
vertical in position. The hmar-unciform facet is large and deeply concave. The
characters of the lunar are also closely related to those of Lambdotherium. A well
preserved distal portion of a radius (= .031 m.) shows this species to have been very
much smaller than any other of the known members of the genus.

P,\L.«OSYOPS MEGAKIIINUS.

I have established this species' upon the characters of a fine skull (No. 10,-
008) in the Princeton collection. Unfortunately most of the teeth in this speci-
men are very badly damaged, only portions of one canine and of the last molar
being intact.

Dentition. — The fangs of the incisors which are pi-eserved show that these
teeth are much smaller than those of P. paludosus, and there is oulj' a small
diastema between the outer incisor and the canine. The canines of P. mcgarhinus
are peculiar in form ; they are very small, round in section and divei’ge Avidely from
the skull. The canine aveolus is very prominent and is a strong character in the
skull of this species. Only the roots of the premolar series are preserved in the
specimen. They were probably all much smaller than the pi’emolars of P . paludo-
sus. There is a considei’able difference in the transverse extent of the last pre-
molar and that of molar 1. The last upper molar is jiartially preserved and shoAvs
clearly traces of only one internal cone, a character which places Avith certainty the
generic jjosition ot this sjjecies. This tooth has a Ioav croAvn and rather bi’oad and

'American Xaturalist, Jan. 1891, page 45.

321

PAL^OSYOPS LEIDY, AND ITS ALLIES.

shallow external V’s which are totally without an external cingulum. The median
buttress of this molar was probably well constricted off. The intermediate conules
of the last superior molar are small and reduced. The measurements of the
dental series agree with those of P. IcBvidens, although in the latter species a small
diastema is present, which is totally wanting in the dentition of P. megarhinus,
this being a unique character of this species.

The Skidl (PI. X, fig. 2). — I have referred two skulls in the collection of Prince-
ton College to this species. The first. No. 10,008, is almost perfectly preserved as far
back as the glenoid region. The other is an occipital portion. No. 10,041, with the
auditory processes and basal region finely preserved. The proportions of the facial
and cranial regions of the skull of this species and their general contour, are
very different from those oi P. pahidosus. The dorsal contour is without any jjromi-
nent frontal depression, this part of the skull forming a gradually rising surface as
far as the middle temporal region, the latter portion being slightly higher than the
occiifftal. The facial region is very short and strongly compressed at the middle
portion, with heavy and overhanging nasals. The cranial and facial axes
form a slight angle with one another. The zygomatic fossa is extremely elongated,
and the anterior boundary of the orbit is more widely prolonged forward than in
P. pahidosus. The orbit is extremely small and Bear-like in this species ; it is
nearly shut off from the temporal fossa by a strongly developed post-orbital process.
The occipital region is proportionately higher and narrower than in the larger
forms of the' genus. The occipital crests are strongly compressed, thin and high.
The sagittal crest is much more strongly developed than in P. pahidosus. It is
very thin, high and extends farther forward before diverging into the temporal
ridges than in the latter species. The anterior temporal ridges are weakly devel-
oped, and the interorbital region narrower and more compressed than in P. pahidosus.

The narrow and nearly straight zygomatic arch is very different in form from
that of the allied species of this genus. The shape of the auditory jmocesses is
another character Avhich distinguishes this species from all others of the genus, with
the possible exception of P. lavidens. The basal region of the skull is narrower
than in the larger species. The posterior narial opening is narrow and has its Avails
strongly compressed. The palate is rather long and narroAv, Avith the roof arched ;
its posterior margin is rounded AAnth a median prolongation. The posterior limit of
the palate is at the second molar.

Nasals and Prcma.villaries (PI. XI, fig. 4.)— The premaxillaries differ in form
from those of P. pahidosus, they are short Avith a small linear-shaped median sym-
physis. The anterior aspect of the symphysis presents a prominent median keel.
Upon each side of the latter the surface of the bone is concave, and is bounded pos-
teriorly by the prominent canine alveolus. ^TeAved from beloAv the premaxil-
laries have a decided triangular outline, Avith a short and oblique contour for the
incisors. The palatal extension of the premaxillaries is more limited in this species
than in P. pahidosus-, and the large and apparently single incisiA^e foramen is

322

A MEMOIR UPON THE GENUS

situated on a line anterior to the canines. The form of the nasals is very character-
istic of P. megarhimis, distinguishing it from any other species of this group. They
are much elongated and convex at the middle portion, becoming wider and
strongly depressed at the extremities which are expanded and broader than
the iniddle portion. This character of the nasals distinguishes them from
those of the other species of the subfamily. The posterior portions of these
hones are broad and they articulate laterally with the maxillaries by broad
23lates. Their jtosterior extension is on a line with the anterior j)art ol the
orbits. The nasal notches ai'e rather short, hut higher than in P . paliidosus ;
their superior and inferior outlines are more sinuous than in the latter s^iecies ; the
part of the nasal notch formed by the maxillary is concave anteriorly and then rises
gradually to the superior termination. The maxillaries take a rather larger share
in the formation of the nasal notches than the premaxillaries, whose superior limit
is above the posterior border of the first jiremolar.

Figures. — Outline of Nasals. 1. Palseosyops paludosus. 2. Palveosyops meg-
arhimis. 3. Limnohyo}^^ laticeps> One-quarter natural size.

Proboscis. — There is a wide difference of opinion among paleontologists as to
the presence or absence of a proboscis in certain groups of fossil animals. As it is
important to decide whether or not an animal bore a proboscis, I shall treat
the question as thoroughly as possible and give my own conclusions upon the
subject. They are derived from the study of a number of different groups
of animals which are said to be jjroboscis-bearing. Prof. Cojje' in summing up the
affinities of the Dinocerata as com2)ared with those of the Proboscidea savs “ the 2)os-
session of a proboscis is proven by the extreme shortness and , stoutness" of the free
portion of the nasal bones, by the very short cervical vertebra?, and by the fact that
the nasals and premaxillary bones are deeply excavated at their extremities, with
surrounding osseous eminences for the origin of the muscles of the trunk. ”

On the other hand. Prof. Marsh,= in his restoration of Dinoceras says : “ the
neck was long enough to permit the head to reach the ground, and hence a pro-
boscis was quite unnecessary. The horizontal narial opening, the long overhang-

'Tertiary Vertebrata, i)age 511.

^Monograph of the Dinocerata, page 166.

PAL^OSYOPS LEIDY, AND ITS ALLIES.

323

ing nasal bones and the well developed turbinal bones are likewise positive proof
against the presence of such an organ.. There is some evidence of a thick flexible
lip, resembling perhaps that of the existing Rhinoceros. ”

We see from the above quotations that these authors hold diametrically oppo-
site views I’egarding the occurrence of a proboscis in the Dinocerata. My
own studies u])on the subject lead me to coincide with Prof. Marsh’s views, and I
consider that the Dinocerata were unprovided with a true proboscis. In order to
form an opinion as to the absence or presence of a proboscis in the Ungulates I
submit the tbllowing statement. The European Palamtheroids form one of the
most intei’esting series in this connection and Prof. Gaudry' has expressed the opinion
that in P . crasswn a proboscis was wanting. He observes that in the last named
species the nasal bones are large and project farther anteriorly than in P. medium.
and consecpiently the jDi’oboscis was more reduced. It appears to me tliat this char-
acter should guide us in deciding whether or not a fossil Ungulate bore a proboscis.
As already noticed in Palceotherium crassum, the nasals do not reach as far forward
as the premaxillary suture, and the nasal notches are well developed. On the other
hand in P. mediu7n the nasals are much more reduced, their anterior extremities
reaching to about the middle of the nasal notches. In P. magmwi the abbreviation
of the nasals is carried still farther, and in tlie recent Tapir we see their greatest
reduction. Coincident with this shortening of the nasal bones in the Tapir is
the development of a large proboscis. In the Elephant, the most specialized animal
as regards a proboscis, we have the process carried to its farthest point, the
the nasal bones being very small and placed in nearly the middle of the skull.
In this animal the proboscis is enlarged into a trunk. Accordingly the presence of a
proboscis seems to depend on the reduction or shortening of the nasals, and their
being placed farther back than usual on the skull. With this recession of the
nasals from the premaxillary region there is, of course, more mobility given to this
part of the face, and consequently, where the nasal tips are placed far behind as in
the Tapir, a large j^roboscis is develojoed, this organ being movable in all directions.
If the nasal tips extended as far forward as the premaxillary suture this free play
of the proboscis would be impossible. The mere shortening of the cervical region is
not the cjiuse, or at least not always the cause of an extension of the nasal region into
a proboscis. In the Rhinoceros, for example, which is a more bulky animal, having
the neck shoider than the Tapir, there is no j)roboscis developed, whereas in the
more slightly constructed Taj^ir a well develojjed proboscis is present. In a group
separated widely from the Ungulates, viz : the hisectivo7'a, there are two
genera, Macroselidcs and Myogale, Avhich have a well developed proboscis. I
have not had an opportunity to examine the structure of the skull in these genera,
but owing to their small size I should think it would not be specially modified
as in the Peiissodactyles. In the genus Cystophora {Pinnepidia) the nasals are

'Les Enchainments du Monde .tninial, etc., page 46.

43 JOUR. A. N. S. PHILA., VOL. XI.

324

A MEMOIR UPON THE GENUS

very much reduced and limited posteriorly, and the animal has a large proboscis.
On referring to the Diuocerata, it is found that these animals have the nasal region
constructed hi about the same way as in the recent Rhinoceros, with the difference
that the nasals are prolonged beyond the premaxillary suture in Dtnoceras. T
believe that they were without a proboscis, but probably had a very large and pre-
hensile lip. I am led to this conclusion by the great posterior and vertical extent of
the lateral nasal notches. Accepting the above data as probably establishing the
presence of a proboscis, I conclude that Palceosyops megarhinus was without
such an organ, because in this species, as in all others of this subfamily as far as
known, the nasal bones are very largely developed and extend so far forward as to
overhang the premaxillary region. The lateral nasal notches of P. megarhinus
are deep, but not high, and probably for this reason the upper lip was not as pre-
hensile as in the Rhinoceros. In Titanotlm'ium the nasal notches are larger and
there was probably more freedom of motion in this region.

Frontals.—^\\Q frontals are rather broad and short. They widen very much
anteriorly, and have only a slight articnlation with the ascending processes of the
maxillary. The articulation between the frontals and nasals is broad and extends
across the Avhole forehead. The interorbital region of the frontals is rather
broad, convex, and sends out long and acuminate lateral postorbital processes. The
portion of the frontals forming the superciliary boixler of the orbit is thick and
rounded off. The po.sterior part of the frontals forming the anterior portion of the
temporal fossa is not strongly excavated and is bordered above by weakly developed
anterior temporal ridges.

Parietals. — The parietals unite along their whole superior extent to form the
sagittal crest. The latter is high, strongly compressed, and arises from the upper
third of the temporal fossa, thus forming the extremely high roof of the cranial
cavity. At the junction of the parietals and squamosals the surface of the temporal
fossa is strongly convex and shows a well marked bulging of the cranial cavity out-
ward. In the skull of P. paludosus the whole surface of the temporal fossa is
deeply excavated, showing a less development of the lateral masses of the cerebrum
than in P. megarhinus.

Occipitals. — The condyloid portion of the exoccipitals is strongly con-
stricted off from the supraoccipital region, thus placing the foramen magnum
widely back from the surface of the occiput. The jmrtion above the foramen mag-
num is smooth and superiorly overhung by the well developed lambdoidal crest.
These crests are well developed as far as the lateral parts of the occiput,
and are proportionately larger in this region of P. megarhinus than in
P. paludosus. The paroccipital processes have much less transverse extent in
this species than in the larger form, and their exti-emities are more styliform. The
condyles are broad and heavy, and their transvex’se extent is as great as in P.
paludosus. Superiorly the condyles are separated by a wide and straight
notch ; their infeidor extremities are prolonged upon the basioccipital and separated

PALJ50SY0PS LEIDY, AND ITS ALLIES.

325

by a slight iiiterviil. The basioccipital is shorter and narrower than in P. paludo-
sus and its anterior keel-like and lateral muscular rugosities are very prominent.
The lateral vacuities of the skull are more elongated and narrower than in the larger
species, and are encroached upon laterally by the periotic bones. The lamina of
bone between the lateral vacuities and the foramen ovale is perfectly Hat and broad
in this specimen.

Sphenoidal and Pterygoid Region (PI. XI, fig. 5). — Just in front of the foramen
ovale the roots of the pterygoid j^rocesses of the sphenoid arise, and they extend
anteriorly to form the walls of the narrow posterior narial ojjening. The posterior
nares in this species is much more contracted than in the Tapir. The wings of the
sphenoid forming its inferior termination are not nearly so widely expanded as
in the Tapir’s skull, and the whole extent of the nares from the posterior limit of
the palate to its termination at the hamular processes, form, as it were, a narrow
trough, the anterior and narrow walls being bent inward and thus contracting the
narial space. The sphenoid sends wide horizontal plates posteriorly, and the ali-
sphenoid extends about half way up the side of the temporal fossa. It articu-
lates with the frontals and was probably shut ofi’ from articulation with the parie-
tals as in the Tapir’s skull. The damaged condition of the specimen does not alloAv
us to define the orbitosphenoidal region. The presphenoid is narrower and more
elongated than in P. paludosus-, it shoAvs upon its ventral surface a prominent
keel, and upon each side of the same are the prominent and vertical Avails of the
alisphenoid canal.

Squamosal. — The squamosal forms about the loAver half of the temporal fossa.
Its external surface is not as deeply excavated as in the larger species of the genus ;
its posterior portion presents a numl)er of small foramina. The zygomatic process
of this species is Amry characteristic and t^uite different in form from that of P. pal-
udosus. Instead of being bi'oad, flat and Avidely extended from the temporal fossa
the zygoma of P. megarhinus is narrow, depi’essed and presents only a narroAV
external face. The zygoma in this species is not set off' so far from the sui'face of
the skidl as in others of the genus, as its extreme j)osterior joortion Avhex’e it
joins the squamosal is narroAV. The course of , the zygomatic arch is more
descending than in P. paludosus, and at its middle part it is thin and narroAv, being
in this respect in strong contrast to the arch of the larger species of the genus. The
auditory processes are peculiar in form ; the postglenoid is very short, thick and
rugose ; the post-tympanics are also short and their surface is rough. The
postglenoid is Avidely separated from the post-tymjxanics, so it is probable that the
mastoid appeared upon the surface of the skull. In the skull under consideration
there is a triangular tract betAveen the exoccipitals and post-tympanics Avhich Avas
probably filled up by the mastoid portion of the periotic. The large venous foramen
situated between the paroccipital and post-tympanic, Avhich is so characteristic of
the larger species, appears to be Avanting in this skull. The glenoid facet is long
and narrow, and the anterior surface of the postglenoid is smooth for articnlation
with the jaw. An internal glenoid process is present in this species.

326

A MEMOIR UPON THE GENUS

bent doAvnward with its superior and inferior surfaces concave. The postorhital
portion of the malar is thin and bent inward. This portion of the zygomatic arch
is weakly developed as compared with that of P. paludosus. The malar post-

orbital process is large and sharp.

Maxillary. — The ascending plate of the maxillary is vertical and its surface is
plane ; its antero-posterior diameter is not greater than its vertical, owing to the
very short facial region of this species. The portion of the maxillary forming the
floor of the orbit is broad and deep, much more so than in P. paludosus. The
antero-posterior extent of the orbital floor is much greater than in the larger
species, and in this character P. megarhinus agrees with Telmatotlieriuni. The
prominent canine aveolus forms an abrupt termination to the maxillary region
anteriorly. The infraorbital foramen is large and situated above the first true
molar. The large lamina between the nasal notch and the orbit is formed mainly
by the naso-maxillary articulation. A small opening at the antero-superior part of
the orbit is evidently for the lachrymal duct. Its opening is small, and the lach-
rymal bone probably only formed a small part of the cheek as in the skull of
the Tapir.

z

/

j

Figurk 6. — Comparative views of the occipital region. 1. Limnohyopx laticepx. 2. Pidpeoxijiipx paludoxim.
3. PalxQsyiypx megarhinm. One-fifth natural size.

Foramina. — The condyloid foramen is large in P. megarhinus and is situated
nearer the foramen magnum than in P. pahidosus. The foramen lacerum posterius
and medium are fused with the large lateral vacuity. The foramen ovale is
large and situated about an inch in front of the foramen lacerum medium. The
posterior opening of the alisphenoid canal is about seven-eigtlis of an inch below the
foramen ovale. The antero-posterior extent of this canal is nearly twice as great
as in the Tapir. The portion of the sphenoid fonning the outer walls of the alis-
phenoid canal is strongly convex and very prominent.

Cranial cavity. — The general form of the cerebral cavity in this species is an
elongated oval, with a very much reduced vertical diameter. This is strikingly
apparent when we compare the cranial cavity of a Tapir with that of Palceosyops

PAL^OSYOPS LEIDY, AND ITS ALLIES.

327

77iegarhmus. In the latter the vertical height of the cerebral lossa is no greater
than that of the cerebellar fossa, whereas in recent Perissodactyles, where the cere-
bral lobes are very large and have a great vertical extent, tlie cereljral fossa ranges
high above the cavity for the cerebellum. The anterior limit of the cranial cavity
in P. 7negarhinus is on a vertical line with the middle of the alisphenoid canal.

In the Tapir this cavity is prolonged farther forward and reaches about the
middle of the wings of the sphenoid. Owing to the low reptilian-like form of brain
that occurs in this species the arrangement of the subdivisions of the cranial cavity
follow one another in regular order, and there is not that superior position of the
olfactory fossse that is seen in recent fonns. In other wmi’ds the floor of the cerebral
cavity is nearly straight, and this is especially noticeable in the region anterior to
the pituitary fossa, which is not so oblique and ascending as in the Tapir’s skull.
Another primitive character of the cranial cavity of this species is that the cere-
bellar fossa is strongly marked off from the cerebral by a well developed ossified
tentorium which extends all around the walls and roof of the cranial cavity,
and is as strongly marked in the skull of P. megarhhms as it is in that of the Carni-
vora. In the skull of the Bear, for example, the large size of the tentorium is notice-
able. In recent Perissodactyles the pi-esence of an ossified septum between the two
posterior subdivisions of the cranial cavity is reduced to a minimum ; in the Tapir
it is totally wanting ; in some species of Rhmocei'os it is also absent, whereas in
other species of this genus a single elongated curtain-like process may be developed
upon the roof of the cranial cavity. This is also the case in Eqims. The olfactory
fossm are elongated and well separated from the cerebral cavity. The elongation
of these fossm is a noticeable character of this species. The olfactory fossa of each
side is separated from that of the other by a stout septum, which rises from the
anterior floor of the cerebral cavit}’. In recent forms the olfactory cavities are carried
upward and are oblique in position, but their primitive position is found in Palceosy-
ops. In correlation with the great lateral reduction of the brain of this species is
the encroachment of the brain-case ujion the encephalic mass. The walls of the
brain-case are extremely thick and heavy; this is especially noticeable in the roof
of the skull, which is over twice as thick vertically as in the Tapir’s skull. The
reduction of the brain is especially appreciated when the extremely deep temporal
fossm ai’e seen from without.

B7'ai7i, (PI. II, figs. 6, 7.) — This is the only species of the subfamily whose brain
we are able to figure. There are a number of brain-casts in the collection, all being
from the same skull, No. 10,041. The brain of Palceosoyps megm'hinus, like most of
the Eocene Ungulates, is very small, and when we compare the size of the brain in
the Tapir with that of this species we are at once struck by the great discrepancy
in their size. In the form and arrangement of its lobes the brain of P. 77iegarh77ius
is intermediate between those of Phc7iacodiis and Taph'ics. Compared with the
size of the skull the brain of P. 77iega7'hm7is was larger than that of Titanotfm'hiiTt.
In the latter genus the breadth of the encephalon is unusually developed as compared

328

A MEMOIR UPON THE GENUS

with its length The axes of the fore and hind brain are continnons, and are not
bent npon each other as in the Tapir’s brain, and that of the higher Ungulates

Ceredrum— The prosencephalic lobes are very broad, short and somewhat
depressed ■ their general outline is a broad oval with only a slight distinction between
the frontal and occipital portion. Viewed from the side the temporal lobe is much
less marked than in the Tapir’s brain. The inferior surface of the frontal portion
of the cerebrum is convex and not concave as in the Tapir. The surface of the
hemispheres is well convoluted ; and in this respect this species shows a marked
advance over such early Eocene forms as Phenacodtis and Coryphodon. The .Sylvian
sulcus is well developed and vertical in position. There are also well marked pre-
and poshsylvian sulci, in continuity with the main sulcus. The surface of the brain
between the Sylvian sulcus and the hippocampal is smooth and strongly convex ; as
there is no fissure between the two last mentioned sulci we may conclude that the
Rhinal and Sylvian sulci have coalesced as in the Carnivora. In the Tapir and
Rhinoceros the .Sylvian and Rhinal sulci are distinct, and the presylvian is separ-
ated from the Syiviaii proper, although its primitive condition is in connection with
the latter. A long wavy fissure above the superior termination ol the .Sylvian sulcus
is evidently the suprasylvian fissure. It extends from the posterior part ot the
occipital lobe well forward to the middle portion of the frontal; in its couise it
throws off’ a number of secondary sulci. There is an indication that the crucial
sulcus was present in this brain, but the coronal, so characteristic of the brains ol
recent Ungulates, is absent. The lateral portion of the occipital lobe above the
posterior prolongation of the Sylvian sulcus is provided with an o))lique fissure,
which is probably the one called by Krueg the posterior fissure. The convolu-
tions of the brain in P. megarhinus compared with those of the Tapir are less numer-
ous and complex. In the Tapir’s brain the longitudinal secondary (issures are more
numerous, and the frontal lobes of the hemispheres ai'e much larger than in P.
megarhinus. This region is also more convolute in the Tapir. The olfacfi)ry lobes
in the brain of P. megarhimis are large and strongly prolonged anteriorly. They
differ in form from those of recent Perissodactyles, where they are more vertically
placed, their long axes being from above downward and closely connected along
their whole extent with the surface of the hemispheres. The olfactory lo)>es in P.
megarhinus were separated, and probably ninch longer than represented in the
drawing, as in the cast they appear to Ije. abruptly cut off’.

Midhrain. — In Phenacodus primcevus the prosencephalic lobes arc widely sepa-
rated from the cerebellum, leaving the midbrain region exposed as in reptiles. In
Paleeosyops megarhinus the brain is more highly developed than in Phenacodus
primcevus. Although the cerebral lobes do not reach the hind brain, they were
prolonged probably far enough behind to cover the corjjora quadrigemina.

Cerebellmn. — Tlie hind brain is imusually large and broad in this species. The
cerebellum is as wide transversely as the whole extent of the prosencephalic lobes ;
it is subdivided into three narrow lobes, the median being the largest and most con-

PAL^OSYOPS LEIDY, AND ITS ALLIES.

329

spicuoiLs. The vermis shows signs of transverse folds, hut the condition of the cast
does not allow this point to be made out definitely. Two small appendages, which
may be the Hocculi, are given off from the cerebellum, one on each side at the
antero-inferior angle of the same.

Medulla. — The medulla oblongata is peculiar in its great breadth, it being
nearly as broad as the cerebellum and strongly depressed. The form of the medulla
differs very much from this portion of the Tapir’s brain, where it is round in section
and much narrower than the cerebellum. The brain viewed from the side shows
no contact between the the cerebrum and cerebellum. The inferior surface of the
brain shows the roots of the optic nerves, and posteriorly upon each side is seen
the origin of the fifth pair of nerves ; a deep fossa between the two latter,
bounded anteriorly by the optic nerves, is evidently the pituitary fossa. The sur-
face of the brain posteidorly to the origin of the fifth pair is higher than the region
of the pons Yarolii, which, together with the inferior surface of the medulla, is
ver}’ flat and wide. Just posterior to the cerebellum and upon the lateral side of
the medulla, are two pi’ominences which are probably the origin of the twelfth pair
of cranial nerves.

Co.MPARISOX OF THE BrAIN OF PaL^EOSYOPS WITH THAT OF OTHER UNGULATES.

Comparing the brain of P. megarhimis with the lower Eocene Amblyopoda and
Condylarthra we see a marked increase in its size and in the dimensions of the
anterior lolies, the posterior prolongation of the latter approaching the region of
hind brain, thus differing very much from the Wasatch forms. Although occurring
in the same beds with Palceosyops we have the abnormally small brain of Uinta-
theriinn, which is unusual in the diminutive size of its encephalon. In Hyrachyus
eximuis, an animal about the “ size of a large sheepV’ we have a form with a much
larger brain relatively than that of Palceosyops. In Hyrachyus the forebrain is
large, with large temporal lobes. There is in the latter genus a marked difference
in the breadth of the cerebrum as compared .with that of the cerebellum, but if the
casts of H. eximius can be relied upon, the convolutions of its brain were not nearly
so complicated as in Palceosyops, the gyri I'unning nearly longitudinally and par-
allel. The general form of the prosencejihalon in Hyrachyus closely resembles that
of the recent Carnivora. The whole bulk of the brain of P. niegarhinus compared
with that of the Tapir, is nearly one-half less, whereas in the brain of Hyrachyus
compared ivith that of Ovis, this difl’erence is not nearly so great. Marsh’s figures
of the brain of Titafiothei'him indicate that the forebrain did not extend at
all over the hind brain, although the hemisjiheres were “ richly convoluted,”
their width and the large deA^elopment of the temporal region being greater than
in Palceosyops. In the convoluted surface' of its hemispheres P. megarhinus
approaches the Tapir and is much more highly developed in this respect than
any of the Eocene forms which I have studied. The great size and breadth of

'Tertiary Vertebrata, page (>72.

330

A MEMOIR UPON THE GENUS

the hind brain in Pakeosyops distinguish this genus from recent Ungulates, approach-
ing more nearly the conditions seen in the Condylarthra {Phenacodus) .

Brain Measurements. ( Volume) .

Taph'us iudicus
Palceosyops megarhimis
Hyrachyus eximius
Ovis aries

320 cc.
180 “
096 “
095 “

Summary of Brain Characters.— following are the peculiarities of the
brain of P. megarhinus -.—X. Reduced size of forebrain, especially the frontal lobes.
2. Separation of fore-brain from hind-brain. 3. Large size of cerebellum. 4. Great
breadth of the medulla oblongata.

Brain Measurements of P. megarhinus.

Total length of brain ....

M.

•100

Length of hemispheres ....

•070

Breadth of hemispheres ....

•Otl.5

Height of hemispheres at temporal lobe

.044

Length of occipital lobe.s of hemispheres .

•0.S4

Lengtli. of frontal “ •

•020

Breadth of olfactory lobes ....

•0:i8

Breadth of mid-brain ....

•037

Breadth of cerebellum ....

•05,5

Antero-posterior extent of vermis

•03(1

Vertical height of eerebellnm

■047

Width of medulla .....

•04(1

Pal.’eosyops minor.

The relation of this smaller species of the genus Palceosyops to P. paludosus has
been shown in our preliminaiy paper.' I will merely add that P. minor embraces
specunens which Dr. Leidy erroneously assigned to P. paludosus. They are illus-
trated by figures 3—6, Plate IV, of his report for 1873.“ They comprise a complete series
of superior molars. Other specimens of this species figured by Leidy are a portion
of the facial region containing the first three preniolars, and a finely preserved lower
jaw which he represents on Plate V, figure 11. In the Princeton collection the
material referable to this species is very limited. There is a partial set of molars.
No. 10,242, and also three portions of jaws with the teeth rather damaged, speci-
mens No. 10,042 a, b, c. I have alreadj^ mentioned the fact that the generic refer-
ence of this species is uncertain. We know nothing of the anterior premaxillarv
region of the skull, which is so important in distinguishing some of the genera of
this subfamily. The characters of the teeth are very interesting, and show on
the whole a more decided affinity to Telmatotherium than to Palceosyops although
'Prelim. Obs. etc., Proc. Acad. Nat. Sci. Phila., Jan. 1891, page 112.

"The type specimens of this species are in the Academy of Natural Sciences of Philadelphia.

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

331

in some respects they retain certain very primitive characters which prove the
intermediate position of this species.

Dentition. — The incisors are not round in section as in P. paliidosus bnt
strongly compressed, with a rndimentaiy internal basal ridge. In the second
incisor there is a lateral heel. The characters of the incisors are intermediate
between those of P. paliidosus and Telmatotheriuni. In Prof Leidy’s report' he
describes two series of superior molars associated with their canines. He notices
the difference in the size of the canines in the two series, as well as the character
of the preniolars in both specimens, and he concludes that the great difference dis-
played in the size of the canines is probably a sexual character. He also remarks
that with the great development of the canines there is a concomitant reduction, as
it were, of the premolars. I have already observed the sexual differences in the
size of the canines and premolars of P. paliidosus and quite agree with Dr. Leidy
in his interpretation of these facts, although in onr examples of P. paliidosus there
is not a reduction in the complexity of the premolars with the increased size of the
canine. This is certainly not the case, as in the female of P . paliidosus with
smaller canines, the premolars are consideraldy smaller than in the male with its
huge tusk-like canines. It is interesting to note that the superior premolar series of
P. minor more closely resembles that of Telmatothcriiim and departs considerably from
the characters of these teeth in P. paludosus. The first premolar has an elongated
croAvn ; it is the exact connterpai't in form of this tooth in T. cultridens ; its para-
cone is curved backAvards and compressed. There is only a verA^ slight indication
of an internal cingulum to premolar 1, but the base has a slightl}^ enlarged heel.
The first premolar is separated by a slight interval from the canine and the tooth
sncceeding it. Premolar 2 has its anterior border very oblique AAuth its internal
cone not strongly marked. Its external lobes are subeqnal, the paracone being con-
siderably higher than the metacone. The anterior V of this premolar and those of
all the succeeding ones ax-e pi’ovided Avith a pi’ominent median rib. Pi’emolars 3 and.
4 have rather high croAvns AAntli equal external lobes. The latter are not separated
by a median buttress. These teeth have traces of a protoconnle, although the
latter lobule is in a A^ery rudimentary condition. The inteimal basal cingnlum of all
the premolars is incomplete and the external cingulum of the third and fourth is well
mai'ked. There is a difference in the ti’ans verse diameter of preniolar 4 and molar
I in this species. The explanation offered by Prof Leidy of the difference between
the two series of pi-emolai’s figui-ed by him is a very important one, and
if his statement be cori’ect that in P. minor there is an increase in the com-
plexity of the antei'ior pi-emolars Avith a decrease in the size of the canines, it
obviates the necessity of making a neAV species out of a specimen, Avhich, in its
true molar chai-actei’s, agrees almost exactly AAuth the typical example of this
species.

'Extinct Vertebrata, etc., page 36, 1873.

44 JOUH. A. X. S. PHILA., VOL. IX.

332

A MEMOIR UPON THE GENUS

Superior 7nolars, (PL XII, Hgs. 14, 15.)— Tlie true molars are of the Telinato-
theroid type, that is with high crowns, axes nearly equal and very prominent and wide
external lobes. The median buttresses of the molars, as in Telmatotheriiim, are strongly
constricted off, and the external liice of the teeth are provided with a strongly marked
cingulum. The portions of the V’s between the buttresses are flat and even, and
there is only a slight trace of the median rib. The internal cones of the molars are
characterized by being very iiyramidal in form, thus diftering from Telmatotherium
where these cones are sharp and round. The protocone of the la.st molar is large
and placed opposite the concavity of the V’s. The intermediate conules of the
molars are only slightly developed. They all have a very small protoconule.
and there is a rudiment of the metaconule on the last molar. Tlie intermediate
conules are in a state of reduction in this species and in that respect are like those
of T. cultridens in which they are nearly wanting. The posterior internal angle
of the last molar is cut off oblicpiely, and has not the square form which is so
characteristic of Tehnatothemmi .

Inferior molars. — The beautifully preserved mandible figured by Leidy,'
with the lower dentition nearly complete, we may consider as the type speci-
men. It illustrates the characters of the lower molars in this species. This
jaw was not found associated with any superior molars, although we find the type
specimens of the upper molars correspond very well with it. The original iiderior
molars which were described by Leidy,^ I have shown in my preliminary j)aper
to belong to P. paludosus. As we have already seen, the charactei’s of the
upper molars more closely resemble those of Telmatotherium than tho.se
of PalcBosyops. On the other hand, the lower molai’s are more of the Pahv-
osyops type ; that is to say, their crowns are low and hi'oad, the arms of the V’s
are not high, sharp, and bordered by deep valleys as in Telmatotherium. Only the
last two premolars ai-e preserved in the jaw belonging to the Academy ; in preniolar
3 the protoconid is much larger than the metaconid, but there is no trace of the
posterior arm of the anterior V jjresent in P. paludosus. The double I^’s of tlie last
premolar are, however, more strongly expressed in this jaw than in that of the
larger species. The entoconid of this tooth, as in that of P. paludosus, is wanting.
The last inferior molar differs from that of P. paludosus in being .somewhat longer
in proportion to its breadth. The jJosterior tubercle of this tooth agrees with that
of Telmatothermm in being a well developed lobe, although its transverse extent is
much less than the transverse diameter of its molar. Both the internal and
external basal cingula are wanting in these teeth. The few specimens of this
species in the Princeton collection show little variation in the characters of the true
molars, and as we have seen, such variation is confined mainly to the jiremolar
series. I may add that in all the teeth examined of P. minor the enamel is
perfectly smooth and generally of a very dark color.

‘Report U. S. Geol. Surv. of Terr., 1873, plate V, figures 10-11.

‘‘Proc. Acad. Phil., 1870, page 113.

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

333

Milk dentition^ (PI. XI I, tig. IG.) — There are two small teeth from the same
individual, which I consider as probably belonging to the milk dentition.
I have referred them to this species provisionally because they closely approach
in form and general characters the molars of P. minor. The first tooth
closely approximates in form to the superior premolar 2 of Telmatotheriutn.
Its antero-posterior axis is much drawn out, the external lobes are very sharp
and high, the internal face is provided with a prominent basal ridge, from
which spring two rudimentary cones, the posterior being more plainly marked
than the anterior. The anterior border of this molar is very obliquely cut
off, and strongly reminds one of the form of tlie second superior premolar of Telma-
tothei'iuni. The second tooth in this series is considerably larger than the first, but
its general form is the same. The external V’s are more strongly expressed, the
median buttress, being of the Tehnatotheroid type, is well constricted off. Both the
external V’s of this molar are provided with well marked median ribs. The internal
cones of the second molar are well developed and of the same size ; the protocoue is
nearly separated from tlie internal cingulum, whereas tlie hypocone is still in its
primitive condition and not separated. In both the above teeth tlie external
cingulum is present, which shows their close relationship to Telmatotherium.
The intermediate tidiercles of these molars are much reduced. A peculiarity of the
external lobes of both these teeth is that they are very thin and much worn. The
slightly worn V of the anterior tooth exhibits the abraded surface of the enamel
much thinner than in the permanent dentition. Because of this character and their
rather low crowns I have referred them to the milk dentition. There is one mandi-
ble among the many in the collection which belongs to P. paliidosus. In
this jaw the last milk molar is present, and, as is usually the case, is as comjilex in
its structure as is the permanent first true molar.

The Skull. — We are unfortunately entirely ignorant as to the form of the
skull of P. minor, and, in fiict, I have seen only one specimen of a portion of the
skull of this species, that figured by Dr. Leid}^ on Plate XXIV, fig. 6 of his work.
I have unfortunately not been able to examine the facial region containing the
molars above referred to, as it is in a private . collection. The specimen figured
l)y Leidy' and the one which I have been able to examine contain the canine
alveolus and the first three premolars. The form of this portion of the skull is
high and narrow and resembles that of Telmatotliermm. The canine alveolus is
peculiar in form : instead of being rounded as is usually the case, the surface of the
muzzle above the canine forms an oblique ridge which runs parallel to the maxillo-
premaxillary suture ; behind this ridge the surface of the maxillary bone is
deeply hollowed out, and posteriorly becomes perfectly fiat. The form of the pos-
tero-superior part of the premaxillary bone, which is preserved, leads me to con-
clude that this region was more slender and elongated than in P. paludosus. The
superior termination of the nasal process of the premaxillary was above the second

'This specimen is now depo.sited in the collection of the Academy of Natural Sciences of Philadelphia.

334 A MEMOIR UPON THE GENUS

preniolar The part of the ])alate preserved in this specimen shows this region to
have been more elongated and narrow than in P. fialudosus ■, the palate was also
strongly arched as in the sknll of Tclmatotherium. A specimen of tins species m
the Princeton collection containing the malar insertion is interesting, as it shows the
close relationship in form of this bone to that of relmatothenum. As in the latter
-enus, the malar arises very abruptly from the cheek and diverges widely from it.
Its superior face below the orbit is convex ; its inferior surface is divided by a sharp
lono-itudinal ridge. A small orbital process of the malar is present in this specimen,
and” posterior to this region, the malar is very thin and strongly compressed. The
orbital floor, like that of Telrnatother'ium, is much elongated. Dr. Leidy, in Ins
description of the facial specimen already referred to, says “ the space behind the
anterior abutment of the zygoma indicates a temporal fossa of large capacity ” ; and
again “the orbit is low and is directed obliquel^^ foreward and downward. In
advance of the prominent anterior orbital margin the side of the tace is nearly
vertical. The infraorbital foramen is rather large, and is situated over the jKisitioii
of the last premolar. ”

Mandible. — The form of the jaw in P. minor closely resembles that of
P. paludosus. The horizontal ramus is rather short, thick and deep below the last
molar. The posterior border of the jaiv is sinuous in outline, but this margin is not
so strongly inflected as in the larger species. The ascending ramus is short and
deep, its horizontal diameter on a line with the last molar is abln’cviated in contra-
distinction to the elongation of this region in the jaw of P. longirostris, wdiere the
ascending ramus is Avidely prolonged posteriorly. The condyle is short and heavy ;
it is horizontal in position and separated by a shallow notch from the long and
slender coronoid process. The masseteric fossa is broad ami shallow, and is not
separated bj- a ridge from the horizontal portion of the jaw. The angular ])ortion
is thin and everted. The jaw symphysis, is very short and not 2)rocunibent.
There is a single mental foramen situated beloAv premolar 3.

AePENDrcrL.AK Skeletox.

Scapula, No. 10,277 A. — A lower portion of a smaller scapula than that of P.
paludosus shoidd probably be referred to P. minor. The specimen is vein" much
damaged, so that is impossible to give all its characters. The general form of the
scapula in this species closely .resembles that of P. paludosus. The glenoid is
deeply concave. The coracoid is very much broken, but its position and form is
the same as in the larger species. The anterior border of the scapula aboA’e the
coracoid is concave, and then rises suddenly to the strongly convex superior portion.
There is a prominent tuberosity upon the posterior border, but it is much more
reduced than in P. paludosus. The origin of the spine is nearer the glenoid border
than in the larger species. The internal surface of the scapula is flat Avith a coiiA'ex
posterior portion. The dimensions of this sjjecimen and its characters correspond
very closely to one in the Academy of Natural Sciences of Philadelphia, Avhich
probably belongs to P. inino7'.

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

335

Femur, No. 10,847. — The femur of P. minor has the same length as that of
the Tapir, its shaft, however, differs from the latter in being broader and heavier.
The specimen under consideration has the great trochanter broken off, but from the
basal portion I conclude it was probably of the same form as tliat of P. paludosus.
The head of the femur is perfectly cylindrical. The neck is not well marked off'
from the shaft. The trochanteric fossa is flattened and deep. The anterior surface
of the shaft below the head is strongly raised and terminates posteriorly in a rounded
surface; upon this surface and just above the trochlear is a well marked fossa. This
is present in the recent Tapir but is only slightly marked in the femur of P. palu-
dos7is. The lesser trochanter has about the same position on the shaft as that of
the Tapir, although it is moi’e prominent and longer than in the latter form. The
surface of the shaft at the third trochanter is very broad compared with the length of
the femur. The third trochanter is longer hut not as prominent as that of the
Tapir’s femur ; its distal portion is broad and strongly rugose. The distal extremity
of the femur is broader in front and does not expand so much behind as in that of
the Tapir; nor is the antero-posterior diameter as great as in the latter form. The
trochlear surface is placed more underneath than in the latter and its surface is
broad and short with the internal rim longer than the external. The inter-
condylar fossa is rather short and not as deep as in the larger species. The posterior
face of the shaft is flattened and broader than that of the Tapir, and like that of P.
paludos7is it shows no fossa for the flexor perforatus muscle.

Tibia, No. 10,357. — The length and diameter of the shaft of the tibia coin-
cides very chjsely with that of the 'hapir. The proximal portion has its facets hori-
zontally placed, whereas in the Tapir these facets are oblique to one another. The
upper part of the tibial tuberosity is subdivided and the crest extends farther down
on the shaft than in the tibia of the Tajiir. The external notch for the extensor
tendon is wanting, as in the tibia of P. paludosus. The distal trochlear surface is
narrower than in the Tapir ; its external process is oblique instead of being cut off
squarely as in the latter genus. The jjosterior trochlear tuberosity is rather long,
slender and more medially placed than in the Tapir. The external trochlear border
is not deeply excavated and shows a straight facet for the fibula. The superior
flbular facet is also well developed in this species.

Fibula, No. 10,352. — There is a fibula in the collection whose proportions cor-
respond closely to those of the above tibia, Imt it was not associated with it. I
shall, however, provisionally refer it to P. minor. This fibula is rather longer
and stouter than that of the Tapir; its proximal portion is broad and flattened.
Superiorly it shows a long and narrow facet for the tibia ; its distal end is rather
broad and heavy, and is bordered before and behind by a rather prominent styloid
process. The astragalar facet is concave and shows an elongated lateral fiicet
for the tibia. The articular extremity resembles more closely in form that of the
Rhinoceros than that of the Tapir.

The Tarsiis, (PI. XIY, fig. 43.) — The tarsal bones ai'e represented in the collec-
tion by a nunfljer of specimens, among them being a very finely preserved astragalus

330

A MEMOIR UPON THE GENUS

associated with the tibia, No. 10,357, already described. The measurements (jf tliis
astragalus correspond very closely with those given by Leidy for this species. There
is also another astragalus and calcanenm, No. 10,288 B, whose characters and
measurements approximate closely to those above referred to. The foot in P. minor
is narrower in comparison with its length than the foot of P. pahidosns. This
is especially noticeable in the form of the calcanenm and astragalus, which are
very much* lighter than in the larger species. The astragalus especially has the
elongated form and rather slender neck so characteristic of that of Lmmohyops. Tlie
size and proportions of the pes in this species are about the same as that of Tapirns
indicus. The foot of the latter, however, is rather more elongated in pi’oportion to
its breadth than that of P. minor. The arragement, form and larger size of the
tarsal facets, together with the shape of the cuboid, distinguish the tarsus of this
species from that of the larger species of Plyrachyus.

Calcanenm. — The calcaneum is long and narrow ; its articular portion being
much narrower than that of P. pa/tidosus. The distal portion of the tuberosity is
wanting in this specimen but the basal portion of the same is preserved and is rather
slender and compressed. The form of the calcaneal facets is nearly identical with
that of the larger species ; the sustentacular is, however, longer and slenderer.
The inferior and sustentacular facets approach each other nearer than in P. paln-
dosus. The inferior facet is long and sharply separated from the cu)x)idal face of
the bone. The cuboid facet is much nan-ower in compari.son with its ))readth than in
the larger species ; it is more nearly horizontally placed than in the latter species-
and slightly convex transvensely. (Juite a deep fossa separates the cuboid and the
inferior facet from the sustentaculum. This calcaneum exhibits a well marked
fibular facet.

Astragahis. — The astragalus of P. minor is nearly as long as that of P. paludosus.
but it is much narrower; its trochlear portion being about one-third less in extent
than in the larger species. The distal part is much elongated and slender. The
form of the trochleas is the same as in P. paludosus. but the height of the external
trochlear is much less, and the isosterior portion of it thins out very much behind,
thus allowing the sustentaculum to penetrate upwaixls more than in the larger
species. The fossa spoken of as occupjdng the external trochlear face of the
astragalus ot P. palndosns is only slightly marked. The most important difl’er-
ence in respect to the facets of the inferior surface of the astragahis is that tlie
sustentaculum and inferior facets are continuous. The ectal facet is very deep and
narrow ; its anterior prolongation is not as great as in P. pahidosns. The susten-
taculum is very long and nearly straight; its proximal end is separated from the ectal
facet by an oblique fossa which runs across the surface of the bone. Anteriorly and
mternally the sustentacidum is bordered by a prominent triangular ridge and the
plane of the facet is oblicpie to it. A slight ridge is present at the junction
of the sustentaculum with the cuboidal facet. The inferior facet of the astragalus
IS narrow ; it terminates above and below by narrow extremities, its middle portion

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

337

being the broadest. The form and length of the inferior facet of tins species differ
widely from tliat of P. paludosus. The inferior facet is continuous with the
sustentaculum. The anterior face of the astragalus is slightly convex from above
downward; its cuboidal margin is verj' oblique and this border joins the ental at
the prominent inferior ridge of the astragalus already described. The astragalo-
cuboid focet is wide above and narrows below to join the sustentaculum. Instead
of running across the whole cuboid margin of the astragalus as in P. paludosus this
facet in P. minor takes up only one-half of the whole length of this border, the
lower portion being occupied by the sustentacular, which, owing to its oblique posi-
tion, runs up on it. In P. pahtdosus, owing to the horizontal position of the
sustentaculum, this facet is limited wholly to the inferior surface of the astragalus.

Nainadar. — The characters of this bone as compared with those of the larger
species are nearly the same, but its calcaneal face is more concave and the depth of
the bone is greater in comparison to its width. The distal facets of the navicular
are subecjual, that for the mesocuneiform being slightly smaller than in P. pahidosus.
The facet for the entocuneiform is not well marked in this specimen. The cunei-
form bones are wanting in this pes ; thej" were probably wider and not as high rela-
tively as in the larger species.

Cuboid. — The cuboid of P. minor is strikingly different in form from that of
P. paludosus. It is a nearly square bone with the depth scarcely exceeding the
width. The tuberosity of the cuboid is large, heavy and medially j)laced. The
proximal face is subdivided by a very prominent ridge separating the rather large
astragalar fiicet from the calcaneal. The astragalar facet is short and broad ; its
plane forming a more acute angle with that of the calcaneal than in P. paludosus.
This portion of the cuboid bearing the astragalar facet is contracted oft' in a
neck-like process quite different from that seen in P. paludosjis. The calcaneal facet
takes up about two-thirds of the distal face of the cuboid and is very broad and
shallow. The distal face of the cuboid is remarkably ffat and square', posteriorly it
narrows, but its transverse diameter is relatively greater than in P. paludosus. The
cul3oid of P. minor can be readily distinguished from that of Hyrachyus. In the latter
it is long and narrow with a small astragalar contact ; its tuberosity is also more
acute and laterally placed in the last named genus. There are two other cuboids in
the collection which correspond in all their characters ^\uth those given for the
above ; they differ, however, in being mucli larger, 'and I tliink they probably belong
to one of the large species of TelmatotJierium. If this supposition is correct, the
specimens are of interest, as they show the close relationship between P. mimor and
Telmatotherium. This affinity has also been proven from the dentition of P. minor.

Metatarsals, (PL XIV, fig. 44.) — The metatarsal region is shorter and more
slender than in the larger species. The shape of the metapodials is, however, the
same. The j^roximal part of metatarsal II is externally abruptly cut off’ and exhibits
no entocuneiform facet ; its shaft is broad and short. The facet on metatarsal II for
the mesocuneiform is elongate and concave transversely. Metatarsal III is more

338

A MEMOIR UPON THE GENUS

slender than that of P. pahidosus ; its cuneiform facet is fiat and oblique. The two
facets on this metapodial for metatarsal IV are large and placed obliquely to each
other; internally it shows no facets for metatarsal II. The distal articular surface
of metatarsal III is more slender than in P. paludosiis, and its tuberosities above the
trochlea? are less conspicuous. Metatarsal IV corresponds closely to the correspond-
ing bone in the larger species but is shorter and more slender ; its shaft is strongly
'bent outwards, and its proximal facet for the cuboid is very flat.

PAL.EOSVOPS LOXGIROSTHIS pp. IIOV.

The type of this new species of Palceosyops a jaw% No. 10,2 To, associated
with a well-preserved radius, ulna, and two metacarpals. All these si)ecimens
are in the Princeton Museum. The type jaw of this species, with the parts of the
skeleton associated with it, was referred by Scott and OsboriP to our P. minor (equal,
in part, to P. paludosus Leidy). After comparing Leidy’s type specimen with this
jaw, I find that there is such a marked difl'erence in some of its cliaracters that I
have to give it a specific rank. The following characters distinguish it from
Leidy’s type. 1. The great posterior extension of the jaAv behind the last molar (this
is a unique character of this jaw. I have not observed it in any other species
of this subfamily) . 2. The symphysis is much more elongated than \\\ 1\ minor.

3. The lower border is straighter and less inflected than in P. minor. 4. The pos-
terior tubercle of the last inferior molar is much larger than in the last named
species. 5. The V’s of premolar 4 are not so Avmll developed as in P. minor, and
there is also a Avell marked diflerence in the size of the first molars of the two
species. In this jaw the first true molar is considerably smaller than in minor.
The canine is Amry large and semi-})rocnmbent, its position in the jaAv resembling
that of T. hyognathus.

Skeletox.

Radttts and Ulna. No. 10,275. — The nirper arm-bone of P. longirostris
is Avanting, but Ave are fortunate in having in the collection both bones of
the loAver arm, Avhich belong to the same indi\ddual as the jaAv aa IucIi has been
already described. This radius and ulna liaAm been ah’eady described by Scott and
Osborn, and I Avill merely insert a comparison Avith the same Ixmes in Limnohyops.
They are nearly of the same size as in the latter genus. The head of the radius is
deeper and narroAver than in L. laticeps. The external trochlear is much deeper
and is not excavated by the radio-ulna facet as in the former species. The total
length of the radius is much less than in Limnohyops. The internal ridge running
from the external border of the bone upAvard to Avithin a couple inches of the head
IS not so Avell marked in this species. The distal articular face of the radius is very
large as compared with the length of the bone. The styloid portion of the articular
face IS not so oblique as in L. laticeps. The ulna is also proportionately short and
heavy. The olecranon is different in form from that of L. laticeps, it being broader,

’Kept. Prill. Scien. Expert, for 1877, page 37-38.

339

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

and more irregular at its extremity. The sigmoid cavity is damaged in this speci-
men. It was broader and not as high as in Lymnohyops . The radial face of the
ulna is concave from side to side and much broader, the oblique ridge upon its upper
portion being more marked than in L. laticeps. The shaft of this ulna is broader,
flatter and more angular than in the last named form. The relations of the
distal extremity are about the same as in L. laticeps, this part being exca-
vated upon its internal border and more set oft from the shaft than in the
latter. The facets of the distal extremity are the same in size as in L.
laticeps. From the size and position of the bones of the lower arm of P. longi-
rostris we may conclude that this species had a shorter and heavier anterior
extremity than L. laticeps. This is farther shown in the size and form of the
manus.

Manus. — The material relating to the manus is as follows : a right meta-
carpal II and IV found associated with jaw No. 10,275, and radius and ulna of
the same number. In addition to the above material I have found a lunar
and magnum which I refer to this species.

Lunar. — The lunar closely resembles that of P. paludosus in its general form
and the position of its facets, although it dift’ers from the latter in being much
smaller. The general proportions of the lunar are broad and low ; its vertical axis
exceeding somewhat the transverse. The depth of this lunar is short compared
with its other dimensions. The posterior part ol the superior facet is much lower
than the anterior, being strikingly so as compared with P. paludosus. The lunar-
magnum facet is larger proportionately than that ol the larger species and
approaches nearer the median axis of the bone. The lunar-unciform is very large
but not as deeply concave and more obliquely placed than in P. paludosus . The
lunar in this species also resembles that of the largest species in having only a
slight prolongation of its inferior face between the magnum and unciform.

Magnum. — The form of the magnum is rectangular; its transverse axis
only slightly exceeds its vertical. The magnum-lunar facet is more nearly vertical
than in P. paludosus, and the anterior part of the superior face is more hori-
zontal, with the pivot less ascending than in the latter. The magnum-metacarpal III
facet is deeply concave and not overhung by a beak-like process as in P. paludosus.

Metacarpals. — The second metacarpal is in a good state of preservation ; it is
much shorter than that of P. paludosus but proportionately broad in comparison with
its length. Its distal extremity is broad and heavy. The facets of the proximal
end are the same as in P. paludosus, the superior one being not so concave as in the
latter. Unfortunately the projecting portion of this metacarpal which articulates
with the magnum is broken, but otherwise the shape of the proximal extremity
closely reseinbles that of the larger species of this genus. Only the proximal part
of metacarpal IV is preserved. It is quite massive and the facet of its superior face
rather more oblique than in P. paludosus. Its radial facets are unusually large for

46 JOITK. .4. N. S. PHILA., VOL. XI.

340

A MEMOIR UPON THE GENUS

tlie size of this metapodial, especially the posterior one. The facets for the meta-
carpal V are also large and inclined to each other. The size and proportions of
the above metatarsals indicate that P. lo?igirostris had a short and broad manus
like that of P.paludosus hut much shorter. It also resembles the latter species in
having wide-spreading digits to the manus. The two carpal bones that have been
just described also point to a carpus with a considerable transverse breadth and a
much shorter vertical diameter.

Measurements of Lower Jaws.

P. minor.

P. longirostris.

Total length from posterior border symphysis to pos-

M.

M.

terior border of ramus

•250

•270

Length of ascending ramus behind molars on a hori-

zontal line .....

•102

•1.30

Depth of ramus below last molar

•068

•066

Length of entire inferior molar series

■164

•155

Length of true molars ■ . •

•100

•001

Last molar ft™''®- ’ ’ ' '

•022

•020

(, ant-post. .....

•041

•042

TELM ATOTHERIUM .

(Sj'n. — Leurocqplialus S. and O.)

This genus was established by Marsh' in 1872 the type species being his T.
validus in the Yale College Museum. Later Scott and Osborn^ described their
genus Leurocephalus, which, as I have already stated, I find upon comparison with
Marsh’s type specimen to be the same as Telniatotherium, of which it is therefore a
synonjun.

Genejdc cluiracters. Dentition. — The upper incisors of this genus form a continu-
ous series and incTease in size from within outward. The basal portion of their crowns
is nearly circular in section, with a posterior and very prominent basal ridge. The free
extremity of the crown is pyramidal in form, being deeply excavated posteriorly.
The canines are long and slender with very prominent anterior and posterior cutting
edges. The canines in this genus are very different in form from those oi Paleeosyops
where they are nearly round in section and without cutting edges. A pre- and post-
canine diastema may be present. The crowns of the superior premolars are higher,
and they are provided with sharper cutting lobes than in Palceosyops. The external
lobes of all the premolars are straight, and the last does not show the median but-
tress which is so characteristic of some species of Pcilceosyops. The first premolar
is a two-fanged tooth with an elongated and comjjressed crown ; a rudimentary
posterior heel may be present. In Palceosyops premolar 1 is generally a simple
cone. The second premolar may be provided with a well developed internal lobe, or

'Am. Jour. Sci. and Arts. 1872, vol. 4.

'Princeton Scientific Expedition of 1877, Pub. Sep. 1st, 1878.

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

341

this lobe may be rudimentaiy. The intermediate eonules of the premolars may be
wanting, or, as in one of the species of this genus, they may be slightly develoj^ed
on premolars 3 and 4. The true molars have their axes about ecpial, thus producing
a square-shaped tooth ; this is especially noticeable in the last superior molar, whose
internal border is square and not obliquely cut off as in the same tooth of Palcs-
osyops. The crowns of the superior molars are very high as compared with
those of PalcBosyops. The external V’s especially are broad, high and with sharp
cutting lobes. The width between the buttresses of the external V’s is considerable
in this genus, and the median buttress is strongly constricted olf. The anterior
buttress is not so strongly developed as in Palcsosyops. The median valley between
the external and internal lobes is very deep. The external cingula of the molars
may be prominent. The two anterior molars are each provided with two internal
cones, which are equal in height. In the last molar the protocone is always
present, but the hypocong of this tooth is totally absent in one species, and in the
other is merely represented bj^ a very small conule. The transverse diameters of
premolar 4 and molar 1 are nearly equal, whereas in Palceosyops there is a marked
difference in the transverse diameter of these two teeth.

Lotver jaw. — The inferior incisors in this genus are more procumbently
implanted in the alveolus than they are in P alceosyops and they are said to be more
compressed and laniariform than in the latter genus. The lower canines are
large, and a considerable post-canine diastema is present. The first lower premolar is
slightly separated from the second, and it is more compressed and elongated than in
P alceosyops. The crescents of the last two premolars are more strongly marked than
in Palceosyops. The protoconid of premolar 1 is twice as high as its metaconid.

In the last premolar the two V’s are more developed than in Palceosyops, and
they approach more closely the complexity of the first true molar than they do in
that genus. The true molars are provided with mucb higher crowns, and their
antero-posterior diameter is much more extensive than in Palceosyops. The crests
of the molars are also much higher, and their V’s much more strongly expressed than
in Palceosyops. The posterior tubercle of the last lower molar in this genus is largely
developed, its transverse diameter being nearly as great as that of the whole molar.
This tubercle is more laterally placed than in Palceosyops and is provided with a
well marked median valley and two lateral crests.

Shill. — As far as known, the skull of this genus is narrower and much
higher than that of the allied genus Palceosyops ; this applies especially to the facial
region. The nasals are long and strongly arched laterally. The form of the premax-
illaries is highly characteristic. They are strongly compressed, with a much
elongated median symphysis, in this respect differing widely from the premaxil-
laries of Palceosyops. As far as I have investigated, I have found no transition
forms betAveen these tAvo genera as far as the shape of the premaxillaries is con-
cerned. The palate is much elongated and strongly arched. The malar insertion
is characteristic, being quite different from that of Palceosyops. The zygomatic arch

342

A MEMOIR UPON THE GENUS

is nearly straight, slender and approaches very closely m form that oi D,pla,odon.
Tl.e orbit is quite large and the great antero-poster.or extent of the orbital floor
is characteristic of Tdmalotim-mm. The axial and appendicular skeletons are

unknown.

Synopsis of the Species of the Genus Telmatotherium.

There are bnt three known species of this genus, wnth a number of interesting
transitional varieties.

1. Inferior diastema large T. hyognathus.

2. Inferior diastema small.

a. Superior premolar 2 with a rudimentaiy internal lobe T. cultridetis.

b. Superior premolar 2 with a well developed internal lobe T. vahdiis.

XELMATOTHEHiaM VALIDUS.

I have already stated in my preliminary paper that the superior molars fig-
ured by Cope' as belonging to P. valide7is should be really referred to this species.
The fact that in this series of molars the second snperior preniolar has a well devel-
oped internal lobe would include it under the specific characters of T. validtis.
Considerable variation exists in the premolars of this species as regards their
internal cingula, and I consider a complete or incomplete cingulum as having no real
specific value, at least as applied to this subfamily. I have treated this character
under the head of P. paludos^is, and showed its wide variation in that species. I
still have another illustration of the wide variability in the character of the cingula
in T. validiis.

Dentition. — Most of the characters which I shall give for the dentition of T. cul-
tridens will apply eqnally well to T. validus, so that it is only necessary to enumer-
ate the specific characters which distinguish the latter from T. cnltridens. The teeth
of T. validus are considerably larger than those of T. culPidens, especially the
diameter of the premolars. The second premolar is much larger antero-posteriorly
than that of T. mlb'ide^is ; it is provided with a large internal lolie and its internal
basal cingnlnm is complete. These characters we see at once, esiiecially the
largely developed internal lobe of premolar 2, are very different from those of T.
cidtridens. The other premolars have high crowns and well marked vertical folds,
the latter character being especially prominent on the external lobes of the last
superior premolar. The last two superior premolars have slightly marked proto-
conules and their internal cingnla are incomplete. In the series of the superior
molars of this species figured by Cope all the premolars have conqdete internal
cingula. The external cingula of all the true molars are not as strongly marked in this
species as in T. cultridens, although in Cope’s examples the external cingula are more
marked than in Marsh’s type sjiecimen. In contrast to the other species of this
genus the intermediate conules are well developed. The first molar has a ivell
developed protoconule ; the second molar has also this conule developed. The pos-

'Tertiary Vertebrata, Plate LI, fig. I.

343

PAL^OSYOPS LEIDY, AND ITS ALLIES.

terior part of this tooth is broken off in Marsh’s specimen, so that the presence of a
posterior intermediate cone is uncertain. In the last superior molar in Marsh s
example the protoconule of one side is well developed, without a metaconule, but
on the opposite tooth the metaconule is well developed. There is no trace ot rudi-
mentary hypocone on the last superior molar.

Telmatotiierium cultridbns.

(Syn. — Leurocephalus cidtridens S. & O.')

Dentition, (PL XII, figs. 12, 13). — The basal ridges of the incisiors are very
strongly marked. The external incisor is a very large canine-like tooth, and is sep-
arated 1:)y ([uite a long interval from the canine. The canine is long and slender, its
external face is strongly convex, the posterior being concave ; the anterior and pos-
terior cutting edges of the canine are sharply marked off from the body of the tooth and
extend along the whole length of the same. The first premolar shows a postero-longi-
tudinal ridge, which has on its internal side a small tubercle in connection with the
internal cingulum of the tooth. There is no rudimentary lobe on the first premolar
anterior to the principal lobe. In the following premolar its external face is nearly
straight, high and not separated by a median buttress. The vertical folds and
cingula of the anterior lobes of the premolars are strongly expressed. The second
premolar has only a rudimentaiy internal lobe which consists of an elongated ridge
with a small, distinct, posterior tubercle. At its posterior portion the internal
cingulum is distinct from the ridge referred to, but anteriorly they coalesce and run
together as far as the anterior buttress of the tooth. The internal lobes of the last
two premolars are slightly concave on their external sides, and give off laterally
crests which do not reach as far as the external lobes. The last tAvo premolars have
strongly marked internal basal cingula Avhich are complete, the internal median
portion of the cingnla rising upon the inner face of the cone of the teeth. There
are no traces of intermediate connles upon the superior premolar series.

Siiperioi' molars. — The external cingulum of all the true molars is strongly
marked in T. cidtridens, and it extends all across the face of the teeth and is
prolonged upon the anterior and median buttress. The median buttress is very large,
and its superior portion is shut off entirely from the median valley of the molar.
The anterior cingulum of the molars is large, its inner half especially having a con-
siderable vertical height. All the molars have well developed cingula, that of the
last molar being complete. The intermediate conules are unusually reduced;
on the first molar there is only a Ami’y small protoconnle ; the second and
last molars are totally Avithout intermediate connles. The internal cones of the
molars are A^ery high and sharp as compared Avith those of P. paludosns. The hypo-
cones of molars I and 2 are smaller, and placed nearer to the posterior internal angle

^Rep. Prill. Scien. Expect, of 1877, 1878, page 42.

344

A MEMOIR UPON THE GENUS

of the teeth than in the larger species of Palceosyops. In the last molar a
very rudimentary hypocone is present. The position of this cone certainly
corresponds with the large hypocone found in Limtiohyops laticeps, and I believe it
is placed too far internally to be a metaconule. The posterior internal cingulum of
the last molar bordering the metaconule is large but is distinctly separated from it,
and extends along the posterior border of the tooth as far as the external lobes.

Lower jaw. — The alveolus for the lower canine is as large as that for the upper,
so that probably these teeth were equal in size, as in P. pahidosus. The post
canine diastema is quite large and the diastema between premolar 1 and 2
is very .small. The first inferior premolar has a well developed heel and
a slight indication of an anterior tubercle. The protoconid of the second preniolar
is unusually large and prominent ; it is very much higher than any of the other cones
of the following premolars. In the third premolar the V’s are not well expres.sed;
the anterior crests of the anterior lobes are large but run nearly directly forward.
In the posterior V of this tooth neither the anterior or posterior limb is well
marked. The last premolar differs from the one just described in having strongly
marked double V’s, both of which are well developed and have their anterior and
posterior crests high and continuous. As in all the species of this subfamily the
entoconid of the last premolar is wanting, but the crest running to it in this species
is large, and shows a decided advance in structure over the condition of this tooth
in P. paludostis. All the premolars of this species have traces of an external cingu-
lum, and in the last two an anterior and posterior cingulum are well seen. All the
cones of the inferior true molars are very high and sharp, the external and median
valleys separating the latter being very deep. The posterior tubercle of the last
inferior molar is large ; its vertical height is equal to that of the anterior lohes
of the molar. The .size of the incisor alveolus which is preserved in a jaw in the
collection, indicates that the inferior median incisor was the largest of the three ; the
external, judging from the size of its alveolus, being very .small or indeed rudi-
mentary.

Skidl, (PI. X, fig. .3). — The facial region of the skull of T. adtridens
has been figured by Scott and Osborn in their report of 1877. This speci-
men contains also the greater jaart of the lower jaw, bearing the teeth.
There is one other fragment of a skull belonging to this genus in the
collection, which from its large size seems to belong to T. validus. Owing to
the lack of material and the damaged condition of the specimen, it is
impossible to give the exact dorsal contour of the skull, although the parts
preserved indicate that the facial region was very high and strongly com-
pressed. The posterior part of the malar insertion is flat and elongated. Two
fragments of the roof of the skull belonging to a specimen of this species in the col-
lection indicate that the posterior narial and interorbital regions were flat and rather
narrow. There is no frontal depression in the skull of T. adtrideiis like that of

PALiEOSYOPS LEIDY, AND ITS ALLIES.

345

P. paludosus. The occipital contour was probably very similar to that of P. mega-
rhinus, the posterior portion of the skull rising gradually from between the orbits
to tbe occipital region.

Premaxillaries. — The form of the premaxillaries is the most important char,
acter of the skull of T. cultridens. These bones differ from those of P. paludosus in
being much higher and more elongated. Their anterior contour is ascending and is
cut oft' abruptly, so that this portion presents an elongated triangular sj^mphysis
which articulates with its fellow of the opposite side and has a prominent anterior
keel. Externally, the superior border of the premaxillaries form an angle with the
anterior, and this border slopes gradually upward, its posterior limit being above
the first premolar. The superior border of tbe pi-emaxillaries is more elongate
in T. cultridens than in P. paludostis owing to the extension of these bones antero-
posteriorly . When the premaxillaries are viewed from above they present a triang-

Figuhe 7. — Internal and ventral view of the premaxillary region.

1,3. Palseosyops paludoms. 2,4. Telmatotlm'iuyn ciiltndens. One-half natural size.

ular outline, their prominent and elongated median symphysis being conspicuous ;
their surface on each side of the median keel is concave, but above and below this
depression- the surface of the bone becomes rounded, and continues the concavity
as far as the slight diastema between the incisor and canines, where the surface of
the premaxillaries is slightly concave. The form of the premaxillaries is so char-
acteristic of this species, that it at once distinguishes it from Palceosyops pahtdosus,
where these bones are short, rounded and without any anterior keel and have a
very short, round and slightly oval symphysis.

Nasals. — The nasals are strongly arched laterally and much elongated,
their superior surface being convex and narrow; at their junction with

A MEMOIR UPON THE GENUS

34G ^

f thPv are flat and wider than at their anterior portion. The extremity

rf tt"na;als 1 'not expanded. The inferior border of the nasal notch is well
l^ved in this skull and shows it to be nearly honzontal m positron and more
etagate than the skull of P. pMosus. The snpenor term.nat.on of the nasal

notch is above the second premolar. + i i

Maxillary.-^\^^ vertical plate of the maxdlary m mnch elongated and
hiMi above the malar region. The infraorbital foramen is large, iflaced above the
anterior border of the first true molar and is more exposed Rian rn P paludosus.
The form of the alveolar border of the maxillary is very different in Hus species
from that of the larger species of Palaosyops. In T. cultr^dens border is
stroiiMy convex and the anterior portion bearing the canine is much higher than the
posterii alveolar region, thus making the anterior facial region rise strongly above
the malar insertion. The horizontal lamina of the maxillary, forming a part of the
palate is much larger and narrower than in P. paludosus, the narrowness being
especially noticeable in the premaxillary region. The inferior surface of the
palate is strongly arched ; this is especially marked when the facial region is
viewed from the front. The superciliary border of the orbit is much more elon-
gated and higher than in PalcBOsyops ; the floor is very broad and long, and its
transverse and longitudinal diameters are nearly twice as great as those of P.
paludostis.

Malar.— T\\e malar insertion is peculiar in T. cultridens. It arises abruptly
from the cheek with an anterior rounded border ; its external face is provided with
a blunt keel separating the bevelled superior surface from the iiarnnv and sharp
inferior portion. The orbital process of the malar is not well marked in tliis skull,
but the superior process from the frontal bordering the orbit posteriorly is large and
not acuminate. The temporal ridge arising from the latter is not so obli<iue in its
course as in P. paludosus, indicating that these ridges were farther apart than in
that species, the forehead consequently being flatter. The portion of the malar pos-
terior to the orbit is very small and oval in section. The anterior part of the
zygomatic process of the squamosal is preserved, and shows this portion of
the arch to have been straighter and narrower than in P. paludosus ; its external
face is flat and its posterior portion narrow in form as in P. mcgarhiuHS. The
zygomatic arch, as a whole, in P. cultridens is much lighter and more horizontal in posi-
tion, and it does not project so widely' from the skull as in P. paludosus. It is inter-
esting to note that the zygomatic arch of Diplacodon elatiis is slender and straight,
and much more closely resembles that of Telmatotherium than that of Palceosyops.
This supports the view that Telniatotherhwi and not Palceosyops is the
immediate ancestor of Diplacodon.

Mandible. — The mandible is longer and straighter than that of P. palu-
dosus. This applies particulaidy to the lower border of the jaw, which is per-
fectly straight from below the last true molar to the anterior premolar region,
the portion of the jaw in front of the latter region being arched upward and forming

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

347

quite an angle with the horizontal part. In P. paludosus there is no such
angular portion to the jaw, and the chin is more rounded than in T. cultri-
dens. The middle third of the posterior border of the jaAv is not inflected in
T. cultrideiis, but the border is thick, convex and straight. The internal face of
the jaw is of more equal diameter throughout than in P. paludosus, it having no
long and convex border just below the molars as in that species. The symphysis
Teeth and Jaw Measurements of TELMATornERiUM.

Upper Jaw.

T. validus.

No. 10,184.

T. cultridens.

P. vallidens.

T. hyogna-
thus.

M.

M.

M.

M.

M.

Entire molar .series ...

■220

—

•190

—

—

Length of true molars .

•130

■111

Length of premolars . . .

•090

■085

r trans.

•020

•019

[ ant.-post.

•025

—

•021

—

^ f trans. .

•032

•027

--

--

ant. post.

•028

—

■023

—

f trans

Molar 11

[ant.-post.

•037

•031

•038

•033

f trans

Molar III i

•050

■046

[ant -post . . .

Lower Jaw.

•051

•045

Entire molar series

■178

•202

•242

Length of true molars .

•105

•121

•141

Length of premolars

•075

•077

•100

.... f length

—

•023

•024

Premolar II . . .

--

•021

f trans.

Premolar I\ j

•015

[ ant.-post.

—

•023

f ant.-post.

Molar I -1

•029

[ trans

—

—

•018

—

—

•048

•055

•057

■063

Molar III ‘ ^

[trans

■018

•022

■022

•026

. r ant.-post.

Molar III tubercle 1

•014

•015

•018

1 trans. .

—

■013

•014

—

•017

Length of diastema before pm. I .

•012

•030

Length of dia.stema behind pm. I .
Jaw.

—

—

■006

•017

Total length of jaw

■345

•380

■420

■470

Depth below last molar at middle

•060

■070

■083

■088

Length of symphysis

•085

•100

■122

Breadth of symph. between pin’s I

•040

•050

•062

Width of lower incisors

-

•075

is more elongated and horizontally placed than in P. paludosus, but not as
much so as in T. hyognathus, which is the largest species of this genus. The region
between the premolars and canines is strongly compressed, and the diastemas present
are much smaller than in the larger species. The position of the posterior limit of

46 JOUR. A. N. S. PIIILA., VOL. IX.

348

A MEMOIR UrON THE GENUS

the eympbyeis is the same in tl.is speeies as i.. P. paludosus The dental foramina
a e situated below the third pretnolar. The descriptmu of the jaw of r cnlMem
has been largely taken from mandible No. 10,(127 m the Pnnceton collection, winch
is associated with the facial portion of the skull already described ; and also fmm
another specimen. No. 10,.381, better preserved than the former, which I consider
as belonging to this species.

TeLMATOTHERIUM HYOGNATIIUS.

(Syn. P- hyognathus S. & 0.')

The type of this species which was partially descrihecl hy Scott and Osborn, is
a finely preserved jaw, No. 10,273 in the Princeton collection. There is also

another portion of a mandible. No. 10,274 in the collection, which I think should

be referred to this species. Both the jaws are from the W ashakie Eocene, and
as yet I have not met with the species from the Bridger proper.

Dentition, (PI. XI, figs. 10, 11).— I have referred jaw No. 10,273 to
the genus Telniatotherium on account of the characters of the last molar,
which agree in all essential points with those already described as

belonging^ to T. mltridejis, namely, a high crown, with the posterior

tubercle of the last inferior molar a well developed lobe. The incisors are
of the Telmatotheroid pattern and are unusually procumbent, as they are
nearly horizontally implanted in the jaw. They are of uniform size throughout,
their crowns are very wide and low, excavated posteriorly, and show a well marked
internal basal cingulum. There is no precanine diastema. The canines are very
peculiar in form, and differ in this respect greatly from those of P. paludosns. They
are implanted very obliquely, and as a consequence diverge much more Irom the
jaw than in any other allied species. The crown of the canine, instead of being
much elongated, round in section and strongly pointed as in P. paludosns, is short
and rather broad, with a stout extremity. The external face of the canine
is strongly convex, whereas the inner face is concave, the external lialf of
the crown being bent away from the main axis of the tooth, thus leaving a broad
inner basal portion which is much abraded in the type specimen. Tlie })eculiar
form of the canines of this species is less well marked in jaw No. 10,274, whereas in
jaw No. 10,273 the inner basal portion is not shai’ply marked off as in the other
specimen. The diastema between the canine and ])remolarT is very long, being
equal to twice the length of the diastema behind the first preniolar. The section of
the first premolar shows it to have been a round tootli and its crown was probably
much elongated. The second premolar is considerably worn, Imt enougli remains to
show that its protoconid was very large and high. This tooth differs from that of T.
adtridens in having a well developed anterior tubercle ; the liypoconid is large, Imt not
nearly as higli as the protoconid. The remaining premolars jjosterior to the last
are all badly damaged in jaw No. 10,273, whereas in the other example of this
species premolars 3 and 4 are intact but much worn. The posterior V of the third

minta Mammalia, page 513.

PALiEOSYOPS LEIDY, AND ITS ALLIES.

349

premoliir of tliis jaw appears to be more developed than in T. aiKridens and the last
premolar differs more from the third in size than in the smaller species of this genus.
It is difficult to decide whether the last premolar in this species is really as
complex as the first true molar, as its crown is much abraded, although the pos-
terior inner angle of the same is not as much worn off as the rest of the tooth, which
apjDears to lack any signs of an entoconid. If this is the correct interpretation
none of the premolars in this species are as complex in their structure as the
true molars. In the best preserved jaw the last inferior molar has a very high
crown with a long antero-posteiior diameter. The posterior tubercle of the last
inferior molar is large and laterally placed ; its anterior crest was strongly developed,
the posterior one being much less so. The large size of this jaw and the peculiar
characters of its sjmiphysis, would naturally lead us to compare it with the jaw of
Diplacodon. The isolation of the first premolar in T. hyognathtis is a character not
found in Diplacodon, in which the first premolar is placed close to the second, a
long single diastema between the former and the canine intervening. The length of the
symphysis in T. Jiyognatlms is probably greater compared with the size of the jaw
than in Diplacodon, (see table of comparative measurements.) The anterior portion
of the jaw in Diplacodon is not nearly so horizontal in position as in T. hyognathus.
The wide spreading canine and nearly straight outline of the incisors correspond
very closely in character to those of Diplacodon.

Mandible. — The jaw of T. hyognatJms is much elongated and narrow. The
region of the symphysis is very Suilline in character ; that is to say, anterior to
premolar 2 the jaw is more nearly horizontal than in the other species of this
subfamily, and this portion forms a much larger angle with the posterior two-thirds
of the horizontal ramus than in the other species. The horizontal ramus differs
from that of Stis in the fact that it is more slender, and in the region below the second
premolar being only about one half the depth that it is below the last molar, whereas
in Stis these vertical diameters are about equal. The posterior border of the ramus
is straight and presents no inflection and posterior concavity so characteristic of the
jaw of P. paliidosus. The region of the angle is very broad, thin, and strongly
everted. The inferior border of tbe angular portion of the jaw is turned inward.
The coronoid portion is destroyed. The alveolar border is straight, and a considera-
ble space intervenes, between the tubercle of the last inferior molar and the
ascending portion of the ramus. The characters of the symphysis of the jaw are
striking. The symphysis is much more elongated in T. hyognathus than in any
other species of this subfamily ; its posterior limit is only slightly more extended
than in other species. The symphj'sis commences at the middle of premolar 3, but
the anterior portion in front of premolar 2 is extremely elongated and narrow.
Between the second premolar and the canine the jaw is very much com-
pressed ; so much so, that when viewed from above there is a striking difference
between the transverse diameter of this portion, and that of the middle region of
the jaw. The narrowest part of the mandible is just in front of the second pre-

350

A MEMOIR UPON THE GENUS

mohr- from here anteriorly it widens, .and between the can.nes the jaw .a ttat
Td t’rongly depressed. We see the beginning of tins e ongat.on of he jaw n, the
lal er species of the genus; thus, in T. c«lM„s the diastemas anterior and ,.os-
e or to premolar 1 have appeared, but they are not so strongly marked as In this
snecies In P. paludosus on the other hand very much reduced diastemas appear
to be the rule. In both examples of the j.aws of T. hyognalhus the menta foramina
are double; the anterior being situated under the second premolar, while the i»s-
terioris much smaller and placed between premolars 2 and 3.

Comparative Measurements of Loiter Jaits.

T. hyognathus.

P. vallidens.

Diplacodon.

M.

M.

M.

Distance from canine to dental foramen

•350

*•314

Length of inferior molars, total ....

•140

•145

•160’

r ant. post

■063

•057

Last true molar -j

•026

•022

Length of symphysis

■122

— — ='

•180

LIMNOHYOPS.

(Syn. embraces Palxosijops as employed by Marsh, Limnohyus as employed by Loidy and others.)

The type of this genus was descrihed by MarslU in 1872 under the name
of Palceosyops laticeps. He also at th.at time described Ins Limnohyus robiistus.
The former genus was characterized by haidug the last superior molar with
two internal cones, and the latter by having this tooth with only one internal cone.
Dr. Leidy,3 previously to Marsh, had fully characterized the genus IWwosyops,
giving the characters of the teeth and skeleton quite fully, his description clearly
showing that PalcBOsyops belongs to the Perissodactyles. Dr. Leidy, in his report
for 1873, adopts Marsh’s name of Limnohyus for tho.se forms which have the last
upper molar with two internal cones, but by the priority of Leidy ’s determination,
both of the genera described by Prof. Marsh had liecome synonyms, and it was not
until 1890 that the latter'* gave his two-coned type of molar the name Limnohyops.

Dentition. — The characters of the teeth in Limnohyops are more closely I’olated
to those of Paleeosyops than to those of Telmatothcrium, although the smaller species,
L. fontinalis, has molar characters which, in some respects, |)oint to its aflinity with
Tebnatotherium. The crowns of the molars in Limnohyops, like those of Palaosyops,
are low and broad, with shallow valleys, the diameter of their transvei*se axes
exceeding that of the antero-posterior. The external V’s of the molars are rounded

* The measurements of P. vallidens are taken from Cope’s plate, the scale of which is incor-
rect, and the above measurements are probably too large.

’Estimated measurements.

’’Am. Jour. Sci. and Arts, July, 1872.

’’Hayden’s Prem. Kept. Geol. Surv. of Montana, etc., April, 1872.

*Am. Jour. Sci. and Arts, June, 1890.

PAL^OSYOPS LEIDY, AND ITS ALLIES.

351

and not as angular as in the genus Telmatotheriuni. The buttresses of the molars
are not so strongly developed as in the latter genus. In both species of Limnohyops
the molars are without external cingula. On the true molars both intermediate
tubercles may be fully developed in one species, while in the other they are much
less so. The internal cones of the molars are angular and may be connected with
the external V’s by slightly marked transverse ridges. In the last superior molar
the hypocone may be large and equal to the height of the protocone, or reduced and
much smaller than the protocone.

Skull. — The skull is mote elongated and primitive in form than in Palceosyops.
From above downward it is much depi’essed, especially so in L. fontmalis. The
facial portion of the skull is short in comparison with the much elongated cranial
part. The nasals ai’e long, narrow and of the same width throughout. The
premaxillary bones resemble closely those of Palceosyops, being short and com-
pressed, with a small round symphysis. The occipital crests may be greatly devel-
oped, much more so than in any other genus of this subfamily. The auditory pro-
cesses are distinct and the zygomatic arch is broad and heavy. The brain was
probably very small and much less in bulk than in the allied genus Palceosyops.

The Skeleton. — Portions of a skeleton which 1 believe to belong to this genus,
show the following characters in addition : The scapula is more slender than
in Palceosyops, with its spine oblique to the plane of the glenoid cavity. Bones of
arm and forearm more slender than in Palceosyops. Carpus highly specialized, the
lunar having the magnum facet nearly vertical. Magnum high and narrow. A
large contact between the nietacaqjal III and unciform. Carpus more nearlj^ of the
mesaxonic type than in Palceosyops. Fifth metacarpal well developed. Tarsus
more elongate and slender than in Palceosyops ; facets of astragalus and calcaneum
continuous. There may be a contact between the cuboid and metatarsal III. There
are only two species of this genus at present known ; their characters are given in
the following table :

Synopsis of the Species of the Genus Limnohyops.

A. Size large.

Hypocone of superior molar III one-half the size of jirotocone, L. laticeps.

B. Size small.

Hypocone of last upper molar equal in size to protocone, L. fontinalis.

Limnohyops laticeps.

(Syn. Palxogyops laticeps Marsh, Limnohym laticeps Leidy.)

The description given by Prof. Marsh" of the dentition of this species is exceed-
ingly brief, and he fiiils to point out some of its most important dental characters.
Dr. Leidy," in his report for 187o, figures a superior molar which he, correctly I
think, refers to P. minoi' (his P. paludosus in part), but having consulted Prof.

*Am. Jour. Sci. and Arts, 1872, page 2.

"Rep. U. S. Geol. Surv. of Ter. for 1873, Plate XXIII, fig. 13.

A MKMOIR UPON THE GENUS

lh«u hen.- «nt.Ti,„0- it wi.len,, and between the cnnlnea the jaw b flat

,le,,n-~.-d. We ».-e the Ix-gnining of thin e ongat.on of the jaw m the

....aller of the gen,..; in T. cuUriden, the d.aetenia. anterior and i,o|e

terior to ,n-,„oh.r 1 I, are a|,|««,x-d, l.ut tl.ey are not no strongly marked as m this
In P paludomsim the other Iiand very much reduced diastemas appear
to U- the rule. In l»oth examples of the jaws of T. hyog7tathus the mental foramina
are double; the anteru.r In-iug situated under the second premolar, while the pos-
t«TU»r is much smaller and placed Ixdween premolars 2 and o.

(.’oMI'AKATIVK MkASUKEMEXTS OF LoWER JaWS.

T. hyognathus.

P. vallideng.

1 Dijflacodon.

M.

■M.

M.

ISxfanrti ftwm raliino t«» denial ftmuiifii

•350

*•314

Ivpniflh of infrriur iiiolars, total ....

•140

•145

•1(50*

( ant. jawt

•0C3

•057

tn.0 molar j

•026

•022

ofrymidiyitla

•122

•180

LIMNOHYOI>S.

Syn. rmlinu'w ok iMni>loyod by Marnli, Limnohym as employed by Loidy and others.)

The tv|M* of tliis genus was descrihed by Marsh’' in 1872 under the name
€»r l\tl<rosyof*s latieeps. lie also at that time described his Limtwhyiis 7'obtistus.
T’he former genus was charaeteri/.ed by having the last superior molar with
two iutenial cones, and the latter hy having this tooth with only one internal cone.
I>r. Is'idy.* pn-vionsly to .Marsh, had fully charactei'ized the genus Paiccosyops,
gi%*ing the characters oi the teeth and skeleton (piite fully, his description clearly
showing that Pn/trosyops Indongs to the Perissodactyles. Dr. Leidy, in his report
for 187:5, adopts .Marshs name of Z/ww/yz/j for those forms which have the last
up|H-r molar with two internal cones, but by the priority of Leidy s determination,
l,.,l, .,f ,l,.«.,il„| by >t„rsl, |,„,| liocome synoi.y..,., «„d it was „ot

'y". twosjoned type of molai- the name Limnohyops.

I l„. Clianieler. of the teeth in Limnokyops aie moie closely related
to 11..... UUosyop, II, „„ of Tc/malolhcrium, althoagl. the s.i.aller simeie.

r , ."fP ".e "■'"'■•Ih i" respects, ,«int to its nthoity with

h!r!n7T'' I f Limnohyops, like those of PalZsyap!,

an 1,,» a, I . will, ,|,„||„w valleys, the diameter of their transve..8e nws

..M„sl,„gll,„l of The extenml Vs of the molars ,„-e ,t„„.de.l

't>tinMtptl iii<tuj.un-iiioiits.

•Am. Jmir. .S-i nnil AI1^ July, 1872.

■'IjW. l^a,. ,i,ol. S„o;„r

Am. J.Hir. Sot. and Art.,

3.^.1

PALMOS YOPS LEIDY, AND ITS ALLIES.

and not as angular as in the genus Telmatotherium . The Inittre.sses of the inolai-n
are not so strongly developed as in the latter genus. In both species of Limmhyops
the molars are without external cingula. On the true molars both intermediate
tubercles may be fully developed in one species, while in tlie other they am iiuiclj
less so. The internal cones of the molars are angular and may lx; connected witli
the external V’s by slightly marked transverse ridges. In the last suix*rior molar
thehypocone may be large and equal to the height of the protwone, or reduciHl and
much smaller than the protocone.

Skull. — The skull is moLe elongated and primitive in form tlian in Palcrosyops.
From above downward it is much depressed, especially so in L. /on tinalis. The
facial portion of the skull is short in comparison with tlie much elongated cranial
part. The nasals are long, narrow and of the same width throughout. The
premaxillary bones resemble closely those of Palceosyops, Ixdng short and com-
pressed, with a small round symphysis. The occipital crests may lx- gix-atly devel-
oped, much more so than in any other genus ol‘ this subfamily. *The audih.ry pro-
cesses are distinct and the zygomatic arch is broad and heavy. 'Fhe brain was
probably very small and much less in bulk than in the allied genus PaUrosyops.

The Portions of a skeleton which I believe to Ixdong to this g»*imH.

show the following characters in addition: The scapida is moia* slender than
in Palceosyops, with its spine oblique to the plane of the glenoid cavity. Ib.m-s of
arm and forearm more slender than in Palceosyops. Cari)us highly s|M-<-iali/.e<l, the
lunar having the magnum facet nearly vertical. Magnum high and narn.w. A
large contact between the metacarpal III and unciform. Carpus more nearly of the
mesaxonic type than in Palceosyops. Fifth metacarpal well develoiM-d. ' 'farsus
more elongate and slender than in Palceosyops ; facets of astragalus and calcaueum
continuous. There may be a contact between the cuboid and metatamil III. Then*
are only two species of this genus at present known ; their charactei-s are given in
the following table :

Synop,sis of the Spkciks of the (Ie.xi's Limxoiivop.s.

A. Size large.

Hypocone of superior molar III one-half the size of jjrotocone. L. latircps.

B. Size small.

Hypocone of last upper molar equal in size to jirotocone. P. fontimxlis.

Lijinohyops latickps.

(Syn. Palxosyops laticeps Marsh, Liuinohym lalicepn Leidy.)

The de.scription given by Prof Marsh' of the dentition of this s|H*cies is exce<*d-
ingly brief, and he fails to point out some of its most imjxu-tant dental characters.
Dr. Leidy,^ in his report for 1873, figures a superior molar which he, corns-tlv 1
think, refers to P. minor (his P. paludosns in part), but having consulted Prof

'Am. Jour. Sci. and Arts, 1872, page 2.

'Rep. U. S. Geol. Surv. of Ter. for 1873, Phate XXIII, fig. 13.

A MKMOIK UroN THE GENUS
... .. K.ftiM- referred this tooth to the last upi^er molar

; w . .e ......

. t\Lm- molur, and certainly ha.s not the characters of LnnnoAjo^s
Suf>rrior /)rniition.-'\'ho nppor molars form a complete senes. The mcisors
.^nan witl.in outwanl like those of P. palndostis. Marsh says the canine is
In this respect it agrees in fonn with the canine
In Marsh’s type specimen tlie external lolx^s of

iinTeais’

larv** and l»n«idly oval at its hast*,
of I lie larjivr sjH*<des of Palceosyops.

of the lariier s|H-<-ies ol / i

,l„. n.,I.Ti..r .m- l.aaiy .lun.agcl. Those of the lx,stenor have their

.•n.« ii« law with .veil ■i.i.rk.vl internal ha.sal cingnia, which are inoxnnplote. In the
halt nn-.»..l,.r the |n,n.<v.ne is n.i.eh larger than the n.etaeone ; this is a ehnnieter
of the toilli niiite .lillennl 1.111 that of. pahidostis, where the e.xtcriial l.ilies of
till, last im-molar aiv generally eipial. A conspicuous vertical told is present upon
the panu-one of the last sniH-rior piviiiolar. The last superior premolar of
/.. latucps is distinguished fmm that of P. pahidostis by the pre.st*nce of a
w .-ll marked protiH-onnle. 'J’he pivsence of an intermediate conule upon the jire-
iiioliir m-ries in any sjHH-ies of this subfamily is a very^ rare occurrence, and is seen
ill only one other s|H*<‘ies. viz: I\i/ccosyops borealis. In P. laticcps the transverse
diiiiiieter of the hist prcMiiolar is nearly ecpial to that of the first molar. All the
true molars have low crowns and shallow median valleys; and the transvei*se axes
of the molars is gnmter than their an tern- posterior axes. The external V’s have
the same general eharaelei*s as the molars of /^. pahidostis. The external faces of
all the true niohirs are without eingnla. and the internal cingula of the nu)lai*8 are
not IIS strongly develo|HMl as in /'. pahidostis. The protocouule and metaeonule of
iiioliirs 1 ami 2 are iimismilly large, and in the occurrence of the la.st named inter-
iiusliiite it dilVers from the molar of P. pahidostis, in which a metaeonule is absent.
< til the lust true molar there is a well marked protocouule. The transverse ridges
eoiiiiivtiiig the iiitermil eone.s w itii the external lobes are plainly marked, hut they
an* very low and only sliglitly eon.stricted oil’ from the .surface of the enamel. In
tin* first and s«*coml iip[H'r molars the transverse ridges arc more developed than
in the lust sn|H*rior molar. The internal cones of the first two molars are like those
of /'. fHdudostis U*iiig ^•.|mll ill size, hut in tlie last upper molar the hyptx'one in L.
Uttiteps x* niuch smaller than the protoeone. As already mentioned under the
ileM-nption of /*. /HthidosHs, certain varieties occur in that species, charaeterized by
the pn*s,*i.n. of a ru.limeutary hyi>,H*one upon the last upper molar; this is due to
the fnet that at the jsistenor internal angle of the molar the cingulum is rai.sed
vertieiilly almve the surface of the tooth and forms a rudimentary cone. In
so,..en...s a nidimentary hyiKieone, or perhaps it may be a metaeomde, is devel-
I I he first .Mtagc* ol the development of the hypocone is the separating
of the cingnlmn from the laisterior intermediate ecmule ; its further clevelop-

•'

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

3r,:{

cones of the last upper molar are lai’ge and etfual in height, there is no such
transition. For the present, therefore, and until more ahnndant material is dis-
covered, it will perhaps be better to leave those forms in which the last upi>i*r
molar has two internal cones in the Limnohyops, with the undei-staiiding that
this genus should not have a generic value equal to that of Palceosyops. A ca.se
parallel to the above is that of Titanothermm Leidy and Diconodoti .Mai>h. Prof.
Osborn' holds that the latter genus cannot be separated from the other, Imcaust* the
hypocone of the last upper molar is found in all stages of develoj)ment in the difler-
ent species of these two genera. He found the ])re.sence or absence of the first
lower premolar in Titanotherium a very vai’iahle character, which is not, however,
the case in Palceosyops and Linmohyops, where both genera have the same miiulier
of teeth above aiid below.

Skull (PI. XI, figs. 8, 9). — The Princeton collection contains a very fine oc'cipital
portion of a skull of L. laticeps. It was collected in the Bridger basin and is one
of the best preserved skulls in the museum. The cranium was ivfern*il by Scott
and Osborn, in their report for 1877, to P. mmor, hut 1 find upon comijaring it witli
Marsh’s original type of Z. laticeps, that it should be referred to Liuntohyops. 'flu*
measurements of this cranium are considerably less than those of .Marsli’s ty|H‘. an«l
it may possibly represent another species, although tlie height of the <K‘ci|»itnl civsfs
and the width of the same region are very variable characters, and may differ wiilely
in their dimensions in the same species, as we can readily iirove by exaniiiiing. for
example, a number of skulls of the genus Urstis.

General fo7'in (Fig. 2, p. 289). — In general form the skull differs from that of P.
paludosus or P. megarhhms. Its doi’sal contour is very much like that ()f the |{hin(H'ei-os.
being slightly- depressed in the frontal region and rising gradually to tin* «M-ci|mt. whiU*
the latter region is much higher than the anterior portion of the skull. 'I’he (KTipnl
is provided with a great development of the lambdoidal and sagittal eivsts. which aiv
much heavier than in any other species of this subfamily. 'I'he nasal n-gion is
rather elongated and slender and closely resembles that of /'. Icreidats in the form
of its nasals. The skull as a whole is more elongated and deiuvssial and has a
shorter facial region than that of P. paludosus. The orbit is rather .small ami
placed well forward, its anterior termination being over the anterior Imrder of the
second molar. The floor of the orbit in L. laticeps is short as in P\ paludosus.
The orbit is separated from the temporal fossa by a well marked jiost-orhital
process. The temporal fossa is rather low, much elongated and very deeply exca-
vated, more so in comparison with the size of the skull than in any other s|K‘cies of
this subfamily. The zygomatic arch is heavy and wide spivading. We may add
that the projecting processes of the cranium ai-e exceedingly strongdy develo|HMl.
The occiput is rather low, broad, with wide projecting pann-cipital pnK'es.-M>s.

iPreliminary account of the Fossil Mammals from the White River Fonnati..n, etc., (wg.- hVs. Hull.
Mus. of Comp. Zoology, 1887 .

A MICMOIK UPON THE GENUS

7u.. n-Kion .,f .lie .k..ll, c„.n|.a.-rf with that of J’. m^ar/Aus, i. ahoHo.. a„,l
'■■'’“/Ww-V/arv r«-«.-The for... of the i,re.aaxinariea ie ..early ide.,tical with

,...r^.^wi«rfthey«..«

are well developed and they fonn a sc^ptum

iM'twfen the two incinive Ihramina. , a n

A'Wr—TI..- ....«.!. aa- .....cl. elo.tgated, ..arrow aiid <lc.ce..d.ng ; h.terally
.l..-.- aa- ..r....gly aa-h.al, .....1 their ....terior extre.nities reach ae far lorw..rd
„ ’.he |.a-...,.xill..ry .y.n|.hy»ia. They .liffer from the aaaale of ali.ed a|X.e.es

1.. l.-i..e ..r the a.....e exlct trattavc-aely ti.rougl.out the.r cottrse. ll.e o..d.
..rth.-..- I»....a. an. ..armw, ah.a.|.tly n>....<lcd a.id show no s.g..a of the trat.sverK
.•X|a...ai,>.. which ia ao rl.an.rU-riatie <if those of P. mcgarhms. TI.ey are d.st...-

fa.iii the iiuMaU of P. pahidosus by less width posteriorly. The nasal
iiutelies ill /-. Itttieeps are narrower and longer than in P. pahidosus.

Frontals. 'Phe dorsal extent of the frontals is probably the same as in the

other allied siKH-ies. The iiiterorlntal portion is much narrower than in P. palu-
dosuSy mill is slightly depressed. From the interorbital region the surface of the
rniiitals rim-s gradimlly upward, and is limited externallj" by the strongly devel-
<i|ssl diverging t«*iii|s»rul ridges which are well marked and are bordeix-d Ixdow by
the d»H*p teiii|>onil fossa. The dorsal jiortion of the frontals be'tween the converg-
ing teiii|s)rid ridges funiis an elongat<*d narrow channel which ishordereil upon each
side hy the eonve.x margins of the temporal ridges. This grcMwe Ix'tween the
teni|Mind ridgt's Ixi’nines shallow at the highest portion of the tenijxiral region, hut
is c-oiiliiiiHsl iM»Ht<*riorly to the junction of the .sagittal with the lambdoidal crest.
The fusion of tin- teni|M)ral ridges to fonn the sagittal crest is placed farther anter-
iorly than ill P , pahidosus, hut the crest has not such a wide antero-postcM'ior extent
as ill the skull of P. tucgarhhnis.

Parieta/s. — 'Phe Inrgi'st part of the parietal is taken up in the formation of the
exiHHsliiigly deep sagittal crest. The depth of the roof of the brain case*, and
the l•oums,uent n*.hictio„ of the cerebral cavity, ar6 very great as compai-ed with
/’. ptludosus.

OrnfA/s.— nu. ...|,r,.-wci|.it,.I mgio.. of L. lalueps i, u..i,,,.c i.. it, l...gi.

1.. ..1.1....1.1 cr.-,l, W1....I. wi,l..|y „vcrl..,..g tl.o i>ln..o of the „ccip..t, a..d who., view.,!

fn.... tl... ..xt...., imlcriofly on „ li,,, witi, the ,,o,te,ior li,..it of the occii,

im' '7 ' f .1 ' , of .lie occipit.,! ere,t arc .athor ,Iiircm.^t

fn..., I „»c ,.l the .,tl„.r alhcd ,,«e.08, beh.g nearly vertical i.i p,„i.i„,.

«r.'ir. rt'" "" 1 ..arrow for..,, whicir is in i,„.„g

^'-'-0 of the 8.,:d,tT:;e,t':i7:“.diKli' z

PAL^OSYOPS LEIDY, AND ITS AI.I.IES.

liV>

lateral expansion of the surface of the lanibdoidal crest extends alsait two-thinis
across the surface of the occiput, and then becomes shaq) and eniitinuous with the
paroccipital region. The constricted portion of the occiput above the huaiinen mag-
num is very small in this skull, and diverges behind to form a prominent notch over
the foramen. Laterally the paroccipital processes are vide and provided witli the
usual styliform processes. The transverse extent of the condyles is much less in
this species than in P. paludostis. The superior and inferior notches aiv also less,
and there is no prolongation of the condylar surface on the basicK-cipital. '1 he
transverse groove upon the surface of the basioccipital Ixdween tlie condyles
and paroccipital process is much less marked than in P. tncgarhinus. I he
posterior pjrolongation of the base of the occiput beyond the ])ar«K'cipital region
is much reduced in this skull, and consecpiently the position of the condyles
is like that of the Tapir’s skull; more underneath and ])rojecting very little
behind. The basioccipital is broad and shoid ; its anterior median keel is strongly
developed, and the anterior prominences of this poidion of the skull are large ami
well constricted off from the surface of the bone. The lateral surface of the hasi-
occipital is thinner and more deeply excavated than in P. paludosus. The lateral
vacuities of the basal region of the skull are bi-oad and short and their anterior
openings are separated from the posterior by the advancement of the periotic acros.s
this cavity'. The basispheiioid is short, and its transverse extent In'twinm the l)od\-
and the glenoid facets is considerable. The lamina suri-ounding the foramen ovale
is small and has a much less antero-posterior extent than in the skull ol P.
hinus. The antero-posterior and transverse e.xtent ol‘ the alis|)lK‘n«)ids is much
greater than in the Tapir, and this applies as Avell to other menilH*r.s <>f this gnuip.
The extent of the alisphenoid is shown in the anterior jirolongation of the ant«*rior
opening of the alisphenoid canal, and its extent superiorly.

Squamosal. — The squamosal forms the largest part of the convex surface of
the temporal fossa, as above the squamoso-parietal suture this fossa l>eeomes deeply'
excavated and forms the base of the perpendicular portion. At the mitldle of its
superior portion the squamosal has two well marked foramina which are appai-eiitly^
absent in the skulls of other species of this subfamily. The /.ygoinatie iKirtion of
the squamosal is very broad, heavy, and widely separatcl fmm the surface of the
skull, thus forming a marked character. With the huge crest ali-eady descrilK'd the
skull’ of this species presents a grotesque appearance. In L. laticcps the ha.-*al
portion of the squamosal differs in extent and position from that <d'/'. paludosus ; in
the latter the glenoid portion is straight and more widely siqiarateil fn>m the skull
than in L. laticcps. The glenoid facet is at right angle.s to the axis of the .skull,
whereas in L. laticcps it is obli.pre in position. The audit<.ry pnK-i-s.sr's cloudy
resemble those of P. paludosus in form; the iiostglenoid is shorter, hn.mler and its
axis is parallel with that of the glenoid facet. An internal glem.id luia-ess is pmsm.t
in L laticcps. The posUvmp‘i«ics are heavier, stouter and nioiv divergent than in
P. paludosus. At their Imsal portion and at their junction with the ,.ar.KTipitals.

47 JOUR. A. N. S. PHILA., VOL. XI.

3:ii5

A MKMOIK L'l’OX THE GENUS

V nrosCMit as in the skull of F. paludosus. The

,!n3”r'.iijbtly -c.|.ar„U.d, .u,d tl.e mastoid probably did not np^ar

malar i..sc.r.ioa of Z laHcfs cloady re^mble.
.1... 7nimalo,l,.rium. It ariaoa abruptly fmm the cheek, its antenor exttom.ty
an«I fn.in this |K,rlion a prominent lateral keel arises from the suiface of
the l*.ne, separating tl.e flattened superior surface from the infermr. 1 osterior to
tl,e orbital pna-esses, the malar is round in section and differs m form from that of
P paludosus, in which the pisterior part of the malar is strongly compressed into a
hnmd Intend ph.U-. The mlation of the malar insertion to the infraorbital foramen

larger species of Falc^osyops. In L. laticeps

I plaU*.

is diflenmt fniin that of the ,

this foramen is <-onsi.lerahlv anU-rior to the origin of the malar, and is there-
r«n- exiKweil. 'riie anterior lx.rder of the malar is above the anterior limit of the

first molar and it is thus considerably more prolonged forward than in P. pahidosus.
'rhe .limeiisions of the palate are nearly the same as in the other allied sjiecies,
although its nsif is num* excavated than in the latter. The inferior termination of
the palate is op|s>site the |M>sterior Isirder of the second molar.

Foramina. — 'I'lie comlyloi.l foramen is very small in L. laticeps and is
phietsi neaivr the condyle than in P. paludosus. The foramen lacerum posterius is
sepiirateil from tin* foramen lacerum medium by the prolongation of the periotic
ncriws the lateral vacuity. 'I'lie foramen ovale is small, and. nearer the ffiramen
Inei'nini meiliniii than in P. paludosus. The posterior opening of the alisphenoid
cnnal is unusual ly hirgi*. and is jdiu'cd rather more forward than in the skull of P.
mrparhiuus. The ptervg«»id plate of the sphenoid, forming the external walls of the
nlisplieiioiil canal is flat and much elongated from before backward. The extent of
the nlis|ilicnoid canal has alivady lx*en referred to in describing the skull of /I
meparlunus ainl it seems to Ik* a eluiracter of this group of Perissodactyles. The
anterior niiiunoii o|M‘ning of the alisphenoid canal and the sphenoidal fissure is very
largi*. 1 his canal is not divided by a hoi'izontal .sejitum sepaiating the alisphenoid
cnnal pn»|M*r fnnn the common canal for the sphenoidal fissure and foramen rotun-
«lutn IIS in the skull of the Taj.ir. At the suijei'ior inner border of the anterior
..|K*ni..gof the alisphenoid canal is situated another foramen, which may lx* the
optic; if s... It has an extremely posterior position ; it is widely separated from
the ahsphenoid canal, as m the skulls of the Tapir and Rhinoceros. In Eguus,
.... .l„.,., ,,.rba,.,l.tb- ,.|,lic !ai,lacri.j„at above the funimon rotu.idum

and on a line with the mferior limit of the alisphenoid canal

f''We.r.-./<y.-The encephalic cavity of the skull of Z. laticeps is much
r . T i" of its brain cavity indicates tlm

Tp iVrW T o»e-ln iV that

JbiZ: .;ftbec..„,.ia, cavity i, ,,.0

- i. .-«-b.u:.i .ihi, ; atiiirr “

more
at the

PAL.EOSYOPS LEIDY, AND ITS ALLIES. 3r,7

Skeleton.

Scapula (No. 10,359), PL XII, fig. 24. — This scapula is not associated with any
other bones of the skeleton, so that its reference to this genus is not certain. I refer
it to the genus Limnohyops because it is quite diflferent from the scapuhv deserilx*il as
belonging to the two species of Palceosyops and is altogether trs) large to lK*long to
Hyrackytis. It may possibly belong to the genus Telmatothcrium. although it is
much smaller and lighter than I should expect to find in thiit genus. It lit.s, nioiv-
over, a proximal part of a humerus whose form and measui’cments corre8|M)iid very
closely with those of the type specimen of L. laticeps in the Yale (’ollege Museum.

The following are the peculiarities of this scapula as compaivd with that of P.
paludosus ■. — 1. The form of the glenoid cavity is higher and nari-ower. 2. The pre-
scapular fossa is much bent inward, and the plate of bone forming it is tliin. 3. 'I he
spine forms an acute angle with the plane of the glenoid cavity instead of a right
angle as in P. paludosus. 4. The tubero.sity is not sepai’ated by a notch from the glenoitl
border, and the tuberosity differs in shape from that of P. paludosus in lj<*ing imux*
triangular in outline and acute at its distal portion. 5. The internal surfia-e is pn>-
vided with a well marked vertical ridge, which is wanting in the scapula of /'
paludosus. 6. The coracoid region is fully as large and heavy as in the larger

Figure 8.— Comparative view of humeral trochlea?. 1. Ihpirux itidictu. 2. Pah-ori/opn miiinr. 3. Mi-

noceros bicomis. 4. Palxotherium latum.

species of Palceosyops, being noticeably large in proportion to the size of the scapula.
The neck is also more constricted off, and much .smaller in this scapula than in P.
paludostis.

Hutnertis (PL XII, fig. 25) . — There are a number of parts of humeri in the collec-
ion which I refer to Z. laticeps, one in particular, No. l(»,o67, whicli fits fairly well 1 lie
radius and ulna which will be described later as belonging to this species. The hum-
erus shows its primitive character in being much longer than the Ismes of the lower
arm. The shaft is rather long and slender and has heavy distal ami piT.ximal |K»r-
tions. The anterior face of the shaft exhibits a prominent ridge, the imsterior con-
tinuation of the deltoid ridge. The description of the pmximal jHirtion of this
bone is derived from another specimen. No. 10,307 A. Comparing tlie pn..ximHl
extremity of the humerus of Z. laticeps with that of Tapirus we find that its liead
is not only placed farther posteriorly, but is more strongly turned jHist-axially. Tlie

A MKMOIH UPON THE GENUS

1 I #1.,. -iiiiu* form US in the humerus of the Tapir. It is
jrmitiT tulMTiiHit \ HIM 11 HI |)roce8ses are not as prominent as in the

lapir. I he j,,id signs of division. The less^er

iipir.

''''“■ humeriniof tl,c Tapir; and d«» not extend a* far

r.vtremity is also more pointed. The deltoid ridge is only
- shaft is deep from before backward and strongly

tulierosity is
forwunl; its anterior

slightlv murki.1. This part of t he shaft is deep troin betore oacKwaru anu s
«.mpn.ss.Hl. The tns-hlear snrfiu-e of the Immen.s is the most charaeteristiyiart
and its fom. ami the .livisions of tlie trochlem are quite different rom any that I
haveexamincsl. altl.ougl. De lUainville’s figure of indicates that the
tna-hlear surface of the hnmerus in that genus resembles that of Ltmnohyops It
we i-oinimre the distal e.xtivmity of the humerus in this species with that of the
Tapir (Fig. S, p. the diffeivnee in cliaracter is at once apparent. In L.

latufps tim plane of the internal ti-ochlea is oblique to the axis of the Ixme and
tnk«-s up mon* tliiin half of the articular surfiice. In the Tapir on the other hand
this tns-hlea is more nearly hori/ontal, and there is no deep concavity of the face
of the linmerus s«*parating the two trochlea*, hi Z. laticeps the external trochlear
hiriiis nearly a right angle with the internal and is strongly convex and separated
nnslially by a nninded keel The external slope is convex and obliipie, tapering to
a toiigue-slnqicd sn|H*rior prolongation. In Paheothcruan the keel of the e.xternal
iHM'Iden is not prominent, and in Ifyrachyus this character of the external slope
of the triN'Idea differs from that of L. laticeps. The condyles are more prominent
than in the hnmerus »»f the Tajiir, the internal being large and rough. The sujiin-
at«ir ricigi* is well markial and longer projiortionately than that of the Tafiir. The
anconeal and siipra-t ns-hlear fos.sa‘ an* very deep, but they contain no perforation.

AW/«j, (X«». iD.tli:]), 1‘1. XII, figs. 20, 27. — This radius, with the
ulna ass<H’iated with it lH*longs to the .same individual as a inanu.s,
No. KMd.'h all lH*ing in the Princeton collection. Corresponding to the
clom- siinilaritx- in form In'tween the humeral trochlea* of Limnohyops and
/'altrof/ienum. we find the form «»f their radii similar. The head of the radius
has the same form a.s in Palcrothcrium. Tlie section of its superior articu-
lar surface is oval, the l.roadest part being internal and correspondinn- to
the half tns'hh.a of the humerus. This trochlea is very oblique, and is sepa-
rat.sl from tin* external by a ridge which is bordered anteriorly and pos-
lenorlv by pronunent pus-esses. The external trochlea of the radius is con-
cave ami narn.wer than the internal. It is narrow externally and bordered bv a
pnamnent hm.k-hke pnn-e.Ks; posteriorly it is excavated deqdy by the external
nuluMduar facet. I he anterior asia-ct of the shaft of the radius^is convex its pos-

The
just

"■ not" A<'uv2 by“a'ri,l'‘""''"

f,,,,.. Tl„. „rtl.e sl.nft of the ra,li i/i, convex, it, p„l

Its

palj:osyops leidy, and its allies.

3a!>

lunar portion is concave, tlie scaphoid surface being oblique to it, and terminating
at the end of the prominent styloid process of the radius. There is no radial
cuneiform articulation.

Ulna^ No. 10,013. — The ulna corresponding with the above radius is a long
and slender bone. The olecranon tapers gradually ironi its base to the ajK'X which
is expanded, flattened and strongly compressed laterally, forming a rather thin
plate which separates the expanded distal portion from the base. The sigmoid
cavity is deep and overhung by the prominent coronoid process. The distal i)art
of the sigmoid cavity is wide, being limited at each side by j)i-ominent pnx-e.sses. In
front of the sigmoid cavity the shaft has a deep fossa limited Ixdow by an obliciue
ridge running across the radial surface of the bone. The shaft of the ulna is triang-
ular in section, wuth its internal side concave, its radial face being obH«pie tt) the
latter, and separated from the internal side by a prominent angidar ridge. The

Measurements or the Appexdicul.vk Skei.eto.v.

P. paludosus.

P. minor.

P. loiigiroHtris.

h. lalicrpx.

M.

M.

M.

M.

breadth of neck

•083

•000

■0117

Scapula 1 length of glenoid

■OCl

■0.53

■ftW

length coracoid ....

■020

■OIS

■fl-jo

f length

--

■300

distal breadth ....

■088

—

■080

Humerus Q,jter trochlea ....

■0.33

■021

inner trochlea ....

■038

■030

1

f length

--

■233

■2V>

Radius \ prox. surface transverse

■048

■0.52

1 dist. surface transverse .

■062

■04!l

■04.5

IJlna-1 total length

■28;i

■308

f total length

■380

•32.5

—

■.158

prox. sur. transverse

■120

■OOS

—

■108

Femur j transverse

■000

■072

d;ii

breadth of shaft at 3rd trochanter

■080

■06S

—

iKV.

r total length

■320

■277

—

—

Tibia ■

prox. sur. transverse

■088

■078

—

dist. sur. transverse

■008

■048

—

distal part of the radial face is twisted upon the axis of the Ixme, so that this iH)r-
tion of the face does not correspond with the upper part. As a result of this n)tu-
tion of the distal extremity backward, the articulation of the ulna with the carpus is
very different from that of the Tapir. Viewed from the fi-ont we obs<Tv.‘
in the manus of L. laticeps that the distal extremity of the ulna is placed far to
the side and backward ; consequently the pisifonn is shut out fnnn forming a
portion of the anterior face of the carpms, this being largely due to the shaiM. of
the cuneiform, which is rectangular instead of being triangular as in the lapir.

aivi

A MKMOIK UPON THE GENUS
•ri,.. fa«.. i. hair cn-^entoia i„ form and bordered exten.ally by

the vertieonniad for tla S9.— Tills is one of the most beautifully

r i , he ciineetLin? and the condition of its facets is fully

r“ir j - “.i:*ieal ia.r,a,se. „» iu recent animals I have referred this
Lnaata the (tenua /.iW,ra/r as. after earefully studying »me remains ol t ie
m , of /.. /W it. the New Haven Milseiim, I find that its cliaracters el„«..|y
^ m-iaiiiil with th,«. of the latter, although the measurements of the metacarpus
»„. .aaiaiileniMv lea. in thi, aia-clinen than those of Marsh's tyiie and may repieselit
a .lilfen-iit aiaa'iea. The hiiiiil of this species as oomliared with that of />. fahidoms
i. very liiaoh lighter in eoiiatriietion, and its general proportions approach more

iifiirlv of tlif Taj)ir. • i i i .i at *

Carpus.— ‘V\w <-ar|mH i» soiiiewliat broader in proportion to its lieiglit than that ot
Ihe Tapir, and tlie general relations of the carpal elements are cpiite diflerent. The
rollowiiig lire ita main iK‘cnliarities 1. Great extension poskn-iorly of tlie lunar
la-lwii-n till- iiiagmnn and nnciforni. 2. Separation of the magiiiiin from the unci-
fonn anteriorly, .‘h Position of the Innar-inagmim facet, it being nearly vertically
plmiil, 1. 'Phe large eontaet lx‘t ween the unciform and metacarpal III. 5. A iioint
to In- olim-rviil in this carpus is that it approaches more nearly the mesaxonic tyjie
than that of /’. /f/ZWow/j; this arises from the fact that the unciform-metaearpal
III iirtienlatioii is greater than in paludosiis, and con setpientl y inetaearpal 111 uii-
|iriNielii>s more iiiMirly the mesuxial line of the hand than in the latter form. In
the Tapir w»* s«h* a more advancetl stage of Mesaxonia wliere the metacarpal III is
very iniu’li larger than the other nietapodials, and the axis of the mnniis divides
tliis ini'taraqMiI «s|ually.

Sotphoid. — 'Pile projsirtions of the scaphoid are rather high and narrow, and
nppnMich thow of the same Ixine in the carpus of the Tapir' The superior face is
lint, hnmil tninsvers«>ly, and i>osteriorly limited by a deep fossa which jxme-
tnitrs aUait one-half the vertical height of the hone. The scaplio-magnnm facet is
mtlicT ohli.iuely placed, as in I\ palttdosus ; it covers the whole superior surface of
the magnum ; the |H>sterior portion articulating with the pivot of the magnum is
l.aigiBaalia|«-.l, and ita aalcriui- laa-tioii foinia an acute angle with tlic part uf the
ra.a-1 aiom aiilcriarly placed. In P. pahulosns the postoiior portion of this facet is
hnaal anil aliorl. alal tlina ilillbra very much in fonn from Hint of L. laticcfis The
-•aplaatni, I facet ia ,,.p„ratc,l fro.ii tl.c |x>atctior part of Hte facet fi.r tl.o magnum
liy a ,l,,.p pit. It ,, ilroplv concave from aide to aide and ia contimioua at ita piwtcrior
l^airt will, the roa,, „elr»|H,m,n faeet. which ia well marked iu this apecilueu, and
forms ipiite n hnmd vertical facet for the traixzium ^

/.aaar.-The h.aar i, the moat characteriatic bone in the carpus of P

backwaru 1: demrai^::,':

PALMOS YOPS LEIDY, AND ITS ALLIES.

3(11

lunar of allied species. The superior face is convex from before backwanl, and is
separated from the posterior by a slight depression externally. A deep vertical
fossa borders the facet above. The lunar-scaphoid facets are long and narrow, the
upper one being deeply concave, the lower more nearly plane and continuous with
the lunar-magnum facet. The facets of the inferior lace of the lunar juv very char-
acteristic of this species. The whole of the lower part of the inferior face is j)ro-
longed into a beak-like process which penetrates posteidorly nearly to the distal fice
of the cai'pus, and thus the magnum and unciform appear to be nearly sepanited
from each other upon viewing the carpus anteriorly. The jxj.sterior prolongation
of the lunar is not subdivided equally, its uhiar side being much larger than its radial.
The lunar-magnum facet is nearly vertical in position, its posten>-suiK*rior part
curving upward and backward to become continuous with the lunar-.scaph(jid
facet, which, at its posterior part, is very narrow and nearly shut off from tlie |m)s-
terior facet for the pivot of the magnum. The facet on the lunar for the j)ivot of
the magnum is much more nearly vertical in position than in P. paludosus, and not as
concave. The lunar-unciform facet is large and dceirly concave; tlie anterior
part of the lunar bordering on this facet is very obli(jue in iM)sition running down-
ward and inward to meet the lunar-magnum facet and form the beak of the lunar.
In comparing the carpus of Linmohyops laticeps with that of other forms 1 can find
no Perissodactyle in which the lunar is so widely prolonged between the elements of
the distal row as in this genus. In Hyrachyus the lunar-maginmi facet is lateral
in position and more vertically placed than in L. laiiccps, but nevert hele.ss its distal
extremity is not prolonged as in this species. Iscctolophus shows a ])rolongation
of the lunar distally, but in that genus the two distid facets of this l>om- an“ more
nearly equal, and have about the same angle of inclination to ejich other. In
Tapirus and Palceotherium the lunar does not cx’oss the middle plane t)f tin* carpus
(at least in P. medium, see De Blainville). Titanothcruwi approaches /’. paludosus
more nearly in the form of its lunar, its lunar-magnum and unciform ndn-
tions being about the same. There are a numher of other lunars in the tadlection
which belong to a form closely allied to L. laticeps, Imt as they aiv m)t asscwiated
with any other bones of the skeleton I cannot identify them with certainty. In
these lunars the proportions in the size of the lunar-magnum facets undergo gn*at
variation. In the most extreme form, No. (>, this facet is nearly vertical, when-as
in No. 5 it is more oblique and very much reduced in size.

Ciineifoimt. — The cuneiform of Z. laticeps has about the same shape as that of /’.
paludosus, although rather more compressed. Its ulnar face is slightly concave and
the cuneiform-phsiform facet is long and narrow. Its unciform face is rather bi-oad.
and more concave than m P. paludosus.

Pisiform. — The pisiform is unusually well preserved in this carpus ; its form is
long and compressed, its distal extremity being rough and compivssed finm side to
side. The neck of the pisiform constricts the tuber from the articidar snri'ace which
presents a narrow facet for the cuneiform. The pisifonn-ulnar facet is triangidar in

A MKMOIU UPON TIIP: GENUS

- <7-: T i:"!::

• rW-i::C:;a comparative., t.,a„ in /.

;v„/«i»ri. i..l.a,, rn',n.K.fore inrcknard ns in tl.e latter s, mc.es, and l.as tl.e

r -‘''"r ;7:

h, r„ri„ rn.,n .Imt of l\ faMosus in n l.icl, tl.is Innie is ), render .and sl.ovs at least
five ruv HuiKM-ior lace of the magnum i.s nearly horizontal in front , pos-

U-rinrlv, tliia fare ia provi.le.l with a prominent ridge, dividing the two oblique fiiceta of
the magmiin for tlie waplmid and lunar respectively. The facet for the latter bine is
more olilique than that for the former, corresponding in position to the vertical limar-

riui'MK a.— Mortiliutoiiy (>r tiu' (iiri'iis. 1. Limiwhyops latice-j>s- 2. Pahronyopn palud(txii». ;{. TStaiiollifriwii
Imlri I 4- Tupirus imlirtu.

iiingtiuni fiieet. 'I'he e.xtenial wide of the niagnuni iw nearly all taken iiji by the lunar,
tlie iinrifonn having only a very slight contact anteriorly, but the inagnuni-unoifonii
fiiei't nriww v«*rtieally ujKin the magnum iiosteriorly, thus ofl’ering a largi*r contact
lielwHUi the inngnum nml uneiform jMisteriorly than anteriorly. The inferior facet
of the inagnum iw dwply coneave fn>m before backward, and is limited Ixdiiml by
theilemvnding imK-ess of the Imiiio. The position of the magninn uiion metacarpal
III is iiion* oblique than in P. paludosus, and this condition arises from the large
pnKvss develoiMMl by metacarpal III for articulation with the unciform.

f The .diape of the unciform is nearly identical with that of P. palu-

dosMs and iw not at all Tapiroid in outline; its transverse a.xis is niucli greater than
its vertical, although the pisterior face is rather more oblii.ue and apin-oaches more

IIS venicai. aitnougii the iH.stenor face is rather more obliipie and appn.aches more
lUMirly the vertical than in P. paludosus. Its cuneiform surface is oblii.ue and
In,..,, I..r„.v Imckward. A sl,„ll<,w f„»na ,,l„c«. tl,c

,.f ,1,0 l«„„. I„„„, iWct pontcionly. The tuhcrcsit, i, h„-L later-

llllv ulfiriHL mill clivortrott ^1... •!> ^ ^ ’

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

3(i:l

lar in outline, the apex being placed anteriorly and oflering only a slight articnhi-
lation for the magnum. The other inferior facets of tlie unciform are as in palit-
dosus, although the unciform-metacarpal 111 facet is larger proportionately than in
that species. The facet for metacarpal V is large, taking up about one-third of the
inferior surface of the bone.

Metaca^'pals. — The metapodials in Lyntnohyops laticeps are rather long and
slender', and their shafts are almost straight. The metacarpal region is more compact,
and the digits do not diverge from each other as much as in P. paludosus. The .«haiK*
of the proximal part of metacarpal II is rpiite charactei'i.stic ; it enlarges gradually
as it approaches the articulating surface of the bone, its intei'iial Irorder Ixdng n»ngh
for muscular attachment. The external border sends u}) an ascending pnn'c'ss for
articulation with the magnum and metacarpal 111. The superior facet ol’this meta-
carpal is triangular in form, its external border being very obli(pie, and forming with
the internal the apex of the triangle. The metacarpal ll-magnum facet is long aiul
narrow; it is very oblique in position from before backward, and inclined lixnn the
vertical from above downward. The metacarpal I l-metacarpal 111 facet is c(»nlined
to the anterior part of the bone, it is situated under the anterior half «)r the facet
just desci-ibed, and is tongue-shaped in outline, the larger i)art lx*ing in fmnt.
Upon its radial side this metacarpal exhibits a small Hat facet lln' the tuiin*/.-
ium. The form of metacarpal III is characteristic of L. laticeps. It is long, straight
and slender, its distal portion being slightly enlarged, and provided as in the other
metapodials with a j)rominent keel. The third metacarpal d<H‘s not show a.s much
disproportion in size to the fourth in L. laticeps we see in the nianus of the
Tapir. In the latter the metacarpal III transmits a larger proportion of the weight
than in Litmiohyops. The superior facet of metacarpal III for the inagnmn is nan-ow
from side to side, but ver}' deep from before backward; its anterior laa-tion is
slightly convex, the posterior half of the facet being inclined downwanl and termin-
ating in a triangular point. On the radial side this metacarpal shows a small and
anteriorly placed facet for metacarpal II. The ulnar side of the third metacarpal
exhibits a large process, the form of which is S(Hiare. with a large, Hat
and oblique surface for articulation with the unciform. The metacarpal III-
unciform facet is very large compared with the size of this im-tacarpal.
comparatively much larger than in the Tapir or Hhinoceros. Ihdow the latter
facet this metacarpal shows two large oval facets for metacarpal IV. They
are not continuous, and are Avidely overhung by the process alKue descrilH-d.
The relation of metacarpal III to the magnum and unciform is dillerent from that
■ of the Tapir’s carpus. Owing to the separation anteriorly of the t\v«> latter carpal
elements in L. laticeps a greater proportion of the unciform transmits its weight to the
median digit, whereas in the Tapir a larger proportion of this weight is transmitted
through the unciform to the metacarpal IV. Metacarpal D' like that of the Tapir
is slightly curved toward the ulnar side of the carpus, but differs from the latter in

48 JOUR. A. N. S. PHILA., VOL. XI.

A mkmoik upon the genus

. . ... ....iv tlie 8i'Ae of metacarpal III than in the Tapir. The

■> I is rather large in proportion to the diameter of

p„..vim.d i.;rt.ou in form/hehrg very deep, narrow and

the hliiill, itn um-> <» i* ig slio-htly concave from side to side. The

fro.,. , , " “,i ” J anterior one being oblique to the

f“"t‘“U''‘''rth: ,Zr; :: le^ri m WeiUon a„d largertmu. the anterior.

»ia!. ,netaear|.al IV ahowa two elongated facete for metac«.Tal
V . an- furv«l .lightly. IVi.eath totli the radial and ulnar iaoctaof tin. n.etin

eai, .l.allow and na.gl, Ibaate. The ilfth metacarpal doe. not differ a. lunch

in L. man nietaearpal II a. in the Tapir, and there .. not such a striking dlller-
4.11CC ill the length of its shaft as compared with metacarpal I\ , as in the carpus of
the Tapir It« pro.ximal cud is very much enlarged, showing an upivard-curved
naigl. tulH.n»sity which terminates in a vertical process bordering upon the siipenor
surface. Kxt«*rnallv the facet for the unciform is convex from before backward,
concave from side to side, and is bordered externally by the process above descrik'd.
The facets on metacarpal V for metacarpal IV are narrow and continuous. The
distal part of t lie former ineta|M)dial is <[uite heavy, the middle part of its shaft
k-iiigvery sb-nder pro|M.rtlonately. The proximal and middle phalanges of the
digits iim nit her bi-oad and sliort. The ungual phalanges are short and wide dis-
Inlly. Thi’ir distal margin is interrupted at its middle point by a deep incision,
whieli is kmleixMl upni each siile by a deep pit. This incision of the ungual phal-
niiges is said to Im* wanting in the maims Hyrachy7is.

h'emur. No. 1(1.21)2 and No. 10,351. — There are two femora in the Princeton
cxtihx'tioii wlios4* form is inoix* elongated than those of P. nihior. They arc inter-
niiHlinte ill this n*s|MH't k*tw»H*n the latter species and P. paludosus. The proximal
mid distal extremities ofthe.se femora closely approximate in their characters those
of the smaller s|H*<*ies of Pu/teosyops, these portions being much smaller than in the
femur of /’ paiutiosHS. (’oinpaivd with proportionate measurements of the anterior
extn*iiiity ol /,. lahceps^ I find that these femora corresjiond with them very well,
so I shall pnivisionally place them under L. laticeps. Their long and narrow
shafts an* strikingly chnraeteristic and distinguish them sharply from those
oi I . minor. In form, their thiixl tnx'hauter is broader and more elongate than
that of / . minor, and this jKirtion of the shaft transversely is much less in extent
than in the latter s|H-cie8. The neck is more pronounced than in P. minor, and
the trial, giilar misiHl ,H,rtion of the shaft below the head is narrower and longer.
I he tiMK-hlenr surface lor the patella is more elona-ated. while the fl.li f «

•eady Ijeeii

PALiEOSYOPS LEIDY, AND ITS ALLIES. 3(i5

referred to L. laticeps, so that I shall describe this tarsus as ])elonging to this sjKTies.
The form of the pes is long and narrow ; its length corresponds almost exactly with
that of the Indian Tapir, but it is narrower. Compared with the f«x)t ol /'. tmiior
we see considerable difference in size, as the pes in that sjyecies is much
broader and heavier than in laticeps. The metapodials are much lighter than
in P. minoi', and closely resemble in their proportions those of the Tapir. The
middle metatarsal is considerably larger than the lateral metapodials, in this char-
acter also approaching the foot of the Tapir.

Figurb 10.— The astragalar and calcaneal facets in the Fal!eo.',yopH-ritauahmiim seriw- /w/ij-

doms, Princeton collection; IHplacodon ? elatus, Princeton collection; Tila„ah-rium (sj.. in.let.), Pnncclon col-
lection, after Osborn.

Calcaneum.— The calcaneum of L. laticeps is long and narrow, with a much
compressed tuberosity which has a concavity at the extremity sulKlividing this js.r-
tion of the bone and resembling in form that of the ctdcaneum of Hyracodon. 1 la-
neck of the calcaneum is deep, and where it joins the articular portmn, it is com-
pressed and continued into the narrow anterior part. The artic.dar surtace is narn.w
and deep, especially so in this species. The ectal facet is broad transversely, and the
anterior prolongation is not so conspicuous as in Palccosyops paludosus. I he
sustentaculum is very long and narrow and is placed close to the ectal facet. 1 he
distal portion of both calcanea which I refer to this species aredamagc-«l, so that it is

memoir upon the genus

-.1 . whether the sustentacular filcet is continuous with the inferior

or not. these facets in continuity. The

iu oo„*lder„blc.-, i.« plane

iiilenor facet la ra a r ' >= the cuhoid facet. The latter is narrow and deep

!i;"!r.Lv. irln-nl • L Lrlace ie concave, and only the „pi>er part of its internal
kl-r i. irancat.al l.v tin. inferior facet. In Z. latueps the lower lx,rdcr o the
mill fa.a-t i. l.arn.w and roun.l ; in the other related fonns it is fiat. A hhnlo

ciilcaiieiiiu facet is not well marked. , i + c d .

lslraf:alus.— \'\w form of the astragalus closely resembles that of P minor ,
i, i, l,„„ «a,l narrow with it. distal lK,rlion well constrieted off. The troch ear aur-
fu.v is sliullow. 'I'he facets of the inferior surface are large, the sustentaculum and
inferior U-ing continuous. The ectal facet is not as deep as in P. minor, but it lias
the same pi-iiend form. Tlie sustentaculum is long and narrow and its plane is
not ns <dili(|ne as in llie smaller species Palceosyops. The distal continuity of the
sHstcnincidnni witli theculHiid facet is not interrupted by a ridge as in P. minor. The
inferior fa<-el reaches alsiut half way across the anterior border of the bone, liefore
C«mlesciiig with tlie mistentaculuin. * The cuboidal facet is long and nari-ower than
in 1\ minor ; its plnne is nearly parallel with the navicular face of the astragalus,
thus differing wiilely from that of /h minor Avhere the cuhoid lacet forms a sharp
angle with the anterior face of the Ixmc. The form of the navicular facet is not
so strongly triangular in out lint* ami is moiv elongated transversely than in P. minor .
'file more liori/oiital jMisitioii of the sustentaciihir facet produces only a sliglit angle
on the internal Isirtler of this face. The characters given above for the astragalus
of /.. laticef>s approach closely tlmse found in the larger species of Ifyrachyus, hut
its large size excludes it fntm that genus.

Cnncifortns. — 'flic eet<H-nneiforin is wanting in tliispes; it is probably much
higher ami narrower than in /’. pa/ndosus, and appi'oaclies more nearly tlie diameter
tif this Isnie in //yrnchyns. 'I'lie inesocuneiform is preserved; it is a very deep
Unie with a sinidl antt>rior lace ; its articular surfaces are concave antero-posteriorlv.

CiiSoid. 1 lie culKiid is still another tarsal bone of this species very closely
n'M'mhling that of Hyrachyus, although it is rather more rectangular and shorter
than ill that g,*mis. Its external iKirder is .straight and not concave as in Hyrachyus.
The tiilH*n.sity of the eiilx.iil is wanting in this specimen, but its position was
|.n.l.nl.ly very similar to that of Hyrachyus. The astragalar facet is large
ami IS aol M.,,nn,t,*il from the plane of the calcaneal fiicet as in P. minor. The
facets for the navieiihir and eetiK'imeiform e.xtend more than halfacro.ss the inh*nial
facH* o the lK,ne ; they im* separate.! by a ridge, and the posterior part of the navi-

,1 st«l artilnr I '■‘T posterior internal border of the bone. Tlie

.hsn Urtieula lac* ol the ouIh... is slightly concave, and is much smaller tlian in
/.nin,^. I he uppr .surface of the cuboid m excavated-

.n tins s,H.i,.s. the contrary this surface is perfectly iat the dital l^e on .

PALJSOSYOPS LEIDY, AND ITS ALLIES.

367

cuboid in the former species has a straight internal border, wliereas in L. laticeps
this border is round.

Metatarsals. — The metatarsals agree in many of their characters with those of
Hyrachytis, hut they difter from them in being longer and broader tluin any meta-
podials in the collection which pertain to the larger species of Hyrachyus. In
Hyrachyus, metatarsal III is considerably larger than the lateral metaiKKlials.
and this character distinguishes it from that of Palceosyops while it agives with that
of Limnohyops. A long metatarsal III, which probably belongs to a large sixjcies of
Hyrachytis, has its shaft much smaller and straighter than in L. laticeps-, it.s distal
articular surface is also much less, so we may believe that the larger 8iK‘cie8 of
Hyrachytis approached L. laticeps very closely in height but that the extriunities
were more slender. Other remains in tlie collection pertaining to a large sjH'cies of
Hyrachyus support this view^ The proximal portion of the secoml metatarsal has
nearly the same form as in Hyrachytis. Its external liorder slopes gnulually tlown-
ward, and was not so abruptly cut oil’ as in P. minor. It agrees witli that of
Hyrachyus in having a facet for the entocuneiform. In the species of Pahrosyops
examined the second metatarsal shows no entocuneiform facet. The suiH-rior facets
of this metatarsal are elongated and concave. The facets on metatarsal 11 I'or the
ectocuueiform are round and widely separated, and the anterior facet is sup]M)rte<l
upon a constricted neck. The shaft of metatarsal 11 is slender and lamt inward,
its anterior surface being rounded, with a tlattened posterioi portion: its distal
articular sinTace is slender with a keel which is not prominent. Metatarsal 111 is
the most characteristic nietapodial of this region and its articulation with the
fourth is c[uite diffei’ent in character from that ohserved in allieil 8|K*cies. I he
articulations between metatai’sals III and IV in Hyrachyus and Palceosyops are nnndi
flatter than in Limnohyops, and there is no prominent prolongati()n of the e.>:ternal
face of these metapodials. In L. laticeps, on the contrary, the anterior external
angle of metatarsal III forms a strongly incurved hwk-like pnx-ess; thi.s
is bordered posteriorly by a vertical facet which is oblii|ue alx)ve and
concave below. Upon viewing metatarsal 111 from the front the pna-ess alx»ve
described becomes prominent, and its irregular curved border terminates alxive in
this prominent process. The ectocuneiform facet of metatarsal 111 is more concavt*.
and more raised toward the external side than in Hyrachyus-, its distal extivinity
is narrow and straight.

Metatarsal lY is more slender and elongate than the corresiM)nding Ume
of P. minor-, its surface for the cuboid is nearly j)laue. Internally and anter-
iorly it exhibits a long narrow facet who.se surface is strongly convex; this
articulates with the peculiar hook-shaped process of metatarsal III. forming n
close interlocking articulation. The distal articular surface of metatarsal I V is narn)W,
the keel of this nietapodial being very prominent and bordered externally by a deep
notch. A strong contrast to the allied forms is the narrowness of the distal ends of
the metapodials of this species as compared with those of P. minor. In another |)or-

A MKMOIU UPON THE GENUS

* • • 1

C 'illu'd to L. /aiueps hwi not identified with

tioii of a I*ea Udonjrinf: to a lar«-er contact for the astragalus. The

i,. i. larp-r. " e I,un also are continuous. Metatanntl

.culuu. «M.I .nlerior ' "f .netatarsal IV as in that already

".L-riuliriirnlTluiU.^ «.eU,level„,^l° There is a large contact between the
cuUml ainl inelatarsal III.

Mk.v.si kkmexts of M.\xcs and Pes.

P. paludo.«us.

P. minor.

L. latic«pe.

' M.

M.

M.

j -220

•195

1 -077

•060

1 -04.5

--

•038

•0S9

•064

•075

•055

•0,34

•027

•o:w

•032

•014

•010

•022

•016

•020

•017

•048

•039

•014

•013

•126

•120

•122

•068

•060

•058

' -032

•030

•028

! 015

•020

•017

•013

•on

•009

•043

•028

•027

•031

•023

•021

__ -064

•058

mo

Imiltli of m»nu» . . . •

Itfrwlih of mnxoi •• niltWIo
Vrnk»l lirluhl tif cTinau*

Tr«n*vrf*r of liicftK of imixiinnl

huiMYlur wirtikv ....

Infi^or “ ....

Tniwivor •’Xioiil of lunar .

Vrftkal lirtulil of lunar
Tran>. rxl. of liinar-niavnuni fan-t
Tram. rtl. of liinar-unrlf«inu fai'i'l
VrftlnJ hrlgla of niairnuni
Tram. rtl. of iinrlfomi
Tram. rtl. of me. 1 1 1 -unrlform fiic-rl .

I.t'nfflh of lamu*

Itrrwilli of lannir al niMtllp
l.4'n(lh «if Mianilamlar farri of raliaiiriini
t.<-n)(ll> of Infrrlor fiM>rt of calraiiriiiii
Itrrtallh of artnvalo-mlMiiil farri
iamcih of wtinutaUrculiuiil farri
Itrradlh of arlnumlo-narirular fnrrl
IWnallli of pratinuil farria of nirlalanvix

LtMtontitr* roxTtxAija.

TliiKaiuulI HjHTies ot Unmohyops has Ix'eii established by Prof. Cope* upon jKir-
lioiiaufn skull which contain the right maxillary bone with all the true molars.
The riirht tciniH.ral region of the skull is also ivell preserved. The left nasal of one
side ia i.ivwnt. The distinctivene.ss of tlie sutures and the porous condition of the
cnuiinl naif show that this skull must have belonged to a young individual. In

si«. A. differs widely from Z. laticeps, being only about one-third as large

ns llie latter s|H*cies.

/IfiMm.—Onh- till. Inio iiiolnrs of the right side ore im'scrved in this
.|.u-uu™; 1 ,,u.u„d ,u|,.rior molar is in as fine a state of preservation but it lias

not l.s.„ i«.|| ch-nml fmm tl.c nmtri.v. The molars are very interesting as they
show cTtam n-hit ions T,h,„,o,l,cH„m corresiwinling to those of the lariS.r species
'f.lxx.nl.Joirlcsl Ilullrlin. .No. 11, p. 1, Jan. Slst. 1873.

PAL^OSYOPS LEIDY, AND ITS ALLIES.

3<;!»

of the genus. A striking peculiarity of the first molar is its extremely small size
as compared with molar 2 ; there is nearly as great a difterence between the trans-
verse diameters of the first two true molars as there is between pi*emolar 4 and
molar 1 of P. paludosus, the latter species showing the ditference in size of these
two teeth more than any other sjoeciesof the genus. Another interesting character
of the first molar in L. fontiualis is that the primitive triangle is moi-e strongly
expressed than in any true molar that I have examined in the entire series of
species. The protocone of molar 1 is very large as compared with the liy|KH‘one and
is placed further to the inside than the latter. The hypocone is small and placed
far to the posterior internal angle of the molar, and the whole tooth seems to have
been in a transition state of development, being in a condition between a premolar
and a true molar. In the latter the internal cones ai-e of the same size. Tlie second
superior molar has quite a high crown with flat and broad external lolics; the
anterior buttress is prolonged, but the median buttress is low and stiungly con-
stricted off. With the exception of the large size of the anterior buttn'ss the
structure of molar 2 shows close affinity in form to that of Tehnatolhcrtum. 'flu?
external lobes of molar 2 hav^e no cingulum, and the V’s are <livided by a faint
median rib. The internal cones arc subequal in size but do not show the groat
difterence observed in the first molar. A Avell marked j)rotoct)nule is jjivsent on
molar 2. Both the internal cones of the last superior molar are well preserved and
of the same height, thus distinguishing this species from L. lattceps in which then* is
a great diftei’eiice in the size of the internal cones of the last suj)erior molar. 'I’he
slight development of transverse ridges on the molars of L. laticcps is wanting in
this species. The surface of the enamel on the molars of L.fontnialis shows a slight
tendency to wrinkling, but the teeth are not the least worn.

Stimmary. — With the exception of the diflerence in size between molars 1 and
2, I consider that the dentition of this species shows an advance over that of L.
laticeps. This is proven in the Telmatotheroid characters of its molai-sand also by
the fact that the internal cones of the last superior molar are ecpial in height ; mon*-
over the hyj)Ocone of this molar does not exhibit the undifferentiated condition that
is found in L. laticeps and in some of the transition forms Iretween Limnohyops and
Palcsosyops.

Skull. — The skull of L. fontinalis closely resembles in form that of A. Uxticips,
especially the occipital region. The antero-posterior axis of the skull is considerahly
extended and the cranium proper is exceedingly broad and depressed. The (h)rsal
contour of the skull is nearly the exact counterpart of that of L. laticcps, although
the sagittal region is slightly concave instead ol convex as in the latter s])ecies. 1 lit*
occipital crest, as in the larger species, is strongly developed for such a small
animal, and it widely overhangs the supraoccipihd region. The cranial rogion is
elongate compared with that of the facial portion, the latter lx*ing abbreviate<l.

Wava/v.— The nasals are broad and short ; their superior surface is Hat and
distally they do not expand. The lateral portion of the nasals is strongly arched

A MKMOIK UPON THE GENUS

3|0

1 * . 1 lu.rrliM' iH thickened and rounded. At the median
iluH-nwanl ami tlie«r fmi* 1« thinned out. The posterior extent of

iia^al aiitiiiy the lames x*toinc . ^ytiire is just behind the po.sterior limit of

the iiawiU i» hiiiite( ‘ jVontals of this specimen is preserved, with the

the ..as,.l which shows that the frontal region between the

imaliaii Mutun 1 mm, „ insertion rises gradually from the cheek and

„Hat«nn.sth«ve,K.m lla Ihcjnal^^

'r.'.3viIiM"hi « orbital I.n«er» which ic turned imvard^ The orbit i» large
n .7 I. Ihl i. nmeh eh.„p.le.l. with a conaidorable breadth. Tl.e zygomatic arcl.

Tloag. .bK-., a, t diverge widely fi-om the skull. Tlie malar part of

,bi. ari-b i. .a froM. side to side and the zygomatic portion proper exhibits

» 11. now extern,. I fare. Tl.e temlHiral fossa is imicl, elongated, tl.e squanio.™] ,»,r-

tion l.■i„g bnmd. Tl.e antoior tcmpor.-ll ridges lamlcniig tins fossa

niM.v.. atf not atnaigly expressc-d, and posteriorly they scarcely unite to fonn a
Migillal cmsl.

.MKA.SfKKMK.N'T.S OK TIIK SkIIX OF L. FOXTIXALIS.

I.rni(li> of "kull ftislll iKVllHIl lo flltl Ilf IIIIMtlM
l.rti(tll uf lrlii|.tntl f<aw«
llrkuhi tif ftMMi nt mitlillu

llmwlili tif «>••■%•€• iK^iKlfiiiiitlit.

Isrticlli tVom lo IwM'uf |Hwtt(li>noi<l

uf init' NiuUir M-ritw .

I iinl.-|«»l.

“"I* '»•••'" ' I iriiiu.. ....

Imil.olHHii.
iniiu..

•2(!0

•KW

■0+5

•106

062

oca

■020

■022

■026

•027

hirUtals. — 'Pile parietals and .sqiiamosals take about ecpial share in the fonna-
tion ol tin* cha-ply excavated temporal fossa. A pecniiai-ity in this species is tlie
extent c»r the tein|Miral fossa Ixdiind the post-glenoid. The inferior lateral teiniMjral
rid(n>s an* strongly develoiwd and Ix'come continuous witli the large lainlxloidal
crest. The inisterior part of the temporal fossa is formed by the anterior prolonga-
tion of tlie hn.ad plates of the supraoccipitals. The large sliare the occipitals take
ill the fonnntioii of tlie teniiioral fo.ssa is uniciue in this species. Prof. Cope descriljcs
Ibis |..rlinn of the skull very well when he says “ the occipital Imiie sends a long
imins. farwuml nn tlie media,, line forniiiig a half gomphosial nrtionlatkm witi, tl.e
imnebil.. Ihe laten, I sutaix. of tl.e two bones is considerably in advance of the
enor aleml en-sl. be postglenoid process in L./mlina/is isdelicnte in Ibnii,
slemlvr, , , d tn,n.,w fonrani. It is widely separated fiom the post-tympanics, much

;;::i:pn"i;in''7i:'r,."‘7,r - - t-""

— ■ 'n.- is narrow

PAL^OSYOPS LEIDY, AND ITS ALLIES.

371

behind the post-tympanics, which I take to he a mastoid exposure. A larfre
exposure of the mastoid may also be inferred from the wide separation of the
auditory processes. There is no foramen pi’esent at the junction t)f the mastoid
with the exoccipitals. The petrous bone is preserved and is situated deeply in the
recess between the glenoid and poshtympanics ; it is placed on a line with the
glenoid cavity and not as far removed from the foramen ovale as is usually the cast*
in the larger species. The foramen ovale, although filled with matrix, is plainly to
be seen ; it is situated on a line with the internal edge of the glenoid facet.

Relationship and Descent.

In treating of the relationship and evolution of the genera and s]K*eies in this
subfamily, I jiropose to confine myself to those forms which 1 have investigated
as thoroughly as the present known material will allow. It appears to me that the
relationship of some of the Wind River forms to those from the Dridger pn)|H*r
is rather uncertain, although I consider that in Palceosyops borealis we have
a direct forerunner of the Bi’idger sjiecies of this genus. Latubdothcrium is the
earliest member of this group and it appears that it may have lM*en the ancestor of
the whole line. The details of the molars in Lambdothcriuin, and especially of its
premolars, dei^art considerably from those of P. borealis and in fact the latter
species is much more closely^ related to Palceosyops and Pebuatotlicriu>n. than t«»
Lambdotherijtm. At any rate it is probable that in an earlier formation than the
Wind River Eocene, a common form gave origin to the genera Lambdolltennm and
Palceosyops and I am inclined to believe that the former genus may lx* a side line,
not leading directly to Palceosyops -a?, by ('ope. and that the latter gt'inis

has not branched dS. ixom Lambdotherium m Middle Eocene times. 'I'his view is
supported by the fact that I have lately discovered material in the l’rin<*eton
collection from the bottom of the Eocene, namely the Wasatch, which is n-ferahle
to Lambda theriuni^ I have found it rather dillicult to decide which of the two
genera, Palceosyops or Limnohyops, is the most primitive in its dentition, although
after considering all their characters and having compared them with nu»re primitive
types, I believe that Limnohyops is more primitive in its dental structuri's than
Palceosyops, although in some of the characters of its apiiendicuhir ski'leton. the
former genus is more specialized than the latter. There is no «pu*stion as to the
phylogenetic position of the genus Telmatotherhmi in the series. It ci*rtainly is the
most specialized genus of the group and represents the direct ancestor in the Hridger
of the more highly specialized genus Diplacodoji. In describing the «*vohitionary
stages of the species of the Palceosyopince, I propose to take uj) the charactei-s of the
skeleton as they have been described in the osteological part of this memoir.

Dentition. — In Limnohyops laticeps the crowns of the molars are low. and then*
is no constriction of the external V’s by a median buttress as in Tehnatotlicrium. \

This specimen is a portion of a mandible including teeth, which Dr. W. H. Scott infonnc<i me i-
from the Wasatch.

49 jonn. a. n. s. phila., vol. xi.

37J

A MKMOIR UroN TJIE GENUS

, . i- .1 which occurs in no otlier species of the group

.Uvi.l.-.l cluinu-t4-r ol this loriii a molars of well developed interinediiiU-

w the ptvM-m-f on tlie ,idges connecting the external V’s with

.•.iiiulcH wliile then- are nu phettacodus and Hyracotheritim the

the internal cones. In such pit n cones, and I conclude that this

, . il::, "primitive thm. iu the Pal.osyop,,

111!.. ,le)!eiienite.l ; this is a spoclillization ill the latter
liii. wlii'r. i..l.l.p.»l fertile ireiierii Tel,mtoll,eriu,n an. D.plawdou I he reteii-

li.:;,' I'ft l»e< s"|H'rier pieiiielar of L. laluep. iiidieii es its |nniii-

character while the anterior external median nb is also prominent Ihc fact
that in /.. hticeps the e.xternal 1oIk-s of tl.e last superior preniolar are Hubc-<,ual may
iM- n-ganhsl as a s|HH-iali/aMl rather than as a primitive character. 1 consider Limn^
/o,.th,a/is as .,nite a highly specialized member of the genus liecaust- the
nietanaiules of the true molars have been lost, and the crowns ot the molars
an- .sanpamtivelv much liigher than in the less specialized species ol the genus,
while the ext«-rnal Vs in L. /ou/ina/is mv wider, and in some respects have taken
on a iiion- strongly Telniatotlieroi*! facies. The greater .size of the protocoiie of molar
I in L/onthm/is as coiiipan-d with the hypocone is a primitive character, tlie liyjM)-
4-one a|i|M-nring as if it had Is-en just added.

I n-ganl Pn/trosyops paludosus as decidedly* the most primitive menilx-r ui
the p'lnis in its dental charactei-s, and it is ])articularly fortunate that such is tlie
eniM- ns the material referalile to this species in the Princeton collection is the most
nhundniit, so that 1 am eiiahh-d t<» point out the central form, as it weiv, of this
s|M-«’ies. and to indicate a numiH-r of interesting transitional varieties whicli an*
gn>u|s<<l nnaind it and liave charai-tei's iiointiiig tow'ard Limtiohyops and Tclmato-
thfrium n-s|MH-tively. Thesi- varieties of P. pahtdostis illustrate how clo.sely the
g«-neni an- ls»iiml togetlu-r by transitional forms. In typical P. paludosus the
incisors an- of n etuiical form without the basal cingula which is so characteristic of
theiM- tt-eth in 7'clnuitoflienum. The canines are large, conical, round in section,
and an- not pmvided with strong cutting ridges. The upper and low er molar series
«»f /*. paludosus have very low and undifferentiated crowns. The superior- pivmolar
without the anterior and po.sterior heels pre.sent in 'Peltualothcr-

i-oing neail.v ..q„.,l i„ trunsvem.

Tl... lir,. I„,v..r pr,.,„„|„r „r />. ,, ,

PAL.EOSYOPS LEIDY, AND ITS ALLIES.

373

ill the latter geiuis; that is to say, the second has its protocoiiid uiiudi siiialler and
the fourth has its V’s less well developed. In P. palndosns, as in all the other
species, the inferior premolar 2 appears to be less highly develojied than in the
genus Lambdotherium, where in some species a well marked rudimentary metaconitl
is present on premolar 2. The crowns of the superior true molars of P. paludosus
are very brachydont and the external A^’s are much rounder and narrower
than in Pelmatotheriuni^ while the external face of the molars is totally without a
cingulum. A primitive character of the upper molar series of P. paludosus is the
presence of a large anterior intermediate coniile on each true molar. Tlie pmto-
conules are well developed in P. paludosus and gradually Ix-come rudimentary in
some of the smaller species of Telmatothcrium. In the most jjriinitive up|K*r
molar oi P. paludosus m the collection (lO.OO!) A), the external \ s are narrow
and each one is provided with a prominent vertical rib. which I take to Ik* the
remains of the convex external snrface of the bunodont cone from which, by the
coalescence of the latter, the external A"’s of this type of molar have iK-eii derived.
The median buttress in this molar is very low and undeveloped. Another primitive
character of the tooth is the presence of both the intermediate connles, the anterior
being connected by a Avell marked ridge with the anterior cingulum. 'I'he inlerior
molars of P. paludosus have their \'’s much lower and their civsts less well devel-
oped than in Telmatotheriu7n . There are no traces of any posterior intermediate
connles on the inferior molars 1 and 2 of this species.

I believe the last inferior molar of P. paludosus has its posterior tulK*rele
highly specialized because in the supposed ancestor of PaUcosyops ( Latubdolher-
ium) the posterior tubercle of molar 3 is an open lobe and not a cone. This is als4i
the case in a less specialized form like Hyracollierium. the bunodont char-

acter of the loAver molars is strongly preserved. In the latter genus the |H»sterior
tubercle is less specialized than in Lambdotlicnuvi. It consists merely of
an open semicircle with its arms running to the external ami int<*rnal face of
the molar. In La^nbdothet'ium, on the other hand, this tniK-rcle has a.>»snmed^
a more specialized character ; it has become more constricted off from the IkmU- (.f
the tooth by the external crest of the tubercle becoming no longer eontimions with
the external border of the tooth, and by running inward its internal crest has Is'cmue
continuous Avitli the entoconid. In most of the i)osterior and inferior mohu-s of the
species of this subfamily such is the condition of this tulKU-cle, but in P. paludosus
and some of its varieties the crests and valleys have become aln.rted and the
orio-inal open and functional lobe has degenerated to a mere cone.

° The first variety of P. paludosus which I shall describe is a iK)rtmn <d a skull.
No. 10,276, from the Bridger proper, in the Princeton collection. It contains a part
of the’ mo’lar series, and on one side the last tAvo uppr molars. The total
dimensions of these teeth are considerably less than in the typical form; their
enamel is smooth with reduced intermediate tubercles. A very mtei-estmg h*atun*
in the last molar of this skull is that its posterior internal cingulum has lus,*d with a

_ ^ M KM 0 1 R UPON TI I E GEN US

I «• r ,1 iMKliiiiciitarv More accurately speaking

Minnll iH^U-rior cone t mih foriiimg ^ dLeneration. If this view is correct

i. i. .I..., .i.n„

I «i>ulil r.'P«nl ” „,„„iti„nal stage between tlie latter si}ecie»

.,.,1 I..M,rfs. „ this series the last n.nlar law a

„„ .,.,v in.en....ng premolars am higher than in the

r“' Trlu The'toi ill. of this mries is not separated by a ...edian bnitress
,i’!!!p.,ien.llv the ca«- in P. paiudosus, while the second and third preinolars have
“Jnnnlele internal cingula, a character confined to the higher genus rdmato.
Ihrrium. Uon«M,nently in this variety we see two lines of variation : one tending
lownni Umnohyops ami the other toward Tehnatothernini. . ...

Then- is n very interesting lower jaw in the collection, No. 10,018, in which
the .-ones of the ino'lars aiv higher than in the typical form. This applies especi.a ly
to molar .S. when- the crown is very narrow and the iiosterior tubercle unu.sually
Urp- for this s|s-eies, lH*ing as hroa.l transversely as the Avhole crown of the tootli
in fnait. while in the typical form this tnkwcle is merely a cone. The variation in
the clianicter of the dentition of the akive jaw would lead us to consider that tins
is a variety l«-inliiig towanl Telnialolherium, as indicated by the elongated and
incn'aMsI height of the cniwiis of the last molar.

Pa/tfoSYops l<n'idens is pmlmhly lower in phylogenetic position than P . pahidosus,
ns its su|H>rior pnaiiolar 'i has only' one e.xternal lobe and this tooth is simpler than
in any other sjsH'iesof this subfamily. The intermediate tuhercles of P. l<evidcns are
nsliicisl ; its lust su|H*rior molar exhibits a .small cone at the po.sterior internal angle
of the tiMith. One character of the skull of P. Icevidcns, to he de.scrihed later,
indicate that the sjMM'ii's is inoi-e closely related to L. laticeps than to P. paludosiis.
In the chariiclers of its skull /*. mcgarhinus dejiarts widely from P. pa/udosus, but
its rather low erowueil molars without external cingula indicate that it is. perhaps,
nioiv closely ndated to the hitter sjK*cies than to any other, although its cranial
characters show it to Is* an alierrant form of the genus.

Pnif. (*o|H* s P. valUdcMs is a very' interesting species, and its dental characters
indicate that it ought to lx* jihu-ed near Tclmatothcrmm. This is pi*oveii by
the characters of the lower molars which have high and elongated crowns, thus
ilepaiting widtdy from the molars of P, paludosiis, although the species shows its
el.ws> afliuity to the hitter in the cone-like form of the posterior tulx-rcle of
inferior molar X TIu- characters of the jaw of P. vallidens are clearly Tehnato-
Iheroal. The pliylogem-tic isisition of P. vallidens is therefore between P\ paludosiis

TchiaMhrriuni. although as a whole this species shows closer relationshiii to
the latter genus.

I n.pinl />. mimr „« Whig iiuicli more closely rclnte.1 to Telmalollicrium

limn I,. /.

'TiT«i«r)- ViTlehnitii, platp LI. Hit. 2.

PAL.EOSYOPS LEIDY, AND JTS ALLIES.

375

which have the broad and flat V’s so characteristic of Tchuatotherium. The
external cingnla are a conspicuous feature of the upper teetli in Palceosyops minor.
Oil all the true molars of P. minor the intermediate tiihercles are much reduced,
which is sui’ely a Telmatotheroid character. Its superior true molars show alliiiity
to P. paludosus in the form of molar 3 whose posterior internal angle i.s very
obliquely cut off, this tooth not having the square form which i.s so characteristic of
Telmatotlierhmi. Premolar 4 and molar 1 show a considerable difference in size ;
the superior premolars 1 and 2 show decidedlj^ more affinity in form to the teeth of
Tehnatotherium than to those of P. paludosus, this especialh’ holding good for the
first preniolar which is elongated and has the canine-like form .so characterisfic of
Tehnatotherium. The superior premolars of P. minor .still retain an incomplete
internal cingulum, which indicates its affinity to Paleeosyops. The external 1o1m>s of
the premolars in P. minor are decidedly of a Telmatotheroid jiattern having high
crowns not separated by a buttress and provided with external cingula ; the last
inferior premolar is moi’e developed in this species than in P. paludosus, as shown
by the size of the V’s which are plainly marked off in the last tooth of this .scries,
their connecting crests being large and sharp. This character of their crowns places
them higher in the scale of development than the teeth of /L paludosus where
inferior premolar 4 is less developed. The lower molars of P. minor are rather
more intermediate in character than the upper ones; their crowns are compara-
tively low ; the posterior tubercle of the last molar is very much degenerated but has
not reached the cone stage, as the tubercle still retains traces of a valley and lateral
crest. The V’s of these molars are well expressed and their crests inoix* sharply defined
than in P. paludosus. The dental characters of P. ininor, therefore, indicate that
this species holds an intermediate position between tyjjical P. paludosus and Tclnta-
tothcrium, although I think it is probable that P. ininor was dei-ived from P. palu-
dosus, or may have arisen directly from P. borealis, in the latter ca.se dmxdoping
parallel wdth Tehnatotherium and not leading directly to it. a view rend.ux-d prnl>-
able bv its small size. It is, how'ever, more probable that P. vallidcus and certain
varieties of P. paludosus are the direct transition forms lx>tween tlie latter and
Tehnatotherium. The characters of the lower molars of P. longirostris prove that
this species is closely related to P. minor.

If I had followed strictly the chronological appearance of the si)ecies of Paheo-
syops I should have been forced to consider P. borealis first, but as the idiarae-
ters of the teeth in this species more strongly resemble in my opinion, tho.'s- of
Telmatotherium than those of Palceosyops, I shall therefore deviati* fnan the ordin-
ary arrangement which I have followed and consider the characters of /’. borealis
here. The first superior molar of this species reminds one strongly in its gimcral form
of that tooth in the genus Telmatotherium. It is square with rather broad external
V’s, the latter being shallow and broad as in Telmatotherium. The pn)toconulcs of
molars 1 and 2 are small. In the first molar the posterior intennediafe is wanting,
or rather the slight ridge developed on the posterior j)art of this t<H)th is the

A MKMOIK UI’ONTJIE GENUS

TfhutMhcriun, r/z/Zr/V/.w oauws (’ope to place this species lower in tlie scale than
r fHtIudosHS, altliough Mai-sh’s T. validiis has the internal lobe of this preniolar
Wfll .levelo|HM|. I have alnwlv thvelt upon the characters of the teeth in Tclma-
tolheriuni and have shown how innch more nearly they approach those of the cul-
tiiinatiiiK jseniis of this line ( Titanotherium). J therefore hold that Tclmatolhcrium
in its ilenl4il characters shows a decided advance over Palceosyops, and a brief
snniniarv of llies«* will. I believe, pi-ove the correctness of this position. The crowns
of the molars of Teltmtofheriuni are verv high, and their external lobes exceedingly
hnwiil ami Hal. wliile practically all traces of the median rib of the external V’s
have Iss-n h»sl on the np]K‘r true molars of the genus. The e.xternal median hut-
Inws an* strongly constricted off; the lower true molars, likewise, have their cones
high, sharp and thin, and their \”s strongl}- developed; this applies espc'cially to
the conms'ting cn*sts. which aix* .strongly raised above the valleys. The
|Mislcrior tulMTvle of the last inf. molar is an o])en and functional IoIk* ; it is not
s|avializ«sl ji.s in /’, paludosus. The last inferior preniolar in Tr/ttiaMhc-
rmm appn»a«*hes inon* nearly the characters of the true molars than in
PidtrosYops. The intermediati* position of Tehnatotheriuni^ together with its
vUm' appnMich to Diplacodon in its dentition is thus demonstrated. liecanst*
of the internal h.U* to sap. pivmolar 2, 1 regard the species T. cjiilridcns as

I the latter. That is. T. culfridcns has the intermediate tubercles nearlv
tmg. wl».n*as in xMis these tubercles are well developed, and there
well dehned pn.hH-onnle on superior premolar 4, which is totallv
tmg m /. cuItridcHs. The latter species has also a very rudimentarv hv-piK-om.
•Anipriosn X«t.in.IiM. IH^.. issT, .\rtiele IVrimslnctyla.

■II tlie formor siK*cipt> and P. pahidomm.

represented by jaw Xo. 10,1,S4. The
nd the posterior tiibereU* of molar 3

PALiEOSYOPS LEIDY, AND ITS ALLIES.

upon sup)erior molar 3 which is wanting in that of F. validus, although, strange to
say, in the latter species this tooth is provided on one side with a well developed
nietaconule. In T. cultridens the internal basal cinguhnn of the premolars isstrongl\'
developed and complete. I regard this completion of the internal cingula of the
premolars as heing a higher dental character than the incomplete cingula. T.
hyognat/ms is the highest species of the genus and is the transition form iK-tween
Telmatothemmi mxA Diplacodon, as will be shown later when I consider tlie evo-
lution of the lower jaw.

The Skull. — The skull presents a great variety of form in this subfamily, and
in some species a great development of the occipital crests with an elongation of the
cranio-facial axis is the rule, while in other species the skull is shorter, with a
tremendous convex development of the frontal region. Owing to the lack of
material 1 am totally unable, unfortunately, to give an idea of the form of the
skull in a number of species. Fimnohyops laticeps has the most primitive form of
skull. In this species, as we have already seen, the cranium is greatly drawn out,
producing an extremely long cranial region and a short facial portion. The orbits
are small and placed veil over the alveolar border of the jaw. 'I'lie occipital ci-ests
are more strong^ developed than in any othei- species of the subfamily'. I'he iut»T-
orbital region is hollowed out and cnhnmates in narrow and elongatetl na.sal.x. In
the form of its nasals and strong zygomatic arches P. /m’dfr;«aj)proaches L. laticeps
more nearly than any other species. The palate in all the species of this siihfainily
is short and never extends beyond the second superior molar. The |)rinlitive char-
acter of the premaxillaries of L. laticeps is shown in their short ami roiind form. It
is interesting to note that the contour of the skull of L. laticeps mon* clo.sely
approaches that of Titanotherium than any other species of thi‘ Palceosyopiuir.

Palceosyops megarhinus apx)ears to have a low grade of skull, its form iH-ing
elongated and much depressed. The orbits are small and placed far
forward. The premaxillary and nasal regions are highly specialized, and tliller con-
siderably from those of the moi'e primitive type of skull seen in P. paludosus. 'flic
characters of the zygomatic arch and malar insertion ot P. megarhinus dilliu' viny
much from those oi P . paludosus and L. laticeps. The broad shelf-like malar of I\
megarhinus is unique in character.

The form of the skull of/’, paludosus is somewhat specialize<l and is hardly in
conformity^ with the low tyqie of its dentition. As Ave see, the marktul excavation ol
the anterior frontal region and its great bnlbiform enlargemenl distinguish
it from other allied species of the genus. The facial region is considerably
elongated and the temporal fossa shorter and higher than in L. laticeps.
P. paludosus agrees with all the other species of this lamily in not having tla* orbit
separated from the temporal fossa, constituting a primitive chaiuuder pei-sisting in
all the members of this subfamily. The premaxillaries of P. paludosus i-etain the same
primitive form as in Limnohyops. The nasals, on the contrary, an* shorter and
broader than in the latter genus. In all the above mentioned species the auditory

S7H

.|,;:'p„»i.ren,.l.l i. very short and thiek^ The se,.»r-
•tkiill I / . K foninien lacerum medmin, and the aiitero-

canal art constant and primitive characters of all
Ihr .kull.exa.»ine.l. lastly a large laterally unossified space borders he ^

kail as la all nmeiit PerisstKlactyles. I have already called atten-
tion ia the de«-riptive part ..I'lliis tneinoir to the presence of an ossthed tentornim
in the -kail ..r »,rjae/o»/«. .is well a. to the redneed size of the hra.n cavtt.v in

ll... Hkiill nf /-. Tlio h.w condition of the brain and the alnuKst entire sep-

uration of it. loU-s .m‘ elmracters which indicate the low development of tl.e hnun
ill the PahfosYophur. In Telmatolhcriiimadtridens the skull is, as far as we know,
nitlier shorter tli.iii that of I\ pMosus, witli its vertical elevation increased. The
ftkiill of /* cu/fridens is strongly <-oin pre.xsed, especially in the facial region. 1 he nasals
lire cloiipitcd iiihI stmn>.dy arclied laterally, hi the premaxillary region of Telmalo-
thfrium is foiiiiil a liiglily specialized portion of the skull ; and perhaps in P. megar-
Atnm, when* the |»n-iiia.\ilhiry symphysis is rather more elongated and narrow than
ill /'. fHthidosiis, we have a kiinl of transition form between the two genera in the
pn-ianxilinry region. This is the only variation of the premaxillary region in
/‘idtroswgs n'smiihling that of Tclmalothcrium. A very interesting character of
the skull of Ti-lmaMhcrium is the slender and nearly straight zygomatic arch
which agii*es in form almost exactly with that of Diplacodon.

ExHiiuhoH of Jaio Symphysis. — The series of changes which the svmphysis of
tile lower jaw has undergone in this scries is interesting. It commences in P. palu-
dosMs which has a rather short symphy.sis, rounded and not horizontally jdaced.
The diameter of the jaw lK*hin«l pivmolar 1 is considerable but the accom-
panying table shows that it ilecrea.ses and then enlarges again in the jaw of
/'. hvflgiMt/iu.%. In /'. ptdudosus there is no iiost-caniiie diastema but the post-
premolar 1 iliastmna is well dcveloiied. There is a great deal of variation in the
siw of the diastemas in F. pa/ndosus. The next step in the elongation of the jaw
is fomnl in a small variety of Tcimatothcrium (Jaw No. 10,184). There is a decided
elongation of the symphysis, which is more horizontally placed than in P. paln-
dosHs. whih* c«.rn‘siH)nding with its growth there is an enlargement of the dia.s-
temas. The |HM.t-mnnne diastema, which did not exist in P. po/itdosus, has IxToine
well imirke,! ill this variety. This elongation of the symphysis and inorea.se of the
diastemasis continnedin 7’. mllridcns and th rough a varietv of 7'. hyocnathus

""'r >'io cul.ni.i-

......11. If .lie I.,..- .,1 .l,.v,.|„p„,c.,.. t.. r. I, yog, , all, u. tl.c symphysis I..., Woome

......I. .■I..ng,...nl ,.,„| „ -kelly p,-,H-.n„lM!nt i„ position while the .liastemas

.l.l.....fl. ... <l...l the lirs. p,x.,.,„l.,r is place.! farthoi- postei-iorlv, tl.we Ik.!,.-

A MKMOIR WON THE GENUS
r.l... .kull r.-i....i.. .....1 there is little variation in their |•..l-ll.

ol tlie Skim nimio. i ^

the subfamily. An excei.tion to this

PAL.EOSYOPS LEIDY, AND ITS AJJJEB.

370

no post-preniolar 1 diastema in the jaw of D. elaius. I have plaotMl the type jaw
of T. hyognathus in the genus Telmatotheriiim because its inferior premolar 4
appears to still retain the simpler character found in all the Palccosyopina. The
following table of measurements will illustrate the variation in the length of the
symphyses above described.

Measurements to Illustrate the Increase in Length of Jaw Symitiv.sis.

P. paludosus
No. 10,009.

T. variety
No. 10,184.

T. cultridens

No. 10,3(31.

Tfhnatothcriuui

No. 10,274.

hyognathus
No. 10,273.

M.

M.

M.

M.

M.

Length of symphysis

•092

•108

•115

•11.5

•130

Breadth behind premolar 1

.065

■043

•050

•055

■OdO

Length of post-canine diast.

•000

•on

•017

022

■an

Length of post-premolar 1 diast .

■015

•018

■015

■Oil

•017

The Axial Skeleton. — I have already described the peculiarities of the a.xial
skeleton of Palceosyops palndosus. In many respects it resembles that of the Tapir,
although in the specialization of the articular processes of the posterior a.xial region
it differs widely from the latter. It was found that the atlas and axis closely'
resemble those of the Tapir, the former being pierced by two foramina for the first
cervical nerve. The transverse process of the atlas is perforated by a large inter-
vertebral canal. The vertebra) of the anterior dorsal region are very lu*avy with
strong neural spines; on the posterior part of the dorsal region the vertebral zyga-
pophy'ses become nearly as involute in form as in some of the Artiodaetyles [. Itililo-
capra). In this character the vertebra' of Palceosyops dei)art widely' from all recent
Perissodactydes except Equus which has the zygapophyses of the posterior dorsal
and lumbar regions involute in form.

Appendicular Skeleton. — The general form of the scapula is, as far as known,
constant throughout this subfamily. In P. paludosus it was rather broader and
heavier than in L. laticeps Avhere the spine of the scapida was (piite obli<pu* in |)osi-
tion. The pn’imitive character of the scapula in this subfamily as compared with that
of recent Perissodactyles is indicated in the ivant of a corac(Kscai)ular notch, by the
presence of a large tuberosity for muscular insertion and, most important, the large
development of the coracoid process. The form of the scapula of Pahrosyops is
found to be rather intermediate between that of Tapirus and Rhinoceros, 'fhe
trochlem of the humerus, in form and subdivision, are rather different from thos«*
of the Tapir, the internal trochlea being large and more obliipie in i>osit ion, whereas
the external part of the external trochlea is bevelled off instead of In-ing concave as
in the Tapir. This is Also the case in the smaller species of the genus. In P.pa/u-
fl'cjzwthe internal trochlea is very large and broad, while the external has a tendency
to become rounded, and does not show its subdivisions as ])lainly as in the larger
species. This character is more strongly marked in the Rhinoceros when* the
external trochlea has no bevelled portion, this face being vertical.

50 JOUR. A. N. S. PHILA., VOL. IX.

3MJ

A MEMOIR UPON THE GENUS

• 1 1 v.MMiitioii in the form of the carpus in this group. In P.

I .kW> ttltftl'l*

t ..t uf /• paluL«s. Lmnohycps Miceps, on tlie other hand, ehotvs the moat
I i.l,h .laa-hdi»Kl e,,r|,n.of the Rntup, and it in interesting to note tl.nt.n th,.,
„1;., it agnan. tvith the .,.|i|H.«ed aneeatral forme of the Pala:osyop,n^ ,-La,, Mo-
p^p.a,jr,au,„ and Pa/aasyaps boyealis, which are the earliest known
„„.„il..ni ..f Ihi. line. In these two forms the Innar is mneh elongated
and it. magnulii liaa-t i. nearly vertical in position, which is «iiial y true
of /. Murps, where, however, it is still farther elongated, its distal extremitv
l..ing diawi. oat and dia-ply imnetrating the second row of carpals. In
I ho Iiiniiiia of P./itticfps there is a decided inclination to .Mesaxonia, mucli
,.,.,n-m.th»ii ill the \^^x^u\ oi P. pa/miosHS. The fifth digit of L. laticepsx^ much
nhortor ihiiii the othein although not a.s mucli reduced as that of the Tapirs caipus.
Thorhnriietersof flu* nirpusof /-. therefore, are not as primitive as those of

the iloiitition. llie HiM*cies in this respect agreeing with the earlier ancestors of the
Knaip. niul iigniii proving that an animal maybe highlj' specialized in some portioms
«if ils Mriicture, although in other characters it may be very primitive.

The pn>|Miriioiis and size of the facets of the tarsus undergo a
groat doul of variation in this subfamily. In P. paludostis and P. minor
llio tnn*as is hnmdor in proiMirtion to its length than in Z. laticeps. As
n ralo the fiie<*ts of the astragalus and calcaneum are continuous in
I ho maallor s|M*ei(*s. and us we approach the larger they become separ-
ntdsl. In V'tfanot/ifrium, the most highly specialized genus of the group, the
snstontaouhir, inferior and eetal facets are widely' separated from each other.
Paiaosyops pit/udosus stands intermediate between such forms as Limnohyops laticeps
niid /’. minor, in which thesi* fimets are continuous, and Diplacodon and Titatiothcr-
inm ill wliieli the tai-sal facets are widely separated. The astragalo-cuboid contact
is slsn allot tier variable character of the tarsus. In Z. laticeps and P. niinor it is
small, whereas in /I it is large, and increases proportionately with the
Irniisvorsi* extent of the proximal elements of the tarsus. This is seen in the tarsus
of rHanothcrium where the astragalus covers about one-half of the cuboid. A
rihnhH’aleniu*uin facet is a rather constant character in this subfamily. There is
gi'iiemlly ii.> contact Ix-fween the cuboid and metatarsal III, although in a tarsus in
the Princeton tx>lhH*tion Ihmi the Bridger, the specific identity of which cannot be
detemniMxl. then* is a considerable contact between the cuboid and this metatarsal.
1 he pmxiinal ix.rtion of metatai-sal III is generally narrow transversely, with plane
nrticnlatmg surfaces, hut in Z. laticeps the articulation between metatarsal III and
W IS highly s,H*c*iahml in the form of an interlocking joint. The shape of the

PAL^EOSYOPS LEIDY, AND ITS ALLIES.

381

ectocuneiform is high and narrow and is characteristic of this group. We have
seen that in this subfamily the reverse type of tarsal articulation never occurs.

In the following tables I have arranged the primitive and specialized charac-
ters occurring in this group in columns, but no one species contains all primitive
characters. The dentition, for example, maybe highly specialized while the carpus
or tarsus may not have undergone as much disjilacement as in another fonn
where the dentition is more primitive.

Primitive Characters.

1. Incisors without strong basal cingula.

2. Canines rather short and stout with-
out cutting edges.

3. Superior premolar 1 a cone without
prominent heel; inferior premolar 1
also simple.

4. Superior premolar 2 with only one
external lobe and with internal lobe
wanting. Inferior premolar 2 with
lobes subequal.

5. Inferior premolar 3 without a meta-
conid.

6. Superior premolar 4 with transverse
diameter much less than that of
molar 1, also with external lobes not
separated b}^ a buttress. Inferior
premolar 4 with V’s not strongly
expressed.

7. Crowns of molars strongly brachy-
dont with external V’s rounded, nar-
row and with a median rib present.
Median buttress not constricted off'
and wAth anterior buttress strongly
prolonged. Lower molars with crests
of V’s not prominent. Last inferior
molar with its posterior tubercle a
functional lobe.

8. Intermediate tubercles of premolars
and molars large and, in the most
primitive form, with protoconule and
metaconule present on upper true
molars (^Limnohyops) .

Progressive Characters.

1. Incisors with strong ba.sal cingula.
Posterior face of incisors vertical.

2. Canines elongated, slender and with
sharj) cutting edges.

3. Superior premolar 1 elongated, with
anterior and posterior tuliercles.

4. Superior premolar 2 with two well
develojied external IoIk's. Internal
lobe of same present, .\nterior
lobe of inferior preinolar 2 much
larger than posterior.

5. Inferior preiuolar 3 with a inetaconid
{Lambdothcriuni) .

G. Sujierior premolar 4 with transverse
diameter nearly eipial to that of
molar 1. E.xternal lobes of preinolar
4 separated by a buttivss. In-
ferior preinolar 4 with I”8 well de-
veloped but without an entocunid.

7. Crowns of molars liigli, with external
V’s very broad and angular. Median
rib of same absent. Median buttress
strongly constricted oil. .Interior
buttress not widely pnilonged. Crests
of lower molars very high and sharp.
Last inferior molar with jMisterior
tubercle specialized in the form of
a cone without cifsts and valley.

8. Intermediate tulx*rcles of su|x’rior
premolars and molars much n*duced.

9. Last superior molar with only one
internal cone.

A MKMOIK UPON THE GENUS

y. Irfint i*uiHTH»r molar with two in-
mnial foiioM.

10. SuiK-rior and inlerior .liaaU-inuH hjiuiII.

11. Kona of i*kiin much chaigaU-d and
dc|m-^m-<l. tK-oipital rt‘gioii higlier
than the iiiternrhital and provided
witli large cn-ata. Orbit ainall and
phicwl well forward over molars.
Floor of orbit short. Zygomatic arch
strongly develojaal. Auditory pro-
c-eK«-s well wparattKl. I’alate short.
I’nanaxilhiries short ami with a short,
rmiiid symphysis. Nasals elongated
and of the sjiine hnwlth throughout.
Alispheiioid canal long. Foramen
ovale s«»parat«*il fnan foramen lacerum
in«Hliinn. Symphysis of lower jaw
short and nnimlecl.

l‘i. (Vaiiial eavity elongated, with ccre-
hnd ami «*erelHdlar fossie separated
hy an ossified ieutorium.

IS. Hniin «»f a low tyjK*. Divisions of
same well s«*pnrated, with olfactory
loU-s niueh elongated. Oix-belluin
and tn«‘«Iulla very broad transversely.

H. .\tlas |M’rfontt(Hl by a vertehrarterial
canal.

15. S'apnhi with a largi' coracoid pro-
«vss.

IG. Pelvis with iliac |)ortion not subdi-
viihsl.

17. t’ar|»us short and hn)ad. with distal
faci'ts of lunar sulHM|ual. The four
•ligits of the mamis well developed.
Manus approaching the Paraxonic

tyis*.

18. Tarsus with facets of astragalus and
calcaneuin continuous. Astragalo-
culsad contact .small. No interlock-
ing articulation lH>twi*en metatarsals.
A fibuloK'alcaneal facet present.

10. Supei’ior and inferior diastemas large.

11. Form of skull may be variously mod-
ified. Crests not strongly devel-
oped. Orbit and Hoor of same much
elongated. Zygomatic ai-ch nearly
straight and slender. Auditory prr>
cesses nearly aiiproachingeach other.
Mastoid portion of periotic not

. exposed. Premaxillaries much elon-
gated and high, with a long median
symphysis. Nasal short and broad,
expanded distally. Symphysis of
lower jaw nearly horizontal in posi-
tion and very long.

12. Carpus narroAV and elongated. Distal
facets of lunar highly specialized, the
lunar-magnum facet being very small
and nearly vertical in position.
Lunar-unciform facet large. Mag-
num high and narrow. Manus aj)-
proaching the Mesaxonic type with
metacarpal 111 larger than the
others. Metacarpal V <|uite reduced.

13. Distal humeral trochleie specialized.

14. Pre- and postzygapoj)hyses of pos-
terior dorsal and lumbar vertehne
involute in form.

15. Scapula with an oblique e.xternal
spine.

Ih. Tarsus with facets of astragalus and
calcaneum widely separated. Infer-
ior facet small. Astragalo-culx)id
contact large. Metatarsals III and
IV may have interlocking artic-
ulations. hibulo-calcaneal contact
reduced. Navicular shallow. A
large contact between cuboid and
metatarsal HI.

3S3

PALiEOSYOPS LEIDY, AND ITS ALLIES.

Conclusions.

The foregoing study of the relationship of the niemljers of thi.s sulifamily lead
to the following conclusions as to their phylogeny : —

1. That Lambdotherimn may be the ancestor of the Pala?osyop.s-Diplacodon
line, although certain specialized characters of its dentition, the loss of tlie first
inferior premolar and the more complex development of its inferior preniolar 3
indicate that Lambdotherimn leads to a side line.

2. Palceosyops borealis appears to lead to a side line, perhaps to P. minor. The
molars of P. borealis point to this conclusion because of their close ivsemblance to
those of Peb7tatotherium.

3. I consider that Lmi7tohyops laticeps is the most primitive memlx'r of this
group from the Bridger, because of its low form of molar, with large intermediate
tubercles, and its last superior molar has two internal cones. The form of
the less specialized skull of L. laticeps^ with short premaxilhiries and much elong-
ated nasals, points to the primitive position of that species. From such a form I
believe P. Icevide7is has arisen, that species being intermediate between L. laticeps
and P. paludosns.

4. P. paludosus has arisen from L. laticeps through the intervention of P.
I(evide7is ; in the latter the simplification of its superior premolar 2 is greater than
in P. pahtdosns.

5. P. vallide7is has developed from P. paludosics by lengthening and increasing
the height of its molars.

6. Tel77iatotherui77t C7dt7'ide7is has originated by increase in height of theemwns
of the molars and widening of the external V’s, and a reduction of the intenuediate
tubercles of P. paludosus. P. vallidens is the transition form Ixdween these two
species.

7. T. C7dt7'ide7is, on account of the simpler structure of its superior pu-molar 2.
is the most primitive member of the genus Tel77iatothcrmm, and was the ancestor of
T. validns.

8. By lengthening of the jaw symphysis of T. validns, with a concom-
itant widening of its diastema, T. /lyogfiatJms has arisen.

9. I regard L.fo7iti7ialis and P. megarhhms as siiecialized fonns and not in the
direct line of descent leading to Tel7)7atotherin7n.

10. As already mentioned several times in this memoir 1 consider that Tcl77ta-
totherhmi is the most highly specialized genus of the Palceosyopi/ier, aiipmaching
more closely in its dental characters to Diplacodon than any other genus of the sul>-
family. TePiatotherumi should, therefore, hold an intermediate position Ixdwwn
Palceosyops and Diplacodo7t.

The accompanying phylogenetic table will make clear the suppo-sed relation-
ships between the species of this subfamily.

Shi

A MKMOIK UPON THE GENUS

T. hyojaiatbus.

T. validus.

Telmatotheriiim cultridens

P. vallidens.

1*. minor.

P. megarliinus.

L. fontinalie.

P. borralU.

Limnuhyopa laticeps.

laimbdotherium.-

APPEXDDv.

Ft ItTlIKK OltSKRV.\TI0X8 lTl>ON' JlIE OSTEOLOGY OF PALA:0SY0PS BORE.VLIS.

I am able U* make nii additional contribution to the osteology of tliis species,
\ZM.m r ‘ out last summer by the American

greater part of a akeleten of

S"“—

P— :rior topte-

iniicli naliirnl anil rone sliaiH'il Crowns of "'al‘ posterior tubercle
Wr/o,._Tl,c lowo a : "®'™r low and broad.

jaw of foWir .8 rather long and slender. The

PALJ50SY0PS LEIDY, AND ITS ALLIES.

385

ascending ramus is high. The symphysis is long and constricted at the diastema.
The canines are round in section and wide spreading. The pi'otoconid of premolar
2 is much higher than in the other premolars. It has a well developed heel. The
true molars show their primitive character in having low crowns, with the crests of
the V’s low, and the valleys shallow. The characters of the last inferior molar are of
interest ; and its posterior tubercle is more reduced than in any species of the
genus.

Humerus. — The humerus is slightly shorter than in Tapirus Amertcajitts,
but the extent of its proximal and distal surfaces much less. The middle portion
of the shaft is slender. The deltoid ridge extends far down upon the shaft, and its
external border is prominent. The trochlem are very narrow transversely, with a
prominent rounded ridge dividing the external from the internal.

Femur. — The femur is much shorter than that of the American Tapir ; its
shaft is long and slender. The lesser trochanter is prominent. The third tro-
chanter is elongated and thin. As in all the species of PaUeosyops the p(»sten>-
inferior face of the femur is flat and shows no fossa for miuscular insertion.

Mamis. — The carpus is about as broad as high. The lunar has a large contact
with the unciform, but does not penetrate below as in Limnohyops. 'Tlie magnum
is very high and narrow, and only has a small contact with the lunar. The unci-
form is Tapiroidin form, and its horizontal axis is rotated more upward than in the
other species of the subfamily^. As a result of these carpal relations the unciform-
lunar contact is a large one. Indications are that the outer digit of tliis sjaTies
was more reduced than in L. laticeps-, and the axis of the manns pa.sses through
metacarpal III (Mesaxonia). The metapodials are wide spreading and slender.
From the measurements of the jaw and limb bones, we may conclude that fhisgrace-
ful species must have been about one-fifth smaller than the Brazilian Tapir, but the
diameter of the limb bones and the light construction of the man us prove that it
was lighter built and more agile than any of the recent species of Ta[)ir.

MEASUREMENTS, PAL^EOSYOPS BOREALIS, NO. 290.

Length of jaw

Depth below middle of molar 3
Entire inferior molar series
Length of manus without phalanges
Length of carpus
Breadth of carpus

M.

■20(»

•040

•128

•117

•034

•035

Length of humerus .
Breadth of distal surface
Length of femur

S^i

i. Ijtidy.J.

A .memoih upon the genus

tuhT.IOGUAPHY.

10.

11.

I‘A

13.

N.

15.

16.

17.

18.

19.

20.

21.

22.

Manb. O.
Cope,K. I>.

SooU, '7'.

Ofborn. H.
HcoU, W.

Hcolt. \V.

VatU. C.

(5111. T.
(iiiudrjr, .\
HrblMKr.

Strinmiui

Nkholaon

Iteport. < of Territories, 1873, vol. 1, pp. 27-58.

aSi* "Xuii.ion of Ver..b„« Life in A„.n». fbid, Vol. XIV, p. 36.
l>ino«r-U. an eating ST A. ’and their allies. Bull. U. S. Geol.

On the extinct ipccies of Khinocerotiase oi x^.

?S^' ;fJSc’Jr™!.'^men. of .h. order Perfasod.ctyl.. Proc. Am. Phil. Soe.,

il^i;,‘Si..d.nuu, Geol..,n».Su,r.r of the Terrimri^, Vol. Ill, 18Sd, p. 697.

Tlic Peri«.MlactvlB. Am. Nat.,>ov. and Dec. 1887.

h! Thri-^nc loacustrine Formations of the West. Proc. Am. Ass. Adv. Sci., 1887,
Ft. Mid n. F. Oslwrn. The Mammalia of the Uinta Formation. Trans. xVm. Phil. Soc.,

i*rtdim'inar^olmcrvaUo’n8 upon Palicosyops and allied genera. Proc. Acad. Nat. Sci.

Phil, Jan.'lHOl.p. 10(5. inn la-o o-tn

ArniiiKenicni of the fiuiiily of Mammals. Smith. Miscel. Coll., 18 <2, p. -30.

.. Kiichainemcnta dll Monde Animal. Paris, 1 878, p. 46. t lu x

M»*. Ih-itriijtc xur Kcnntnisa der Stammesgeschichte der Hufthiere. Alorp. Jarhbuch,
Ihl. XII. iHM-.pn. 18-22.

Mid I Kiilerlcin. Elcmcnle dor Paheontologie. Band II, 1890, p. 776.

Mid Lydckkor. Manual of Pahcontology. Vol. II, 1889, p. 1371.

PAL^EOSYOPS LEIDY, AND ITS ALLIES.

387

EXPLANATION OF PLATES.

All specimens are in the Princeton Collection unless otherwise sj^ecified.
Plate X.

Fig. 1. Pal^eosyops paludosus.

Skull, lateral view ; so. supraoccipital. Academy of Natural Sciences, Philadelphia.
Fig. 2. Pal^osyops megaehinus.

Skull, lateral view.

Fig. 3. Telmatotheeium culteidens.

Skull, lateral view.

Plate XI.

Fig. 4-7. Pala:osyops megaehinus.

Fig. 4. Skull, anterior view.

Fig. 5. Skull, basal view ; as. posterior opening of alisphenoid canal ; f. o. foramen
ovale ; f. 1. m. foramen lacerum medium; f. 1. p. foramen lacerum posterius ;
e. a. m. external auditory meatus ; c. f. condylar foramen ; Per. penotic.

Fig. 6. Lateral view of brain cast; sy. sylvian fissure; ss. suprasylvian fissure;
h. hippocampal gyrus.

Fig. 7. Superior view of brain; 1. 1. lateral lobe of cerehellum ; v. vermes.

Fig. 8-9. Limnohyops laticeps.

Fig. 8. Skull, posterior view; f. pm. paramastoid foramen.

Fig. 9. Skull, lateral view.

Fig. 10-11. Telmatotheeium hyognathus.

Fig. 10. Lower jaw, lateral view.

Fig. 11. The same, superior view.

, Plate XII.

Fig. 12-13. Telmatotheeium culteidens.

Fig. 12. Superior molars, crown view.

Fig. 13. Inferior molars, crown view ; both these figures are taken from the skull
figured on Plate X, Fig. 3.

Fig. 14-16. Palaiosyops minoe.

Fig. 14. Superior molars, crown view. This .series of molars is the tyjK? of this species,
and is in the collection of the Academy of Natural Sciences of Pbilndeljdiia
Fig. 15. Second and third molars of same series, external view ; ab. anterior bultrcss ;
mb. median buttress ; eg. external cingulum.

Fig. 16. Milk molars, crown view.

Fig. 17-23. PALiEOSYOPS paludosus.

Fig. 17. Superior molars, crown view.

Fig. 18. SupeVior molar 3, crown view; pi. protoconule; ml. metaconulc; eg.
cingulum.

Fig. 19. A left superior molar 2, crown view.

Fig. 20. An inferior molar 2, crown view'. Figs. 19 and 20 are taken from Leidy’s
original type specimens, in the National Museum.

Fig. 21. Distal end of left radius, anterior view.

Fig. 22. Distal view of same; 1. artieular surface for lunar; s. that for scaphoid.

Fig. 23. Sacrum, internal view. •

Fig. 24-27. Limn°ohyops laticeps. , , . . ,

Fig. 24. Eight scapula, external view ; tb. tuberosity ; cr. coracoid jirocess.

Fig! 25. Left humerus, anterior view ; e. c. external condyle ; i. c. internal condyle.
Fi^! 26. Left radius and ulna, anterior view. .

Fig 27 Distal view of same. Last two figures are from the same individual as
manus, Plate XIV, Fig. 39.

51 JOUR. A. N. S. PHILA., VOL. IX.

SMS

A MKMOIK UPON THE GENUS
Plate XIII.

Fio. view v vertebrarterial canal.

vie': U L.»m. for 8™. .piu.l oerve.
Axi*. latcrnl view.

A cervical vertebra, anterior view.

An anterior doraal vertebra, anterior view.

JjUeral view of same.

Fig. -Ji).
Fig. 30.
Fig. 31.
Fig. 32.
Fig. 33.
Fig. 34.
Fig. 35.
Fig. ;i6.
Fig. 37.
Fig. .3M.

JjUeral view oi same.

A iiorterior dorsal vertebra, lateral view.

Poiterior view of same; pz.postzygapophysis.

Lumbar vertebra, lateral view ; pz. postzygapophysis ; m. metapophysis.
Right scapula, external view.

View of the glenoid cavity of the same.

Fio. 39-42. Limmoiiyoi-s laticki-s.

Fig. 39. licft nianus, anterior view. -e

Fig 40 Pint row of carpals of same, distal view ; s. scaphoid ; 1. lunar ; c. cuneiform ;

U. facet for the trapezium ; td. facet for the trapezoid ; mg. the two
anterior fnoeU for the magnum ; t. m. the two posterior facets for the same;
uc. facet on the lunar for the unciform.

Fig. 41. Right |>ea, anterior view; f. b. fibulo-calcaneal facet.

Fig. 42. A right metacarpal III, anterior view ; from same individual as the last figure.

Fia 43-44. l’Ai-»uiaYoriiMixoK.

Fig. 43. Right jica, anterior view.

Fig. 44. MctaUrsals, jiroximal view; c'" facets for ectocuneiform.

Fiu. 45-49. I’Ai..tM»»Yoi-s pAH iKiai'H.

I>cfV maniis, anterior view ; this figure is a composition,
licft pcs, anterior view ; a composition.

left ealcaiietini and astragalus, lateral view ; a. ch. astragalo-cuboid-facet.
Anterior view of same.

lx*ft culioid, anterior view; c. c. calcaneal facet; c. as. astragalar facet;
C. nv. facets for ectocuneiform; from same individual as figure 47, .

Fig.

4.5.

Fig.

40.

Fig.

47.

Fig.

48.

Fig.

40.

THE FOSSIL AVIFAUNA OF THE

389

A STUDY OF THE FOSSIL AVIFAUNA OF THE EQUUS BEDS OF THE OREGON DESERT.

By R. W. Shufeldt, M. D.

Early in March, 1891, Professor E. D. Cope placed in my hands for description
two collections of fossil Birds. Both of these were obtained at Fossil and Silver
Lakes in Oregon. The first consisted of some seventy or eighty s^jeciinens belonging
to the private cabinets of Professor Thomas Condon of Eugene City, Oregon, and
were collected by him in the aforesaid region ; the second, and by far the larger col-
lection, consisting of several hundred specimens, belonging to Profes.sor Coja* himsedf,
having also been collected at Silver Lake either by himself or his assistants.

Soon after these collections came into my possession I bestowed uiM)n them a
preliminary examination of quite a superficial charachw. Nevertheless it was suf-
ficient to enable me to present the results of such an initiatory study in a pajx'r
entitled “On a Collection of Fossil Birds from the E(pms Beds of Oregon” which
was read by me before the Biological Society of Washington at its regular
meeting on the evenmg of the 21st of March, 1891, and was subseipiently publisluul
in the April number (of the same year) of The American Naturalist without change
of title (pp. 359-362).

Professor Cope, prior to submitting the.se collections to me fur a description,
had given an account of three new forms of birds they represented and had
determined some seven others as having belonged to species considered by him t<j
be identical with species now existing in our avifauna. Those accounts have Ikhmi
published in various places, and it has been from such .sources, taken in connection
with my conversations with their author, that most of my first infonnation of the
kinds of birds that flourished in those times, and all my information alxmt the ivgion
in which they were procured, was derived. With respect to my knowledge of tlie
locality, it was principally obtained from his paper in. the issue of The American
Naturalist of November, 1889, entitled “ The Silver Lake of Oregon ami its Region ” ;
and the other papers I shall refer to fixrther on.

On the 13th of March, 1891, Professor Condon wrote me fr<»m Eugime Cit\-.
Oregon, giving me permission to retain in my keeping such specimens as Ixolongmd
to him,’ until the entire collection was described and printed. My thanks are hen-
tendered him for his courtesy and assistance.

THE SILVER LAKE REGION.

Two fi-ures of Silver Lake are presented in Cope’s article in The American
Naturalistl^med above, and I learn from still other sources that that shec-t of

water i» uiM'*”-' , middle part of the State, it has an extreme

.-.inewliat t4> .rmLt width being not more than eight

length arc’ alkdine, it has, nevertheless, fresh water pass-

r,','inta it fn,M, Silver C„fk over .. ewampy delta near ita northwestern extrennty,
and a anmll. clear atreum of pure water also enters it from die westward.

\l*.rt'a Lake. coiiHiderubly larger than Silver Lake, is found some fort>-five
...ih^'tothe ^mthward and eastward of it, while at various distances from the
latter and in .livers direetmiis in the same region are to he found similai ones,
all agn..i»g nant. or less with them in their character. Fossil Lake is more in the
<)n.p.n.Ls<Tt regi..ii,and is about forty miles east of Silver Luke, and is a lake
now only In name, for its former waters have long since dried up. By digging,
However' water may yet lie obtained at a depth of two or three feet from the sur-
faw of the grouiul, or whut was formerly the bottom of the lake. Tlie surrounding
country is civered with “sagebrush”, and presents the usual topography of the
west.-rn desert r<*gi«»n. Hut Silver Lake islxmnded on the west and east by precip
iums Imsnltic bliifl’s, wliicli, on the south, present their dip edges to the lake, the
gmiernl strik.* Indug north ami south. Cope has further said that “on the north
side this lake is Uainded by a range of low hills, terminating in a bold Hat-topped
butte to the east, which is coiiiikisimI of volcanic mud more or less irregularly strati-
fusl, A low shore and plain separate this range from the eastern bluffs, and at this
|Miinl ovcril.iw from the lake nuiches a low tract to the eastward, which, when it con-
tains water, is known ns Thorne’s Lake. It was dry at the time of my visit (1879)”.

“t>n climbing the bluff wbicii iMnnids the lake on the west, the observer .stands
on I lie «slge of a plain which extends to the foot of the ancient volcano which I
INisMsI (III the way to the lake. It is here seen to form but a single mountain with
its foolliills, forming a line north and south. It occiniies the position of the so-called
“ inter Hangi> ” of the V. S. War Department maps ; but it is rather entitled to be
calhsl \\ inter Mountain than a “ range ”. Its summit is bold, but had no snow on
it at the time of niy visit. Its sIojhis are thickly clothed with forest jiine {Pimis
fHfMdtrosaW

“Fniiii the snnunit of the bluffs on the east, the eye ranges over the Sage-
brush desert of Central On*gon. Its surface is diversified by hills and bluffs, which
have generally one s1o|k*, and one pivcipitous side runuing generally north and
wHith. The surface was everywhere dotted wdtli the ubiquitous Sage-brush
(.'/r/m/xMl with lieivaiid theiv a generally distorted cedar iymiipcrtis). This
s^Mie extend,.! as far as the eye could reach, being bounded on the northeast by
the long, low outline of the W agontire Mountain ”.

M.«.t of the U‘st siH>cimens are found at Fossil Lake, and as I have already

-i-tod by the cattlemen of ll.e

•vncl.«...^ t|,.„ depnving science of them and their study. Professor

KQUUS HKDS OF THE OREGON DESERT.

• . I r .ind ill latitude 43° 05' N. and longitude 43° 25' W., being

■■'r''.'''".’;''" I ,.f tl.e ...iddle part of the State. It has an e.vtreme

THE FOSSIL AVIFAUNA OF THE

391

Thomas Condon was the first scientific man that visited Fossil Lake, with the
result already stated above. Cope and his assistant, Mr. Charles 11. SternlxTg,
came later, and gathered up many hundreds of bones and fragments of them. By
them the name of the Silver Lake Region has been applied to the entii*e
country about, and for our present purpose its character has now been sufficiently
well portrayed in the foregoing paragraphs.

OBSERVATIONS ON THE PRESENT FAUNA OF THE REGION.

At the small lake known as Christmas Lake, one of the system now under con-
sideration, Cope found in its 'waters “ abundance of larvai of dipterous insects, and
crustaceans, as Cyclops”, and various waders among the liirds were feeding njK)n
these. C^uantities of small white shells also abound ; they are principally of the
species knowm as Carinifex newberryi^ and they occur both in the fossil and living
state. In some places the former bottoms of the lakes are white with them, and
undoubtedly they too contributed to the food-supply of many of the tertiary l)ird.s
and mammals. At the present time Carinifex lives chiefly in Klaniatli Lake.
But few varieties of fishes are found. Plenty of Salmo purpnratus aix* to Ik* found
in Silver Creek, which, as I have said, empties into Silver Lake, but they do not
enter the lake, owing to the alkalinity of its Avaters. But in the hitter we find
another form, and only* one, it being Myloleticus /ormosus of (lirard, one of the
Cyprinidee. Batrachians also are rare, but one species has thus far lx*en taken
in the region, and that a tree-frog {Hyla regilld). It is abundant on the shore.x of
Silver Lake, though it does not resort to the timher. But two lizard.s liave thus
far been reported, namely, Uta stansburiana and a variety of Sceloportis undulatus.
The latter is frequently seen sunning itself on the bare volcanic r«K*k of the lake-
shores. Only* two snakes occur in this arid region, — the rattle-snake, known a.s
Crotalns corifluentus lecontei, and Etdania stria lis parietalis.

Bird-life, however, is abundant, and at all times of the day are to Ik? .‘H*en,
either on the surface of the water, or in the marshes and on the lake-shore.s several
species of the Avestern forms of Grebes; probably gulls and terns; ahvays [K-licaus
and cormorants ; nearly every variety of the anserine tyqies, including plenty of
SAvaus and geese. Various Avaders also occur, and I presume, although Pmfessor
Cope does not mention them, numerous shore-birds, as plovers and sand-iiiiH'i-s.
Coots also are common in suitable places, and very likely some of the Hails.
OavIs Avere noted, and among the Accipitres various hawks undoubtedly ix'sort them
attracted by* the great abundance of game.

Among the land birds, Myiadestes iomisendii, Hcsperocichla neevia, Oroscoptes
montanus, and the Avoodpecker Melanerpcs torquatus, attracted most attention, but
I have eAmi’y* reason to believe that numerous other Passeres make up the list.

Many of the Mammalia are abundant; chief among the.se are the Black-
tail deer; the antelope; Cams latrans) with badgers and skunks. Rodents am
especially* numerous, as Photiiontys bulbivorus ; Panttas a. qnadrwttlatus\ a small
species of Spermophilus; at least four hares, namely, Lepus canipcstris, L, cailolis,

jlj,, KyL'L'S liKDS OK THE OREGON DESERT.

/. «n.l /.. OtI.en. than these Professor Cope does not men-

**"" mammalian types were overlooked, but what

hM juHt Ut-n givtMi will Ik.- Huflicient to indicate the kind of mammals winch at the
pn-m-nt time are uKaociated with the existing avifauna.

HKICr KKMAKKS I'l-O-V TIIK 1-KKlII.STOKIC VKRTEBRATE LIFE OF THE REGION, EXCLUSIVE

OF BIRDS.

The Silver Lake region of Oregon is considered to be of the latest Tertiary
fonnafiou, of the horizon' known as the Equus Beds. These beds exist in other
,mrU of North America, but those furnishing the greatest number of Vertebrate
f.-Miils exist in luhlition to the Unmlity now under consideration, in the valley of

Mexieo. ami in Soutliwestern Texa.s.

The ()n-g«»n eollw-tion furnished Professor Cope with several fos.sil fish fonns,
the mnjoritv «»f which were new to science. These were Leucus altar cus, Jilyloleucus
gihhartus, Cliola au/^uslarca, Calostomtis labiatus, and C. batrachops.

Fossil .Mamnmlia of the region were particularly remarkable, the following

Is-ing a list of them :

llolomcuiscus vitakerianus Cojie.
Holotncnisciis hestcrniis Leidy.
Eschatius lonprostris Cope.
Eschatius conidens Cope.

Equus major DeKay.

Equus occidcntalis Leidy.

Equus excclsiis Leidy.

Elephas priuiigaiius Blum.

Cauls lairatis Say.

Lulra ? piscinaria Leidy.

Castor jiber L.

Ai’icoia sp.

Thomotuys bulbivorus Licht.
Thomomys ? clusius Cones.
Mylodon sodalis Cope.

Tlie phalangi' of a Ix-ar was also found, and as there were numerous fossil
iKim-sofniainmals and fishes and other vertebrates commingled with the bones of
f.MM.il hinls s,.i,t on to me, I can further say that the above list could be extended
by a mmilK-r of the smaller rodentia such as rabbits, gophers and others

It will l«. .>l«.mHl lliat tl.oro is an absence of tapirs, peccaries, opossums and

wlm-li. ( „|a. «.js, “ one would dml in similar company in corresponding
bwls 111 the Kastcni States . no

As to the pn-senee or absence of
teml everj where in the dcixisit were

man the authority just quoted says, “ Seat-
tle obsidian implements of human mamifac-

THE FOSSIL AVIFAUNA OF THE

393

ture. Some of these were of inferior, others of superior workmanship, and many
of them were covered with a patine of no gi’eat thickness, which completely
replaced the natural lustre of the surface. Other specimens were as bright as when
first made. The abundance of these flints was remarkable, and suggested that they
had been shot at the game, both winged and otherwise, that had in former times
frequented the lake. Their general absence from the soil of the surrounding region
added strength to this supposition. Of course it was impossible to prove the con-
temporaneity of the flints with animals with whose bones they were mingled, under
the circumstances of the mobility of the stratum in -which they all occurred, but
had they been other than human flints, no question as to their contemjMjraneity

would have arisen. Similar flints have been found by Mr. W. T. McGee in IhhIs •

in Nevada, -which he regards as of identical age with that of Silver Lake; but

whether diagnostic vertebrate fossils are found at that locality, does not appear to

be known. The probability of the association is, however, greatly increa.sed by the

discovery, by Mr. Wm. Taylor, of paleolithic flints in beds of corresponding age, on

the San Diego Creek, Texas

This point interested me not a little and when I came to go carefully over the
great mass of fossil bird bones, every fragment and bone was carefully examined for
any indications whatever of their former owners ever having 8u.'<tained any
wounds or fractures of the same, but nothing of the kind was discovered. In this
connection I would say, though in no way whatever as a counter-argument to the
remarks of Professor Cope as given above, that it is by no means an infreciuent
occurrence to find in the old skeletons of the buffalo on our Avestern plains. Indian
iron arrow-heads sticking in some one of the bones. Bullets are ahso found (KTUpy-
ing similar places. It would be too great a digression to further discuss such a
point here, and it but remains to be said, that it yet lies quite within the range of
possibilities to meet Avith the fossil bone of some large mammal or bird of Silver
Lake, in Avhicli may be imbedded the point of a flint ari’OAV-head.

AS TO THE NATURE AND CONDITION OF THIS COLLECTION OF FOSSIL lUKD.S.

If we select Fossil Lake as an example of the character of the ground in Avhicli
these fossils AA-ere obtained, it will be seen from Avhat has been said above, that its
former bottom, formed principally of sedimentary deposit, is noAV dry, hnise and
very friable. BeloAA^ this at the dejith of a foot or tAA’o aa'C come to AA'ater.

In one or tAvo instances the fossil skeleton of a single bird, or one or tAvo liones
belonging to the same individual Avere found in the damp soil just alxive the water.

The collector had wrapped such in separate parcels, and they aa'cix? easily distin-
guished by me Avhen received, from the fact that they Avere more or less coven-d by
a very thin layer of clayey mud. Material of that kind Avas found to lx* jiarticu-
larly useful and valuable. In the loose and highly mobile surface layer or soil,
however, the fossil bones Avere more or less mixed up, and AA'ere apparently collected

'■The Amer. Nat, Nov. 1889, pp. 979, 980.

HKDS DK THE (JKEGDN DESERT.

1 * without regard to the species or individuals

by >ly ''“'"1..^,"^ „|„,c!men »a8 most completely fossUD-ed, abeotetely

to winch they xdon>?i«l. y 1 indeed, exhibited their characters

fn^. fnm. ! prepared bones of recent birds. In color they were

... nnniy cux-s as well a« frts 3 11 instances. Many of them were

r ..avm.juet been ..bed i„ dea..

VII .f the'iu were very brittle and easily broken by a slight blow. , , , . ,

I mml u,K.n e.^mining the collection that Professor Condon had selected
hUH,KH-imens with es,K.iial rc-gard to their being perfect and unbroken examples.
They wen. ean.fully wnippe-d in cotton and paper, and as separate objects
wen valuahle aa a means of comparison. The main collection. Professor Co^ s, was
,mck.Hl in a nmnlx.r of separate Ixixes of various sizes, and some attempt l>a‘l ^n
Inmle to i-lentify the lames Ix-yond the species he had already descnlx^d. fliose
i,lentifientioiia were not altogether satisfactory to me, and in some instances they
had again lxH.«ine mixed up. So, with his permission they were disivgarded, and
the entin- mat*.rial iKdonging to him mixed in one mass in a large tray for identifi-

study by the present writer. 8o much then for the character of the

fiwsils and their condition. The bones ranged all the way from those of a size
Udonging t4i ii v«*ry large swan to those which evidently had belonged to small
imsn-rine tyjH.M. They were in all stages of completeness from slivers and fragments
<»f all si/ea to laines cpiite iMrrfect in all their parts.

vimion.s .viMUTKi) ix studyixXG such a collection.

_ 9

I’nifesaor (\»ik*’s part of the collection consisted of some 1500 Ixmes and frag-
nieiita of lames, and by can.*fully going over it bone by bone, and piece by piece, I
eliminated, lirst, all the fo.ssils that were not from birds. Ne.xt all the Ixmes that
Isdongial t4> the same part of the skeleton, irrespective of family, genus or species,
wen- ass4irt4xl out int4) separate lots. This threw all the vertebra, together in one
hit, all the f4.niorn in another, all the coracoids in still another, and so on until
the iiial4>rial was all oxlum.sted.

K«illow iiig next in oixler came the identification of groups; this tcKik considcra-
hh- time, ninl miuind uo little care. It also proved a check upon the first process
mid C4.rnx’t4Ml such ermrs ms Imcl then been made. The division into groups
ihmiandiMl the rigid comparison, Ixnie by bone, Avith the corresponding ones in the
skclcl.ms of 1.11 the existing types of birds available. In this connection I am under
great oldigat Kins to the U. 8. National Museum, and to Mr. Lucas of its Depart-
of A„nlm„y, for tbc loan of mouy akeletona of birds to be- used

»>.->terinl to tbe

.\uer nil tins had beer

^ coiacoms, lemora, tibio-tarsi and so forth

:r,:ir:Tb::')::;;x:-

THE FOSSIL AVIFAUNA OF THE

3(»5

were in one lot ; all the coracoids of Grebes in another ; all tlie coracoids of Cormo-
rants in another, and so on for all the other bones of the skeleton, and for the dif-
ferent groups of birds to which they had belonged.

Now by carefully studying all the broken bones and fragments, and the use of
splints and strong glue a good number of the fractured bones w'ere restored. In
some instances they were made complete, wdiile in others so nearly* so as to make
specific diagnosis certain. With such work every piece, however small, is of value,
and thi’ows light upon the solution of any problem under consideration. EsiHJcially
is this the case in the long bones of Waders and Herons.

After the collection had been gone over a number of times and studied up to
this point, two lots of specimens were set aside irot to be used again. One of
these contained the fossil bones of vertebrates not birds, and the other a ma.xs ol
broken fossil bird bones too fragmentary for any fui’ther use.

Taking the Pygopodes now in hand, I placed all the coracoids, for instance, in
one lot that seemed to belong to the same species, then all the tarso-metatai-si in
another lot, and so on for all the bones of the skeleton. Group after group was
treated in this way, until the entire recognizable part of the collection had lx*en
gone over again. In one or two instances this actually showed exactly how many
species were represented in a particular group. For e.xample, supposing in thus
assorting them I found nine kinds of coracoids of Ducks, then upm assort-
ing the ulnrn of those birds, I also found nine dillerent kinds ; then nine
kinds of carpo-metacarpi and so on until the Duck bones were all as.sortcd into
specific lots. It would be fairly good evidence that 1 had nine species of fossil
Ducks before me. Group after group was thus studied and their lx)nes classified, and
when this had been accomplished it resulted in another small lot of Injiies Ixung
set aside as “ doubtful ”. Some of the latter were used again, but after all
the species had been either identified or named as extinct and new siK'cies thei-e
still remained a small lot of bones set aside as ‘‘ not identified which lot must
remain until more material is collected at Silver Lake for additional light to
determine them.

After the collection had been treated in the manner tlius descrilxnl I was able
to undertake the determination of the specific forms it represcmted, and I at once
passed to a consideration of the Pygopodes.

PYGOPODES.

Prof Cope found three Grebes represented in the collection and gave it as hi.s
opinion that they were Podiceps occidentalis Lawr., Podiceps californints I leenm, and
Podilynihis podiceps Linn, and of the first named he said that one of the most
abnndant species was a grebe, which I could not distinguish from the one so com-
monly seen in Silver Lake, {Podiceps occidentalis Lawr.”-)

^The Amer. Nat., November, 1889, pp. 978 and 980.

52 JOUR. A. N. S. PHILA., VOL. XI.

1{KI>S (^F THE OREGON DESERT.

. , , known as Aichmophoriis occide^itahs and

n^U.pso<ndentan,^ „une including parts of the superior

1 find m especially perfect specimen of its tibio-tarsus in

inaii.lible ttiul J'*"- particulars with an example of the

I ring v«rv «,n,e>vl„a In length, but the major, y of the specm^is

»r “ ,,ic«l. I lhnn.1 .... hn...er,.. ..nite ,n, large ,.B that hone ... the ex.et...g ^c.e.,
Im. .l.L.«.a. ..u. ». very ...n..y exn.,.ple. of It h. the collect.on, .....I p.-„h«l.l.v no
l.n,.T were- neenml. I.. the f..».ll bird too, the d.stnl margm of tl.e nh.ar
cn"t, or that loonier l>oui.di.ig the fossa wherein the pneumatic foramina are found
in other hirtln which imisbchh pneumatic humeri, is rather fuller than it is in the
l.ninerus of t he existing sia-cies. This very slight difference appears tn Ije constant.

Another Cnda* whicli is also (,uite abundantly represented by its fossil remains
is Colpubus hoibitlli, and it upi>ears to lx* identical with the existing siiecies Ixaring
tlmt nnnie. It is a notably smaller species than yE. occidetitalis, and its fossil
rt'inains an* easily distinguished from it.

Nninenms Ismes of Colytnbns nigricollis californicus were also found, and in
tin* cnM' of the long Isnies of the ja'ctoral limbs of this Grelie, it required esiiecial
cnn- to distinguish them fnuii the corresponding ones of the fossil .specimens of
J'oddynibus p<hiiceps. They are nearly of a size, but I had ample material Ix'fore
me for roinparison. As 1 have just intimated, the Pied-billed Grebe {Podilymbus
poiH(eps) nlm» ligiinsi in the ancient avifauna of Silver Lake, and the sjmcies pmba-
hlv ngnssl iihnost exactly with the form we have with us at the pre.sent time. Four
humeri (two |M>rfe<'t), tlm>e ulnas, two coracoid-s, and two tibio-tarsi and other bones
tif the fossil s|Mt'i«<s which 1 have sek*cted agree in all particulars with the corivs-
|sinding Imhicm of a s|x*cimen of Jhidilymbus in my ow'ii collection, obtained by me a
niimlN’r of years ago. There still nunain a few fossil Grebe bones in the collection,
but. fn»m tin* lack of material, I cannot at present be certain as to the species
to which they Udoiig. They consist of the proximal third of a humerus; three
tansMiietatnrsi (two ixrfwt) ; an up2H*r mandible, and a coracoid. They are consid-
erably lan?er than the corivsixjmling Iwnes in any of the smaller CIixdx?s. and far
t.«) small for C. holbitlli. Moreover their characters are entirely different. Two
ortho tanavn.etatarsi ami the coracoid from their color and characters apixar to
have Is-longjMl to tl.e same individual ; but possibly the specimen was subadult. I

command, but I am inclined to

merv n .1 ‘‘‘"T- .’""J ^ the sjx^cies with a

«I»ery III the suhjoiiuil list. ^

wll'lmvh.r’ "'‘.''T-' '•'•“"S' •» '"-y, of a,.y Bi«.cles of Loo.. (CV.W-

lond^\ liaMi.g existed in the former fauna of the - ^ ^

entirely abM-iit from the collection.

region, and their fossil bones are

wo have

•''' avirau..a .vhlcl.

THE FOSSIL AVIFAUNA OF THE

307

^'Echnop hones occidentalis (Lawr.)

Colymbus holbcelli (Reiiih.)

Colymbus auritus Linn (?)

Colymbus nigricollis californicus (Ileerm.)

Podilymbus podiceps (Linn.)

LONGIPENNES.

Apparently there was a complete absence of tlie Alcida or any fcjnns especially
like them, but this was not the case with the Gulls and Terns for there are numer-
ous bones to testify to their presence.

Unfortunately, skulls of Gulls or Terns are entirely missing from this fo.ssil
material, nor did I find any vertebra; that could Avith certainty Ije said to Ixdong to
any larine forms. On the other hand several patterns of the liuinerus were col-
lected, ranging from those of very small size to one of a large Gull. There aiv four
distinct kinds of coracoids, also varying greatly in size, and there are Auirious tai’so-
metatarsi, carpo-metacarpi, a finger joint of a Gull, a feAV tibia', but nothing more.

There is a distal two-thirds of a right humerus that is identical in size, form
and character with the corresponding bone in the skeleton of Larus argentatus (No.
18,167, Coll. U. S. Nat. Mus.), and it undoubtc'dly belonged to an individual of the
species noAV knoAvn as Lams argentatus smithsoniamis It is not repiescMited

by any other bones.

Next I find a perfect coracoid of a Gull, considerably .smaller than the coracoid
in L. argentatus smithsonianus, but only a trifle .smaller than the Ijone as it (K'curs
m Larus glaeicus, with AAdiich it agrees almost exactly in character. It is the cora-
coid of the left side. There is also the distal moiety of a left ulna of a Gull appar-
ently of the same size, as it differs in the same proportion Avith the ulna of Larus
glaucus, with AAdiich it otherAvise agrees. I am of the opinion that it kloiigmd to
the same species, though perhaps not to the same individual. Two large tibio-tarsi <if
Gulls are also found,— one lacking the proximal extremity, and one the pn»ximal
moiety. These are stouter than the tibio-tarsi in Larus glaucus but Avere not (piite
as long. Possibly they may have belonged to the same species, Avhich may have
had stouter iiehdc limbs than Lams glaucus although not quite .‘»o large a binl. As
this fossil coracoid belonged to a Gull considerably larger than Icarus a. smifhson-
ianus, it could hardly have belonged to Larus occidentalis, of Avhich species unfor-
tunately I haAm no skeleton, but it is about the size, judging from external mea.Muv-
ments, of L. a. smithsonianus, and probably has a skeleton of nearly similar proiMU-
tions. The coracoid is too small to have belonged to a Larus marinus, and at any
rate it is not at all likely that it was that form. Moreover it Imlonged to a larger
bird than Larus cachinnans, a species no larger than the common 1 lerring Gull.

Indeed I mu,st believe that there Avas a large Gull present in the fonner avi-
fauna of the Silver Lake Region, during later tertiary times, which has since become
extinct. It Avas somcAvhat smaller than Larus glaucus, and if the tibio-tarsi,
described above, belonged to the same species, it had stouter and shorter legs.

3^ KC^I-L-S HKDS OK THE OREGON DESERT.

, the nu.ue of i- tl- -w extinct species.

Ui.f- •!.. nov. ^ coracoid of the left side, which is i^erfect e.vcept

Tina H|H-ciea « ^ ^ » the tip of the scapular process, and

for the lirt-okiiiK «> gternal facet at its lower end. The bone

*• and stouter tlian the corresponding element in Larus glaucns,

tl^^il i sehanu-tersare almost identically the same. was a

; 1 ™H.er smaller than L. glancns which it may easdy have been closely
nit.™ Jmlging fn.m its coracoid, it differed not a htt e rom the s^c.es repre-
^.ingthe “ Herring Hull ” group, as the characters of that bone differ quite j^r-
r..plihlv in them. The coracoids of Gulls, however, of all sizes are very much alike
in the matter ..f characters. Some long bones of the limbs, obtained in the same
hrality, many lawsibly have Ixilonged to a species of this Gull. The data at my
roi.iiii«n.l will i».t iKTinit me to say whether this species was abundant during the
time in which it existeil. (See figs. 1 and 2, PI. XV). It was discovered by Pro-
feMor K. I>. Po|H*» assistant, .Mr. Charles II. Sternberg, in tlie E<iuus Reds of the
Silver hake n*gion, On-goii.

CAUroMKICfsT

Five <x>niroiils in the collection, more or less imperfect, are of about the right
siw to have iK-hnigiil t.) this siK'cies of Gull. There are also the lx‘st part of two
hunieri. |H*rfect ns far as they go, and a tarso-metatarsus, all of which may repre-
wnt this hinl. Though carefully compared, the species is only entered hem pro-
visionally until iiiore material is secund.

S|K*ciinens uhtniiuHl ns in the last described sjiecies.

laNl** OHKOOKCS sp. DOV.

This s|M*cies. now extinct, was about the size of Larus dciatvarcttsis, and is
InunhI u|M>n two humeri lioth fixim the left side of two individuals. There
is also a |KTfwt, or very nearly iierfect, coracoid, and the superior half of another
«»iie. togi'thcr with 8t*veml tarso-metatarsi, which may have belonged to the same
sjuTies. The hiiinenis not lx*ing perfect I cannot give its length ; its shaft is
stouter than the hunienil shaft in iMrus dclawaretisis and the proximal extremity,
the wlmle head of the bone, is almost exactly alike in the extinct and existing
siKvies. Then- is, however, a very good distinguishing character, for the osseous
I^ition that .hvides that gn-at concavity uito two compartments overarched by
the ulnar cn-st, is in L. dclatcHircisis, oblique to the plane of the long a.xis of the
shaft, when-as in Larus oregonus it was about parallel. In this character L. oregonus
G^Inl ^ distmguishing one among

OmaMr""''"'' Cope in the Equus Beds of Fossil Lake,

THE FOSSIL AVIFAUNA OF THE

309

LaRUS PHILADELPHIA.

A nearly perfect humerus and the distal half of another in Profe.ssor Cope s
collection agree in all particulars with the humerus of a specimen of this Gull in my
own private collection. The species apparently was not abundant during tertiary
time in the Silver Lake region, or I must believe more examples woidd have been
found.

This fossil was collected in the same locality as the last described species, by
Mr. Charles H. Sternberg,

Xema sabinii.

There is a fine specimen of the left humerus of a Gull of this species in the
collection of Professor Condon, which agrees in every detail with the cori-esimnding
bone of a specimen of Xema sabinuYo. the collection of the U. S. National Museum
(No. 93,429). It too, must have been a rather rare form in the tertiary avilaumi
of Silver Lake.

This fossil specimen was collected in the Equus Beds of the Silver Lake region
of Oregon by Professor Thomas Condon of the University of Oregon at Eugene City.

Sterna elegans?

Professor Cope’s collection contains two humeri and three carpo-metacarpi of a
large Tern that for the lack of proper material I have not been enabled to fully
determine. They may have belonged to this species,— a Pacific Coast Tern of the
present day.

Fossils collected in the same locality as the last by Mr. Charles H. Sternlierg.
Sterna eosteei?

This is a smaller species than the last, and in Professor Cope’s collection J <>'*‘1
two perfect coracoids, two carpo-metacarpi, and a humerus (imperfect) of a Tern,
which, in the absence of more complete material, 1 provisionally ivfer to this
specie! They belonged to a larger bird than either Sterna antillarum or Hydro-
chelidon nigra surinamensis (Gmel.), and I have carefully comjiared them
skeletons of both those fomis. In the avifauna of the present day, Fosters Tern
has a general distribution over all North America.

Mr. Sternberg also collected these fossils in the Silver Lake region of Oivgon.

Hydeochelidon nigea surinamensis.

A single humerus (not quite perfect) of this species is in Professor Cojic’s col-
lection I have compared it with the corresponding bone of a Black Tern kdonging
to the collections of the U. S. Museum (No. 17,688), and find it to agm- sii closidy
that there can be no doubt as to its identity. No other bones of this siiecies were

Collected at Fossil Lake, Oregon, by C. II. Sternberg for Professor Cojie.

I have reason to believe that other Gulls and Terns existed in the avifauna of
the region under consideration during the later tertiary time, but the material in
the collection is too fragmentary, beyond what has been given almve, to make them

44^)

K(^L* US J$KDS OK THE OREGON DESERT.

TIu- .lim- tlK-y wcx. di-covercd will well repay going over again.

The fuliuwing i. tl.e li»t of the Longipem.ea ae I have identihed them a)x,ve.
L^rus argentatus sniit hsoutcintis .

Lams robustus sp. nov. (extinct.)
iMrus cali/orniciis ?

Lams oregonus sp. nov. (extinct.)

Imkus Philadelphia.

Xctua sabinii.

Sterna elegatis?

Sterna /ostcri?

IlydrochelidoH nigra siirhianiensis.

STEGANOPODES.

riUUACIUX'»»«AX MAC-KorUH.

ThU extinct (’onnornnt is the Graailus macropus of Cojje, first descriijed
ami rlinmrterizml hy liiiii in the IJiilletin of the U. S. Geological and Geographical
.Siin'ey, Vol. IV, No. 2 (1S7S) |»j>. 38G, 387.

The present eiilleetion contains the following bones :

I Su|HTior ninmiihle (left lateral half.)

1 |{nnins of ninmiihle (right jMisterior half.)

3 Cervical vertehne.

I iKirsiil vertehm.

1 Pelvis (iin|M>rliH*t.)

'i Ciinimihls (3 nenriy |K*rfiH*t.)

I Sleninin (only the conieoidal grtH)ve.s.)

1 Ilnnieriis (only the distal third, right limb.)

1 rinn (only the proximal eml, right limb.)

1 Itnilins (only the distal end, right limb.)

4 (nqynotarnriH (iniiK-rfect. includes two in the Condon collection, one
nenriy |HTfwt.)

1 I’hnianx of index digit (proximal one, right limb)

1 Keimir (left side. iin|H*rreet.)

2 pbi.Htarsi tpn.xinml and distal extremities only)

,l"r' -ove.. fro,,, kn li,..ba , o..e or hv„

" iHTh-ct; gixMit variation in lengths.)

.Ir. K A. I aims, in « pa,H‘r entitled Co?itribntion to the History of Pnllai

largest species of existing

», or to the /’^|^rr<vX^a-*suhgenLi^^ I-*-*- lieavy-billed group of Cormo-

ri..r inniidible exhihitisl ,» long concavitv 7 powerfnl hooked, supe-

cngconcaMty along the inidlongitudinal line of the

rantu.

THE FOSSIL AVIFAUNA OF THE

4U1

culmen. Its dentary margin was cultrate. Most of its skeleton was non-
pneumatic.

Measurements (in Millimetres) of CoRREsroNoiNG Bones oe Phal.\ckocor.vx

MACROPUS AND P. CAR BO.

[All measurements are in a direct line and not along curves.]

VARIOUS BONES.

P. macropus

Cope collection.

P. carlx)

Yale College .Museum,
No. 535.

Coracoid.

Length •

93

87

Femur.

Length

75 (appro-x.)

70

Tarso-metatarsus.

Length

87

72

Proximal transverse width

18

16

Distal width

20

18

Proximal phalanx, index digit.

Length • •

21

not given

Greate.st width

12

The posterior end of the ramus of the mandible had characters that (iiiite agn*e
with P. U7'ile, and that bone was strong and powerful. The superior lip of either
coracoidal groove of the sternum presented the usual vertical, sulM)val facet for
articulation with the coracoid, a more linear one being developial on the lower lip
of the groove nearly opposite the first. It was by these characters that 1 wa.s at
once enabled to diagnose the small bit of the only sternum of P. macropus that was
to be found in the collection. The sternal manubrium was rudimentary and lay in
the plane of the carina.

All Cormorants vary greatly in size for the difterent ages, and to thi.s P.
macropus offered no exception. As 1 have shoAvn above, its tanso-metatarsns nica.H-
ured in extreme length 87 millimetres; a small one in the Cope collection imaisiuvs
in extreme length but 75 millimetres. Fossil specimens of all subadult binls ai*e
pale gray in color and are characterized by having a roughish surface.

In the main the characters presented on the part of its skeleton agree with
those Cormorants now retained in the subgenus Phalacrocorax, rather than with
the Urile group.

Cope has said in the paper quoted above that “ This species appears to have
been common in the Pliocene of Oregon, where it was discovered by Charles 11.
Sternberg. ❖ * h: * ❖ * « the extinct G. idahaisis

Marsh, nearly agrees in measurements, exceeding a little the corresponding parts of
the living bird”. \P. dilopkus']. (p. 387).

Pelecahus erytheoehynchos ?

There is in the Cope collection the distal end of the right ulna of a Pelecan, a
perfect specimen. It belonged to a bird very slightly larger than Pclecanus fuscus,

»KI>S OF THE OREGON DESERT.

1 tlie corresponding part in that specimen and

tertiary ei«K-l. »f that region Professor Cope.

KuMtil nijfciiiieii collected in saint locaiuy uj i , • ,1 tt.

TrijU ing SUgam/^cl^s, thon. occurred or p.-obably occurred m the Equus

Ueilt of ()n*gon : — *• f \

Fhahuroeorax macropus (numerous and now extinct.)

PtUcauus trythrorhynchos ?

ANSERES.

A gn-nt innnv HiK*cies of existing forms of Swans, Geese, and Ducks at the
,.n‘m.nt time res..rt unminlly to Silver Lake during the migrations, so ive would
iintumllv lo»»k for numerous siiecies of the same group in a locality where fossil
fumis ufliinls so iibumlantly occur. In this there is no ground for disappointment,
and ill the tHiUwtion now in liand the Auseres are well represented.

Mon- or fewer of these are found to be identical with western species now
cxhiing, while sevenil closely allied six-cies have become extinct, and in one or two
instniMvs very dilfen-nt tyiH-s have shared the same fate. It seems to be in the
naliiml onh-r of things that large bulky fonns of any group of vertebrates sooner or
Uti-r ilisap|>ear fnnn the face of the earth, hut it still remains quite problematical why
Nil Nvemge sijuil Duck, a go<Kl flyer, living on the same food as its immediate kin,
and nothing |MH'uliar alsiut it, should, with more or less suddenness, so disappear.
Itiit that such cns«-« have iHicurreil, and are continually occurring, there is no doubt;
to cite n well known instance one has but to mention the remarkable case of
extinction exeinplifnHl in the laibnulor duck {Camptolawius labraciorius). That
hinl, ns is well known, cpiite sudilenly iK-came extinct upon our North Atlantic
(ViNst, anil, ns it were, under the very eyes of all ornithologists. No adequate
reason for its disnp|H>nmnce has yet lieen furnished. With this example before us,
no one would at the pn-sont time exjH-rience any' surprise were.any other one of
our eoiniiioii s|H-cies of ninH.-rine fowl to disappear in the same manner. Having the
history of Cafuptolamus 'm my mind, when I came to study the fossil Afiseresonh^
«lver Uke region I naturally looktnl for at least a number of species that had long
since «-nse«l to exist, and ujHui completing that study felt no small degree of sur-
prise III finding s.> iiiaiiy fo.ssiI forms which, in so ftrr as their osteology was concerned,
apiH-an-.! to U- identical with those Auseres still in existence in our avifauna.

in tin K O il'i* "r?’. ^F'^Jes which have thus for been discovered

« I-s,uus Ik-ils of ()n.go„, „„a they are all represented in the present collection.

Ix>ninl>TTRS t-fCl I.I.ATrs.

f°.;rc„rac„id. an ...e ngi.. aide,
e erganser. Upon comparison they’ ai’e found

THE FOSSIL AVIFAUNA OF THE

403

to be identical in all particulars of character with the corresponding Ixjues in a
skeleton of Lophodytes mcullatus in the collection of tlie U. 8. National Museum
(No. 18,597). The fossil humerus is perfect, and all the other bones very nearly
so. Length of humerus 70 millimetres ; length of carpo-metacarpus 43 millimetres ;
extreme length of anyone of the coracoids 47 millimetres.

Co]3e collection : Equus Beds of Oregon.

Anas boschas.

Two carpo-metacarpi and a radius, both from the left side of this si)ecies,
together with the anterior moiety of a right scapula, agree exactly with the cor-
responding bones of a specimen of this Duck in the collection.s of the S. National
Museum (No. 18,598). Length of carpo-metacarpus 5‘9 millimetres ; length of radius
74 millimetres. There were no fossil bones of the Mallard in the Condon material.
Cope collection : Equus Beds of Oregon.

Anas Americana.

Fossil bones of the Baldpate are not abundant in the collection, hut a right
coracoid and a left tarso-metatarsus are identical in all their characters with the cor-
responding bones of an example of this Duck in the osteological collection.s of the
U. S. National Museum (No. 18,599). Extreme length of coracoid 4 ’9 millimetms.
The low bulky hypotarsus of the tarso-metatarsus is once perforated and twice
grooved for tendons. Length 4-2 millimetres.

Cope collection : Equus Beds of Oregon.

Anas carolinensis.

Numerous fossil bones of the Green-winged Teal were di,scovered, and 1 com-
pared a number of them Avith the corresponding bones of a skeleton of the .x|H'cit*s
in my private collection. These consisted of five humeri, two perfect (left side),
and three imperfect (right side), also three coracoids, two ulna*, a cariMHiietacarpii.s,
and a tarso-metatarsus. They agree in their characters quite as closely a.s do the
corresponding bones taken from tivo specimens of this Duck as it iioav exist.s, ami
compared together 1 am inclined to believe that the species was a numerous one in
former times, or during the later tertiary period. Length of humerus <10 mm. ;
length of ulna 50 mm.; length of coracoid 35 mm.

There is a humerus of the Green-Avinged Teal in Professor Condon’s collection.
It is from the right limb of the individual to Avhich it belonged.

Cope collection : Equus Beds of Oregon.

Anas discors.

A perfect humerus and other bones of the pectoral limb, together with several
coracoids represent this Teal in the collection. The humerus is someAvhat shorter
than the same bone in a skeleton of the species in my private collection, an old
female. The fossil humerus probably belonged to a subadult specimen of a female ;

53 JOUR. A. N. S. PHILA., VOL. XI.

mcus OF THE OREGON DESERT.

,|,c. I.....K.ru» of an old male A. carolinensis refe,-md to

II I. in-Pia-i.lil.lj larp H" " millimetres.

with the cones, xmding ones in skeletons of the exist-

illir nljfCHt*.

(•4,1,1. wilIcH-tion : l->iuu« Ui cJrt ol Oregon.

AK*ii rv*xon^»:K*T
I

ruiii|mnw,li
funiit.

riifortunau-lv I failwl t" «-eum a lecent skeleton of the O.n.mmon leal for
It i. » verv abundant Duck in many loeaht.es m the ^I cst where in
,.,n,a r Til the writer iia. kille.1 many of them. In the present collection I find

[""riniineri itline iwriW-t) ; seven iihiiv (six iierfect) ; five oar,^me,aearpi ( wo
Lriv i.Tfis-t): riiiir niilii (imrfeet) | three coracoids (perfect,; an i.n|)erfeot
.•.,.i;i. tlins. reliion, (two iw-rfeet) ; two tihimtarsi (nnporfeet) ; and two tarso
I,i,.;„i„i,i (one nearly lerfm-t) all of which In-longed to a Teal Duck larger than
Uas diseors. Taking i.yi.rvtl.ing into con.si<leration it would seem most probable
Ihnl lli.-m. r.amil la.iifs iK-loiigi.il to HiK'ciiuens of this species. Indeed, I urn of the
4, pinion that tli.- tlmn. Teals imw found in our avifauna, wbicli have been eniuuer-
al.d nls.%-1.. i-xisUd during tiTtiary time (Pliocene) without much, if any luaterml
changi* in llioir stnicture.

IsMigth of hiinieriis (17 inillinietres.

Is'iigtli of ulna (■<(» milliiiH.tres.

Is.nglli tif niriM^nietarar|>us do inilliinetre.s.

tHhor lames of pn,|H,rtioiiut<. lengths. Tlie shafts of the liumeri, relatively as
Midi ns ai'liiiilly inucli sleiiden.r than in A. discors.

|.«*Ihn'tion : Kipius IIimIs of Oregon,
si-in i.* n.via.ATA.

TIh* Shovi'ller is n.pres4.nti.il by nunierous fossil bones in the collection, and
n|s,n coiiiparisoii I find tlu.iii to lx* identical wdth the corresponding ones as they
iimir ill sk«.|<.toiis of that Duck in my own private collection. At the present time
il is a v».ry (.oiiiinon siKrics in innny parts of the West.

Pli«xH.|ic o( On-goii (Silvi‘r and Fossil hakes) : Cope collection.
l»*rn.A AciTA.

Hcpn'si.iitiHl ill die eollection by a iH*rfect humerus (right side), a jiair of cora-
ciils. and S4.v».nd wnpuhc, the last more or less imperfect. The humerus of this,
tin* Pintail Duck, is .piitc characteristie, and the fossil specimen in Professor Coiie’s
4'..||.v(ini, njrnx.s aUdutely in all particulars with the right liiniierus of a specimen
U.|..iignig to fi skcle(„ii of this s|KM:ie8 in the U. S. National Museum (No. 18,002),
with which I have iM.mpare.d it. Tlie sliaft of the bone is of large calibre for its
«ii(d I ant t 1C sc\era] ehnrnctcrs of the extremities are strongly developed. It is
m U 1 ' 't‘**,v light both in the fossil and recent specimens. The

Iiliinrrir*t I i"'!i- **'V,.""** deep notch separates the humeral head from the

nliiBrrn.st. Ix-nglh 8, millimetres

THE FOSSIL AVIFAUNA OF THE

105

At the present time this species is abundant in many parts of Oregon.

Cope collection : Equus Beds, Oregon.

AlX SPONS.X.

A perfect humerus, nunierus coracoids, and several other Ixnies represent
this Duck in the collection. Upon comparison with a skeleton of the s|>ecies in
the U. S. National Museum (No. 18,612) they all agree very closely in their char-
acters, and in all probability the Aix of the Pliocene Avas the same form of bird,
in so far as its osteology was concerned, as we now have in our avifauna. Length
of humerus 72 millimetres. Length of carpo-metacarpus 47 millimetres. The cora-
coid, somewhat compressed in the autero-posterior direction, measures in length 44
millimetres. The bones of the pectoral limb seem to be slightly slenderer than in
fossil specimens, but it may- be due to individual variation, and the skeleton of
the existing species at my hand may have been taken from a I’ohust bird.

Equus Beds of Oregon (Silver Lake) ; Cope collection.

Aythya maeila neaectioa ?

I find in the collection a humerus, an ulna, and two coracoids which evidently
belonged to an Aythya. They have been compared by me with a skeleton of the
Canvasback Duck [Aythya vallisncria) \ also Avith a skeleton of a Hedhead (.7.
americana) ; and also with A. affinis and A. coUaris. The specimens are too small
for vallisneria and americana, and too large for affinis or collaris. 1 have no
skeleton of A. marila nearctica, but know it to he a larger bird than either A.
affinis or A. collaris, and so for the present I refer the above named 8i)ecimens to
the American Scaup Duck. It is as Avell to remark that both the humerus and the
coracoids appear to have belonged to a subadult individual, as they exhibit tlie
peculiar gray tint and the very fine granulated appearance of the surface. Lmgth
of humerus 90 millimetres ; greatest breadth of proximal extremity 20 millimet ivs;
greatest breadth of distal end 12 millimetres. 1 am not inclined to regard thi.« a.s
an extinct species of Aythya.

Cope collection: Pliocene (Equus Bods of Silver Lake) ; Oregon.

Glaucionetta islandica.

This species was very abundant during the Pliocene in the Silver Taike Kegion ;
perhaps the most abundant Duck. Professor Cope’s collection has in it 26 siH-ciinen.s
of the humerus of Glaucio7ietta islandica, ten of which are as perfect a.s though
iust taken from recently killed individuals. There are also numerous other Ik.iu-s,
but no part whatever of the trunk skeleton. All these fossil hones agive m the
minutest details with the corresponding bones of specimens of the species as they
exist to-day. To establish this fact, I compared them all carefully with skeletons
of Glaucionetta islandica contained in my own private collection. Luigth of
humerus 84 millimetres; length of ulna 74 millimetres ; lengtl, of cariHHiietacarpus
51 millimetres, (absolutely identical in fossil and existing species).

Cope collection : Equus Beds of Silver Lake, Oregon.

K(iUL'S liKUS OF THE OREGON DESERT.

r •:”%“. l:::;.;,,:,,™ h.. m t^ey diner r™.. «,. ti.

Tiuv e.,,,..n.n,l. F..»,il ulna „f stout and heavy, extrem.hes

rail, or ..ruuily dovoluH- '-•■'if"' ““

(W follfction : IMioceiie oi On-gon (Siher Lake). •

I llnvc not nt .nv foni.nun.l Hkeletcns of Charztonetta albeola nor Htstrtomcus
AhtMcus, oinl I think it likely that the first named species occurred on Silver
loakc and it« aiater hUo.‘U> of water during the later tertiary. There are four tarsiv
,„..|«Un.i ill CoiK*-- collection that lielonged to Ducks evidently related to either
t.hHcionftta or CharilomUa they may have lielonged to Ducks long since e.xtinct
hut in the nlweiiw of the skeletons of birds I have mentioned above, I prefer at
pnKent to |Mu*s them over to the non-identified material, and give some future
ul.MTVer an op|Hirtunity to compare them with the forms that the present writer
lacks. Then* an* a nuinlKT id* other lxnie.sof the Aiiatidcp that I could not identify
ipiile to niy satisfaction. 'These for the present 1 have also laid aside. I
strongly siis"|HH-t that Isdli Mcr/ianser serrator and americaiius occurred during
Tliin-ne limes on those* lakes; they may, so far as I know of anything to the con-
trary, iMvur then* to-ilny. Anas slrepera and Erismatiira riibida may also have
figiiriil in former times along with the other fossil forms w'e have been examining.
1 have not had s|M*cimens of this skeleton for comparison. Nothing at present
leads me to lu'lleve that then* wen* Ducks during the Pliocene in Oregon which
havesinci* Imiimiii* extinct, hut then* may have been, and no evidence on the subject
has ns yet «nne to light. My own idea is that the Anatida;, at least, existed pretty
much the same in thosi* times as they do at the present day, and their descendants
in our ivc«*nt fauna exhibit hut few. if any, marked structural departures from them.
It is a gn*nt pity that then* is such u total absence of the fossil an.serine skulls, for
that )Mirt of the skeleton would show changes, had any in reality existed, better than
any other part of the economy.

.\»»r.a oosDosi Kp. nov,

I his (tiMua*. now extinct, must have lx*en nearly as large again as our coinmon
wild raiindn Gihmu* [liratita eanai/ensis). Its remains are represented in Professor
t o|s* s colUH*tion hy a fract«n*d os furcula and the parts of two others.

Ihe..s*I have most can*fully compai-ed with the furcula* of a number of our

r« l •■'"'’iTi"?' Dcndrocygfia and Olor,

/” ****”" ‘ “* "*'”**^* majority of its characters are most like such a

gtnwc as . I Hsrr alhi/rons.

limhofthe^ left^Vt" ”*'*C'*** lower arc of the furcida, a nearly complete upijer

Uu^ v" corresponding part from one or hvo

W^ m im r <>ur existing Geese, the o^ furcula of condoni

- pnunnnttc. es,Hv.ally the su,K*nor limbs, atrd it is upon the side of the

THE FOSSIL AVIFAUNA OF THE

407

latter that the pneumatic fossae are to be seen, Avith tlie openings at their bases
leading downwards. Noav in Atiser albifrons the pneumatic holes are upon the
outer aspect of the limbs of the os furcula, the reverse of the case in the Swans,
including Cygnus paloregomis of Cope, with Avhich I have comjiared them all. But
either free extremity of the os furcula in Cygnus paloregonus is long and pointed,
being narrow vertically, and thickened transversely as we approach the extremity.
It also lacks the peculiar process upon its upper border, so characteristic of 8(Jine
Geese and nearly all Ducks. In the Swans, of course, the lower mesial portion ol
the os furcula is very much modified so as to allow of the passage of the trachea
into the sternum. Nothing of that kind existed in Anscr cmdoiii Avhere the lower
mesial part of the os furcula is almost exactly as we find it in Atiser albifrons. The
upper free end of a clavicle in A. condoni also differs very much from that bone in
the Swans, for it is inclined to be deep vertically, compressed transversely, Iduntly
pointed distally, and possessed the peculiar process seen in A. albifrons upon its
superior border.

There Avere no other bones of Anser condoni in the collection, and I am inclined
to belieA'e that that ponderous goose must have been Avell nigh extinct, Avhen the
other anserine forms I have described above Avere flourishing in numlxTs.

Mid-vertiail depth of mesial

Anser

Branta

Anscr

Ulor

portion of os furcula given in |

condoni.

canadensis.

albifrons.

liiiccimitur.

millimetres

16

8 !

■ .

10

Our Branta bernicla is a foot less in total length than its congener li. cana-
densis, and Anser condoni must certainly have been twelve or fi)urtecn inches
longer than Branta canadensis.

I take pleasure in dedicating this extinct species to Professor Thoma.s Condon
of the UniA’ersity of Oregon, the first naturalist Avho discovered and collected any ol
the remains of fossil birds in the Silver Lake Kegion of Oregon.^

The specimens of the os furculaj of this goose are in Cope's collection : hpms
Beds of Silver Lake, Oregon.

Branta hypsibatus.

This extinct Goose has already been described by Professor Coix', and 1 have
examined the material upon Avhich he distinguished it.'

Be-anta pkopinqua sp. nov.

In describing his collection Professor Cope speaks of having discovered a (hKise
that it contained, which upon comparison he found to come “ near nigricans .' I he
fossil remains of the bird are Avell represented in the collection, and it imivos to lx*
a small, true Brant Goose closely allied to nigricans. For it I propo.sc- the alx.vc
name.

iCope E D Bull. U. S. Geol. Siirv. Terr. IV, No. 2, 1878, p. 387. See also Kra,./a A. O. V.

Code anfckL List of N. A. Birds, 1886, p. 364. Bra,Ua hyp.^Mes Coues MS. There w.u, but one bone of
this bird found, a tarso-metatarsus, and probably it was not an abundant species.

Ubid p. 389.

•lUH

KiiUUS IlKIW OF TIIK OUECION DESERT.

Millimetres.

107

95

62

65

75

r.9

of humeruH . • • • ’ '

lA'iifrtit of ulna

U-iifTth of rariMMiutacnrpiia

L iiKtli of f‘ «n«'’ * • • ■ ■ ‘

U-iifrtli of tarao-inetatarsua • •

l4.njniutliiial iiii«l-vertical axis of coracoid
The m-apuhf apntHl with tlH,He of Brania, and the left side of a specimen of its
,t..n.um nUoL.\ it to seven facets upon that costal border. A sternum of

Branta tanaiitHsis ( N«.. 1 ^^0 V. S. Nat. .Mus.) has eight hammpophysial facets upon
fit her ctwtnl Umler. B. prop! tt qua jK)8.sessed an os furcula agreeing in fonn with
that lame oa now fonml aiiiong our Hrant Geese. There is a specimen of it in the
clhvlion nearly la-rfiM-t. IiidtH-d all the lx)nes of this species are in a beautiful
(.late of |m-«T>ati»ii iiial many of them complete. Type Ixnie is the humerus
nhiiwii in fig. 17, I’l. XV.

Cilia* ('ollection: l’li<H*ene of Oregon. Silver Lake Region.

IlmorrA ca>*ai>»:i‘»i".

Niiinertnn* lames fmin various parts of the skeleton of the Canada Goost‘ am to
la* ruiiinl in the eolliH’lion. some |H*rfect, sonic more or less so, and some fragmentary.
.\ stinly of thes4* iiinl (Hiinparisons with the cori-e.sponding bones of a rt'cent skeleton
of this Gimnm* (No. IS.fitUt V. S. Nat. .Mus.) convince me that the sjK'cies of the
Ks|uus lhals an* iwti-ologically iilentioal with the existing species, or in other words,
thet'iinnda (mh-si* which thrived during the later tertiary time of the western part
of oar rout inent wen* similar to the Geese we now call Branta canadensis in onr
Rvifimnn.

The .'^waiis and (Jeew of that ancient time seem to have siilfered Iroin a
laviilinr ilii*eas«* of the lames. It was confined to the superior angle of the jiollex
inetnmr|ius of the enr|ai.nietaoarpus. It ajipeared to be of the natiii-e of a small,
ltilM*iyulnt«‘4l exfoliation of the lame at that {Miint, and the evidences of it am to be
w-en in many of the car|M>-inetacnri)i of those birds in the collection now under con-
aidemtion.' Co|k. has almaily ixiinted out the fact that the remains of the Canada
thaaa. .ax-iirriMl in the Kipius Ih*ds of Silver Lake (Bull. U. S. Geol. Surv. Terrs.,
1R7K. IV. p. .‘IStt.)

Co|a. eolleetion: IMha-ene of Oregon (Silver and Fossil Lakes.)

Aa«i a Ai.nirnoxM oamiiki.i.

F...... ilT Vi- "'-r '"■'"K'd ""t tl.e f„ct of the c.-;istciice of this bird iu the

I*7S I V."!' S- -

The s|M>oiiiieiia am in his collection.

THE FOSSIL AVIFAUNA OF THE

lU!)

Chen hyperborea.

Judging from the fossil remains of this (loose in tlie collection, it, to(j, must
have been nearly as abundant in the region as the Canada (loose. I have deter-
mined its existence there through a compardson of the specimens with Ijones oi
Chen h. nivalis (No. 18,611 of the U. S. Nat. Mus.) It was no doubt identically
the same species as exists over the same range at the present time.

Equus Beds of Oregon : Specimens in the collection of Professor Co|X‘.

CYGNIX.E.

Olor paloregonus.

This is the extinct Swan described by Professor Cope as Cygniis paloregonus,
the description being based upon “ four tarso-metatarsi, two of which are nearly
perfect It was a species rather larger than O. buccinator and .somewhat smaller
than O. columbianus, that is judging from the ahove named bones. Apart from the
skull and pelvis, its remains are represented in Cope’s collection by many lK)nes
from a Humber of individuals. There are also several specimens in Professor
Condon’s collection, including a humerus, wdiich unfortunately lacks a part ot
either extremity. Osteologically, it differed but little from existing Swans, kdng
probably most closely affined to Olor colimbianus. 1 have compared itslsmes witli
the corresponding ones belonging to a skeleton of O. buccinator, a siH*cimen pre-
sented to me several years ago by Mr. (1. Frean Morcom, of Chicago, and since
placed by me in the U. S. National Museum (No. 18,5()!J.)

Professor Cope’s paper contains full measurements of the tarso-metatarsi ol
Olor paloregonus and to those I add the folhnving. given in millimetms.

Length of humerus (restoration from tw'o individuals)

.Millimetn*s.

2!M»

Length of ulna

Length of carpo-metacarpus

141

Length of proximal phalanx of index digit

110

Length of femur .

Length of coracoid (long axis) . . • ...

!h

Length of basal phalanx, mid.-anterior toe

1)7

“This Swan was discovered by Ex-Governor Whitaker, ot Oregon, in the
Pliocene formation of that State. The same bird was afterward pnamivd by my
assistant, Mr. C. H. Sternberg ”. (Cope.) _ _

To recapitulate, my investigations go to show that the following anserine forms

occurred in the Pliocene (Eqnus Beds) of Oregon : —

Lophodytes cuctdlatus.

Anas base has.

Anas americana.

^mdem. pp. 388, 389.

Ki/UUS ItKDS OF TllK OKKGON DESERT.

carolinaisis.

Anas discars.

Anas cyanoptera ?

Spatnia clypeata.

Dafila acuta.

Aix sponsa.

Aythya marila ncarclica ?
(Aauciottella islaudica.

C/an/pda hyetnalis.

A user condoni sp. nov.

Jtrania hypsibatus.

Jtranla propinqua sj). nov.

Jtrania canadensis.

Anser albifratis gantbeli.

CJtcn Jcyperborca.

Olor patoregonus.

ODONTOGLOSS.®.

|*itir.xi(-orrt:MtnK up. nov.

It in tt fuel «»f no little* intereHt that a P'lutningo inhabited the shores of the
Inken of the Silver hake region of On*gon during the Pliocene epoch. It wasii bird
ebimdy nllieel to (»ur e.<cisting IVnvnicoplcrus ruber, and slightly larger than it.
Feindil nuimiiiH «»f the n|H*<MeH. which iK-longed to two or more individuals, are in the
rolleetioii of Profe'nnor ( Vi|h*, and they consist of the following lajiies : a left os
quadralMtH (nearly p»*rftH’t), a right coracoid (very nearly perfect), a pro.xiinal
plinlanx of the iinlex digit e>f the right |)ectoral limb (jierfect), a right tibio-tarsu.><
from a aulmdiilt individual (lacks the proximal end and outer condyle), a left tibio-
tamiin from an adult individual (iin|K*rl'ect. has the distal end and inner side of the
lower half «if the nhafl), a tarso-inetatarsus from an adult individual, left pelvic
limb (distal hall only, jawfecl). a lower end of the same bone from another speci-
men (|M*rf.-ct ns far as it gm-s), a basal phalanx of the mid-anterior toe of the left
Hvic limb (adult, and in-rfect), and several other fragments of long Ixjiies, includ-
ing a tnCMMiietatarsiis of a very young bird.

I l,.vr all tl....;. U..„, ,vit|,',l,o correspomllug ones f.x,.n a akekton

1 am convinc.,1 that the extinct fonn was f""' "''^h those of the existing species

onger winged and longer legged and

THE FOSSIL AVIFAUNA OF THE

ill

toed than P. 7'uber. Some of the best distinguishing characters are seen in the
coracoids of the two birds. While the sternal ends of tlie.se hones agree very well,
their summits are different. In P. ruber this part is tuberous and bmad trans-
versely and a general concavity exists just below it upon the mesial aspect of the
upper part of the shaft. In P . copei the summit is niarkedh- narrower while the
mesial aspect of the shaft just below it is a circumscribed, Hat area. The scapular
process in P. rtiber is narrow in the vertical direction, — broader in P. copci. The
distance from the anterior edge of the glenoid cavity to the anterior border of the
shaft in P. miber measures ten millimetres ; in P. copci only eight millimetrcs.
(See Figs. 41, 42, and 43, PI. XV, also Figs. 28, 29, 38, PI. XVII.)

In dedicating this species to Professor E. I). Cope of Philadel[)hia I feel that 1
pay but a very slight tribute to one who has done so much to advance the science of
paleontology in America.

Phcsnicopterus copei was discovered at Fossil Lake, in the Pliocene formation.
Oregon, by Mr. C. H. Sternberg.

, THE BONES. !

Greatest length of proximal phalanx of index digit (including disral proces.s)|

Greatest width of the same

Coracoid (longest diameter)

Coracoid greatest width, sternal end

Greatest width of distal end of tibio-tarsns

Antero posterior diameter of inner condyle, tibio-tarsus ....

Greatest width of trochlear end of tarso-metatareus

Length of ba.«al phalanx, mid-anterior toe

HERODIONES.

Aedea pai.occidentalis sp. nov.

Represented by the lower part of the shaft and distal trochlea' of the right
tarso-metatarsus. This bone, from a medium-sized Heron, 1 have compaivd with
the correspionding one in several of our smaller Ai'dcidce^ as Ardca candidissima. .1.
cwj'ulea, A. virescens and the Black-crowned Night Heron {Nycticorax n. ncreius).
and although it agrees very closely with most of them in its ostcological characters,
it agrees with none of them in point of size. It belonged to a Heron larger than .1.
cajididissima and smaller than A. egiAta, and I am of the opinion that the s|)eeies
is extinct. Transverse diameter of trochlear extremity equals eleven milliinetres.
(See Fig. 31, PI. XVII.)

Cope collection : Pliocene of Oregon.

PALUDICOL.®.'

FhlICA AMERICANA.

Cope has alrecady proven that the American Coot was rcpre.sentcd in the

Un February la.st (1892), Professor Cope did me' the honor of submitting to me for .lewriplion the fewii
bone of a bird from Texas. My description appeared in a paper published by liiinself mid entitle.!. " A Con-

54 JOUR. A. N. S. rniLA., VOL. IX-

r. ruber

P. riiiKri

.M.

M.

4.'{

40

10

10

(>8

0.'>

35

.■P)

17

17

20

20

20

22

47

4S

liKlyS OK THE OREGON DESERT,
r ( • a.ul uiK.n examination I find that it was probably the
!;rHudLX“ gt-nua that of tbl'^'Qu

n^7irvr"l-Ml‘«’t;rT\dnnula species judging from the long series o^ bones
n r,vHi comparing them with the corresponding bones of

rrr^ri .7„ri.riv«u. ;-.i.inet, a /)-/« which I ^

, x"« SuiU I lii..! •I--” *«»«■'- i" <-!«> “■! character.. The

L.. .,«a-K- exi,.«l then «a .uav, and the anc.en mare hea of the lake,

kne. Ihia hint .|uite a. well m do all sim.lar places throughout the In, ted
.Stan** nt the pn*s«*iit time.

(ViiM* collwtion: E<|UU8 He«ls of Oregon.

Feuf* mikok up. nov.

\pn-eiiig «>*te«l<.gicany with the bust lait a much smaller species. Keprcsented
l.y « pair »f humeri, a pair of coracoids, and a right femur, apparently from as many
iiHlivi.hmli» na then* an* siMi-iinens. When first examined by me I was inclined to
la*lieve that the difll-n'iiee in size was merely sexual, but it is too great for that,
aitil the w.xes hi /'. americami agree in size. Moreover the bones of Fulica minor
an* nut fniiii siilmdult sjK*<Miiieiis, tliey exhibit all the evidence of having belonged
tu fully adult hinls. 'I’hey dill’er with the same bones in lonornis and Gallinula.
I make the following comparative mea.surements in millimetres. Tyjie bone is a
hntneniit shown in i'l. XVII, fig. -12.

F. aviericatia

A minor

M.

-M.

Height of ctimeuid

32

27

lo’iigth (iriimiieni*

70

02

ls*ii)rth uf femur

57

51

t*o|H* eolh*rtion ; I’lhn'eiie of()n*gon.

lHiwii<.a to iIm* V<-rtrlifai«> l'kl.-..iiiii|(,|pr of Toxajt”, it const itiitinjt a contribution to tiie Proceedings of the
ItilPwoiilik*! .Sicicty (Vol. XXX). llrprints of that ijaper were issued April 14, 1892. Tlie fossil to
• hW. I rrfM- lli.-rriii .Imrils-,! (pp. 125-127) ami secmwl to me to have belongcl to some rail-like bird
^U«*. I uriidimlly tho luine of HtiUouies fora genus to contain it, giving it at the

^ limr Uk* fipnriflc name of iWKimiu In a private note. .late<l Philadelphia, Fehruarv 14. 181)2. Professor

7, .7"' ""In*’,.* is -vox hybrida’ (i. e. latin ami greek)

,f,(t b cm-k for lUlluii : » ill Crwui.Ux or ('reccoims answer ? ”

•Ch-Jllrbr* **'" criticism and suggestion, I at once adopted the name

newarnu^and as CVmo.,i,/„ it ,luly apix-ure^l in the Proceedings above mentione.1. It
"T . Alfred Newton, F. R. 8. the distingtiished

College, Cambridge, England, 11 May, 1892,
fVcccofdr.^1 tl.i„k you should have written

the \ o 1? nilw <if mmirnrUliin. signify Crecca for Teal-like and by

biwnd by lb«tn ". Iniliiii plare I divirl* to thn “ ""1’'*®''’’*’^. ^ flatter myself that some of us here are not
««d I" <•» that I aim flatter nivmiru t i^fi^sor Newton for having iwinfod out to me this error.

si bend “ by the A. O. U. rules of

a* tymmln. inetrwl of *< fWoHfr,*' || '"11" '^onsi<'‘^i'ed in this note, to stand

tirene**, aa it was origmally prmtexl in the Proc. Amor. Phil. Soc. for 1892 (p. 125).

•/W. p.

THE FOSSIL AVIFAUNA OF THE

LIMICOL^.

Phalaropus lobatus.

The Northern Phalarope is represented in Professor Cope’s collection bv three
humeri all nearly perfect. Upon comparing them with the humerus belonging to
a skeleton of this species in the U. S. National iMuseum (No. 13,(id8) 1 find the
agreement substantially exact in all the characters and so conclude that this sjiecies
also figured in the avifauna of the Pliocene of Oregon. I’ery likely there were
other small limicoline birds represented, but their bones being small and light,
they probably have, from time to time, been blown away by the wind when they
worked up with the other fossils in the loose soil that formerly constituted the
bottom of the lake. A number of the cosmopolitan Triugeo’ no doubt fnajuented
the ancient shores of those lakes, and it is to the probable fate of their remains that
I refer.

The three humeri of this Phalarope were the only fossil bones of any of the
Liniicolce discovered. Lengtli of any one of the specimens is 21> millimetres. In
the case of the Eed Phalarope {Crymophihis ftilicarius) the humerus is considerably
larger than this, wdiile in Wilson’s Phalarope {Phalaropus tricolor) it is smaller. I
have compared these fossil humeri Avith specimens of those bones as they (K-cnr in the
majority of our existing Avestern forms of Triiigece and small Plovers, and they fail
to agree with the characters of any of them. I Avas much pleased to find that the
osteological characters of a single bone in so small a bird, could Ije used to so gi-eat
advantage.

Equus Beds of Oregon : Cope collection.

GALLING.

My private cabinet contains specimens of all the various s})ecies of existing
United States Galliucs, as Avell as skeletons of the Avihl Callus bankiva of India,
and other gallinaceous types, so that Avhen I found the fossil remains of several
species of this group in Professor Cope’s material, I felt that I could make the most
exhaustive comparisons between them and the existing specie.s. This has Imen
done, and the folloAving forms of fowls fiourished at Fossil Lake, or rather in that
part of the country Avhere Fossil Lake existed, during the Pliocene eixM-h.
Tympanuohus pallidicinctus.

A perfect humerus (right side) and several more or less imiH*rfect ones. tAvo
coracoids (left), the upper third of a femur (right), and two carpo-metacarpi nqm*-
sent this Grouse. They are all identical Avitli the corresponding bones as we find
them in the existing species, and are interesting from the fact that they go to sliow
thatin former times the range of the smaller species of Prairie Hen was far mon*
extensive than at the present day. During violent wind-storms probably some of
these birds were bloAvn into the Pliocene lakes and this would account for the
discovery of their fossil skeletal remains being mixed iq) with those of the water
birds. Perhaps, too, they Avere also dropped into the water by raptorial species.

K,^UL-S HKUS of the OREGON DESERT.'

or.-.-... :

I'tWOC-rTia. I-HAMASKIXIH tOI.LMlUANUS. .11, 1

V ,.„.n..T ..r tlK. I«.n- <.f tl.elin.ta and a nght coraco.d, all more or lees
„.rr.;' a .I.e |.n*-i.ce. of this six^eie. of Grou^ .a the same geologrcal forma.

•m ^ .1 • Im... a. I of the opiaion that both species were qmte abundant

^.,7 iK- 1....^ terliary K-riod of the west. Osteological y, these fossil tae,
raiZ l» .li.lii,gni.lnal fn..n those of the e.visting species, of which latter I have
M'VfrnI ••kflftoiiM in n»y |M>«»eKAioii.

(•o|M? c*»Ilfcti»M : Ik'ds of Oregon.

i-fc’AM •(>. nov.

Vn .-xtiiH-t, ninl at the wune time ii larger and heavier Pedioccetes than any
..iMvie* of III.- gfiiuH now e.xiHting in our avifauna. Represented by three uhue, two
tihi.i.tnn.i, iiiul a tarao-nietutannia,— some of the specimens being nearly perfect.
(MK.A.SfHKMKXTS IN MILI.IMKTRES).

1

; P. p. columbiaiius

i

• P. lucasi

Lrti«.li iiC ultts . . . .

60

Go

|.rn(.li larBi>-nM-.slBrMiii

42

44

.\»« fnr III* iny material goea to show, the two species w'ere in their osteological
rlwiniet.-n. eioM-iitially th.- saiiu-, but the several bones compared are in P. lucasi
ninrke4lly stouter witli their extremities more powerfully developed. For instance
the gn-nlesi triiiisvers.- diameter of the distal end of the tarso-metatarsus in P.p.
.dumhhtuMS measures hut D mill, while in P. htcasi the same diameter measures 11
inin. niid this relative pn)|M>rtion is 8u.stained for the ends of all the other long
iMiites. I III- shaft of the tarso-metatarsus in the existing species is rather inclined
III U- slender. — ill I\ lucas$ it is very jH-rceptibly stouter and stronger. These dif-
fen mvs w.-n- um|uestionahIy exteiuled to other parts of the skeleton of the e.xtiiict
s|s-oies, resulting in the eonsiderably larger form which it undoubtedly was.
Tyis- a iM-rf.-et right ulna, 1*1. XVII, fig. 30.

I take pleasun. in dedicating this species to Mr. F. A. Lucas of the Depart-
ment of r«u,,M.rative Anat.imy of the U. 8. National Museum, in recognition of his
laililislusl Inisirs m avian iwteology, and his past and present Museum work, both
III |inl*<oiitology and avian ost.-ology.

Ksiuiis I kils, Oregon : ro|)c‘ collection.

|•|:l•ll* I TIJ. XJ.KCS up. linr.

..f siJ. H.rs sisH^r^ ■ n ^nd P. lucasi only in the matter

cel^riica consideration does not

t" a. ^-o extinct forms are in both />.

th. pn.s..ut s,K-cnes stouter, with more strongly developed exti-emities

THE FOSSIL AVIFAUNA OF THE

41."

than at present exist in P. p. colwnbiamis, which would seem to jwjint to
P. lucasi and nanus being the more nearly alfined forms. It is especially unfor-
tunate that no skulls, sterna, or pelvis belonging to these species were discovered ;
they would have shed no little light upon the subject of their true kinship. The
measurements are in millimetres.

P. Im^asi.

P. naniw.

Length of tarso-metatarsus

44

:«

Greatest transverse diameter of proximal end

11

t»

Greatest transveree diameter of trochlear extremity

11

10

Pedioccetes nanus has proven to be the smallest species of the Gallinec coIlect«*d
thus far in the Silver Lake I'egion, and I found no fossil remains of either tlie
Ptarmigans or the Perdicincs. During my examination 1 made fretpient compari-
sons with skeletons of the existing genera Dcndragapus and Pomisa, two or tliive
species of each being in my jjrivate collection. (P'igs. oG and ?>7, PI. XVII.)

Pliocene of Oregon : Cope collection.

PA.LV.OTETRIX GILLI gen. et. sp. uov.

In that part of the collection which was made by Mr. 8terid)erg at Fos.‘<il
Lake, I found the right carpo-metacarpus of a Grouse that was new to me. 'I'lie
specimen belonged to an adult individual, and in fo.ssili/.ing has turned nearly pure
white. In* some instances the specimens that lielong to the older forms of l>iial.s
of this horizon exhibit that character, but it is by no means always the ca.se. 'I'lie
specimen now being considered is nearly perfect, and evidently Ixdonged to .some
tetraonine form that in point of size was smaller than an adult female Ccnlro-
cercus ttrophasianus, and conspicuously larger than the largest of our other exist-
ing species of Grouse ; Tympanuchus for example. 'Phis being the ca.se it is
unnecessary to compare it with any of the smaller Grouse or the Ptarmigans.
Apart from the question of size then, it differs from Ccntrocercus in one very
marked character, for we find that the articular surface at the summit of the Ihiuc
on the outer side is continuous with that other articular surface found uimui the
outer aspect of the proximal end of the medius metacarpal. In Pu/ecoMrix this is
distinctly interrupted, and the first mentioned portion of the articular surface
terminates posteriorly in a raised, rounded border. This latter character is most
nearly approached by Pedioccetes, and to a lesser degree by Tywpanuchus, hut is
exactly alike in none of them. It is very probable indeed that such a well marked
character as this was associated in the skeleton Palccotctrix with excellent di.s-
tinctive generic characters even stronger than it. More remains of the species,
however, must be discovei-ed before this question can k* decided, and thesi' no
doubt will come to light in due time. I find the length of the carisMiietacarpus in
Ccntrocercus, Palccotetrix, and Tympanuchus to be 50, 40, and 40 millimetres,
respectively, the first named being chosen from an adult female. (.See Fig. :55. IM.

VMVI'H HKDS OF THE OREGON DESERT.

IHlW I

I fulllKl liotllillir to t*ll|»|M)rt bwv. -

ty,.-. ill fxi-U-..ce that such a carpo-metacarpus a, dtd

'"'‘'Tm'tm- thb'»*aTi.’.'ili la.iK.r ofiiiy friend Doctor Tlieodore X. Gill, the distin-
iniiKlie<l Amorirnn imtiiniliHt and iclithyologist.

S. fur w I know tlii» in all tlic material that has been discovered up to the
|,r,*.i--nt tiiiif of thin extinct Crouse, and it is the sole species of the genus, which
I hen* cn*nte t*» «i»ntain it.

l-i.miii* H«h1h «»fOn-jr«»n : (’ojK* collection.

'I'lie ffillowing is a list of »|H*cies and genera thus far discovered in this horizon :

Tympanuchus pallidicinctus.
Pedioccrtes phasianellus cohimbiaims.
I'edioctfles lucasi sp. nov.

I'f(fioc<rtes nanus sp. nov.
Paltrotelrix yilli gen. et. sp. nov.

ACCIPITRES.

A<<i‘n.A ri.io«*Mvrs *|i. nor.

ladirnt«-<i liy but one Ijone in the collection, — the basal phalanx of hallux digit
of the right |Mdvir linib. After comparing it with the corresponding element
ns it iircun. in the skeletons of all our existing North American hiagles and a
niimlier«»f foreign ones. I tind that it dws not agree with any, but belonged to a
binl n-lnt.tl to ylquila chrysactos. As indicated by the bone under examination,
however, the feet of this Kagle wen* moix* slender than they are in our Colden Eagle,
and the joints inenly a trille longer. I am inclined to the opinion that this e.xtinct
F,«gle was n si«. Uirger, though iK‘rhnps a slighter bird, than any of our now^xist-
ing I nite«l States Eagles.

me.\.sirkmexts.

(jn-ntest length of the hasjd joint of hallux "33^

tinati st diameter, proximal extremity 1'

Transvenn* diameter, middle of the shaft G

Tn....v..n,. di.l«n«. U.i„,.cu the anterior troclileai bottlers f,

THE FOSSIL AVIFAUNA OF THE

417

In general form it has all the characters of the podal joint as seen in tlie
Eagles now with us, and the fossil specimen is perfect. Until more material is
forthcoming I have thought best to retain this species in the genus Aquila, and
have bestowed upon it the specific name of pliogryps, composed r)f plio from plio-
cene, and gryps, a griffin (Gr. ypu4'), convinced as 1 am that it was larger than a
large Eagle, but from its more slender build, probably M'ith habits more like a
Falcon, in which case it no doubt stood among the most dreaded of the raptorial
birds during the time it flourished. (Fig. 33, PI. XVII).

Equus Beds of Oregon ; Cope collection.

Aquila sodalis sp. nov.

This is another, and considerably smaller Eagle tliat co-existed with tlie last
described one. Possibly it may have been the Aqtiila danana of Mansli, wliich he
describes as “an extinct species of Eagle nearly as large as the modern (lolden
Eagle”.' In the present collection it is represented by tlie proximal fourth of the
left tarso-metatarsus, more or less imperfect. (See Fig. 33, PI. XVII). .Marsh's
specimen of A. danana is described by him from the distal portion of a lel’t tibia ”,
with “width of condyles in front” ecpial to eight lines. Now the greatest trans-
verse width of the proximal end of the specimen in my hands alsso measums eight
lines, or perhaps rather less. From this I am inclined to think that A. sodalis was
perhaps a smaller bird than danana, and somewhat smaller than either the (lolden
or White-headed Eagles. There is also in the collection the mesial third ol’ an os
fiircida of a medium sized Eagle, and it also very likely belonged to an individual
of the pi-esent species. Its characters are ([uitc like the characters of that part of
\\\& os fw'ctdam any of the typical modern Eagles. In this connection I would
say that there may be considerable specific variation in the form of the os furcula
in any of the existing sjjecies of this group of the Accipitres. A. danana was di.s-
covered in the Pliocene of Nebraska.

A. sodalis had in the proximal moiety of its tarscHiietatarsus all the usual
characters found in the present representatives of the genus Aquila. The tniKurle
for the insei'tion of the tendon of the tibialis anticns mu.scles is stmngly pro-
nounced, being rather to the outer side of the longitudinal mid-gr(M)ve on the
anterior aspect of the bone. This tubercle is eight millimetres long, and sitnateil a
little less than five millimetres below the two antero-i)Osterior perforating foramina
found between it and the head of the bone. The inner one of these foramina
appears behind, just at the louver point of commencement of the inner and largt*r
process of the hypo-tarsus. In this last character it agrees with a specimen of //.
leucocephahis at my hand. There is not sufficient material at my command to
decide whether the posterior points of emergence of these foramina in the Eagles is
constant or otherwise.

To be of the best service our large Museums should have at least seven or
eight skeletons of each species of our United States Eagles, and then the paloonto-

^Marsh, O. C., Am. Jour. Sci. II, 1871, p. 125.

K(irUS HKDS OF THK OREGON DESERT.

. . 1 the GovcM-nnient,^A^tliey have been duly described

lii^dral coIlec'tnMiii Uduiif. fe . . witli their description, should be placed

by the |»«*n«»n niitlionml , access to them, and not stored in

wliMv lilt* Ittud«*iit III I'll |'«|' " aiiiiply compare ouch specmieiis witli

,, rival.. li.i.~.ulii. wlim- every IW>

the, ,...11 perhap» others, that were repeated
1 l.t « rt u-rtiarv m-riod of Oregon,— a large one, larger than our

",'.«!.'„rll^!r»"iri 11..I ... heavily pn.|«'rti,>ne<l (A. pliospfs), and a lesucroae, a
r.ulu,.ni....hhMth., having ,a.rhi,» both affln t.es with r/n-yrarto and

Ihr,«tlHS IcHtoecphalus, hut more closely affined with the former (^. sodalu).
( ojH* collcrctioii : K<juuh lieds, Oregon.

STRIGES.

Ill W> VIIIMlJtlAJIUII.

I fiiiil the <;n*ut Horned Owl repn'sented by an almost perfect left carixwneta-
rnnaw mid n to»-joinl. 'I*he former is identical in character in all iiarticulars, with
the rorni*i»oniling Ikjhc in a skeleton of B. v. stibarcticus with which I have com-
|mn^l it. The limb hmes in Ji. v. subarcticus are a shade less stout in their pro-
imrlioiis thiiii they mv in /t. vir^nianus, a fact 1 have satisfied myself alxiut by
niin|mring a nunilM*r of tlie skeletons of lK)th forms.

This foMtil, however, may have Ixdonged to an individual of some one of the
other suli*«|M.einr nneestnil stocks, for thme well-marked ones are now easily to be
nvogniiuxl. 'I’hey nre //. v. subarctiais, B. v. arcticus, and B. v. saluratus. At
the im’M'iit day B. I’irf^hiiauus rangi's west only to the Mississippi Valley.

('o|M» collection: IMiocmie of On*gon.

PASSERES.

H(tiii.i»v«raAors Arnxifi up. nov.

.\ lUaekhinl of tliis genus rejiresented by two humeri (left), a coracoid (left),
Slid three ulme (right). .Ml these Ixmes are in a beautiful state of pR’servation
sad very nearly is-rf.xjt. quite so in the case of most of them. Their osteological
rhnrNetem an- iilenticnl with Scoieeophag^is cyanocephalus, and the long Ixmes h.ave

very slightly slender more in the calibre of their
shnfts. .S. was a somewhat Inrgrer species than A. carolimis, and probablv a

.•ns nihnsl hinl than A. cyanocephalus. No other fossil hones of small passerine
hinls wen. d.scovenxl ,n the .'Silver Lake Region, and this Blackbird was pn.bably

■ 'r''"; '"f "f .hiT... of ti.„.o „ncie„t l„ke.. It i, i.oi uiimi..-

71) ."T'T I T"'" 'T' "«<’ .'.ppoi tcd sedgy

7rll»v » 1 T ItlackhWs have similar

« . ..Ml,,, „„,1 T |,„vo ritn,iK.|,.ly seen .V. o'a«o..p/,2s in the maiwhos in the

THE FOSSIL AVIFAUNA OF THE

419

In determining this species I compared its fossil bones most carefully with the
corresponding ones in skeletons of representatives of the genera Sialia, Hespe-
roachla, Mertila, Turdus, Myadestes, Campylorhyncims, Harporhynchns, Miuius,
Oroscoptes, Laniiis, Ampelis, all our large conirostral species, western and other-
wise ; all the medium sized I cte7'tdce ; Otocorts ; and specimens of the species of
western Tyranmda. It agrees alone, in all characters, with the genus in which I
have placed it. My own cabinet afforded the above material. (St'e Kiff 10
PI. XV).

Specimens of fossils all in Professor Coj^e’s collection : Erpins Beds, Silver Lake
Region, Oregon.

CoEVUS ANNECTENS Sp. nov.

Recognized through the discovery of a right tarso-metatarsns, j)erfect with the
exception of the loss of the inner articular facet at the summit. Having exactly
the same characters as the corresponding bone from a skeleton of Corvus corax
sinuatus, it nevertheless belonged to a species a full size smaller. Havens of the
present day vary much in size, the smaller forms being found in the .southwestern
parts of the United States, and the largest specimens in Alaska, while Ixdween these
two limits the intermediate sizes gradually approach each other. 'Die skeleton
I have for comparison in the joresent instance is from a female I shot in New .Mexico,
and probably represents the minimum size of the modern bird ; Cor~i>tts anncctcns is
very perceptibly smaller than it, as may be seen by the following measurements irj
millimetres.

Length of tarso-metatarsus
Transverse diameter, mid-shaft

C. c. sinuatiis. t’.

04

aiinccteiiH.

01

4

Transverse diameter, trochlear end <) g

Height of hypotarsus 4

In the absence of other material it would appear that the simillest .\merican
Ravens are the extinct forms, and that the species has increased in size since the
Pliocene epoch, especially the boreal branch of the original stock. The gradation
appears to be almost perfect, yet it would seem that between the pi'csent extinct
species, and the largest Alaskan forms, there exist good specific difterences. (8c*e
Figs. 14, 15 and 16, PI. XV).

Cope collection : Pliocene of Oregon.

CONCLUSIONS.

To briefly recapitulate the events in the geological history of the continent
west of the Mississippi River that led up to the epoch which has engaged our
attention in the present memoir, it will be remembered that during the cretaceous
times a great, shallow sea of broad expanse covered the entire central jiart of the

55 JOUR. A. N. S. PHILA., VOL. XI.

K(/ui-.s in-:i)S OF tjik oregon desert.

and western continent. General and slow
now rniled .States, lorininK ‘ period, gradually obliterated that sea,

co:.t ra„gL of the Paeifle were
aii<l the valley of tla . 1 changes were

j.rfiH,l With the •'I’l'*'"' “ to the eastward of the MiasiMippi Kiver

..ill Iwing e„~.U,ldun»g tl e ,„^tward, in the great Plateau Kegion,

„,e Chiei among then. wen,, those great

north aad^ath of the Uiatah Hou..tai„a; but the ones
.Itt-t -nwt u. aawl hen- are th,»e that gradnally fonnrf ,n On..gon. hoi owing
,.l»„„..nt Chang... that tooh plaee i:" .d

caiUKHi the dmiiingv i i i i *i

WAS slowly depresseil, thus creating once more enormous Miocene lakes where the
iiilniKl cn*ta4H-««is sea formerly e.visted. Then followed the formation of the Coast
miip* of iiumiitnins rnumMi hy the crushed up, complicated upfolding of the ancient
M>A<lNittntii of the then I’ucific (Vean,— the long land-wrinkle thus produced finally
remniiiiiig ns the afon'said mountain range. Once more the region of the Plains
WAS «|e|m*ss«nl, eMending tlie givut Pliocene lakes already e.xisting, and bringing
alMiiit «»ther nMiinrknhle cliaiiges. As the time for the Quak^rnary i^riod approached,
or in the lnt«T tertiary time, shiw upheaval of the continent again ttxik place, and
ohiitemlion of the lake sysUnns over much of the area we have been considering
was iiiniigtinite4l. /\tri /ntsstt with these scenic topographical changes were the
gnwhini evoliitioiuiry onos (hat tisik place in the various faume of the tertiary as a
whole. TIm* vertehmte wries appmnehed more and more closely its character as
we an* n«»w eiinhled t«» study it in n*cent times. Large and cumbersome forms in
alt the various classes, in many instances jxiorly suited to their several eiiviron-
menta, €ir their eiivinnnnents as a whole, wei*e slowly disappearing through e.xtiuc-
tioii,— while others, |M‘rhnps of more pliable organization, lingeix*d along through
fta'iMie and MI«sH*ne time, to finally |K*rish in the Pliocene.

1 hnaigli the pn>vious lalstrs of Professor Cope, and from what we have been
enahhMl u. bring out in the pivsent pa|,er, one can, I think, succeed in picturing to
the inmd what must have lieen a daily scene, during certain season.^, at one of those
"P. “• for !..sta..cc, the old Orogoniai. Foauil Lake

of I'iloreiie tune.

kimwn problematical whether man was

and a whni’ .7. 7 « i« demanded to decide whence came,

' ,1 ;r "nplements of human manufacture, commingled as

found in the n-niJr i;rnrof?i:erkr‘*'i^

"nh':r„:;:;ifLk!Thre„fheC:s^^^^

THE FOSSIL AVIFAUNA OF THE

421

They probably resorted there for the same purjxjses as modern elephants now come
to certnin drinking-pools in their haunts in Africa. Mammoths among the large
mammalia were not there alone, however, for at least four kinds of Llamas were
associated with them in that fauna, and one species at least of these was as large as
a camel, and the others not very much less. Horses of several varieties also i-esorted
to those shores, and it is quite within range of possibility that at certain times one
might have seen Mammoths, Llamas and Horses all there together, but in what
force they came we now have no means of knowing. Modern Horses and
Elephants often associate in their respective regions in great tnK)p8. and the
habits of our recently extirpated Buffalo are well knowm. Yet, with respect to the
latter, how scanty are their remains at their former drinking places. It is (piite
possible that the Horses of the Pliocene were equally abundant, and had linbits m)t
so very widely different. There was another remarkable mammal that occasionally
figured in this Pliocene picture, — a great Sloth, which was full3’ as large a.s our
existing grizzly Bear; and there is evidence that Bears likewise were to Ik*
seen there. Of the smallest carnivora and of small rodents there was no lack, for
as we have seen, their abundant remains are to be found to-da^’ in what was the
former lake’s bottom. There were Otters there, and Beavers, and no end of Hares.
Gophers and their kin. Coyotes and perhaps other Canidtc were there to pivy u|Mm
these, and they no doubt occasionally attacked the larger mammalia, especially the
Llamas.

Passing to the bird-life, which we now know' w'as very abundant, the scene
would not be so very dissimilar, in so far as it was concerned, from what we might
observe upon any of the large alkaline lakes of the Avest resorted to at the presc'ut dav
by the wild-fowl during their migrations. Great flocks of Swans, Geest* and Ducks
were there, feeding on the marshy shores of the lake or disporting thenrsclves u|H)n
its waters. With but few excejAions they wmre of modern genera and siR-cies. A
ponderous Goose appeared among them, perhaps but sparingly during Pli(M-ene time,
for it must then liaAm been nearly extinct. And a Swan tcK), who.st* race ha.s sinct*
died out wms also there, but it was of a size quite in keeping Avith present day Swans.
SeAmral species of Grebe sAvam upon, and dived in those ancient Avaters ; tliey weiv
all like our existing Grebes, and most probably had similar habits. To the.se groui)s
we must add many individuals of a species of a great, strange Cormorant (/'. macro-
pus), larger than any of our existing Cormorants, though probablA'. t(M), with habits
not unlike them. Gulls and Terns in numbers Avere in the air, and donbtle.xs files of
Pelicans along the shore lines. But the strangest figure upon the scene among the
birds Avas a true Flamingo. It could not have been very abundant for it hm* left
but scanty remains. Still it Avas there, and its presence has its meaning.— it may
even suggest ideas as to Avhat the climate may buAe been in those times. Herons
were to be seen, and in the marshes cackled Coots and flcAV flocks of BInckl)ir(ls. no
doubt Avith notes and habits very similar to those of their descendants of the present
day. Tringecs and Phalaropes coursed along the low shores of the lakes margin,

UlvDS OK THE OREGON DESERT.

. .. w- .....n. ru-m-d lionkTH may have been seen Ravens perching, or even

..!■ U.e Itaptorial group, Fn.rther back fro.n tl.e lake, limit,
r .'11.1 .m-. will' -vn.l »|K«c« of Clrou«, and tl,e»t were perl, «p. occa.
^ L.v.h1 uiM,n hv the l«lcon-Iike Eagle and its companion, the lesser form,

:;ri^.!rXv:'u:aL^^^ .l.e overhead. Doubtlo.. th„»> eagle.

chiHly mdiiiM*-.! upai the Hares ami other smaller mammalia, as they do m certain

n*in<*ns ii«»w-«-<layH. , , . ,1 1 .i

the dnv cIcNsd. ami night came on, its stillness no doubt was broken by the

Ixsit of a lMio«Mie liubo, in no imiKirtant resjiect differing with his bulionine descend-

■ins of this iiayclioxoic era. . , r 1 r

Theft.* npiH*nn*«l to Ik* no large or even medium-sized Keptilia, while the fish ot
the Uke. although miiiienms, were limiU*d in the matter of species. Many of the
various gn»iipM ami classes among the Invertebrata were doubtless present in great
ahiiiiclaiK'e. and wlieii of suitable kind aflorded an iiie.xhaustible supply of IIkmI for
the wild-ft»wl.

To s|M>ak again of tlie rliniaU*. it might well be compared with the present
eliinnte uf Florida ami the lower part of Louisiana, with the vegetation fully as lu.x-
iirinnt ns it is now in th«*se parts and with the Palms more abundantly represented.

Taken ns a whole then, of the various vertebrate's in the scene of a Pliocene
Uke ill the n*gion we have under consideration, we would be most naturally struck
by the rtinspieiious difli*penee s<H*n in the mammalia. Although the majority of
them* are <if existing gi-iiera, they now only occur in widely differt*nt parts of the
world, .\pnrt from one or two striking sptw-ies, it would probably take the i*ye of
an ornithologist to deti-et any marked departure among the birds. The large Goose,
the KIntningoes. and the gn*at (’orinorant might be recognized by popular eyes.
To the general naturalist, no doubt, the birds would offer the nuxst attractive objects
for Miidy— for hinls had feathers and jK'culiar co/ot'ations of bills and ft*et. and
thou* chnmeters may have changi*d considerably since the Pliocene ejKich. Such
m-emdary rharaeteristies of «*.\ternal structuivs are far more liable to change
thnaigh the intliieiice of eliimite and surixmndings reacting upon habits, than

" n- ......„„„l p„H ,.f

lli."m«i!'.rilv i-il 1'”” ■’"'"'*''1 "1 <lic iKuly uf my memoir, i]i tlic ca* of

,wiv„ „i,

woukl Imvo Uot) ititcr.-.(irii. to li „ I'-lits were past all recognition. It

compare,! the depths of the ilimischiac noleh

THE FOSSIL AVIFAUNA OF THE

423

upon the posterior borders of those pelves with the same indentation as it now
occurs in the corresponding species of tlie existing avifauna.

The writer entertains the idea that not only were ancient Divers, such as
Hesperornis, or ancient larine types, such as Ichthyornis^ possessed of teeth and a
permanent posterior separation of the ilia, ischia, and pubic styles, but that the
ancestors of a good many of our existing groups of birds enjoyed the samecharactei-s
in their skeletons. That is to say could we trace back by means of fossil remains
the present day Cormorants, or Anseres, or Accij)itres and Striges, or perhaps even
representatives of still higher groups, we Avould, sooner or later, meet Avith fonns in
the lines of their ancestry wherein the skeletal characters named alwve Avould
obtain. Not that all would have them, but that many might. Some modern
Ostrich-forms have the individualization of the pehdc lx)nes ])osteriorly, yet they
have no teeth in their jaws. Still the ancestors of Tinamusm the Emeu may have
possessed teeth Avhich have been lost in their descendants Avhile the pelvic charac-
ters were retained. Surely all very early birds lacked a keel to the sternum siKHicr
or later. Noav Icthyornis is assuredly a very early avian ty})e, biit Iclhyornis
is a bird, notwithstanding it has teeth and vertebra^ Avith icthyic characters.
Could we but find the line of fossil ancestral remains of that genus, Ave must
believe that in the still earlier forims, after they became really mon* avian than
reptilian, their sterna lacked the carina, a feature it did not attain until featliers
and flight AAmre possessed, or Avere developed pari passu with them. There an* tho.se
Avho believe Archcsopteryx had a keelless sternum, and no one doubts tliat
it was a fair flyer for short distances. We very mnch need more material in tlie
Avay of fossil birds, both land-birds and Avater-birds, from the geological horizons
prior to the Cenozoic era. We cannot hope for much more liglit on the subject
until such material is obtained.

The study of the material upon Avhich the present memoir is based still
further establishes the fact that the birds of the later tertiaiw time Aveiv .simply
the direct ancestors of existing genera and species of birds, from Avhich in the
majority of instances they, osteologically at least, scarcely departed at all. Dis-
regarding for the moment those that became extinct during the lMit)ccne or early
Quaternary, we may say in other Avords, that the remainder arc e.ssi'ntially
identical Avith the Psychozoic species they represent. As to the extinct fonns.
Avhat they teach is not alAAmys clear. We may ncA’cr knoAv, for example, the
reason for a large, powerful Cormorant passing completely oil’ the scene and Ik'coiu-
ing extinct. It is not at all likely that any of the small and existing ('ormorants
are its descendants. It is easier to comprehend Avhy a tertiary' Flamingo shoidd
perish, as its habitat was sloAvly transformed into a desert region, but it Avill
not throw much light upon the disappearance of a SAvan, the latter no largt>r <»r
smaller than its congeners upon either hand. In .some cases the descendants
are larger and more poAverful than their Pliocenic ancestors, and this may aj)ply
to the Ravens. A small Fidica may have died out in the ordinary struggle

HKDS OF THK OREGON DESERT.

. its lamer congener, more plastic or better

for of »tn . , , j^g destined to pass down its kind into

suiUHl .« the Hub«.,uent Arouse and the like, we have, in the

futurity. For offer towards the solution of such,

lnl;ivr,i’nI.'M ".Lin .he- -ml, camptolnimic problems. No .loubt m»ny biris
!'muL Silver Lake Keginn of Oregon during the Phoeeue, the fos.,1 remama

Ifthic «. ,et not iKa-n dteovered. Fifty apec.ea are e„u...erated or

.Lril-.l in the |m-,.-i,t .ne.noir, and tl.i. tvould md.cate that the avifaima of the
mriia, wa. far rieber in forma then than it is at the present day. Changes m
climaU., t«i-»Kn.i.l.y,-aiul secoinlarily, changes in vegetation, have no doubt con-
iribiiUtl to the pnHluctioii of such a result.

KXTLANATION OF PLATES.

(All Umj in llie I’Uun were drawn by the author from the speciraen.s, and are of natural

in each cawj.

1*I,ATK XV.

I>irert mmial a»|iecl of left coracoid of Lirto* robnthis. (Cope collection).
tHrecf anterior ajiiiect of the left coracoid of Lama robxtstus. Same bone as shown in
Figure 1, with the "costal process” restored in dotted line in each case.

Anconal asiiret of left hiimcnis of LiriM oregomta ; distal extremity indicated by dotted line,
hr tnr awisUiico of the corresjionding bone from a skeleton of Larva delawareutia.
Anconaf a*p^ of left humerus of Aon/* delawarensia, showing the obliquity of the osseous
|iartilian in the fnaaa /meiimatietig, as compared with the same structure seen in A.
orw^NH* (fig. 8). (Author's collection).

Anterior M|>cet of the proximal fourth of the left tarso-metatareus of Aoi«'/o aoda/ia.
(( ope rolicctioii).

IHrret anterior view of a specimen of the right coracoid of Phakicrocornx wacropus. Imper-
corresjionding bone from a skeleton of Phalacroeorax

Anlerior view of a left tarso-nietataraiis of Phalacroeorax macropus.

liiroet outer view of a left lare/emetaUrsus of Phalacroeorax maerojma. .Same siiecimen as

IS shown in !■ igtire '

Idcft Mijierior 0^118 mandible, and the hinder part of the mandible of

the present dav. * * tendons. They agree with the Ravens of

ght humerus of a sjiecimen of Branta propinqva.

Flo. 1.
Fio, %

Fio. 8.

Flu. 4.

Fio. 5.
Fio. B.

Flo. 7.

Kio. «.

Flo. ».

Fai. 10.
Fio. 11.
Flo. 12.

Fio. 13.

Fio. 14.

Fa*. 1.1.
Fio. IB.
Fio. 17.

THE FOSSIL AVIFAUNA OF THE

425

Fig. 18.

Fig. 19.

Fig. 20.
Fig. 21.

Fig. 22.
Fig. 23.
Fig. 24.
Fig. 25.

Fig. 26.

Fig. 27.

Fig. 28.

Fig. 29.

Fig. 30.
Fig. 31.

Fig. 32.
Fig. 33.

Fig. 34.

Fig. 35.

Fig. 36.
Fig. 37.

Fig. 38.

Plate XVI.

Inner aspect of the upper part of the right side of the osjurcula of Olor paloregunut. This
piece, here correctly figured, is the same that did duty for the left side in Figure
25. This fragment is iii the possession of Professor Cope.

Inner aspect of the upper part of the right side of the os furciila of Anser condoni. This
piece is the same that did duty for the left side in Figure 26. Dotted lines restore
its apex as before (Fig. 26). Cope collection.

Upper view of the bent, posteriorly projecting part of the mesial portion of the otfuretila of
Olor buccinator (18,509 U. S. Kat. Mus.) Compare with Fig. 21.

Upper view of the bent, posteriorly projecting part of the mesial portion of the osjureiila of
Olor jjaloregonus. Imperfect part restored in dotted line from the opposite side or
perfect portion of the fragment. This is the same specimen which figures in the
lower part of Figure 25.

Outer view of the left side of the os /urcw^a of Atuer albifrons (Spec. 18,610 Coll. U. S.
Nat. Mus.) Presented for comparison with Figure 26.

Posterior aspect of the lower mesial portion of the os furcuta of Anser albijrons. ^ From the
same bone shown in Figure 22. Presented for comparison with Figure 27.

Outer aspect of the left side of the os fureula of Olor buccinator (Spec. 18,509, Coll. U. S.
Nat. Museum).

Outer aspect of the left side of the os fureula of Olor paloregouus (^CoU. of Cojw). Imper-
fect part restored in dotted line from the bone shown in I'igure 24. The external
characters, as the pneumatic foramen, etc. were obtained from the inner nsiiect of
this same fragment in order to present the same view of it a.s is shown for Olor
buccinator in Figure 24. The real aspect of this part is given in Figure 18.

Outer aspect of the left side of the os fureula uf A?iser condoni, (Coll, of Cojic).^ Im|>erfect
part restored in dotted line from a specimen of 4n«er albifrons (Swc. 18,610 Coll. U.
S. Nat. Mus.) The internal characters, as the pneumatic forunicn, etc., were
obtained from the inner aspect of this same fragment in order to prcmil the sumo
view of it as is shown for the specimens given in Figures 24, 25 and 22. The rwil
aspect of this part is shown in Figure 19.

Posterior aspect of the lower mesial portion of the os fureula of A user condoni. Same frag-
ment as is shown in Figure 26.

Plate XVII.

Anterior view of the right tibio-tarsus of a subadult specimen of P/uenicopterus copci. Almut
the distal two thirds. _ . n- i

Anterior view of the left tibio-tarsus of an adult specimen of Phanicoptenu cnpei. Distal
portion. Fragmentary.

Anconal aspect of right ulna of Pedioemtes lucasi.

Anterior aspect of the lower part of the shaft and distal trochleie of a right tarso-niPlntnrsiis
ofArdea paloctndentalis. Upper part of the bone simply indicated in dotted lines,
the restoration having been made by the assistance and use of correSiwmiing bones
in the skeletons of several of the smaller United States Herons.

Anconal aspect of a specimen of the left humerus of Fulira minor. ^

Superior aspect of the basal phalanx of hallux digit of the right pelvic limb of a specimen
of Aquila pliogryps. Type: Cope collection. • • , i

Palmar aspect of the right carpo-metacarpus of Palwotetrix gilli. Inij^rfect portion in d<>tt«l
lines, and restored by the use of the corresponding bone as it occurs in nearly all

Tetraonidw. . p ^ , < •

Palmar aspect of the right carpo-metacarpus of a specimen of Centrocerrus wophMtanus.
From a skeleton of a small female in the author’s collection. Introduced for com-
parison with the type given in Figure 34, from the Cope collection.

Anterior view of left tarso-metatarsus of Pedioccetes yianus. i 1 1 j-o-

Palmar aspect of left carpo-metacarpus of Pediocates nanus : I robably a dittcrent

individual. . t.,- i » j i.

Anterior view of a left tarso-metatarsus of Phoenicopterus copei. Distal portion. Adult
individual. (Type : Cope collection).

Journ. Acad, Nat. Sci.Philad. 2^'^Ser. Vol.IX.

PI 10

R. Weber, del.

l.PALAEOSYOPS PALUDOSUS. 2.R MEGARHINUS . 3. TELMATOTHERIUM CULTRIDENS.

Journ.Acad.Nat.Sci.Philad. 2'^!^Ser. Vol.IX,

R. Weber, del

Lith WemeiiWmtt; R n X

4-7. PALAEOSYOPS MEGARHINUS 8,9. LIMNOHYOPS LATICEPS 10,11 TELMATOTHERIUM IfYOGNATffUS.

Journ Acad. Nat. Sci.Philad. 2"'^Ser. Vol.IX.

PI 12.

■ R. Weber, del.

12,13 TELMATOTHERIUM CULTRIDENS 14-16 PALAEOSYOPS MINOR. 17-23 PPALUDOSUS 24-27. LIMNOHYOPS LATICEPS.

Journ. Acad. Nat. Sci.Philad. 2'>'^Ser. Vol.IX

PI 13

lith W- , lit.

R- Weber, del

35.

28-38 PALAEOSYO'PS PALUDOSUS.

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NEW AND J>1TTDE KNOWN l>ADEOZ()l(’ AND MK>()Z()K’ h'ISHES.

By E. I), (’ope.

ELASMOBRANCHII,

Genus SY.MMOHII AM U.)i)e.,

Hvmmokipm hbnipoume Cope, Amer. Naturalist, 189.S, p. t»9t). Plate XVI 1 1, Figs. l-o.

Char. gen. Deiititioti a.s in Cladodus. Pectoral tin .supported on liasal .seg-
ments, of which the anterior articulate with the scapulocoracoid element, and the
po.sterior to the metapterygium, the whole rorming a nniserisil tin. .Metaptery-
giuni unsegniented and fused with the basal elements which it .snp|)ort.s.

The specimen on which this genus is founded throws much light on the struc-
ture of the Cladodont pectoral tin, and through it, on the question ol'thc evolution
of this organ among fishes. The fin basis de.scrihed is mostly well pre.scrvcd. and is
clear as to details of structure. It confirms the characters ascribed by Trat|uair to
the pectoral fin oi Cladodas from the lower carboniferous of Scotland,' the only
important difference being that in the latter the metapterygium is distinctly seg-
mented, while in Sytnmorinm this element I’orins a single piece, except po.ssibly at
the extremity. According to Tracpiair there is an "oblong” proximal segnnmt of
the metapterygium, “whose anterior portion seems to have absorbed the basis of
one or two adjacent rad ials.” \\\ Symmorium reniformc. -aW the l)asals (ratlials of
Traquair), are fused at their basis with the metai)terygimn. I'lie basals are also
more numerous than in Dr. Traquair’s shark, for he says “some small radials are
seen attached to the preaxial side of the first two segment.s — none on the others."
My specimen agrees with Traquair’s in the absence of basals (radials) from the
postaxial side of the metapterygium, where indeed they are not to be looked for.

As this species is the only (JIadodont from the coal measures in which the lin-
structure is known, it is premature to suppose that all the .s])ecies ol'that liori/on.
of which there are described, according to Newberry. oS species of the
genus alone, belong to the gyixwe, Synuiwriuni. But it is not uidikelN-

that such will prove to b(‘ the ca.se. The name Cladodus is applical)le to the species
of the lower carboniferous, to which it was originally given by Aga.ssi'/,. where the
metapterygium is segmented.

On a knowledge of the fin structure of the paleozoic sharks depiaids the s(e
lution of the question whether the tri- and plnribasal fins of the modern Elasmo-
branchs and Teleostomi have been derived from a pinnate archiptcrygiuin as sup-
posed by Gegenbaur, or from a, lateral fold supported by rays, as sup|M)sed by

‘ Geological Miiguziiie, Feb., 1888, ji. Sll.

5e JOURN. A. N. 8. PH I LA., VOL. IX.

NKW AND IJTTLK KNOWN 1‘ALEOZOIC

... -I- ..IV.T iiMtiidv of liis sijeciiuen, decliircs that it “is

Tl.«cl.. r .iimI J the paired fins, at present so popular

“ utinm'-i rJsts-" n c I) 83) Dr. Smith Woodward' adopts

-rill. -imlofiiiM- and emhrvolo-,sts; (I. c. j). i

wilii

lailli of tin* «|.|»o»iiif.' views.

d.-riviiijr the modern fin, like (le-renlninr, from an

::Lr.;T;'^n;;:rnn;.:i.Tivi„« ..... -,..1..... n...... ti,e ....... ...i r,..,. ic.

I l.,.Ll .•n-cll.-.l .. Plych,/,lrnfnm. Tlii» is base,. .... a of tl.c

Cl., I a. .I.c' '-aae ,.l' tl.o low..,- .■a,.b..,,,fc.mo„n

ln*l in»iii iin* ' i* _ , -.1 T X i\ \r 1

H,io.„a...e.l hs N\.«l,.rry <:/./.W«i/v/r''/Vand C. herzerii. Acconlingd. Dr.Uood-

iranl aii'l Mr. D-aii.- wlio eoiilirms the ol.servation, the pectoral fin in these
1. -iii.p.rMl l.v fiasal ossifications, wliiidi issue in nearly parallel relation
fnaii llie l«sh Willi. Dr WiMsIwanl d.H-s not refer to the e.xistence of any skeletal
..|...,i..,il n. r. iMsal support to I I.ese hiusal rays ; but Dr. Otto JaekeP asserts that
llicn- iin- l.a-iil plat-s coiiiparal.le to the metapteryfriuin of the modern sharks, and
li.-a.'.- infers the la.Hlcrii elianieter of the fin. He e.xpresses this opinion after an
l•\nilliMnli■>ll Itf »«Miie of the s|a*eiiiieiis studieil liy Dr. Woodward and Mr. Dean.
|>. W.rsiwiinl -ays "ihe si-jfiiieiitatioii of the rays” (of the pectoral fin of
"VLtUInt /K/r-r//'i. tin* persisUMiee of one of the middle rays, with theconcoiiii-
laiil pirliiil fuMion of the still further eiiiwded and reduced horderi up: rays, would
iHHNi. ill the writer's opinion. i*esiilt in the aridiipterygium of (legenhanr. It is
iiionsiiiT aigiiilieaiit that the anti rior (preaxial) rays are much more rohust than
till’ ptaterior (ptstiiMall rays, exactly as in all known examples of the “arcliip-
ti-rtitiiiiii Ml W'issiward also admits the possibility' <>f the single basis (mesop-
tery aiiiiii I «»f th*’ andiipterygium, having iH'sidted from a fusion of .several hasal
eliMii-ut*. «i« •iipiMixsl hy Dr. Aiitiui Krit.sch. as in the dorsal fin of Hhipidoptery-
tfiaii li■h•‘s

‘file h-swiii iiiii);||| |,\ the s|MM'iiiieii of Syntinoriuvi renifortne is as follows :

I he iiietaptery uiiiiii is Hot funiied by the enlargement and segmentation of a median
ray. or hnsilar. hut already exists as a plate or .series of plates probably enclosed in
till' Usiy Mali or in its primitive fold. This metupterygial fold Ijecame siibse-
•pK'iitly fns* |ststeriorly from the ImkIv wall. The arehipterygiiim is then formed
froiii the pty ehopterygiuiii hv the addition of basilars to its po.ster()internal face;
while the tri. Hiid plurilaisal liiis of niiMlern Khismobranchs and Teleostomi ai-e the
n-iilt of enhinPMiient. nshietion and fusion of the proximal radials. Thus the fin-
«tni< tim* 111-00% ensi hy I nu|nair. contrary to his .supposition, supports the
ptyrhopt.-ryinuin tla-ory. and the in.Hlern fin is not derived from the archiptery-
gnim. hut Iroin the ptyrhopterygiuin. From this we conclude that the Ichthv-
oto„,M|.,p 1, j the reverse; a resultwhich

'• ' * n pa i>oiH«dogie sneeessioii. The converse supposition Avhich 1 have
'-"''-i'l'’ "itli this onior, ,18 lcl.tl.v„u..i.i aw

_ ;^iMri.l Srymor. \tw, |.. tsiri i. m

• s..o.oi^.' Jci;.

AND MESOZOIC FISHES.

429

Fig. 1. Xenaoanthns deefienii (joW. From Fritsch, 4ei' (iaskoiile ii. ti. Kalksiciii

mens. Much reduced.

known from beds older than the Coal Measures, while Selnchii are Uiiowii Iroin the
Devonian.

The structure of the paired fins here i)oint( d out snstuins the views alrea<ly
announced by Mr. Bashford Dean in the paper (pioted, and this author is to
be congratulated that the view which he has put lorth is so lully sustained hy
the material now described. One hypothesis which he holds rtapiires lurther <‘(in-
tirmation, viz.: that the metaptorygiuin is formed by the fusion ol tlie basal ele-
ments. The extensive fusion seen in the later genus AVwwerh/?;/ as compared
with the earlier genus Cladodiis supports his position so tar as it go(-s; hut tlie
origin of the primitive segments is not thus explaineil.

Mr. Dean refers Cladodiis fylerii to a genus distinct from CUidodns, which
he calls Cladoselache. The character ot the (ims does not seem to dilfer Irom that
ascribed to Cladodiis by Trarjuair, and the geological horizon is tliat ol tin* latti’r
genus.

Mr. Dean thus states his conclusions, (1. c.): —

“It would appear that this shark form presents the most manifest eviileiice as
to the lateral fold origin of the paired (ins. The fins, as state<l hy Smith Woodward
are actual remnants of the derm fold. The unjointed rod-like radials proceed from
the body wall directly to the lin margin ; the fin surface. tlu>refore, is as yet lack-
ing the specialization of the dermal margin and dermal rays. It would now apimar
that the basal plates exist but in a most primitive condition ; their liision into a
plate is seen to occur to a partial degree in the pectoral lin, but the rotation out-
ward of the posterior end of this trunk of basals does not as \-et take place; the
entire fin stem is still imbedded in the body wall. In the ventral a most interesting
condition occurs,— a more primitive arrangement would lunv vi-ry naturally be
expected,— hsals in the body xvall are as yet tinfused. and are represented
by rod-like bars of cartilage, which outwardly resemble basal joints belonging to
the radials. and were, in fact, so interpreted by Jaekel. The lu-oximal ends of the
basals are in actual process of concentration near the anterior lin margin ; the
radials, however, are still more or less at right angles to the axis of the lish. Smith
Woodward has already recorded one of the most significant features in the fin
structure,— the marked way in which the radials are crowded together side hy side

NKW AND IJTTl.K KNOWN PALEOZOIC

li.. H-. i" speeiali/ation

of n ,...M,.«.-| ....l««I.T TIm* writn- that this tendency tn compress the

in the anterior fin nnufrin mu.l.l only occur when the hue of the
l««,U i*«. ..till iniU-d.hHl ill the IhmIv wall.— and would trace this conclusion still
further to m-eoiinl for the aiioiiinlous liii spines oC the Acanthodians. In Parexus,
r..r exuiii|.|e. it Mould MH-III .|iiite clear that the broad fin spine is structurally corn-
|..lln•l. aii.l limy Me|| n-pn-si-iil the fusion <.f the radials in the anterior fin
iiinr^'iii

••III the ventral of OnM*srla(hc is repivsented the most primitive condition
Inlherto kiioMii in the onto^reiiy of the paiivil limbs. The fin is still outwardly a
ImmIv ileriii folil. thrice as loiitr ns broad, hlmiterl anteriorly where the radials are
laviniiiii;; to U» chiHicnil ; the basal siip|M)rts. in number scarcely less than the aji-
|s-nde<l niiliiiU. are still iitiriisiMl. although the pna-e.ss of concentration anteriorly is
clearly lo In* marked "

To tills I have addeil.' I lint nil ol)s«*rvations on Symmorium, together with
ihoM* of Tmi|iiair, .laekel niiil Dean, show that t he median a.\is of the archipterv-
Kiinn is l•••| |>ropler\>'ial or iii«'s«»pt«*rvgial, hut is metapterygial. This greatly sini-
idiliis till* eoiieepl ion of the history of the Sidnehian fin (Fig. 2), where the iiietap-
lery jiiiiii aii|i|Nirts the greater iiiiiiiIkm- of the other segments. The Ichthyotonii are
ihAiMii out of the phylogeiiy of the sharks, and are left in a position more likely
lopnive niH-i'sInil to the 'relisistoinatoiis fishes: but nothing jiositive on tliis jioiiit
• an Is* alliniMHi.'

Kio. 8. Sri/iiio form, left
HhmiUler-girdle; (’m, iMwttemiNiral ;
/>', epiclavicle; D, <'lavifle: /!', ixiet-
elHviele: ■V, scapula: Co {('(), inra-
••iiid; ,1/' AV/. hasihu-s; A, seai)ular
roraiuen; //.S', A’.S', liii-rays.
tViedersliciiii.

AND MESOZOIC FISHES.

4.0

It is t'urtliei' to be observed that the essential distinction now discovered be-
tween the inetapterygial and other elements of the paired fins, must he maintained
in our future studies of them. A clear distinction between baseosts and axonosts
in the paired fins has been hitherto wanting. For the present it may he convenient
to regard the inetapterygial elements as axonosts, and those which have originally
been branches of that axis, as baseosts. The scapular base of the Selachian fin
(Fig. 2) consists then of one axonost and two baseosts. The Actinopterygian fin
will have as its scapular base, according to (legenbaur’s homologies, baseosts only,
the inetapterygial (axonost) elements having entirely disappeared (Fig. d).

TaxoTiomy. — As a result of the preceding observations, I have removed the
Cladodontidae’ from the Ichthyotomi, where Dr. Woodward placed them, and have
relegated them to his order of Acanthodii. The definitions of the three orders de-
rived from the fins, will then be as follows ; those of the second and third lK‘ing the
same as given by me in the American Naturalist hir 1889 (October, p. 8b4):

Paired fins ptychopterygial ; Acanthodii.

Paired fins archipterygial ; /chythotomi .

Paired fins hasilo-metapterygial ; Sclachu.

Char. Specif. — This species is established on the anterior part of the skeleton
of an individual from the shales of the Coal Mmisures near (lalesburg. Knox (A).,
Illinois. The fragments include parts of the skull, hyoid arches and pectoral andi,
in a damaged condition. The jaws, which are preserved, display a considerabh' num-
ber of teeth more or less displaced. One mandibular ramus is identifiable, but the
other tooth-bearing elements are not certainly determinable.

The teeth display all their surfaces, so that their characters are readily a.scer-
tainable. They are all alike, differing only in size, those near the center of the
specimen being smaller than those more distant, and representing probably a more
posterior position on the jaws. The base of the tooth is reniform in outline, the
anterior border concave, the posterior convex, and the extremities obtusely rounded,
or subtruncate. The principal cusp is about as high as the base is long. It is flat-
tened anteriorly, and very convex posteriorly, and is curved backward. The
anterior surface is finely striate, and the posterior face is more .strongly and sharply
striate with close and fine ridges. The two faces are separiite<i ly a cutting i-dge.
The a])ex is smooth, and pjresents a low angle on the anterior face. There are two
basal cusps on each side, the external larger, but much smaller than the median. It
is curved backward, has no cutting edges, and the surlace is striate-grooveil. 1 he
middle cusps are smaller, and acutely conic. All the cusps stand on the anterior
border of the base.

The characters above enumerated show that this species diflers Irom ea<di of
the numerous forms described by Newberry in the reportsol the ( icological Surveys
of Ohio (Vol. II). and Illinois (Vol. II), or by St. John in the same (\oI. \ l).orby
Newberry in his work on Paleozoic Fishes in the Monograph No. X \ 1 ol the I . S.
Geological Survey. It resembles most C. lanuundes Xewb. and C. intercostatus,

' Anier. Naturalist, 1898, Nov., p. 999.

XKW ANI. I-rlTI.E KNOWN PALEOZOIC

, ....I I . /«/*«•/ ol- St. Jolu, (I. C-., v„l. VI), From the Iir,t.,.a,„rd it

d,ir.-n.i,. i.. R-.iir..n„ in. to I' -.■iiurirruL.r b«.se, and the ,, oases, on ol two

instoul oI- Fn.„. C. in/ercodatm it differs m the absence

of ,li.iii.et rhlB.- ..r I Hie nhsoiceor tnlKro,sit,e.s ol the lulenorsiir-

fa.-.- of III.- Ikiih- In C. /uJJerit tin* is ol’ lenticular outline, and in C eccentri-
tm ll i- .-xnivat.Hl U-low. clmnicters not seen in any of the teeth of C.

r<mformt% 1 alioiil.l. however, have hesitated to add another name to the list of
.I»vi.-«..r lliiatfemis liut for the interest which attiudies to some portions of the
im'.tiii|Ntiiyiiii{ skeh'tiiii. to which 1 will now devote a short space.

The rrniiiiiiii is too imirh .-nished to fnrni.sh nstdul information. There is no
inu-e «»r apiiH-. sin-h as .H-curs in Xetiacatiihus. Posterior to it the muneroiis

Ill* ,if the hyoid nn-hes show that the epihranchials terminate in free acute

alsive. as in n-.-ent sharks. Then* is a scapuloeoracoid which has nnich the
form of thni of X*Hiu>tnf/ius, as ilescrihed by Fritsch in his admirable inonofiraph
of this i.-.-iiiis ' Knnii tin* external aiiple of thi.s element there extends the elongate
MX is of the |H-.-ionil fill It is not conipletelv se<rniented, the anterior portion being
by .•.inlinnons gniniilar ossification. The |M)sU*rior border is divided eomb-
like int.i iiiiiiH-runs short divisions, with s«pian-iy truncate extremities, which appear
to hax-e siiiiiMirtiHl the hiisiil eh-ineiits of the fin, although but few ba.sal segments
liavi’ l■•«•n im-m-rvisl. nn)l but I wo of them appear to be in place. They are much
tiion* •l.-ii'l.-r ihnn the triineiit.- articular faet-s. and the two referred to articulate
with n •iiiitl.- one of the lfilt«*r.

.MK.X.SfKKMK.VTS.

.MM.

5

10

6

12-5
9-5
12-5
LSO
170

m, .h.nl.. .1^'. X’"'""'-' •<> !'• K- •JelliH'--, t» " I™'"

OIIODI S .Virip....
is-t l-lMic XVII I. Kl«*. .W.

tenor half of the |l•||gtll of *ii*fish '*1 ^odeshurg, Illinois, contains the an-

niM*. t»r Iht- .•|.•nlellts of tl -If.!*. as a granular carbonaceous

«»e ••d.> Ar«' disiiiicilv oiitliti I *i ***!*' "*’t'>dibular and scapular archesof

• .he dc.titio,, i, preserved h. c

l».Mm..|..n...f Us., of i.s.il, No. I ‘ '‘Utei-oposterior;

1 transverse ;

l>iiiin..|..rs <.f lms..or i.M.ih X„. 2 «"tero|K)sterior;

I transver.se ;

Klevnli.>n of eniwn of No. .'5 ;

Is-iiclli of Inis., of N„.

Is iiKth ..f h.ng,.r hraiicli of S4.upul<H.oraeoid ;

Is-nptli .if nxisof |Ns.|oml fin;

Width of arliculntion .if Imsihir oii axis •

I cm.- til,.

U-liK. Uor iVrinforinationi. JJoehmens

con-

Band III, Heft I.

AND MESOZOIC FISHES.

4.13

fused condition. The teeth can be seen from all points of view, and a good idea of
their characters can be obtained.

The muzzle does not project beyond the lower jaw, so that the nioutli is termi-
nal. The teeth are confined to the anterior half of the mouth. They are narrow,
and are arranged end to end in arched rows. The crown is keeled on the middle
line, a part of the keel not exactly in the center, rising into a low angle. The edge
is not serrate nor beaded, but is feebly crimped in some teeth, and apparently .smooth
in others. The surface is otherwise entirely smooth ; but there are on one side
three low vertical keels. The base of the crown projects over the root on both
sides, but on one side much more than on the other, so that teeth lying on their
side, look like short cylinders. Tlie root is coarsely porous, the openings being fre-
quently as large as the space between them.

This species resembles in dentition, in some measure, such I'orins as 0. mitins-
cuhis N. and W.’ and O. elegantulus N. and W.'* The former has. according to its
describers a distinctly beaded median keel, and in the latter the crown is trans-
versely ridged; in neither is its swollen base described nor figured. Tlie presence
of vertical crests on one side of the crown, places the 0. basalis in the section Agas-
sizodus St. J. and Worthen. In this genus it resembles 0. virginiantis St. .1. and
W.,‘ and O. scibdus' St. J. and W.; but it is more slender, and has fewer cia'sts
than the former, and is less slender and moi’e symmetrical than the latter.

The mandibular ramus becomes shallower jjosteriorly than at the middle. 'I'lie
scapular arch has the position usual in sharks, and the horizontal anterior ]>()rtion
rises gradually into the much longer vertical jiortion, which has the anterior Ijorder
straight. The pectoral fin is too much damaged for interpretation.

Measuke.wknts.

MM.

Length from end of muzzle to superior apex of scapular arch ; 225

Length of mandible to cotylus ; 11*'

Depth of mandible at middle ; --

Depth of inferior limb of scapular arch ; .21

Length of a tooth ; *'‘'^

Depth of same tooth at apex;

Depth of crown of same tooth; .

One half of the slate containing the specimen above described, is contaimal in
the State Museum at Springfield, Illinois. It was kindly lent me by Dr. .losliua
Lindahl, State Geologist. Through him I learned that the other half was in posses-
sion of Mr. Frederick R. Jelliffe, of Galesburg, 111. Mr..Ielliffe very kindly sent me
his specimen, together with the one already described as Symmomim renijorvie ; and
I here express my appreciation of his kindness in so doing.

' Report of the Geological Survey of Illinois, II, 67 ; PI. IV, Fig. 11.

2 Report of the Geological Survey of Ohio, II, 67 ; PI. VI, Fig. 6.

» L. c. VI, PI. VI, Fig. 16.

< L.c. VI, PI. VIII, Fig.

SKW A

Nl» IJTI'I.K KNOWN PALEOZOIC’

Aomm'

: .. <iuli sDiiie referable to the genus Listva-

“'-•-7;;;;: r ....a w. 1, i. wen

N i.nn « “'I- For the greater part of the length tliere

|.n.«i*rv««l. 4liM|.l«\iiig * Hiirliiee, hut at the base tliere are ten. New-

«n- eiithl ‘‘Jj J '\I j i„ l,i’„ (igure. represents the Z. as hav-

::;A.:in::^rr;"t:u,.t'..g t.,.: uni..., t.. la..,. ,„id„ie„f ae u,g,i„ h„t

.h...h;~.ri|.li..i.. I cannot make a eertan, nlent.hcatma. It

!• 'Ml I’lale XIX. Hg-

• Jriiiii. ••rrYI'I'OH AHIH (r'ois?.

XX. ••■'IP'-

I'.lahli-lMil ui. the ai.teri.ir part uf a fiah. inchi.ling the head, scapular arch.
Hr., fnan lue oml -lalea ..f < h.li'sliurg. Illinois. The details of the structure are not
Mi.|| pnwrvi.il. lull iiiniiy an- visible.

nrtilntfe U <*oven-<i hy a closi- fi'SKellation of minute o.s.sifieations. The

iin- n-iiiarhnhle for the iilU-iiee of tlie expanded basal portion or root wliich
rhariK lehiu- the nlli.sl Ki-neni OmiiHiun, I .attibeiodus, etc. 'I’he ha.se of the crown
M shfihlly ex|iniidisl, hut the ns.l pn»|M'r is wanting or rudiinental. The latnal
.leiiiirh- an- nunimlly wiiuling, although in tlie anterior part of the lower jaw a
l•ll•ih i» pn*i«*T\«s| with a denticle attached hy a slender basal connection. I refer
tin- •iHS'ies pntvisioiiidly to tli<* genus .V/v/>/e^rt.v/.v wliieli I ])ropos<*d' for a probable
I ‘liidiMloiil Mithoiil ex|Miii<l<.d risit or dentich'. altliougli it i.s ipiite possible that
wlieti •keletaiii,- iif the .S* ttfu/rata and .S*. knightiana are hetU*r known, they
iiiRV U* roiiiul lit Is’loiig to dinereiit genera. It is |M)Hsihle that the genus termed
.lA-wtar/ifi/iR/M < hy t’lay|sde» will turn out to Im* identical with .SViyi/it/iir.w, although
the Itan- ol the tisith is ill the former a little la*tter developed.

t MO eleiiieiitK U'hiiid the sktill apiMuir to la* the scapular. They are subtri-
aiiKular. M ith the a|a-\ sii|M-rior: the aiiti'rior lairder projecting forward as it ex-
I mU doM II Miinl and the |Mts|erior Isinler laMiig nearly vertical. A trace of the
Imm. of the |MaM.tral tin is pn-m-iit. hut is in |ator preservation.

( bar. .syvri’//.— I he s|ie«’iiiien diH's not riiriiisli clear characters in some it'siHH'ts.
-the hen.l rnidnsl nnd distorted, and the dorsal region of the laaly is very iin-
1-rfe. t Nevertheless, the rorin of the lower jaw and the charm ters 'of the teeth
”!*' " ' ^ ***’ ^••***•r an* lying in confiisi'd ndations along the palato-

p erygmd ai.d iiiamlihi.Ur l-nlers. hut at one place the bases of several are

h.M« t>f> Ii* !' jaw. riiey are of dilTenmt sizes and forms, as fol-

whirh «%n- nl * I **'"^**""’' jaws the tii'th Inive long and slender crowns

^ '-I* 'lianmaT. On.lm

Nil.) ciirv hT * I** ''7”'*’ '**’* '"*****' .*lmrtcr ami iimiv rolmal. Imt arc

-■llmrr...... ' <i7 t’lV', ml "“irk'-rl

■ tiNn 111 iIh- 1111.I1II.. In,, „„ I I I mrta ol Hic jaws, the Uclli am .Imrtcr

ro. . .. w I ■■'■gi..... A aiagic Ka.tl,

AND MESOZOIC FISHES.

435

here presents the appearance of having a ininnte denticle on one side separated by
an attenuated line of base. The surfaces of all the.se teeth are closely and sharply
grooved from the base to near the apex, which is smooth. Where clear view.s can
be had, the base of the crown is seen to be round; and although the crowns are
compressed, there seems to be no cutting edge, and the apex is round and
needle-like.

Measurements.

MM.

Length of an anteinor crown ; 2

Length of a median crown ; 4

Diameter of a median crown at base ; '75

Length of a posterior crown ; l'5D

Diameter of a posterior crown at base ; 'To

Length from extremity of lower jaw to scapula; 1'45

■ Anteroposterior width of scapula at pectoral fin ; "20

This spedes was found by Mr. Frederick R. Jelliffe near Galesburg. Ill, in the
shales of the Coal Measures, at the same locality as that which 3-ielded the Sy»it?to-
rium and Orodus here described.

Genus DELTODUS N. & W.

Dei.todus planidens sp. nov. Plate XX, Fig. 6.

Two teeth of the inferior series represent this cochliodont shark. One toot li,
which belongs to the left side, is completely preserved, and shows a transverse in-
volution which amounts to nearly an arc of 360 °, but of a depressed outline, and
much more curved, at the apex than at the base as is usual. The surface of the
crown is distinguished by the absence of ribs and grooves transverse to the di-
rection of the ramus of the jaw, but the anteroposterior .section is uniformly slightly
convex. On the other hand it is marked by shallow grooves running parallel to
the convex internal border, which become more pronounced and closer together as
the apex is approached. These grooves fade out on the longer or jiosterior border
of the crown, but terminate abruptly before reaching the anterior border, at the
internal extremity of the crown. On the external and narrower part of the crown,
the groov^es extend to both boi’ders. The pores are uniformly distributed over the
surface. The length of the grinding surface round the curve is 57 mm.; length of
long chord of tooth, 31 mm.; width of interior base of crown, 30 mm.

This species belongs to that small section of the genus in which the teeth
possess longitudinal grooves. In this it resembles D. undulatus and D. cingji-
latus of Newberry and Worthen. But the teeth of the former species have ribs
and a wide groove transverse to the jaw; while the latter inncli narrower teeth
with the pores in bands corresponding to the longitudial (transvere) ridges.

The present species was found by Mr. W. F. Cummins on Tecumseh Creek,
northern Texas.

57 JOXJRN. A. N. S. PHILA., VOL. IX.

43(S

NKW AN1» IJTTLIC KNOWN PALEOZOIC

PLEURACANTHID-SJ.

0,.rr. ./ tl.e catalogue ol foss.l h»hee in die linl.sh

Ag... lual a,o„.tr„,Mys Tra.,uai.-. In the Fauna of the (.askohle,
..,r .Imalv cit.al. Dr. A. FritacI, adopts three genera, yn., Heura-

<VM4r,..M.r'an.l SamcmOn,!. Dr. Wooihvard, m commenting on

,|,i. ciii-ut I...... lot agn-e ivilh Dr. Kritach ill separ.ating these forms

„ griirnt. a I«r.ili..ii aliicli a|.|K-iirs to me to Ire well taken. Dr. F ritecli s siieci-
■Iieii. include -UIIC ill wliicli the cniiiiii me ill a good state of preservation. These
•li.m liinl llii- rnmlal onruliifen-.- an- not |>ro<hictHl posteriorly into two cornua as is
lli.g willi llie Amerirau a|H*cie« wliich 1 have described troin the Permian

UmaliiMi ttf Texm. iiihUt I lit- generic name of Didymodns? It is evident there-
furr ihni thi* gentm ilistiiK'l from Pleuracattl/ins and should not be united with
It. R* lia* lie«-ii done liv I >r. WiRMlwanl in the catalogue of the fossil fishes above

TELEOSTOMI.

RllIPIDOPTERYOIA.

.M^:^l.\l,l(•|mlYS Abiwm.

MAI Nol^iXI-K. I*UU- XIX, IIk. I.

I*tgw<r«l \ntFt. I’lilh* HiwHrty, iv.rj, |i. iji,

K*lnhlii>lM*d oil the gr«*al«T part of an individual from the Carbonic system of
Kniivn* \\ itii the l•\<•(‘ptioll €»| n short interval just Wiind the head, tiie speci-
men U r«iiii|>|ete ns to its length ; the |>ectoraI and ventral fins are damaged, and
the rxln-mily of the niial is hmken oil. The scales of one side of the body only
■rv vtsihle ill the pn-seiit state of the s|H‘ciiiien, and a good many of those of the
■hfiiHniiinl region nn» |in>|

The geneml rhnmclers timy Ik* enuinernted as follows : The form is slender,
le (KA tm nre Inrge ninl rhoinhic, with rounded extremities. The supratemporal
(rlieekl tones and c.|Kivnln are very large, and are much extended posteriorly.
Tlieeiiantel ,s pn-M-nt on the su|M.ru „f the skull in small and irregular

rinselv •'"* ? the rest of the external surfaces. It is everywhere

and nnniitely nnpres.s<.,hp„„ctate. The bones of the skull are thin and

iKiiijt ohlitemti^l' .n*^ii*** distinguishable for the most part, the sutures

u " •'•' ■■-'D- (-|i.aii..«i.U T™,„i,iir) .m

i - 'oiigoi tiim. the The

l-len.ir bonier of the p«rietrir''Tir t'7'l posterior to the

e tahuhiria are large (supratemporals

AND MESOZOIC FISHES.

437

Traquair). The operciila are very large, and in this specimen they are shoved up-
ward so as to overlap at the median line. Their length enters the total length of
the sknll three and a half times, and is a little greater than that of the parietal
bones. Their superior margin is beveled off from a low longitudinal thickening
from wdiich some low wrinkles radiate downward. Enamel is jrresent on the supe-
rior surface of the skull, on the border of the frontal bone posterior to the orbit, and
on the anterior part of the postfrontal bone. There are grains of enamel scattered
on the parietals. On the supratemporals there are closely placed, concentric, inter-
rupted lines on the superior part, and irregular patches of larger size on the inferior
part. There are large patches of enamel on the opercnla. The superior bones of
the skull are everywhere roughened with minute tuberosities, which fuse into
transverse ridges on each side of the sagittal suture. The maxillary bones are dis-
played partly on the superior, partly on the inferior faces of the specimen. They
are rather slender, and their distal extremities are broken ofi’.

There is a short pyriform s^nnphyseal, entirely closed by the mandibular rami,
and a median gular bone wdiich joins the gularswith a concave suture. Tlie gulars
are large, and measui'e three times as long as wide at the middle. They are cut off
obliquely on the inner side, posteriorly, by the chevron-sha])ed arrangement of the
pectoral scales. Several large external gulars. The posterior e.xtremities of tlie
mandibles are bi’oken so that their proportions cannot be exactly ascertained, hut
the length preserved is six times the width o^iposite the anterior gular. The sur-
face of their inferior portions is marked by coarse impressed punctures besides
the usual minute ones. The former are not present on any other part of the fish

The scales are large ; between the bases of the iiectoral and ventral fins can lx?
counted about twenty-one rows, and between the ventral and the first dorsal imme-
diately above, eight rows. The first dorsal fin is above the ventral, and the second
dorsal above the anal. Thex'e are two large scales on each side wdiich embrace the
base of the first ray of the first dorsal and anal ; the other fins are too imperfect at
the base for description. The caudal fin is shortly heterocercal, and there are six
broad fulcral scales projecting from the side of its inferior border. In all the fins the
rays are segmented. A half dozen rays near the border are coar.se, but the remain-
ing rays are finer. In all the fins the coarse rays are distally subdivided.

Measitremexts.

MM.

Total length of specimen (20 mm. intercalated behind head) . . 9o0

Length to anterior border of orbits . . . 40

Length to posterior border of parietals . . . . .143

Length to posterior border of oixerculum ... ... 230

Length to anterior base first dorsal fin . ... ... 020

Width between orbits ... . ... ... 33

Width of parietals and jTOstfrontals anteidorly . . . ... 38

Width of parietals and pterotics posteriorly . . . . . .75

m

NKNV ANI> l.riTLE KNOWN PALEOZOIC

15

13

120

no

135

85

50

of nuuplivwwl •

ofniiU-riorgiilur

of Kul"*"

of fintt donuil lin

l>*njrth of .niulnl fniin iiift-rior to huik i ioi- Iree apex
of ImmIv lit lir»*t ilonrnl

I). ptlt of limly lit iMH-oml don*al

Tliii. 1* not iMMirlv iillital to tlie Hpecies IVoin the Penman of Texas,

,1/ Coin-, whirli ia mimUer aii.l more robust in form. It has its scales and

|{»ii..iiH*. j:.*iiemnv. iHTf.ftlv siinaitli. and tliere are but fourteen rows of scales be-
m.s.|i III** iM-i-to’ral ami ventral lias. From the European species with punctate
Kmiiiiiie il ililTen* in the lonjier gular Inmes and more elongate head, so far at least
M r»iir«-nii> A/, hiblttrlii and M. laticeps. In M. pygviaus the scales are des-
cribwl a* c«»«»n-*lv lainctale by A. S. Wooilward. Its dinumsions are alxait ecjual
io ili.nn* of M. hiblxrtii. The crescentic <ranoine scales of the muzzle of that
and At mtiiiui arv al»wnl from M. macropotnus.

I owe the o|i|iortniiily of examining tlie iHuiutiful specimen which is descriljed
alaive. to niv friend Mr. H. IL Lucih*, of I’ittston, Penna., whose valuable collection
Ilf |iiileo>oir fo»<ilii iaofftiieh utility to students of the subject.

P CR0880PTERYOI A.

HfKHMATODf.M <!o|k;

Nr«liM4t«a>< • m *11 onl • «»ti. rl. IHrt-, Kl«. 4.

I k^r — lta<Nsl on the led half of a skull, which includes the median ele-

nienls. |Mrietid and frontal nUive, and bnsiiK’cipital and para.sphenoid below; with
maxillary. |>alatine and niandihular bones, and one-half of the branchial apparatus.
TIh- |-..t.-rior la.nler nml iHa.tero-lateral angle of the skull are broken off.

The l^i.«ci,.iinl shows a eotylus for the first vertebra in front of the position
of the l..mmen nm^niim. sine*, the latero-suiH.rior parts of the bone ai-e produced
|Mis|ino \ ay ond ihe c*itx Ins. The axis of the Isuie is almost entire! v ensheatlied
m IlH* |«rns,,he„o,d. u hirh is eniarginate |K,.stenorly. It is elongate and rather nar-

Its anterior fourth is openly
atilenor .".I i.." 7 “'l " I"^'!* connects the lateral with the

filT'-rT n n. nw«nls. A patch of densely placed small pisi-

JrJtiria!" tl>e length, and extendi as

Thov an* m*’i bifurcated so as to avoid the median

' bone on the ac-

t..rih an* .dll-TTatirliT t'ho robust teeth. No

"'-^T is bn.k..n.nn*l ,h*. latt'er

• n* ,s a wHI m«rk,.,| transxvrse gnsiyo at the jiosition of the coronal suture.

AND MESOZOIC FISHES.

439

B

Fig. 4. Spermatodus jjustidosus Cope; A, B nat. size ; a-dx 4. A from above; 3 from
below ; a supposed palatine teeth ; b pustules on the frontal bones ; c do on the nuixillarv ;
d paraspheuoid teeth. 3/a;, maxillary; ih;;, hyomaudibular ; parietal; /ffl, basiweiiiilal;
J^s, parasphenoid ; Bid, basihyal ; CH, ceratohyal ; J, 11, III, eeratobranchials.

NKW ANI) LITTLE KNOWN PALEOZOIC

TIm- limiifliial ii|.|Mir.itUH of basilijal and a series of lateral pieces

wliirh the eeniKiliyal, and three or four ceratobrauchials, according as we

lejfnnl III*- fin.! hitenil element as mandible or ceratoliyal. I wdll iirovisionally as-
sume lli«l ill*- hmnchial u|»|mratus includes a ceratohj al and three ceratobranchials.
The tvmlohyal is single, and is compressed. The ceratobranchials are

ralher *leml*-r. The Imsihyal is ina.x.xive, has a single truncate surface, and resem-
hle» miiim-m lint that of l‘oiyplcrus, but is larger relatively to the other elements.
TIm- iMsibranrliial is hifurrnte |K»steriorly ; whether deeply or shallowly depending on
the iiili'r|m-tnlion we adopt of two fissures which cross each branch sjunmetrically
■ •hort ilisinnee |s»ierior t«» the f<»rk. If these are suture.s, the elements distad to
them an- ill*- (nssiiiinil) tliinl ceratobranchials. The.se elements ai’e flat as in the
nim’s|M>ii<ling |mrls of Potypiffus.

The iN*iil|iliin- of the su|H*rior surfaces consists of minute tubercles of enamel.

The n-M'iiihhinee of tin- *'orres|Kin(ling part.s of this skull to that of Polypterus,
•iigP'sl* lliiil it is a nieiiilM-r of the su|iei-order Crossopterygia. This is seen in all
the isiiiil* nlMi\e desiTiU-d. The base of the .skull is widely different from that of
which I dewrilH-d in 1S83,‘ and i.s one which is characteristic of

iiKHh’ni fiiilic* It n-inains an unsolved problem whether all Rhipidoptervgian fishes
••xhiliil tin- sinieiim' mt u in Megalichthys. The basal elements in Spcrmatodos
differ rroiii those of PtdypUrus in the absence of the lateral processes of the latter,
which siniiil.ile rcverlisl hnsiptcry'goids ; and in the much le.ss production of thebasi-
iavi|Nial «-oiyhis The characters of the basihyal bone, the parasphenoid teeth,
and the rmiiial •s'ldpliire have «*«uisiderable msemblance in the tAvo forms.

i h.,0 .S/Vr//— The gt-m-ral sliajH* of the head is broad and Hat. The occipital
eoiylii. I. circular in ..inline. The parasphenoid tooth-patch has an elliptic posterior

'"»• inea.smv from 4 to -.3 millimeter in dia-

iiM-t-r III.- parasph.'iioi.l is o-o times as long „.s wide at the middle. There are
two nm. .,r uvih. hut whether they are on different bones or on a single

Tit “* tli^^played on the superior surface

11 " I''"-- '■•■‘Pifo™., with acumi-

lu.A ir'" 'I'lwt ata.Kl four i„ a apace of five milli-

U 1 ^1 I T , '"-A-' a millhaetet in .liametcr. In the
1-Mv l; n -igl-' teetl.. The cranial sculpture is

!•«, iim,, il .1, .. i 1- n «il lection of minute pustules. The

HI in till. ltilM.rclf Tl V'l " Out enamel is lost there remains a

1... 11. ■ rlllinri! "" -‘-''-I-'

This face is not di-

With one Uhih siih- lint hi,.] the .tT bichir. It is a transverse oval

■v™-. ..... I Ji: I: becomes

AND MESOZOIC FISHES. 441

quite thin 2iosteriorly. Its anterior extremity is excavated into an oval cujx The
suiiposed mandible is flat, and in a horizontal iMaiie, but is more robust than tlie
ceratohyal. If there were any orbital bones they have left no traces.

Measurements.

MM.

Transverse diameter skull near posterior end of maxillary ; 200

Length of parasjihenoid ; 30

Width of parasphenoid at occipital cotylus ; 25

Width of parasphenoid at middle; 20

Diameters of anterior face of basihyal ; 1 1 1

I transverse; 27

Width of basibranchial ; 9

Length of ? ceratohyal ; 39

The specimen above described was found by Jacob Boll in the Permian forma-
tion of Texas.

ACTINOPTERYGIA.

LEPIDOTIDJE.

MACREPISTIUS Cope.

Maceepistius aeesatus, geu. et. sp. nov. Plate XIX, Fig. 2,

Cha. Gen. Dorsal fin elongate, consisting of niany rays ; caudal fin demi-
heterocercal, with fulcra on the superior border ; anterior to this fin the fulcra are
little different from ordinary scales. Scales rhombic. Teeth on jiremaxillaiy bones,
vomer and palatines, all with obtusely rounded crowns on short jieduncles. except-
ing those on the premaxillary and the opjiosing part of the dentaries. where
they are a little more conic. Usual head bones present, including supraorbitals,
suborbitals and preorbital.

This genus appears to be referable to the Lepidotidce^ , as defined by Prof.
Zittel,^ although the evidence will not be conclusive until the anal and the paired
fins are known, It differs from Lepidotus in the elongate dorsal fin, and in tlie al>
sence of “ meisselfbrniigen Zahnen ” on the jiremaxillary. I jjrojrose that it be
called Macrepistms. I add some other characters which may be of more than
generic significance. The maxillary bone is well ^M’oduced posteriorly, but the man-
dible is jiroduced much farther. The ceratohyal is well developed, and tlie
branchiostegal rays are osseous and robust. No gular nor intermandibular bones.
Preojoercular and other facial bones, unarmed. A considerable fossa anterior to the
position of the ethmoid, which is bounded by an osseous bar on each side ; but

1 Palseoutologie, Palwozoologie, III, p, 207.

^ lu the Aiiiericau Naturalist for 1880 (December) I proposed the names of DatJediidie, Lenidotidm,
Macroeemiidw and Aspidorh.vnchidm, m place of the uauies Stylodoutidie, Si)haTodoiitidie, SfiupKlon-
tid* and Ithynehodontidie of Zittel : names which are not taken from genera contained within them, and
one of which (Saurodontida') Is preoccupied.

NK«' ASU MTTLE known PALEOZOIC

ll.—- i.rc-in.ixillnri'

or not, can not be made out in the prea-

eiil of the i»|iifiinei».

iIh* pciilf* on llieiii an* iilfiiticnl in clinracter.

Tho f.»nii of the ImmIv wiu* apparently fusiform. The radii of lx)th the dorsal
and minUI fin* an* mther finely hninclied at their distal portions. The scales are
•iiliciual an.l an* rather aliarply rhoinhic, ami are arranged in the usual oblique
lanidn. They extend iniieh farther on the iipiK*r than on the lower base of the
caudal An Their (taiioid surface is marked by a few shallow and irregular fossa?,
which are nnm* clo*a*ly a|m*H*«l on the scales near the head than elsewhere. The
scale* an* of nM*diinn six**, and then* an* twenty-three in an oblique row, commencing
at the aupiMMMsl |Hmition of the first ray of the anal fin, and extending upward and
furwanl to the dorsal An. 'I'lie |Mtrtiun of the dorsal fin which is re])re8eiited in the
»|a*rinien c'oiitain* thirty-two rays, or spact*s for them. They are moderately stout,
ainl an* whmi divhhsl.

The head is short. •and the |in*ma\iltnry bonier overhangs the dentary bone.s.
The pniAle desc4>iids "t«*<*ply. anti almost vertically, in front of the orbits, and rises
fnaii the h*»« sloping fnnitnl n*gion to the jMisterior parietal border. The front is
nearly Hat in the tmiisverw* din*4*tioii. The su|K‘rior plane of the skull is formed by
the fniiiUl and imrietal Inniea, and ptemtica ami wcipitals are not visible. An im-

Mr.ASrKKMKXT.S.

MM.

272

117

AND MESOZOIC FISHES.

443

Dej)th of body at a point 115 mm. anterior to base of inferior caudal lobe ; 75

Length of superior lobe of caudal fin from middle of base of fin ; 85

Do. from last scales ; 46

Long side of a scale ; 7

Short side of a scale ; 5

Length of head from muzzle ; 90

Length of head to end of maxillary bone ; 48

Length of head to free border of preoperculum; 74

Depth of operculum ; 4(>

Interorbital width ; 24

Parietal width ; 39

Depth of skull from posterior border of [)arietal to interoperculum inclusive; 78
Depth do. at middle of orbit to dentary bone inclusive ; 53

This species and genus are of considerable interest as representing lor the first
time in our knowledge, the Jurassic family of the Lepidotidm on the North Amer-
ican continent. The generic type is a modification of the typical form, appropriately
to the fact that the horizon from which it was obtained is generally supposed to lie
at the base of the Cretaceous system, and Comanche series, of Hill. Dr. Hill,
through whom 1 obtained the specimen, states that it was derived from a calcareous
stratum which lies betwmen the upper and lower sands of the Trinity series, at
Glen Rose, Texas. Other vertebrate remains obtained by Dr. Hill at the same lo-
cality I determined to belong to a small ci’ocodile. Dr. Hill informs me that numer-
ous mollusca are found at the same hoi’izon, which he has determined to be of
Neocoinian age. Dr. Lester F. Ward has determined plants from the same, to be of
Tuscaloosa (Potomac) age, which is nearly^ Neocoinian. I take the present oppor-
tunity of noting here that several years ago, Mr. Chas. H. Sternberg sent me from
Kansas several teeth from the Dakota (upper Cretaceous) sandstone, which I suspect
to belong to Lepidotid fishes.

PYCNODONTIDJE.

The marine formations of the Jurassic and Lower Cretaceous systems are the
horizons in which species of this family abound. As neither of these formations
is widely distributed in North America, but few species of the family have been
observed by American paleontologists. The only species thus far described have
been derived from the upper Cretaceous formation. 1 now describe live s]tecies
which ivere found in beds of lower Cretaceous age in Texas and Oklahoma.

MESODOX ^Vaguer.

MesODON DIASTEMATTCrS sp. nOV.

Founded on a vomer of an individual of large size, which supports a consider-
able number of the teeth in place. There are five series of teetli, of which those of

58 .lOURN. A. N. S. PHILA., VOL. IX.

NKW AND IJTTLK KNOWN PALEOZOIC

the ....Hlian .m- larger than thone of the lateral rows. There re-
main oiilv four teeth of the median series, and one has been lost,
the eiitiri- munk-r k-ing five. The outlines of their crowns are
^ j -- ohhile findes. the anterior one absolutely circular. They are
^ «.|.unit«*d hv interspaces eijualing nearly or (luite half their fore

V nml art .Iiainetei-s. The teeth of the first lateral row have
L r Hiid snbround crowns, which alternate with those

of the median row, and are therefore separated by spaces equal
to their tiwii diameters. The anterior two median teeth are
ihinkiHl each by a very small tooth of the first lateral row, and
the same is true of the posterior tooth. The number of teeth
in this n»w is thu.s eight. The teeth of the external row are
Isith iipiM»site nml alternate to those of the median row; and they
are ther«*foie in contact and more uuinerous, numbering ten on
each side. Their transvei'se diameter is generally a little
«n‘Mier than their anlen»|>osterior. The lateral borders of the dental tract are
parallel. None of the crowns are inipresseil.

Km. ^

m om-w* (* •!«,
OMiff b4<>s.

.Mk.v.sikkmknts.

of vomer k*hiw :
Widlli €if Vomer k*low ;
Klevntiini :

Ifiameiers of iMmiiltiiiia

.M.M.

77

38

4(5

I anteroposterior;

1 transverse ;

10

12-0

1 anteroposterior ;

7

I transverse ;

7

1 anteropo.sterior ;

1

( transverse;

8

-I-- "Oieii »ne nimve sjH-cies is tounded was obtained by Mr.J.B.

a in witiie terrnne of the I* n‘dericksl)nrg series of the lower Cretaceous system
I L * '** Vf " **f'*'vnish yellow color similar to the Pvcnodonts descrikd

kh.w fn.m near Fort Supply. ^ U was submitted ^o me by Dr. E. T.

Damble. Il.ivrior of the (;,M»l»gic .Sirvey of Texas.

finmUrlVoi^; Pr.K’eed. Amer. Philos. Soo. 1892, p. 128.

hair ami Tl " support.^

ine.1 hy i»lef>|«ees. The exten.niT ' ” pavement, but are separ-

either nHirnl or slightlv tmi

larger and llie rntwim nre nil '** ‘>f' the thii’d row are

nm The ihini i.mih fr^„n tlu"rn”7 *' the third

«lu Iront, ns prc*served, is much larger, but is exceeded

AND MESOZOIC FISHES.

445

by the fourth; while the fifth is half as large again as the fourth. The sixth and
last is a little smaller than the fifth. The teeth of the fifth row are as small a.s
those of the first and second rows, and extend posteriorly to the anterior part of
the fourth row, and not beyond. The crowns of the teeth are perfectly smooth
and without keel or depression.

Measurements.

MM.

Length of tooth series ; 17

“ “ six teeth of external row ; 10

“ “ six teeth of third row ; ILo

“ “ six teeth of fourth row ; 1 0‘5

^ X- f anteronosterior ; 3

Diameters ot fifth of fourth row 1

( transverse ; t

The horizon of this species is not exactly known, but it is probably Lower
Cretaceous or Neocomian. It gives me much pleasure to dedicate it to Dr. E. T.
Dumble, Director of the Geological Survmy of Texas, through whom 1 received the
specimen.

URANOPLOSUS Sauvage.

Uranoplosus aectatus sp. nov. Plate XX, Fig. 8.

Represented by a vomer which supports five rows of teeth in good couditiiin.
I refer it to the genus Uranoplosus of Sauvage,' since it presents the characteristic
peculiarity of the inferior surface. This presents three planes, a median and two
laterals, which subtend an angle of the dental face on each side of the median row
of teeth. These angles divide the grinding face of the most anterior tooth of tliat
row preserved, but fall outside of the posterior teeth. But six teeth of the median
series are preserved, and five of each of the laterals.

There are but five rows of teeth; the small intercalated teeth found between
the larger lateral rows in the type of the genus, U. cotteaui Sanvg..' being al>
sent. The teeth of the median row are enlarged transversely, being about twice
the diameter of those of the adjacent lateral series. Their anterior and posterior
border’s are nearly sHaight, and their grinding faces show, where unworn, a sliallnw
transverse groove. The teeth of the first lateral series alternate or not with those
of the median row, and are a little wdder than long. Their anterior borders are a lit-
tle concave, and the posterior convex, and continuous with the lateral conve.x bor-
der. The crowns are slightly concave w’hen imwmrn. The temth ol the external
row have the outlines of the crowns snbi’ound, and a little smaller than those of tlie
first row; convex posteriorly, and a little concave anteriorly. All the crowns of
the vomer touch each other, with a few slight exceptions.

' Bulletin Society des Sc. hist, et nat. del’Yonne 3d Ser. T. I, p. 47.

2 Loc. cit., PI. I, Fig. 1.

444

NKW AN1» IJTTIJ-: KNONV'N PALEOZOIC

Measlkemexts.

of MTifi* of nix teetli ;

I anteroposterior;

of M-.-OI1.I t.M.tli of iiiuUlle series - .

, . f anteroposterior ;

.. .. •* “ •• seeonu senes

( transverse;

... . ( anteroposterior ;

tliird series ^

MM.

40

6

14

5

8

5

G

This s|H-ri.-s differs fnmi fl coUcaui in other characters besides the absence
of I he inlen-oInl.M t.-elh. Tims the teeth generally are closer together in U.
anIalH*, nml the tmiisvers** extent of those of the median row is greater.

‘riie «»nl\ sjsHMiiM'ii of this sjKTii's known to me was found by Prof. A. P.
of the I'niversity of I’eiinsylvaiiia. who accompanied me on an e.xpedition
uiiileiinkeii ill the interest of the Academy of Natural Sciences during the suninier
of It was found in ii iiiiirine lK*d of Ia»wer (,'retaceous age aljout six miles N.

W. of Fort Sii|i|dy, (fklahoiiiti. This Isal Prof. Brown believes to represent the
('oiiiniiehe Peak lerniiie of the Kivilerickshurg division of the Lower Cixdaceous.

I'Misiiriiim • ri reriix sn •!>. iiiiv, l*Ule Kla. ».

fUtnlilishiMl on a part of a palate from the .same locality' and formation as
I ardttiMi I his votner has the same angulate character as the latter sjiecies and
like it. siipiMirls five s4<ries of t«*eth. It iliffers from U. arclattts in the greater
s|Mriii|t of the l«s*ih, u'hieli an* randy in contact with each other, and in the form
of the |e«-th of the central row. Tlies*- are strongly concave in front, and convex
l«»l..rM.rly. giviiiit the form of a cn-s<vnt. with the horns obtusely rounded. The
sin- is also imieh less, the tmnsversi- whlth of the three median series of teeth,
npiahiiit that of the central m-ries of C arctaius. But .ske alone is not a good
rnti rvin of s|MTifH* iliiYen‘nf*e in fishes. The ci-owns are more worn however, than
Untseof the Imv- sjsries. but this is in part due to attrition in moving water.

• I 'TVi' only repre.sented by fragments. The crowns of

the niHhIle n.w show when- le«.Ht worn, a regularly convex smooth surface.

Uagth of fonrcn.wns of first lateral row ;

Ihani.-ten. of t<s.||i of ,i„.,li„„ ,x,w j *‘'’^<‘''»l>'>»»terior;

I transverse;

BmiiM-ters of I.S.II, „r |ir„, * “iitei-oposterior;

, . , , 1 traiisvurse ;

he a,

MM

16

4

AND MES0Z(3IC FISPIES.

447

COELODUS Heckel.

OoELODUS isRowxii sp. iiov. Plate XX, Fig. 10.

Represented by a iiart of the left mandibular ramus which supports the bases
of five teeth in anteroposterior line. Two rows, are distinct!}^ represented, and a third
internal row is represented bj^ the extremities of the bases of the teeth only.

The distinctive character of the species is seen in great transverse extent of
the teeth of the middle row, and the depressed ledge of the jaw just external to the
smaller external row. The teeth of the middle row are narrow anteroposteriorly, the
long diameter being about two and a half times the anteroposterior. They are in-
clined slightly backward externally. The crowns of the teeth of the external row
are not over half the transverse diameter of those of the second, while of similar
anteroposterior diameter. They are directed more obliquely backward than those
of the second row, and they stand on a convex ridge of the bone, so that their
grinding faces project beyond those of the second row. All tire teeth are in con-
tact. The only crown preserved is rveathered ; it does not display a median de-
pression.

A single separate crown found near the present specimen, may belong to the
same species. It is elongate, transverselj^ gently arched, and its surface is without
depression or sculpture.

Measurements.

MM.

Anteroposterior extent of five teeth of external row ; 24

Diameters of tooth of second row I ^

(transverse; 14

Diameters of tooth of third row I , 5

( transverse ; i

From the same locality and horizon as the two species above de.scribed. The

specimen on which C. brownii is founded was discovered by Prof. A. P. Brown,
to whom I dedicate it with much pleasure.

EXPLANATION OF PLATES.

Plate XVIII.

Fig. 1-5. Symmoriiim renifor7ne Cope, part of specimen de.scribed on pages
428-32, one-fourth natural size. Lettering: Sc, Scapulocoracoid ; P, Metapterygium ;
Eb, epibranchials ; s, skull ; j, jaw.

Figs. 2—3. Symmorium reniforme Cope, mandibular teeth, natural size ; 2—3
from front ; 2a, from below ; 2b, from above ; 2c, lateral denticles, enlarged.

Figs. 4-5. Branchial teeth, much enlarged.

Fig. 6. Orodus basalis Cope, head and part of body, two-third.s natural size.

Fig. 7. Cope, tooth, internal side ; rt, external side ; h. section.

S2iecimens in collection of F. IL Jelliflfe.

NKW ANU LITTLE KNOWN PALEOZOIC

IIS

Pi-atk XIX.

Fifc- I Mtgaluhthys macropomus Cope, side of body and inferior surface of
|,r«a. om*.f..urlli natural size; a, head from alx>ve, three-eighths natural size. From

cullrfliuii II. 1>. lawtH*.

Fig. '1. MacrtpnHus arenalus Cope, side of head and body one-half natural
•iir: colh-ctioii K. I». Co|»e. Fig. 2a, head from above; 2^, mouth left side, some
Itt'iii nupplittl from right side, natural size.

Fib. 3. Lystratanthtis hystrix f N. and W., nat. size; from codec. F. R.
Jellim-.

Pi,atk XX.

Fig*. 1-6. Styptolhisis acuieatus {lo\yo % coll. F. K. Jelliffe. Fig. 1, nat. size ;
Figm much eiihirgiHl ; Fig. 2, ossecjus elements from mandible ; Fig. .3, anterior
liBilli ; I, tiMtliaii, and 6, |M>steriur tooth.

Fig. 0. i)(/t0<ius p/itntt^fHS Vo\n'\ nat. size. Coll. Geol. Survey of Te.xas.

Fig. T-lll. lyrHOfiontidfr, teetlj, nat. size. Fig. 7, Mesodon damblei Cope,
cull. (M-id. Survey Te.xaa. 8, L’ra»oplosus arctatus Cope; Mus. Academy, Philada.
a. L‘. p/rt^drm Cu|m>.iIo. Ill, Coelodus broumii V.o\^v:, do. 8a, 9a, 10a. end views; 8-9,
up|icr •••riea ; 7-10, low er iM»rie«.

ox CYPHORXIS, AN EXTINCT GENUS OF BIRDS.

By E. D. Coi’E.

The genus Cyphornis is established on a species of bird which is repre.sonted bv
the superior part of a tarsoinetatarse. This fragment was obtained bv Dr. (ieorge M.
Dawson from a bed of indurated greenish clay of unknown age from Vancouver is-
land, and is the property of the Geologic Survey of Canada. The tarsoinetatarse
is perhaps the most characteristic part of the skeleton of a bird, but under ordinary
circumstances the determination of the present specimen might await better ma-
terial, owing to its imperfect condition. The early ae([uisition of new material is,
liowever, very uncertain, and as the characters are conspicuously peculiar, the best
course seems to be to give it a place in the record.

The fragment has about the diameters of the corresponding hone in the Amer-
ican ostrich. The shaft is hollow, and is free from cancelli, and its walls are very
thin. The three elements are distinguished by the presence of two septa, whose
position shows that the lateral elements are of uneipial diameters and very much
more slender than the median. The tibial articular surface is im])ertect, the lateral
and part of the posterior border having been broken away, but the greater part of
the internal face remains, together with the proximal end of the hypotarsus. 'fhe
intercondylar tuberosity is large, and the surface posterior to it descends steejily to
the proximal base of the hypotarsus. The external cotylus descends steeply to
the anterior face, and is convex anteroposteriorly, but concave in an open groove
transversely to the shaft. Posteriorly it descends steeply to the hypotarsus. form-
ing a transverse obtuse ridge, wdiich is concave transversely. The proximal end of
the hypotarsus is depressed below the level of the tibial faces. The anterior face
of the shaft is concave, forming a wide open groove, bounded on each side by an ol>-
tuse angle, that on the inteimal side becoming acute above. It is perforated proxi-
mally by’ an enormous pneumatic foramen, Avhich shows only a trace oi vertieal di-
vision at its distal part, deep within its cavity. The external Avail of thiscavity ri.se, s
directly to the angular border of the shaft, Avhile the internal border is separated from
the internal border of the shaft by a ledge-like continuation of the anterior face. The
insertion of the flexor meiaUirsi ixw&ows is of moderate size, and is divided into tAvo
unequal imrts by a shalloAv grooA’e. The posterior aspect shoAvs the basal jiarts of
tAAm hypotarsal crests, Avhich have been broken aAvay. Of these the external is
short and AAode, and the internal is longer and naiTOAver. From the latter the inter-
nal side of the bone descends steeply, and Avith a gentle concavity, and then con-
vexity, to the anterior lateral angular border. Nearer to the internal hyiiotarsal
crest than to the interior border, issues the rather large and subround Internal pos-

ON C'VrUOKNIS. AN EXTINCT

.• .. IL.tu-.HMi the hvpotar.sal ridges is a groove in the

te„ckm of the Hexor digitorum muscl^

..lU, .1... tlH- “f S’'""'- ">y te 'l"--- »ned.

K«u.n..l lo tl,. i» tlu- Imm.l !.»«. tl.o extimal hypotarsal ir«t. It» sulv

.l«,™ i. ««.~ ly .•.•llular, i. n-t t ravers...! by any gro.»ce. Its .nlcrior ex.

InMuily i- hut little lieluw the transverse- line of the inteni.al i>osterior intero-ssettus
formiiK-ii. Kxtemal t.. it is n seeon.l groove, which is narrower than the gnxtve
pit-vienisly il.-scriM. and it is ls.iin<letl exteriiallj by a well-defined, but low ridge,
whirh is cHiiivex |i.»steri»»rly at the inferior part of the groove. PVoin this ridge the
external siirfatv is gently eonve.v to the antero-extenial. Between this gnx)ve and
the iiirerior |*art of the external hyiMitarsal mass, is an oval foramen, its long axis
|Ninille| t<i that «if the lajiie, pnil>abiy the external intero-sseons foramen. The sur-
fsrr of the Isiiie is every when* siniMith.

.Mk.\.s| KK.MK.\T.S.

.\rliinl transverse pmxiiiiai .liaineter;
l{f«|tin'<l diaiiielers of liliial faces

when* Imtken

M.M.

38

22

44

21

24

17

5

6

3 •

( anteroj>ostt.*rior ;

I transverse ;

IHameien. of sliaH when* Im.ken j «"teroi>osteri.,r, at middle ;

I transverse;

I Haiiieien. of niilerior pneiimatie rorainen ^ !

I transverse ;

Wnlth of Iwse .if external hy|HitarsaI crest ;

of iNiseof iiitemni hv|s.larsal cn*8t; 3

Kn.i,, «,M.x orinten*.«Hlylar tiilM-rosity to internal ix.sterior foramen (axial) ; 20

somewhat emharra8se*d bv the
u7s ne ."'“.T- L 'Their very coarsely cellular char'acter

1I.0 .,n,.^r Z iZn" Pid" p". tins bone with

eipilres, f’et'oiiiiirtilin. f*i . ^ '*^oyge.s. Psittaci, Iletcrosmnidyli,* Ac-

.» ...|«.rfivin|. lw\rnZ’'irit”it ,lit"..''^“'^ ‘''""'"i' ,

the first Iiam, Ml. this g,.„„^enn only Ik* P.. ^teganoiKules. Among

crests, which an* the lUieidn* V.m.rv ' 1 h> the genera with two hyjx.tarsal

IhmwnilhHln* the lanminelalarsi. I ff ’ Ih'nornithida'. From tli.at of the
Urge .*iirl.«s.M| pneniiiatic cavity withmit" ^ t«'>mity of its walls, and the

I'cniof the other families it differs in ii y*'**^^‘ ****** From the known niem-

*uigle anterior: ami iM.|a*einIlv imsterior pneumatic foramina, and

' • ■" minced six.. „r .l,c eorrespnd-

•n*. \Vrtrt.«,.. J„,y. ,

1. 1>. .W (Hteai..rnithlda!).

GENUS OF BIRDS.

451

ing posterior foramen. In none of these genera is the exterior tibial surface de-
flected anteriorly, and in none of them is it elevated into a transverse ridge poster-
iorly. The corresponding region in Gastoruis is imperfectly known. So lar as
described by Lemoine,^ it agrees in these points with the other Ratitae, as does ahso
Diatryjna. which has also but a single hypotarsal crest.

Comparison with the Steganopodes shows much greater resemblances. The an-
terior aspect of the bone is almost exactly like that of Pelecamis. The posterior
aspect resembles that of none of the order, in the absence of most of the tendinous
grooves. This part of the bone resembles nearly that of some genera of Callinm,
especially Meleagris, where, however, the tendinous groove is enclosed. This genus
differs from it in every other respect, including the non-pneumatic shaft. Compari-
son with birds of the cretaceous period reveals a single point of resemblance to Hes-
perornis. This is the ridge-like elevation of the anterior part of the external tibial
facet, which is in both genei’a connected with the intercondylar tuberosity. In no
other respect is thei’e any resemblance. No resemblance between this bone and
that of the Dodo can be detected.

If we compare this bird with the Steganopodes we have as points of agreement
the anteriorly deflected external tibial facet, the grooved ])osterior face, the narrow
internal and wide external hypotarsal processes, and the high degree of pneu-
maticity. As additional points of resemblance to Pelecamis we have the huge an-
teidor pneumatic foramen, and the narrow open groove of the external face. The
posterior foramina have a similar situation. But the presence of a single tendinous
groove indicates a wide difference of character, and the transverse ridge of the ex-
ternal tibial facet is scarcely indicated in any genus of Steganopodes.

In view of the above facts we may suspect real affinities with the Steganopodes.
combined with affinities to more primitive birds with a simple h3potarsal structure.
The Steganopodous foot, with its long second digit turned forward as in other ver-
tebrates, is itself the most primitive foot among the Eurhipiduran On the charac-
ters adduced I propose the genus Cyphornis, and name the species C. magnus,
which may be regarded as defined by the measurements and other specific characters
above enumerated. It is saicF that the birds described by Owen under the names
of Argillornis and Lithornis^ from the Eocene London Clay are allied to the Ste-
ganopodes. In none of the throe species of these genera is the tarsometatarse pre-
served. Thej' are all much smaller than the present bird.

The characters of Cyphornis indicate that the bed from which it was obtaine<l,
is not older than Eocene nor later than Oligocene.

As regards its habits it maybe said that the pneumatic character of its foot bone
renders it improbable that it depended on this member for habitual locomotion on
land. In all the birds of terrestrial habit which I have examined, and of which I can gain

‘ Recherch&s sur le.s Oiseaux fossiles des Terraiues Tertiaires iufeiieur.s ties Kinin.iiK de Kcuuh, PI.
I, p. 53.

2 By Lvdekker in Newton’s Dictionary of Birds, I. p. 283. . i .>j c- t- i

’Annals and Magazine of Nat. History, XIV, p. 26.3. Trairs. (leol. t?oc. London, 2d Ser., \ ol.
VI, p. 206.

59 JOUEN. A. N. S. PHILA., VOL. IX.

ON CYPIIOUNIS, AN EXTINCT

.1..- i. cither tilled w.tl, aetcellou, t,»»ue de,

the ..II. ..r the .h»rt ..n- thick, .. in the Emeu. The presutned nfhn tv tv, h the

...e.,...„..le. huhit., and probable capacity lor Hlght. .Shcld

huv.. IK.-II i.. Cyphornis magnus,\i will liave been much

lilt, larv'i.iii bini of IliL'Iit tliiiH far kiimvii.

EXTINCT BOVID.E, CANID.E AND FELID^ FROM THE PLEISTOCENE OF THE PLAINS.

By E. D. Cope.

During an expedition undertaken in the summer of 1893, in the interest of the
Academy of Natural Sciences, I obtained some mammalian remains from southern
Kansas, and western central Oklahoma, which add to our knowledge of the latest
extinct fauna of those regions. At Wellington, near the middle of the southern
part of Kansas, I obtained an almost entire mandible of an iidult Elephas pri7ni-
genhis with the third molars only present, and half worn, said to have come from a sand
bed on the western border of the town. Accompanying it were fragments of the skull
of a large ox related to the bison, which is described in detail in this paper. From a
similar sand bed on the eastern edge of the town, 1 obtained fragments of bmies and
a tusk with a molar tooth of the mammoth. From a locality about fifty miles west
of the town of Hennesey, Oklahoma, I obtained teeth and bones of the mammoth ;
and associated with these were the teeth and part of the skeleton of a saber-toothed
cat as lai’ge as a lion. The man who found these fossils informed me that the bones of
the cat were mingled with those of the mammoth, and were generally on them, as
though death had overtaken it while feeding on the carcass of the mammoth. This
feline is the subject of a description in the following pages. The Oklahoma fossils
are stained with the red ? Permian clay of that region, more or less of which ad-
heres to them. This formation would furnish the material for any later deposit of
a local character, or would become sufficiently soft in wet periods or places to engulf
or overwhelm animals of the land.

CANIS Linn.

Canis indiaxensis Leldy, Jour. Acad. Nat. Sci. Phila., 1869, 368. Cunis prmKunm \x\<\y . Pnv
ceed. Acad. Nat. Sci. Phila., 18-54, 200 ; Jour. Acad. Nat. Sci. Phila. 18.56 III. 167. PI. II.

Fig. 11-12. Plate XXI, Figs, 14-16.

Portions of the superior dentition of a large dog were found by Prof W. F.
Cummins, in the Equus horizon of the Tule Canyon, on the Staked Plains' ot
Texas, and submitted to me for determination. Considerable interest attaches to
the specimens, for the larger Carnivora which were associated with the horses,
camels, etc., of the Equus Fauna, have been hitherto unknown.

The teeth indicate a dog of considerably larger dimensions than the wolf, and
one differing from it also in the relatively greater anteroposterior diameter of the
first superior true molar. The dimensions a little exceed those of the typical speci-
men of Canis indianeiisis of Leidy, which 5vas described from a right maxillary

1 See Annual Report of the Geological Survey ot Texas for 1892 ; Report on the Vertebrate
Paleontology of the Llano Estacado by E. D. Cope.

454

EXTINCT BOVID^, CANID^E AND FELID^

bone with teeth from Indiana. On comparison with Leidj’s type which is in the
museum of the Academy of Natural Sciences of Philadelphia, I find the following
differences :

The second premolar is distinctly longer, and the external cingulum is much
weaker. In C. indianensis this cingulum surrounds the crowm posteriorly, and here
in the present species the trace of it is especially weak. The internal root of the sec-
torial (first premolar) is inserted opposite to a point wdiich marks the po.sterior third
of the tooth in front of it, while in C. indianensis this alveolus is opposite that of
its paracone. In the first true molar the protocone is more conic than in the Texas
dog, having a round section, while in the latter it is lenticular. The external cin-
gulum in the Texas dog is weaker.

The specimen from the Staked Plain belongs to an older dog than Dr. Leidy’s
type, which partly accounts for the weakness of the external cingula. I am in-
clined at present to regard it as an individual of the same species, suspecting that
new material will confirm the reference. Leidv has referred a lower jaw from
California to C. 'indianensis. This species and Dinobastis serus represent the larirest
Canid® and Felidm of the Ecpius bed respectively.

American Naturalist, 1893, p. 896.

Generic ^ character far as preserved, the parts agree wdtli those of the genus
Smilodon, with one exception. This is that the superior sectorial tooth iiossesses
no internal root, not even a rudiment. The protocone is wan ting in Smdodon, but
its comspondmg root is present, but in this form the root also has disappeared, so

that it may be regarded as presenting its last stage of specialization in the cats, a

circumstance which is appropriate to its late appearance in time.

DINOBA.STIS SERUS Cope, loc. dt. Plate XXI, Figs. 1-13.

The known remain of tills species include parts of three metacarpals three

five mcsots two superior canines, .and two molars, one of them tiie snm.rior sec
orfcXoTtrfrnXotX"^^^^^^^^ Macained fun size, hut the opiph.vsis
lion {Uncia leo), of the same ao-e • m H +1 ’ ^ are ecpial to those of a

those d Smilodon LeidV and f^tl

Lund, of South America. ‘ smaller than those of A. neogcrus

Specific characters. — The mulno +^,^.+1

crowins, a little more convex on the external compressed

edges are finely serrate Then + n i internal face. The cutting

,f^^.«in thatiUurnsinwmrdtowLrthebaS of Smilodon neo-

S. neogceus this edge is not incurved rp. ^ presenting inward. In

ior basal lobe and a laidimeiit of n 1

tain the importance of a lobe as itToL ^ ^'iterior base. The latter does not at-

terior to the paracone forms ’about one-Crtl/oft/’

uitli of the longitudinal extent of the

455

FROM THE PLEISTOCENE OF THE PLAINS.

crown ; in S. fUalis, it forms about one-tliird. The paracone is prominent, and
is strongly convex on the external face. The metacone has a nearly straight edge,
and its external face displays a shallow vertical groove near the middle. The long
diameter of its base is 1-5 as great as that of the paracone. The crowns of the ex-
ternal incisors are oblique, and slightly incurved ; they have robust cutting edges,
which are finely serrate, and no basal lobes. The incisors 1 and 2 have small conic
lobes at the base of the crown, which are well separated from each other at their
bases. Those of I. 1 are subequal, while the external of 1. 2 is smaller than the
internal, md nearer the base of the crown. The crowns proper of 1 and 2 are
acutely conic with semicircular section, the posterior face being fiat. The edges of
I. 2 are feebly crenate ; those of I. 1 are smooth.

The raetacarpals represented are II, IV and V ; of these No. IV is best pre^
served. It differs from that of the lion in the smaller transverse diatneter of the
head, and in the fact that the superior face of the diaclasfi is nearly continuous
with the proximal or unciform surface. The shaft is quite as robust as that of the
lion. The shaft of the fifth metacarpal is on the contrary more slender. Its section
is a triangle with convex limbs, and the obtuse apex external. The piholanges have
forms and proportions similar to those of the fifth digit of the lion. The second
phalange is a little shorter’, and the margins display but small traces of the bases
of the sheath, which has been broken off Otherwise the ungual phalange resem-
bles that of the lion.

Measuremexts.

Diameters crowm superior canine

Diameters crowm I. 3

longitudinal ;
transverse ;

MM.

22

13

80

28

12

35

Diameters superior carnassial | ygrtical
rlimnpt.or of head of feinui ;

Diameters superior carnassial

paracone ;
inetacone ;

Length of phalange ? V, 1

? Y, 2
? V, 3

40

22

15

10

11

38

24

22

U

For explyuytion of this ^

of the Geological Survey of Texas, 1892,

Report ofVwtebrate Paleontology of the Llauo

456

extinct BOVID.E, CANID/E and felid.e

This species, which I propose to call Dmciask serus, increases the number of
P&locene Felidre to four. The three other species are Smdcdon fatal, s Leidy,
X. gracilis Cope, and Felis atrox Leidy.

Bos CRAMPIAXUS Cope, sp. nov. Plate XXII, Pigs. W.

Founded on that part of the skull which is anterior to the orbits, the greater
part of the left horn-core ; and a smaller part of the right horn-core.

The muzzle displays characters simihar m general to those of Bos amert-
canus, including the concave palate and the incurvature of the alveolar border an-
terior to the premolar teeth. Thenareal borders are also similar to those ot that
species, and the nasal bones are not generally difterent in form. Their extremities
are lost in the specimen, as are those of the premaxillary bones. The expanse to the
anterior orbital border is such as to render it evident that the width of the cranium at
the orbit is greater relatively and absolutely than in B. americanus, the orbital
border itself being broken away. The species is especialy distinguished by the great
size and peculiar form of the horn-cores. The entire left core is preserved, exeejit
that some pieces have been lost from the inlerior side, and the basal border is Avant-
ing. As it is, the fragment measures twenty-nine inches on the chord of its curve,
or nearly three times the length of the longest core of the American bison vA'liich
I have seen. The latter, which is part of the skull of an old bull in the museum
of the Academy, measures eleven inches in the chord.

The hom-core is strongly curved, the apex pointing upAvards and forwards. Its
diameter diminishes regularly to the subacute tip. The surface is coai’sely grooved
longitudinally, the widest groove being on the posterior face. The posterior face is
flat from near the base to the apex, the flattening being most conspicuous on the
distal two-thirds of the length. It results that the section of the core is a triangle
Avith a broadly rounded apex. A flattening of the superior face of the last ten
inches of the length is at right angles to the posterior face, and forms Avith it a
prominent angular ridge. The section at this point has a convex and tAvo flat sides.

The great size of the horns renders comparison necessary with Bos lah-
frons only. The museum of the Academy^ contains the fragment of the skull from
the Big-bone Lick, Kentucky, described by Leidy, Avhich supports the basal third
ot the left horn-core. This specimen offers no trace of the flattening characteristic
ol B. craniptanus. The only perfect cores of B. latifrotis knoAvn to me are
contained in the museum of the Society of Natural History of Cincinnati. They
Avere found in a gravel bed in southern Ohio, and are figured by Dr. J. A. Alleiff in
his monograph on the American bison. These horns (from both sides) are repres-
ented as having a sub-circular section, and are without flat planes at any part of
t leir length. The curvature is less, but this character may haAm a considerable
range of variation.

' Memoirs of the Museum of Comparative Zoology, Cambridge, iMass.

FROM THE PLEISTOCENE OF THE PLAINS.

4') 7

This species is dedicated to Mr. Charles Cramp, of Philadelphia, who is as well
known to the scientific community for his benefirctions to our institutions of re-
search and education, as he is to the general public as the most extensive builder of
ships in the United States.

The dimensions of this species are as follows :

Measurements.

MM.

180

140

100

300

720

150

95

130

90

Vertical diameter of cranium at posterior end of diastema ;

"Width of palate at diastema;

AVidth of nasal bones at posterior border of nares ;

Probable width at preorbital border ;
liength of horn-core on outside curve ;

Anteroposterior diameters 1

ir 1 r i fat base;

' Ut middle;

Professor Leidy regarded Bos crassicornis (Richardson) from Alaska, as
identical with his previously named B. antiqmis, a conclusion confirmed by Dr. J.
A Allen. Leidy subsequently regarded this B. antiqmis as identical with B.
latifrons of Harlan. AMith this identification Dr. Allen does not agree, but he holds
that B. antiqmis is a large race of B. americanus. The material in the pos-
.session of tlie Academy entirely coiilims Dr. Allen’s views. None o. these forms
possess charactci-a of the B. cmmpimm. Those who i-egari the group Bison a.
a distinct genus, will call this species Bison crampianus.

Bos .SCAPHOCEEAS HR. uov. sp. Leidy, Proc. Acad. Nat. 8ci., PhUa., 1886, p. 275.

A horn-core of the left side represents this species. A smaller core which ac-
conipiies it. and which was found with it, presents the
spicuous degree, and may probably have be onged to a con ^ |

Horn a formation in the n-thern i^rt of Nmart^a to winch

made l.y Leidy Hydrochoerus and Megathernm.

of Equus, Bos.Elephas

As Leidy observes, this locality ^ ^ southern station on the

don previously known. I n ou t . previously

American continent for B/cp/uis . , fauna is interesting as furnishing

found south of the valley or r exico. Pampeanof South Aintwica and

a geogi’i iphical and faiinistic are here found with Toxo-

the Equus bed of North America, s Elethas is not distinguishable from

don .m,d Meiothenu,n. The mngle l» * of n,;,, p,„ted form

that oi E.primigenius americanus, ^ America rather than the heavy-plated
which lived in the eastern part ol i>oi ’ ^ of

tvpe which prevailed in Texas or Mexico.

458

EXTINCT BOVID.E, CANID/E AND FELIDAE

a different species from that which is indigenous to North America, and I accord-
ingly describe it under the above name.

The horn-core of the supposed bull is very robust, more so than in Bos ameri-
caniis. AFhile the length equals and possibly exceeds a little that of the existing
species, the diameters, especially at the base, much exceed the corresponding ones
in that species. The horn is also more strongly recurved. These characters would
not indicate more than race diversity^, but the shape of the core is in other respects
entirely peculiar. The transverse section is a triangle, the apex representing an in-
ferior median angle, while the base is the section of the concave superior face. The
plane of the deep anterior face of the horn produced, meets the plane of the superior
face at an acute angle; while the plane of the posterior face meets that of the su-
perior face at a right angle. Both anterior and posterior superior angles are
rounded, the posterior the most so. The superior surface is flat throughout most of
its length ; rounding off conspicuously only at the base. The surface is not much
grooved, but there is a shallow open sulcus on each side of the inferior obtuse
median keel. There are several sharply defined parallel grooves near the apex on
the superior face; the median commencing near the middle of the length, the
others more distally ; all issue from foramina. The small arterial foramina and
grooves of the liosterior side, are in lines at right angles to the axis of the skull,
and therefore form an angle with the outlines of the core.

In the supposed cow, the characters are not so pronounced, but the keel of the
inferior middle line is prominent nearly to the base. On one side of the keel is a
long and strong sulcus, and on the other are two similar sulci, and a third short
one. The superior face is strongly convex. In both cores the apex is broken away,
give the length of the larger core as I restore it.

Mea.surements of Core No. 1.

-MM.

420

292

97
113

98
80

Length on outside of curve, restored ;

Length of fragment on inside of curve ;

Diameters of core near base | ''epical;

( transverse :

Depth of anterior face 100 mm. from base ;

Depth of posterior face 100 mm. from base ; g(

much more S\hrs\elt?r^arr7^^^ «P'vards, and it is evident thai

have been incurved at the a'pex.^^ americamts, and may probably

others from this locality anrforinaV^^^^^ pi'esented, together with the

Dr. B. F, Guerrero- and I am ’ n i i University of Pennsylvania, by Mrs
examining and determining them! ^ authorities for the opportunity oi

FROM THE PLEISTOCENE OF THE PLAINS.

EXPLANATION OF PLATES.

Plate XXI.

469

-13. Dinobastts serus natural size.

-5. Superior dentition of left side from without; do. from inner

Premolar ; a, apical view.

Fourth metacarpus from front ; ya, inner side ; jb, proximal

Fifth metacarpus from front.

Distal end of ? fifth metacarpus, from front.

First phalangeof fifth digit from front ; /oa, do. from distal extremity.
Second phalangeof fifth digit; iia, proximal extremity ; iib, distal

Ungual phalange from above ; 12a, from side.

Head of femur, nat. size, from head; a, proximal view.

46. Canis indiamnsis Leidy ; natural size.

Superior canine, from external side.

Superior molars from below.

Premaxillary bone with incisor from inside; 3a, do. from front.
Plate XXII.

Fig. 1. Bos crampianus Cope; anterior part of cranium with left horn-core
from front and jepthorn-co^^

Fi". 3. Do. section at middle of length.

Fio- 4. Section at 75 mm. from extremity. rntnral size

Figs. 5-9. Bos scaphoceras Cope, lett horn core,

Fig. 5. Posterior view.

Fig. 6. Anterior view.

Fig. 7. Superior view.

Fig 8. Section near base.

Pi* 9. Section proximad to first distal fr^ture.

Figs. 1-
Figs. 1-

side.

Fig. 6.
Fig. 7.

extremity.

Fig. 8.
Fig. 9.
Fig. 10.
Fig. 11.

extremity.

Fig. 12.
Fig. 13.
Figs. 14-
Fig. 14.
Fig. 15.
Fig. 16.

60 .TOUBX. A. X. s. PHILA., VOL. IX.

THE STRUCTUEE AND RELATIONSHIPS OF ANCODUS.

461

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

By W. B. Scott.

(Investigation aided by a grant from the Elizabeth Thompson Fund of the A. A. A. S.)

It might well seem that after the extensive investigations of Kowalevsky (No.
3) and Filhol (No. 1) any detailed description of the structure of this genus would
be entirely supertluous. This, however, is far from being the case. The Kuropeiin
specimens are made up from scattered bones of numerous individuals from widely
separated localities (some of which bones would appear to be incorrectly referred to
this genus), which by no means give a complete account, of the osteology ol the mmi-
erous Old World species. In the second place, it is very desirable to establish the
points of resemblance and difference between the approximately contemporaneous
species of Ancodus in America and Europe. In both continents the genus is con-
fined to the (upper) Oligocene and has, therefore, but a limited range m tune.

Hitherto little has been known of the American species of Ancodus, because ol’
theB- rarity and the fragmentary condition of most of the specimens, since only in
the recently identified Protoceras-beds are they at all common. Leidy was the brst
to announce the presence of the genus in this country; he described part of the
dentition of a White River species under the d Hyopotamus americamis No.

5 p 202) Marsh has given an extremely brief account of another species winch
hVna, J H. defiectus (No. 6, p. 024). Both of these ,pc<:i» are from the , tao
therium-beds at the base of the White Eiver g.-o„p. In lOOo '

the manue of a epecies from the Protoceraa-bede at the sunmntot he ' ■ •

Shotvina that it possessed a weii-developjed pollex (N... J, p. llw). t'sl,,.iii ,nii
Wortmaa ha.e recently described .,ul figured a line

eehieh eras coiieeted in t^ ^ t H ti::"!;* ---

and have also added to the Araciic oiQ-^oi Ho- (LA and B).

ture dealing tvith tine f ‘ Dakota by the Prineetoa

In the e^pteattons of ti e h.tejwe, ^

Expeditions ol lSdo and U JT) , sandstones of the Prolo-

:Lt-;:Zld IcMir subject of the following description. These speci-

462

THE STEUCTURE AND RELATIONSHIPS OF ANCODUS.

mens display several interesting constant difi'erences from those of Europe, as figured
in the works of Kowalevsky and Filhol. The most important specimen comprises
the skull and lower jaws with the greater part of the skeleton of an old individual
which maybe referred to the A. brac/iyrhytichus oi Osborn and Wortinan, though
there are some differences, perhaps sexual, from the type of that species.

I. TH15 DENTITION.

The dentition differs but little from that of the European species from the
Oligocene of Ronzon and Hempstead, and the formula is the same. Osborn and
Wortman report that in their specimen of A. amerua7ms the first upper preinolar
is absent, but it remains to be determined whether this is more than an individual
character.

A. Uppti' Jaw. — The incisors are large, of hastate shajie and nearly uniform
size. Their arrangement is most like that of A. leptorhy7ichus, the median pair
separated from each other by a considerable interval and presenting forward, the
second and third nearly at right angles to the first, and presenting laterally. In A.
americmius the incisors are implanted quite closely together, while in A. b7'achy-
rhynchus VciG\ are spaced well apart. The canine succeeds the lateral incisor alter
a short diastema, as is also the case in A. velamms, not as in A. Aymardi or A. lep-
torhynchus, after a long interval. The crown is small, not much exceeding those
of the incisors, but longer, more slender and pointed. It is much smaller tlian the
peat, curved, tusk-hke canine of A. leptorhynchiis, though not so much rediu;e<l as
in the other two species of Ronzon, in which, according to Filhol, it has th(> form
of p. tliongl, dist.nctly smaller. How Ihr 11, e .liirere.icos betrvee,. tlio suppose, I
.species ol Rouzoii, rogonliiig llie fern, and size of tlie eiiiiiin.s. ai-e sexual, eainiot at
pi-eseal be defer,,,,,, ed, tboagl, it is sig„ific,,„„ ,l,a, of ,|,e s,,,.,-!,,,,.,,., so far

il" I'yo “>"',08 comparable ii, size to tl,o.se of A. Upiorl,y„c/ms.

two '.’''“y*’'”’*''™ 1 '-e,-,. 8, nail, si.ople tool!,, i.aplaoled by-

two doergmg laogs and will, a coinpresse,! conical c,-ow„. Its posili,,,, is soblect
o soiae v.irial,,,,, „, die different specimens of A. brachyrhyuchm : in the type it

these, and especiallv in A J f ["''"'I of the Ronzon species. In

rated. In A. a77ie7'icami^ wE 1 ' species pi and p: are also widely sepa-

caniues and the nremola.l I?’’ 'j^^t'veen the

gulum than is usual in them It is of prominent cin-

intotnal dngnlm.,, im f™! !’ witl, st,-„„.dy developed

It may be sep.arated from lliat tooth bv » 1 “y*’ “ '"V ho in contact wit I, ]>?, or
extended than in Aymardi TP T, ■ however, is much less

■ >n.a,d,. The th.rd , wen, oh,, i, like the second, hot larger

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

463

nnd especially wider. A strong cingulum surrounds the crown, which is particularly
prominent on the inner side and at one point broadens to form an incipient deute-
rocone. The fourth premolar is shorter and wider than tlie third and is made up,
as in the selenodonts generally, of two transversely placed crescents; a prominent
cingulum encloses the crown on three sides, being absent from the external lace.

The molars increase regularly in size from ml to ml; the former is protruded
early and always shows more extreme abrasion than any other of the iiermanent
teeth. The pattern of these molars is too well known to reipiire any description,
and differs in no point of importance from that found in the European species.
There is a certain amount of variation in the development of the cingulum ; in
some specimens it is strongly marked on all sides of the crown except the internal,
while in others it is interrupted upon the lingual laces of the two internal crescents
{proto- and hypocones).

B. Lower Jaw. — The incisors have broad hastate crowns ; the second is con-
siderably the largest of the series, and the third the smallest. The canine follows
the incisors without any diastema longer than the spaces which separate those teeth;
its crown is shaped like the incisors and is smaller than the second of the series.

The preniolars are of compressed conical shape, and of quite simple construction,
except in the case of pj. In none of the specimens is the crown of pq preserved,
but the alveolus shows it to have been smaller than in A. Aymardi, and that it was
supported upon a single fang. This tooth stands isolated; the space which separates
it from the canine is slightly longer than that which divides it from p)2- I he latter
is relatively small and is compressed, with sharp front and hind borders ; faintly
marked anterior and pjosterior fos.sa' are visible on the inner side of the crown and a
postero-external one also, bnt there is no cingulum. This tooth is inserted by two
roots, and in some specimens from the upper beds it is distinctly separated irom piii,
though not in others ; it suffers much less from abrasion than the other premolars
of the mandible. The third premolar is much larger than the second, particularly
in the antero-piosterior direction; it is like the latter in shape, but the inner foss®
re better marked and an incipient deuteroconid makes its appiearance. The fourth
remolar is the largest and much the most complicated of the series; deiitero- and
.aracoiiids are distinctly developed .and enclose a deep valley, ion.img an opiai
rescciit with the protocoiiid ; the posterior fossa- arc both enclosecl, the miter o
by the cingohim and the iiiaer one by a ridge descending from tlie _

FUbol's figures show this tooth to be of considerably simpler eonstmet.on

Xl'mis reipuire no p,articular description. As in the
crown is composed of four h.comp«e ^ Inf m tvt [^di’lnd

STs V ^

ferent species and even m individuals.

pr
piarac

464

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

II. THE SKULL. (PI. XXIII, figs. 1-3.)

It is not practicable to compare in detail the elements of the skull in the
American and European species, because of the imperfect preservation of the hitter.
In Europe entire skulls have been found only at Ronzon, and of these Filliol says:
“ Malheureusement, comme pour tons les autres cranes dont je parlerai dans la suite
r&rasement subi par les os a 4te tel, qu’ au milieu des lignes multiples correspoii-
dant aux points de rapprochement des Eclats, il est absolument impossible de
retrouver une trace bien d^finie de suture.” (No. 1, p. 99.) Comparison between
the skulls of the species of Ancodus found in the Old and New Worlds, respectively,
must therefore, for the most part, be confined to the general form and proportions’
111 the fossils from Ronzon figured by Koivalevsky and Eilhol the skull is
remarkably long, low, and narrow. This elongation does not aflect the cranium so
much as the face, for the orbit is placed rather far back, with its front mar-* in o\'er
nr, while in Oreodon xi is over m!. The muzzle in front of p? i.s especiaUy con-
cerned m the elongation, and in A. leptorhynchiis it reaches an astonishing de<- rce
o length and slenderness, while it is least extreme in A. velauiius. The length of
the_ muzzle is materially increased by the elongation of the premaxillaries. which
pioject much m front of the canine. The cranium is not very long, as is indicated
by the position of the orbits, and is narrow and of small capacitv. The occiput is

border of m?. A. leptorhyndm^Ax t^-^'W»dnig to the hinder

opposite to the posterior half of m« wMlfin 7Z

molar series. The palatal a is entirely back of the

slightly inflated. The mandible haTo auditory hiilhe are but

and ,i large prominent angle with' “,™, "'“'’r “•‘"''lll'Oii.rreoiital riiiniis

nel.ativel, little above the . t

triang„larsl,.a|,e. The masseterle foe “'’“‘“‘tl lf<*™s is low and of

The AnreHoan spec“)r™ Urn Fm 'T' J""'-

have been enumerated. In 2 ITerfZZZZ characters which
little less so than in the shortest-headed of the R elongated, but

brachyrhynchiis has a face of only morlc r i species, A. velaunus, but A.

in this respect to “'."“I,'"-- " ‘‘

more rounded and capacious, and the 'f; ^

marked. The forehead is much wider and profoundly

considerably longer. The zygomatic arch is processes of the froiitals .

curving more downward in its course to tC „“ Tl

t- I he occiput is low and broad,.

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

but the posterior surface of the supraoccipital is deeply concave and overhanging
and projects beyond the condyles much naore decidedly than in A. velaunus, show-
ing a tendency to the formation of wing-like processes, such as occur in the oreo-
donts. The anterior nares are small and have a less oblique position than in the
European species, presenting more directly forward. The posterior nares open very
far hack, the palatines being in contact for some distance behind the line of the
molars and forming a narrow tube suggestive of aquatic habits. The tympanic
bullm are decidedly larger than in any of the species figured by Filhol and of quite
a different shape. The mandible has a higher coronoid process, of a shape entirely
unlike that of any of the French species, more resembling that found in the rumi-
nants, with a deep and regularly curved sigmoid notch; the masseteric fossa is
deeply impressed. The size and shape of the coronoid process and the relative
length and slenderness of the horizontal ramus of the mandible vary considerably
in the different American species.

The White River specimens of Ancodiis permit an exact determination of
most of the bones of the skull, as the European ones do not. A careful description
of these elements is by no means out of place, because the skull structure ol the
Anthracolhcrium group is still little understood and much depends upon an

accurate knowledge of it.

The basioccipital is not broad, but heavy, and subcyliiidrical m shape, tapering
soine>vl,at tmv«rd tlie anterior end. Near the eonJjle! no tubercles are developed,
but a large pair, tvitli roughened surfaces and of oval shape, appe.y on the hone
hot ween the auditory bulUe, and are separated from each other by a shallow groove.
Oil the sides of the basioccipital are depressions to accoiinoodatc the laigel) in-
III, ted Ivmpanios. The exoccipitals are low and very b,«d ; in the ‘ “

cerebeliar fossa form., a broad convexity, on each side ol winch ,s a sliallm do] Rs-
.sioi, while the wide lateral portions are slightly concave n, the transverse direct,,,,,.
Tlie'foi-aiiien iiiaomiiu is relatively small and of subcii-cular outline. R con ,y os
•f . vriie Tut !!; no oreirt vei-lieal height, and they do no. pmject so ,n,,el, helow

wmrd upon tubercles of the Uisioccip ^ suilliiie in shape; they stand

The paroccipital processes are ruminan • j ^^^e not cm

well in advance of and exterior te the “ f ij, to

by ridges. wTh the tym.

slender and elongate piismatic lo . 1 opening of the stylomastoid

panic bullm at two points, between »>'■“' ^ the conriiiuation of

Lramen. A gmove on the anterior ace « ^ ,3„„„ri„r siirfaco is

this canal. The supraoccipital is rat p^^power lateral depressions which

concave m the middle, with two smaller the occiput is

are separated from the Terhangs considerably behind the plane of

htrirpoTlon „Ahe s- T,.e wlng-Uho processes

466

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

of the supraoccipital are less developed than in 0. Culbertsoni, more so than in (9.
aracilU The upper margin of the bone is arched regularly from side to side and
slightly notched in the median line. In this region, also, is considerable develop-
ment of diploetic structure, separating the two tables of the bone. Even in young
specimens it is by no means easy to determine the position of the sutures between
the supraoccipital and the parietals; the former appears, however, to take part in
the formation of the cranial roof to about the same extent as in Oreodon and otlier
primitive artiodactyls. Comparatively little of the lambdoidal crest is formed by
the occipital bones.

The basisphenoid is a heavy, subcyliiidrical bone, shaped much like the basi-
occipital, but narrower and with an uninterrupted ventral surface. Its junction
with the presphenoid is concealed by the vomer. Both the basisphenoid and the
basioccipital, aside from the large tubercles on the latter, have very much the liirin
and proportions seen in Oreodon. The alisphenoid is well developed; its ascending
jiortion is narrowed at the base by the foramen lacerum anterius and foramen ovule,
which are placed quite near together, but above these it widens out. The ptery-
goid process is stout, but of no great vertical height; it has the peculiarity of ex-
tending to the auditory bulla, with which it comes in contact and thus encloses
the foramen lacerum medium in a deep fossa. This is an unusual feature. The
presphenoid is not visible, being covered up by the vomer, and the limits ol' the
orbitosphenoid cannot be made out with certainty in any of the specimens.

As in the primitive artiodactyls generally, the parietals are extremely long
and make up most of the roof of the cerebral fossa. For the greater part of their
length they unite to form a high, thin sagittal crest, which is gently arched from
before backward, rising both from the forehead and the lambdoidal crest; anteriorly
it bifurcates into twm low and slightly roughened temporal ridges. The parietals
themselves likewise diverge at this point and receive between them a tongue-shaped
pro ongation of the frontals. For most of their course the parietals are nari-ow,
the arge size of the squamosals preventing any great expansion laterally. In H-ont

Let rpTeLoilir™''’

“ *''‘*'*‘ P”' “*■ '™'l Of ‘I"-' “■■anial

laLdliial "’“''S'" “P n-e

dude! til neriotie f J 7 '7 exoccipital and squamosal almost entirely ex-

slidit foS! skull, butinferiorly thetwoelements diverge

^ the periotic is exposed

process of the squamosal is closely appliertothV'" tubercle. The posttympanic
below the tube of the auditory meal; The extends

backward and is separated only by a narrow slf ^ strongly

region of the skull is very silla^r indeed 7 n T ^ P‘>d tympanic. This
gracilis, in which the postdennlrl • Oreodon and especiallv of O.

w»,'. The "'7 «».. in d C„/-

y large, extending nearly the full width of the xvgo-

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 467

matic process, and is plane transversely; antero-posteriorly it is made concave by
being continued upon the postglenoid process. The latter is long, stout, and taper-
ing d^tally to a blunt point, and thus has an entirely different shape from that of
Oreodon,m winch it is broad, massive, and of uniform height. The zygomatic
process is very like that of Oreodon-, its root is much extended in the fore-and-aft
direction, reaching over the auditory meatus and posttympanic process, its raised
outer border passing into and continuous with the lambdoidal crest. The zygomatic
process itself is thin and compressed, but has considerable vertical depth ; it arches
downward and forward, pursuing a less straight course than in the Eonzon species.
Anteriorly the process tapers to a blunt point which is received into a notch of the
jugal beneath the orbit. The zygoma is not so long as in Oreodon, which has the
orbit considerably farther forward, but in other respects the resemblance is close. In
Oreodon the contact of the zygomatic process with the jugal is shorter and hence the
former is less attenuated anteriorly.

The jugal is quite a massive bone; beneath the orbit it is deep vertically, but
gradually tapers backward, where it passes beneath the zygomatic process. It is
relatively longer than in Oreodon, and is not separated from the glenoid cavity by
so wide an interval as in that genus. The postorbital process, though short and
not nearly reaching that from the frontal, is nevertheless more conspicuously de-
veloped than in the European species. The jugal does not appear to be much ex-
panded on the face in front of the orbit.

As in Oreodon the lachrymal is large and forms much ol the anterior boundary
of the orbit, but there is no such pit or depression as occurs in that genus. The
foramen is single and is placed within the edge of the orbit.

The frontals together make up a short, broad, lozenge-sliaped area. Pos-
teriorly they send back narrow prolongations, which are received between the
parietals and form a very limited part of the roof of the cerebral chamber. An-
teriorly they are deeply notched to receive the nasals, while the nasal processes are
long and have extensive sutures with the raaxillaries. Owing to the prominence
of the orbits, the forehead is very wide, much more so than in A. velaunus, and is
slightly concave transversely, not being inflated a..d roonded bv e.nueee as .a he
case i„ Oreodm. As in the latter, the anpraorbital Ihremma are placed near l e
medhan line, but the va.eeular grooves which run forward iiom them arc longer and

T ,1 • j Tlio nnstorbital process of the frontal is considerably'

more distinctly impressed. I he postoroiiai piucf . The

longer than in 1 velaunus, h.i the orbit remains widely open behind.

temporal ridges encroach but elongation of the muzzle;

The nasals are very long, somewhat convex from side

they are broadest narrowing a^i premaxillaries and

to side. The anterior ends project little, it at an, y

are notched in the middle. antero-posterior extension, the in-

The p,e,na,villarie, have » sanrc fore-and-aft line,

oisors being well spaced apart an aw „ process is long, low.

The alveolar portion is solid and massive,

61 JOUEN. A. N. s. PHILA., VOL. IX.

468

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

.„d bro»d, having an extensive sature with tho aaaal There- is no distinct pala-
tine ntocess.and the premaxillarj spine is a slender cylindrioal lod, nhicli, on ing to
its fragility is very generally missing from the specimens. The antermr nares are
notably small, bnt they are less oblique in position and present more directly for-
ward than in A. velmims. The incisive foramina are very narrow, but quite

elongate.

The maxillaries are of great length, the extraordinary elongation of the
muzzle being due principally to them. The alveolar portion is low, in correspon-
dence with the very brachyodont character of the molars, as is also the vertical plate
which forms the side wall of the nasal chamber. This plate is, however, con-
siderably higher than in the Ronzon species. How far the very low inaxillaries
and, consequently, very depressed face of the latter are due to the crushed condition
in which they are found, it is difficult to say, but the greater height of these bones
would appear to be a constant character of the American species. The face is con-
stricted in front of p^, and again and more decidedly in front of pi. The masse-
teric ridge is very prominent and is continued forward to the infraorbital foramen,
which opens above pi. Long as the maxillary is, its contact with the nasal is a
rather limited one, the sutures with the premaxillary and frontal occupying so
much of the length of the nasal. The upper margin of the maxillary descends
anteriorly, its vertical height decreasing toward the front. The pahatine processes
are long, narrow, and of nearly uniform width throughout, the inner sides of the
two molar-premolar series forming straight and nearly parallel lines. The bony
palate is slightly concave from side to side and almost plane from before backwuird.
The palatal notches are deeply incised, but less so than in A. leptorhynchus. The
maxillary is not continued so far behind the last molar as in the hitter species, nor
is it so broadened and inflated at this point as in A. velaumis. The posterior pahv
tine foramina occupy the same advanced and unusual jjosition as in Oreodon,
namely, opposite ph

The palatines are united together for a long distance, which shifts the posterior
nares much farther back than in any of the European species, so far as the latter
are known, though A. velaunus approximates the American type in this respect,
^e tubular shape of the canal with its narrow opening behind recalls that of
HycBuodon and might suggest aquatic habits, were it not for the somewhat similar
arrangement which occurs in the deer Cariacus, wlych, of course, is altogether

tendl l so far backward, ex-

twl ''—r, high enough in

into l„„ch.„.hevs, ae

than in the European sMSsaL*°o™ “*7 considerably more so

with a miirked deitression on the t dillerent shape. The form is oval,

clepresmon on the ventral surface, internal to the tnedhan line. This

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 469

gives it a very different appearance from the regular, almost spherical bulla of
Eporeodon. As in that genus, the bone is thin, though dense, and the cavity is free
from cancellated tissue. The auditory meatus is a quite elongate and incomplete
tube, lacking the dorsal wall.

^ The cranial foramina cannot be determined in the French skulls, but in the
White River specimens they are nearly all plainly shown. The optic foramen is
small and placed rather far forward. The foramen laceruin anterius is quite large
and irregular, somewhat as in the deer, though smaller. The foramen ovale pene-
trates the root of the pterygoid process of the alisphenoid, which extends to a con-
tact with the auditory bulla. The foramen laceriim medium is concealed in the
deep space enclosed between the bulla and the alisphenoid. The foramen lacerum
posterius is a narrow slit between the auditory bulla and the basioccipital, while the
stylomastoid foramen is large and conspicuous. The glenoid foramen is rather in-
ternal to than behind the postglenoid process. The condylar foramen occupies
much the same position as in Cariams, but lies a little farther forward, and hence
is not so much concealed by the overhanging of the condyle. The posterior palatine
foramina are not placed in the neighborhood of the maxillo-palatiue suture, but
perlbrate the palatine plates of the maxillaries on a line with the last premolars.
They' occupy the same position in Oreodon and in Protoceras they are even more
advanced. The infraorbital foramen is large and opens above p!, while the supra-
orbital foramina open on the surface of the skull near to the median line.

The mandible displays considerable differences among the various specimens from
the upper beds. In one individual the horizontal ramus is thick and heavy, but
quite shallow vertically, and thus appearing to be quite slender, when viewed from
the side. The symphysis is procumbent, and its lower border is raised but little
above that of the rest of the horizontal ramus. The coronoid process is rather short
and slender, very decidedly recurved, and separated from the condyle by a broad

sigmoid notcl,. In other specimens, which may represent different species, he
horizontal ramus is considerably deeper and heavier and he "3'

abruptly to the proenmbent ohin, the inferior margin of wliieli lies

higherleveltliantliatoftheotherpartoftheranius. ^

the an-le more prominent, the coronoid process much higher and broadei and k s
strongly recurved, which, renders the sigmoid notch narrower and ess -loop T me s-
The aUgle is more prominent « prodnced^h*w the ^^vel
ramus, and the masseteric fossa is >”8“ ,ide the articular

condyle is much extended transverse y, an ^ r , facet for the postglenoid

snrfiteC is reflected over npon the tl e mSu ar rami aif some-

process of the squamosal. In aged individuals the two maiiui

times an kylosed. _ „+ra+ka+nfrd«rfif/«^withriianifolddifrer-

has a mandible of similar yp the very much shorter horizontal

ences of detail. Of these the most striking . tlm j i

portion, without diastemata, coirespon § abruptly back of the condyle, but

whole facial region. The angle projects more abrup )

470 THE STRUCTURE AND RELATIONSHIPS Ot ANCODUS.

desceuds less below the inferior border of the horizontal ramus. The coronoid pro-
cess is less elevated and recurved than in the American species ol /Incodus, more
than in the European, and the condyle is much less extended transversely and
especially on the outer side. The symphyseal region is much more steeply inclined
and less procumbent. In all of these particulars the later oreodont genus, Meryco-
cluerus, presents a decidedly closer approximation to A^icodus than does Oreodon
itself, though never attaining such an extreme elongation of the face.

II. THE VERTEBRAL COLUMN.

The atlas differs from that of Oreodon in being proportionately longer and less
extended transversely. The anterior cotyles are separated dorsally by a wide and
deep emargination of the neural arch ; the latter is quite strongly convex from side
to side, and the neural spine is represented by a prominent rugose tubercle. A lyrate
area, formed by ridges, encloses the spine and descends abruptly at the sides, which
are perforated by foramina for the first pair of spinal nerves. The transverse pro-
cesses are not greatly extended laterally, nor do they reach so far back of the sur-
faces for the axis, as is the case in Anoplotheriim, though their shape is more like
what we find in the latter genus than that in Oreodon. So far as I can determine,
the transverse process is not perforated by the vertebrarterial canal. The facets for
the axis are large and but little oblique in position, presenting more backward than
inward.

If Kowalevsky has correctly referred to Ancodiis the axis from Puy (Ronzon),
which he has hgured (No. 3, PL XXXIV, fig. 7), then the American species of the
genus differ very radically from the European with regard to the character of this
bone. There can, however, be but little doubt that Kowalevsky’s specimen has
been erroneously identified, and that it belongs to some very difterent genus, proba-
bly a perissodactyl {Ronzotheriumf). In A. brachyrhynchus the axis has a lom>-
broad, and much depressed centrum, which is but feebly keeled upon the ventral
side and has no hypapophysial tubercle. The anterior cotyles for the atlas are very
broad, extending out laterally much beyond the rest of the centrum, but, at the same
t.,„e.ll,eyl,ave„o great vertical height and do not reach far enough upward to
enclose more t „n a small part of the neural canal. The articular surfaces of these
cotyles .re s^dle-shaped, slightly concave transversely and convex dorso-ventrnlly.
ca ie, he wlTT"’ of the shape which might almost be

pXlriZ lZlZf h’ '■ '-’f Agriock«:rus, Ancodus,

betlen the two n 1.“.“ j "" but iulermediate

ve„t::,:r":ctrfxt:t^iirrrfyZttr

and the process gradually controls a„terlor(y uli’ti t endnifa hi®'‘; ^ T

have elsewhere shown the great probabilitv of il • n j ^ ^

charachr h,

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 471

it is correlated with increased length and curvature of the neck. That Ancodus
should be added to this list of parallelisms is obvious from the comparison of the
process in the species from the lower beds with those from the upper sandstones.

In the American Museum of Natural History, New York, is preserved a frag-
mentary skeleton of A. amen canus, from, the Metamynodon-beds (or middle Oreodon-
beds of the White River), for an opportunity to study which I am indebted to the
kindness of Messrs. Osborn and Wortman. It is in many ways different from the
skeleton of the large A. brachyrhynchus, which forms the principal subject of the
present description. In A. americamis the neck is shorter than in A. brachy-
rhynchus and the axis especially is different ; it is smaller and, in particular, shorter
(33 : 46) with lower, but relatively wider atlanteal surfaces, which present more
directly forward. A more important difference is in the character of the odontoid
process, which is conical, though slightly depressed, the transverse diameter some-
what exceeding the dorso-ventral. The ventral face of the process is flattened and
much less strongly convex than the dorsal, which is the reverse of the shape in the
later species. The odontoid has an upward as well as a forward direction and is
longer and more slender than in the pigs.

The posterior face of the centrum is wide, depressed, concave, and oblique in
position. The neural arch is broad and high, enclosing a large canal, a:nd the neural
spine resembles that of Agriochcei'us, forming a great plate with curved and slightly
thickened border; its anterior end projects over the atlas in the form of a blunt
hook. The postero-superior angle is broken away in the only available specimen,
preventing the determination of its exact shape, but the thickening at this point
indicates a posterior rib-shaped prolongation, such as occurs in Dicotyles and Oreo-
don, though not in Agriochoerus. The postzygapophyses are large and prominent
and present directly downward. The transverse processes diverge widely from the
centrum, projecting outward more than backAvard, but with their free ends recurved
somewhat toward the median line. These processes are obscurely trihedral in
shape and are proportionately heavy; they are perforated by the vertebrartenal
canal, and their anterior ends are connected by low ridges with the articular facets
for the atlas.

The other cervical vertebra; have moderately elongate and heavy, opisthocoe-
lous centra, with obliquely set faces; they have very faintly marked ventral keels
and the liypapopliysial tubercles are either rudimentary or altogether .absent. Ot
the cervical series the 7th is the shortest, and next to that the 6th. In relative
length the neck considerably exceeds that of and even that of Oreoim n
the case of the latter genus the comparison cannot fairly be made with the sku 1,
on account of the extreme shortening of the face, which in Ancodus is as extremely
elongated. But Ukiiig the humerus as a standard of comparison, the neck is pro-
portionately longer in Ancoiia brackyrhymhm than m Oreodm. The neural
Lhes are broad and low, and the pedicels of the neural amhes are not perforated
for the exit of the spinal nerves, as they are in the pigs. These pedicels have very
little antero-posterior extent, while the tygapophyses are very prominent; those

4,2 THE STEUCTUEE AND RELATIONSHIPS OF ANCODUS.

n . nrp verv widely separated, while the an-

of theoppoA-* brought close together. This is

tenor jmd postenor processes 0 „eunl ‘itches together with their short-

i„co..se,ue,.ceof the g«.t resdth o he^^^

rve';”Ch«e nean, f«s. and present
IrdLctly upw^diydownward, with hut little ^"the 3d'

neural spines increase in height successively rom

vertebra the spine forms a low and inconspicuous ridge, while on the 5th it has

attained considerable heightand thickness. The transverse processes mos resemble
those usual among the Pecora, aside from the differences caused by the smaller
elongation of the centra. On the 6th the inferior lamella is very large and dist.nctly
differentiated into two parts, much as it is in and the diapophysial element

is as conspicuously developed as on the 6th. The latter has a still larger inferior
lamella, with thick and roiighcued free m.argin and relatively short diaixiphysis.
The last cervical is, as usual, without any pleurapophysis, and the transverse process
is in the form of a long, stout bar, with slight upward curvature. All the cervieals,
except the atlas and the 7tli, display the vertebrarterial canal.

The thoracic vertebrcc must have numbered at least thirteen, since that many
ribs of the right side are in position in one of the specimens. The nine anterior
thoracic vertebrm have centra of almost uniform length, which (piite strongly
resemble those of the deer. The Ist and 2d have the broadest and most distinctly
keeled centra. The spines are compressed, slender, inclined very strongly back-
ward and are rather short, as compared with those of Sus or of the larger Pecora.
The transverse processes are of no great length, but they have very large facets for
the tubercles of the ribs.

The lumbar region must have contained at lecast six vertebrm, that many being
preserved in the New York specimen of A. americanus, already referred to, which
indicates that the number of trunk vertebrm cannot have been less than nineteen,
though the number of thoracic and lumbar vertebrm was doubtless subject to specific
variation. The first lumbar has a centrum which is long and deep, but slender, tri-
hedral and contracted in the middle; the faces are slightly opisthocoelous. Passing
backward, the centra become more and more broadened and depressed, a change
which reaches its maximum in the sixth. In spite of this progressive diflerence of
shape, the first five vertebrm have centra of almost uniform length, while the 6th
is considerably shorter than the others. The processes are nearly all broken away,
but enough remains to show that the neural arches are low and short antero-poste-
riorly, and that the transverse processes are very broad and thick.

Of tlie sacrum the first vertebra is preserved in the same skeleton, which has
yielded the lumbars. The anterior face of the centrum is very broad and low and
the posterior foce much narrower and lower still. The neural canal is likewise very
ow, but wide. The pleurapophyses are very large and heavy, both vertically and
transversely. Apparently, the pelvis was borne entirely by this vertebra and had

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

473

no contact with the second ; this, however, is uncertain. From the character of
the sacrum it may be inferred that Ancodus did not possess a very long or stout tail.

No caudal vertebrae are preserved in the collection.

With the exception of the atlas, which is longer and less broadened transversely,
all of the vertebrm which have been described are extremely like those of Oreodon.
They are, of course, much larger than in that animal, but their construction is
essentially similar, while their resemblance to the vertebrae of the pigs is but re-
mote.

III. THE RIBS AND STERNUM.

The ribs are somewhat more modernized than those of Oreodon, which are
remarkable for their slenderness, though the dilference is in some degree to be cor-
related with the great difference of size in the two genera. In Ancodus the first
rib is short and nearly straight, the thorax being very narrow in front. Behind
this point the ribs rapidly lengthen and become more and more strongly arched out-
ward ; from the 3d to the 11th they are very long and indicate a capacious thorax.
The first eight ribs are I’ather slender proximally, but for the distal two-thirds of
their length they are much broader and more flattened than in Oreodon, though less
so than in Anoplotheriimi. The 9th is more slender, while the posterior ones become
decidedly so. The tubercles are remarkably large and prominent up to the 11th.

Of the sternum the three anterior segments are preserved. The first segment is
not entirely like that of either the Suina or the Pecora. In the former it is “com-
pressed and keeled, the articular facets for the first pair of ribs are close together
on its upper surface; but the mesosternum is broad and flat, the first segment being
compressed in front, broad posteriorly.” In the Pecora “the presternum is narrow,
rounded in front, and bearing the first pair of sternal ribs close to its apex. The
succeeding pieces gradually widen, the posterior segments of the mesosternum being
square, flat, and rather massive; they are hollowed at the middle of their lateral
borders ” (Flower, No. 2, pp. 96-97.) In Ancodus the shape of the presternum
is most like that of the ruminants, but it is much narrower, more compressed and
less expanded at the free end. The facets for the attachment of the sternal ribs
are not clearly shown, but appear to have been near the apex. The mesosternum
is quite like that of the Pecora, save that the lateral borders are not so deeply
ernm’ginated. The sternum of Oreodon differs in no important respect from that of

Ancodus. fobe-limb.

The scapula resembles, with some differences, that of the European species which
Kowalevskv has described: “The general aspect of this new specimen presented
great similarity to the one figured from Hordwell [i. e., of Diplopus\, begmnm
fr^rtlTneck the bone broadened rapidly to its upper and broken extremity, and
aco uired tlie same remarkable breadth which is so eonspicnous a feature of the scapula
Toilhm The spine of the scapula was also very oblique, nicUnmg outwards, as
t toltpulafigLd in Plate XXXV. The fossa glenoidea had precisely the same

A. brachyrhynohus, left
Bcapula, about } natural
size.

4,4 THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

exceedingly circular outline .s is seen in the figured scapula j the coracoid process
17L p4ect much and was reonryed in the same charactensfe manner On the
^ ^ outer margin of the neck, however, where I found a deep

fossa in Dip/o^us, the scapula from Puy presented only a flat-
tening.” (No. 3, p. 32.) _ 1 1 Va

In A. brachyrhynchus the scapula is relatively much

higher and narrower than in Diplopus, or even than in Ano-
plotherium, and is proportioned very much as in Oreodon.
The neck is narrower and more slender than in Diplopus,
and there is a more distinct coraco-scapular notch ; the spine
is not so high or so thick, the acromion much shorter, not
extending so near to the glenoid cavity, and the coracoid is
much smaller. The coracoid border forms a thin edge and
curves convexly forward and upward from the coraco-scapu-
lar notch. The glenoid border is nearly straight and some-
what elevated and thickened; its divergence from the neck is
at a moderate angle. The suprascapular border is also nearly
straight, and curves gently into the coracoid border, while
making an acute angle with the glenoid border. The general form and proportions
of the blade thus approximate quite closely to those which we find in the rumi-
nants, and depart in a marked way from the type of scapula which Kowalevsky
has described from Eonzon.

As in the primitive artiodactyls generally, the spine is placed almost in the
middle of the blade, which is thus divided into pre- and postscapular fossm of nearly
equal width. The spine terminates well above the glenoid cavity; it is high, but
compressed and thin ; the acromion is short, not overhanging the neck very far, nor
descending to the level of the glenoid cavity, and ends in a roughened tubercle.
The glenoid cavity, which in AnoplotJierium is very oval, departs very little from
the circular form, the antero-posterior diameter only slightly exceeding the trans-
verse. The articular surface is a shallow concavity. The coracoid is a large, corn-
pres.sed and prominent tubercle, but not hook-like or recurved. The scapula of
Oreodon agrees with that here described in every particular except size, while the
differences from that of the European species of Ancodus are obvious.

The humerus (PI. XXIV, fig. 5) differs considerably from the one which Kowa-
levsky has figured as belonging to Diploptis, and more resembles that of Oreodon.
The head is rather prominent and convex and projects quite strongly backward,
the external tuberosity is very large and massive, rising far above the level of the
head, and extending across the whole anterior face of the bone ; its internal end
forms a short, blunt hook, which overhangs the broad bicipital groove rather more
Th^Zn tuberosity is small and compressed, but rugose.

has a great antero-posterior diameter,

taw upon the shaft. The drstal part of the shaft is transversely expanded and

475

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

depressed, though not perforated, by the supratrochlear fossa ; the supinator ridge
is well developed. The trochlea differs from that of Dipbpus, Anoplotherkmi and
Oreodon in the narrowness of the intercondylar or median ridge, which is not the
rounded, bulging protuberance found in those genera; in other respects it agrees
best with that of Oreodon, not possessing the downward, flange-like prolongation of
the internal portion, which occurs in Diplopus, and to a much nioi’e marked extent
in Atwplotheriimi. The internal epicondyle is exceedingly prominent, even larger
than in Oreodon, and forms a great, swollen rugosity. The humerus of Agriochoe-
rus offers but little resemblance to that of Ancodus, having become differentiated in
a way extremely like that of certain creodonts, particularly of Mesonyx.

The radius (PI. XXIV, fig. 6) differs from that of Oreodon in several respects.
As in that genus, the trochlea for the humerus is divided into three facets, the
middle one of which is, however, much narrower than in Oreodon, the inner one
wider, and the outer one difierent in not descending oblicprely forward. Of the
proximal facets for the ulna the external one is a deep concavity. The head con-
tracts sharply to the shaft, the upper portion of which is slender and rounded, but
continually enlarging as it descends, becomes both broad and thick toward the distal
end. The shaft is strongly bowed forward, but the radio-cubital arcade is short and
narrow, because the ulna has a very similar curvature. In Oreodon the shaft of the
radius is much more decidedly slender and subcylindrical throughout. In Ancodus
the distal end is quite massive and heavy^, and has a broad tendinal snlcus on its
anterior face, enclosed by elevated ridges. The carpal facets for the scaphoid and
lunar are obscurely separated; that for the former is the larger, convex transversely
and concave antero-posteriorly, more oblique in position, and is reflected upward as
a broad band upon the postero-internal angle of the bone. The lunar facet stands
at a somewhat higher level than the scaphoid; it is broad and concave in front,
narrower and convex behind. The distal ulnar facet is large and deeply concave.

The radius referred to this genus by Kowalevsky differs in several respects
from the one here described. The outer proximal ulnar facet is convex, not a deep
depression; the carpal facets are broader, less extended in the dorso-palmar direc-
tion, less oblique in position with reference to the transverse axis of the distal face,

and more distinctly separated. i j- mi

The ulna is but little reduced and proximally is heavier than the radius. I he
olecranon is very large, but low and erect, projecting backward but very little, while
the antero-posterior diameter is rel.itively very gre.rt. The summit of the process
is straight, thickened, and somewhat overh.aiiging to the radial sid^ and the tendinal
sulcus is deeply incised, with greatly elevated internal margin. The sigmoid i.otcl.
is low and, except proximally, the articuhar surface for the humerus is coiUiied to

the inner Sidei there is also a ininnte distal external aeel for the humerus. The

shaft is of the laterally comprassed, trihedral shape found by Kowalevsky in he
species from Ronton ; it diminishes in site inferiorly. “ ^
distal end to fit the corresponding depression on the ladius. le ^
the cuneiform is narrow and conve.x, passing behind into a large flat facet

62 JOUEN. A. N. S. PHILA., VOL. IX.

476

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

pisiform. This ulna is, on the whole, much more like that of Oreodon than that of
Anoplothermm, but the olecranon is relatively lower, and the shaft has a stronger
curvature toward the anterior side. In Kowalevsky’s specimen the olecranon is
not so heavy and deep antero-posteriorly, but higher, and projects more strongly
backward than in the American forms.

The vianns (PI. XXIT, fig. 7) has already been described in detail by Kovvalev-
sky, but it is necessary to go over the ground again, because his material was very
imperfect, being taken from many difierent individuals and widely separated locali-
ties, and also because of certain differences which obtain between the American and
European species.

The hand displays many and significant resemblances to that of Oreodon, and
the differences, though not unimportant, are of hardly more than family rank. The
carpus is broad and, as in the ancient artiodactyls generally, relatively very high.
The scaphoid is high, narrow, and deep, difieriiig in shape from the scaphoid of
Oreodon, wliich is of nearly cubical outline. The radial facet is very slightly con-
cave and oblique, descending toward the inner side, but not reflected down upon the
dorsal face of the bone, as it is in Kowalevsky’s specimens and in Oreodoji. The
lunar facet is single and confined to a band, which runs along the proximal border
of the ulnar side. The distal surface is occupied by the facets for the magnum and
trapezoid; the former is slightly convex and is not prolonged backward into a con-
cave surflice, as it is in Oreodon. The facet for the trapezoid is large and concave,
situated behind, as well as internal to that for the magnum, while the surface for
the trapezium is very small and confined to the postero-internal angle of the distal
side. As in the Ronzon species, “the posterior extremity of the scaphoid is elon-
gated into a thick, recurved portion, which bends inside the carpus.”

The lunar is cpiite different from that of the European sjoecies in the presence
of an extension of the proximal portion toward the ulnar side to meet the unci-
torrii. The radial facet is oblique, inclining toward the internal side as it passes
backward ; it is broad and convex in front, where it also rises towards the ulnar
SKle, and „ nanw and co,ic.a,e behind. This facet differs from the correspo.,di„K

well'” I™*',"' 7 “‘"'exity and larger posterior concavity, as

well as ,n the „hlK,mty „i its position. The distal beak is longer than In the liuro-

as HI tl.c l.itter. The magnum facet is considerably narrower than lhat lor the

reZh” v:::"d

the conditma found ,n that genus m being concave rather than coniex in front and

The utter Z;Xne

deptZ Ttfr; Left ^"-Oaln,«r

«haZi it is high on Aelnnertfdt'LTre

IS much reduced. The pisiform facet i« a of the bone

IS not eonlmuonswith the surface for the tln°a

Ulna. Uii the radial side of the cunei-

477

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

form are two facets for the lunar; the proximal one is small and confined to the
dorsal raargjip while the distal one occupies the whole depth of the bone. The
unciform facet is rather small, not taking up the whole distal surface of the cunei-
form, and is rather concave. The cuneiform of Oreodon is lower, but deeper antero-
posteriorly than that of Ancodus, and more cubical in shape. The pisiform is not
preserved in any of the specimens.

The trapezium is relatively well developed ; it is narrow and compressed, but
quite high and deep. In view of the comparatively large size of the pollex, it is
somewhat surprising to find that the trapezium has but a small facet for the scaphoid,
and articulates more extensively with the first and second metacarjjals and with
the ti’apezoid. The surface for the trapezoid is situated rather high up on the ulnar
side of the trapezium, and below it is a small facet for the second metacarpal. The
distal facet for me. I is narrow but deep, convex and broader in front, concave and
contracted behind ; the distal end extends a little below the level of the trapezoid.
The trapezium has not been found in the European species, but, as Kowalevsky
showed, the facets on the trapezoid and me. II demonstrate its presence in these
forms. The trapezium occurs also in the oreodonts, but its shape is known only in
Mesoreodon and Merycochasrus^ in both of which genera the pollex has disappeared
and the carpal is reduced to a mere nodule.

The trapezoid is narrow, but much extended antero-posteriorly, thus reversing
the proportions found in Mesoreodon. The proximal end bears a rounded, convex
facet for the scaphoid and the distal end a narrow, saddle-shaped one for me. II. On
the ulnar side is a plane surface for the magnum, which occupies the entire height
of the bone, but only about one-half of its dorso-palmar depth. The trapezoid of
the European species does not differ in any important respect from that of the
American.

The dorsal face of the magnum, exposed when all the carpal elements are in
position, is broad and low, but toward the palmar side it rises to a considerable
height, though not forming a well-defined, rounded head. Posteriorly the magnum
is provided with a long, stout, and somewhat decurved hook. The scajihoid facet
takes up most of the proximal side; it rises toward the ulnar side, wdiere its junc-
tion with the lunar facet forms a high crest. It also rises gradually toward the
palmar side, and is transversely concave throughout; there is, however, a very faint
indication of a dorsal concavity and palmar convexity. The lunar facet is lateral
rather than proximal ; in front it is narrower and nearly plane, descending almost
to a junction with the surface for me. Ill, while behind it rises to form a broad
convexity, which is more proximal in position, and is reflected well over upon the
palmar side of the bone. Distally there is a large saddle-shaped surface for me. Ill,
as well as a narrow, plane facet for me. II upon the radial side.

The mamnim of Oreodon, while essentially like that of Ancodus, has stdl many
points of difference. (1) There is a distinctly developed head, and the scaphoid
facet is very clearly divided into dorsal concavity and palmar convexity. (2) The
lunar facet has a more completely lateral position, and does not broaden out behmd

478 THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

to anything like the same extent. (3) The posterior hook is very much smaller.
While these differences are very marked, the resemblances are even more important.
In the carpus of both genera a displacement of the magnum toward the radial side
and a tendency of the lunar to rest entirely upon the unciform are obvious, but
this displacement has been carried farther in the oreodonts than in Ancodus. In
A. (vnericanus i\\e shifting of the magnum has proceeded farther than in A. brachy-
rhyuchns, and the contact with the lunar is more entirely lateral. The distal beak
of the lunar is more prononnced, and the resemblance to the lunar of Oreodon more
complete. In the European species of Ancodus the magnum has an even less dis-
tinctly marked head than in the American, and the relation of the proximal facets
is reversed, that for the lunar being larger than that for the scaphoid. The palmar
hook is broader and more massive. Kowalevsky calls attention to the perissodactyl
character of this bone. (See Monographie der Gattung Anthracotherium ; Palrn-
ontographica, XXII, pp. .303-4, Taf. XI, fig. 39-42.)

The unciform is the largest bone in the carpus, though not greatly exceeding
the lunar in bulk. Its roughened dorsal face is considerably higher vertically than
that of the magnum, and the palmar hook is broad, massive, depressed, and decurved,
but not elongate. The proximal surface is unequally divided betwmen the facets for
the lunar and unciform, the latter being considerably the wider of the two. Tlie
lunar facet is somewhat oblique in position, broader in front and narrowing behind,
somewhat concave transversely and strongly convex antero-posteriorly. The facet
for the cuneiform has similar curves, but narrows toward the ulnar side. On the
radial side is the large, infero-lateral hxcet for the projection arising from me. Ill, and
above and behind this a surface for the extension from the ulnar side of the mag-
num. The distal surface displays a large and nearly plane facet for me. IV, and a
narrow, concave one for me. V ; the latter is almost as much lateral as distal, and is
continued back the full depth of the palmar hook. The unciform of the European
species of Ancodus much the same as in the American, but is broader in propor-
tion to its height; its ulnar border is less abruptly truncated, and is drawn out into
a sharp angle. The lunar facet is also somewhat wider, the displacement of the
magnum toward the radial side having hardly advanced so far. The unciform of
Oreodon is somewhat higher in relation to its width, and the posterior hook is de-
cidedly more compressed and slender. The lunar facet is muol, more distinctly
divided into anterior convexity and posterior conenvity, while the cuneiform facet
.s rounded .nnd convex in both directions. The highest point of the bone is not, as

“ f.T r j’-'' ."‘‘S' two fscets, but by the sninmit of tlie

arched surface for the cuneiform.

dactv'l r'T" ’’ P- of it Ponta-

Sv Ime Lm ? "’‘"'''/“f. *>0 called welWeveloped, and tliongh it can

hardly I a,e been of much functional importance, it is relatively larger than in any

V;: e S i'a" ' boon dem„™tr!rd.

along t e med arrj i I; “f tocond, measured

g median line, it has an enlarged, rugose head bearing a narrow facet for

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

479

the trapezium, which is lower and slightly concave in front, higher and somewhat
convex behind. The shaft is compressed in its proximal part, but of considerable
dorso-palmar depth ; it tapers inferiorly, expanding again to the distal end. The
distal trochlea is well-developed and of almost hemispherical form, wdth a carina
w hich is confined to the palmar side. It is obvious that this metacarpal must have
been provided with both phalanges. The pollex of Oreodon, and even of the earlier
and more primitive is considerably more reduced and slender than that

of Ancodus, and it is surprising to find a White River genus, so advanced in many
respects, retaining such an ancient character in so perfect a way.

Kowalevsky did not suspect the possibility of the existence of a pollex in
Ancodus, or, indeed, in any artiodactyl, and hence his figures of me. II do not show
wdiether it had the facets for me. I, which occur in the American species.

The second metacarpal is much larger in every dimension than the first, and
has about the same relative development as in Oreodon. The head is narrow, and
is excavated on the radial side to receive the head of me. I, for which it has distinct
facets. It is also in contact, to a slight degree, with the trapezium. The trapezoid
surface is narrow and oblique, rising toward the ulnar side, concave transversely
and slightly convex in the antero-posterior direction. The ulnar border of the
proximal end overlaps the head of me. Ill, and abuts against the magnum by a facet,
w^hich is proportionately better developed than in Oreodon, and extends along the
entire dorso-palmar depth of the head. The shaft is flattened and compressed, but
stout and considerably curved. The distal trochlea is rounded and prominent, and
demarcated from the shaft on the dorsal face by a narrow depression. ^ Except for the
larger size and greater prominence of the magnum facet, this bone is almost a copy
of the corresponding one in Oreodon. The Ronzon specimens of me. II, figured and
described by Kowalevsky, would appear to have a less prominent projecting process
for the magnum and a straighter and more slender shaft.

The third metacarpal is the longest of the series, rising above me. IV proximally,
and descending below it distalij, but, on the other hand, it is a little narrower tans-
versely than that bone. The head is broad and heavy; on the radial side, below
the head, the shaft is excavated to receive an expansion of mo. II. There is a
relatively large surface for articulation with the distal side of the projection which
me. II sends to meet the magnuini this surface is divided into two parts by a nar-
row sulcus. The posterior projection from the head is longer wider, and more
massive in proportion than that of Oreodon, and the portion of the magnum facet
which extends upon it is broader and inclined more ‘""'I
main portion of the same facet is rather less strongly convex from

^uJLiVrTanarpIll^rtaZer'’^^^^^^^^

shaft widens transversely tow,ard the

low, confined to the palmar side, and hardly visible from the anterior side.

480 THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

Kow»lev*/8 ngure (No. 8, PI. XXXVII. fig. 20) the two media,. ..mtacarpals
(III and IV) a, -e shown » being of the same length, and n,c. IV ,s much the more
AnJcr of the two. Whether this joroportion really characterizes the Lui-opean
simchnens, or is due to the association of bones from different
same inanns, cannot well be determined. Filliols figure (No. 1, PI. 24, fig. 116)

would favor the latter conclusion. , i i j

The fourth metacarpal is somewhat wider and markedly shorter than the third.
The head bears a nearly plane fecet, of subtriangular shape, for the unciform, which
extends somewhat farther back upon the posterior projection than m Oreodon, and
the depression on the ulnar side for the head of me. V is rather more deeply marked
than in that genus. The lateral hicets for the.adjoining metacarpals are large and
Hat. The shaft is somewhat more compressed in the fore-and-aft direction than
that of me. Ill, but is otherwise like it, as is also the distal trochlea.

The fifth metacarpal is shorter than the second, and is consequently the shortest
of the series, except me. I. It is somewhat heavier in proportion, but otherwise
almost exactly like the corresponding bone in Oreodon. The head is quite rugose
and heavy, and carries a narrow, oblique, and saddle-shaped facet for the unciform.
The articular surface for me. IV on the radial side of the head is broad in front,
becoming very narrow toward the palmar side. The shaft is stout and of trihedral
shape, broadening regularly to the distal end. The figures of Kowalevsky and
Filhol show this bone of (juite a different shape in the Ronzon species; it is longer
and straighter, with a less expanded and rugose head, and is less distinctly enlarged
at the distal end. Filhol’s figure appears to indicate the extension of the distal
Carina farther upon the dorsal face of the trochlea than occurs in the American
species.

pJialanges oi the pes are much better represented in the collection than
those of the manus. It will suffice for the present, therefore, to note a difference
which obtains between the proximal phalanges of the fore and hind feet. In the
manus the first ^^halanx has a subcircular proximal end, with shallow concave
facet for the metacarpal, notched on the palmar border for the carina. The shaft
is nearly straight, its distal portion becoming wide and much compressed in the
dorso-palmar direction. The distal trochlea is very low, very obscurely divided in
the median line, and not reflected upon the dorsal side of the bone. The lateral
processes for ligamentous attachments are inconspicuous.

V. THE HIND LIMB.

The/./m is not represented in the collection at all, except by some fragments
which show that the ilium was quite broad and probably like that of Oreodon.

f 8) only the distal portion is preserved in the spe-

cimen of A. brachyrhymehus; it indicates a much larger and more massive bone than

Surface fri i " is heavy and trihedral in shape. The

form a deen n't ° Pi^^haris muscle is large and rugose, but does not

form a deep pit or depression, as is the case in the European species. The rotular

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 481

trochlea is very prominent and massive and of asymmetrical shape, the inner
border rising considerably higher than the outer. The condyles are large and pro-
ject strongly backward, and are of unequal size, the outer one being distinctly the
larger and more prominent. The strong backward projection of the condyles, and
the great prominence of the trochlea in front give to this portion of the femur an
unusual antero-posterior diameter. In other respects the femur resembles that of
Oreodon^ except for its much greater size.

In A. americanus the femur has a widely expanded and antero-posteriorly
compressed proximal end. The head is rather small and set upon a short, but dis-
tinct neck, dilfering much in appearance from the long, slender, and prominent neck
of the femur figured by Kowalevsky. The head is far removed from the great
trochanter, with which it is connected by a long, compressed bridge of bone. The
great trochanter is high, rising somewhat above the level of the head, very deep
antero-posteriorly, massive and rugose, with recurved posterior border. The digital
fossa is deep but small, having but little extent either vertically or transversely,
and there is no distinct ridge connecting the great and second trochanters. The
shall is very long, slender, and rounded, not nearly so heavy as in A. brachyrhynchis,
and is notably less massive distally. The condyles are much smaller and less
prominent than in the latter species, the rotular trochlea less elevated and, conse-
quently, the whole distal end is much less extended from before backward than in
the last-named species.

The patella is a remarkably large and massive bone, which may be described
as being like the knee-cap of Oreodon with the addition of a long, broad, and thick
tuberosity, which covers nearly the whole anterior face. The proximal surface is
abruptly truncated and slightly concave, with raised anterior border. The antero-
posterior diameter is greatest along this line. In its upper three-fourths the bone
is of nearly equal transverse and fore-and-aft diameters, though the anterior iace is
narrower than the posterior, while the distal portion narrows abruptly to form an
incurved hook, which has hardly more than one-third the fore-and-aft depth of the
rest. The articular surface is unequally divided by a ridge into two facets for the
trochlea of the femur; transversely the two are of the same width, but the outer
one has the greater height. The inner border of the internal facet is somewhat
recurved, so as to slightly cover the mesial face of the femoral trochlea. The same
feature occurs in Protoceras, but in a very much more marked degree.

The tibia is considerably longer than the radius, much more so, proportion-
ately, than in Oreodon, but in construction it is exceedingly like the tibia of that
genus, though, of course, much larger and more massive in every way. The proxi-
mal condyles are less oblique in position and less strongly convex in the antero-
posterior direction; the spine is bifid and higher than in Oreodon and the groove
dividing.it is deeper, but not so wide. The cnemial crest is very heavy and promi-
nent, eSteiiding farther down the shaft than in Oreodon, and not terminating so
.abruptly below: but sloping graduolly into the shaft, wlule proxima ly , tends m
very in.assive and rugose surface for the attachment ol the patehar ligament, 1

482

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

extensively invaded by the large sulcus, which, just as in Oreodon, crosses the
intercondylar ridge ; this ridge forms a somewhat more prominent anterior tongue
than in the latter. There is a well-defined distal facet for the fibula in addition to
the lateral one on the distal end of the shaft, the fibula extending considerably be-
neath the tibia. In Oreodon this also occurs, but the displacement is less, and con-
seciuently the facet in the distal face of the tibia is less developed.

Of the fidu/a only the distal end is preserved in any of the specimens, but it
is plain that no coalescence between the two leg-bones occurred at any point, and
that the shaft of the fibula, though slender and reduced, was, in all probability,
complete and uninterrupted. The distal end is narrow and transversely compressed,
but considerably expanded antero-posteriorly, much more than the depth of the
calcaneal facet. This facet is somewhat saddle-shaped, concave transversely and
convex from before backward; it is broadest about the middle of its course, narrow-
ing toward the ends. A strong shelf projects inward from the mesial side of the
fibula, which extends underneath the tibia and bears a facet on its proximal side
which articulates with the surface already described on the distal face of that bon'e.
The mesial side of this fibular projection bears a large facet for the astragalus.
Kowalevsky’s figure (PI. XXXV, fig. 3) shows that in Diploptis the distal end of
the fibula is much like that of Ancodus brachyrhynchiis, but the calcaneal and
astragular facets are larger and of a somewhat different shape.

The pes (PI. XXIII, fig. 4 ; PI. XXIV, fig. 9) is, in some species at least, much
larger than the manus in every dimension, and especially in vertical height. The
tarsus is, on the whole, very mnch like that of the oreodonts, but with some
characteristic features of its own.

Ihe astragalus is relatively ranch higher and narrower than that of Oreodon.

I he proxirniil trochlea is more symmetrical than in the European species of Anco-
dus, owing to the lesser height of the external condyle, and the median groove is
broader. The distal trochlea is proportionately much higher than in Oreodott, and

separated from the proximal one by a wider interval; the navicular fiicet is much
narrower and the cuboidal wider. The calcaneal facets of the astragalus are very

r*hnrn/'+4iria+in oi»/1 ^ i °

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 483

the outer, but extends much farther distally, where it terminates upon the plantar
face of the ridge separating the cuboid and navicular surfaces of the distal
trochlea, while it does not extend so far proximallj by a corresponding amount.
This accessory facet is inclined in position, facing obliquely toward the external and
plantar sides. Of the external calcaneal facets, the proximal one is very unusually
prominent and very deeply concave, describing almost a semicircle, which closely
embraces the corresponding protuberance on the calcaneum. This facet is also
divided by a sulcus into two parts, proximal and distal, which are separated by a
considerable interval. The distal external facet for the calcaneum is large and
plane. The whole mode of articulation between the calcaneum and astragalus is
peculiar and implies a very uncommon freedom of movement.

So far as can be judged from Filhofs figures (No. 1, PI. 26, figs. 132-3) these
characteristics do not occur in the astragalus of Ancodtis leptorhy fichus, which is
more like that of Oreodon, nor does Kowalevsky mention them in his description
of tire other species.

Tim calcaneum is correspondingly difterentiated to suit the changes of the
astragalus. The tuber is long, compressed, and deep, with nearly parallel dorsal
and plantar borders, somewhat expanded and club-shaped at the free end, which is
marked by the sulcus plantaris, so general among the artiodactyls. The distal end
is not, as in Oreodon, suddenly contracted to form the cuboidal facet, the plantar
border remaining straight throughout. The sustentaculum differs markedly from
that of all the oreodonts in its much greater prominence, and in the possession of
an accessory facet for the astragalus. These two facets form a continuous articular
surface, but being placed at different angles, their junction forms a distinct ridge
which fits into the reentrant angle between the corresponding facets of the astraga-
lus. The external facet of the sustentaculum is the larger of the two, is simply
concave, and presents obliquely toward the distal and dorsal aspects of the bone;
the inner facet is narrow, nearly plane, and presents distally and internally. It is
this internal accessory facet which gives its great prominence to the sustentaculum,
which in the European species does not project much more strongly than m Oreodon
owing to tlie absence of the inner facet. The fibular facet forms a hrgh, elongate
prominence, whicl., when seen in profile, has much the same shape and pi-oportions
as in Fillrofs d, -awing of A. leplcrhy,uhus, but it is thicker transversely than ,n
that sirecies, and on its internal side are two conve-X facets for the astragalus Be-
low the Hhular prominence the calcaneum has a greater dorso-p an tar ‘ “

in the European sirecies, and the cuboidal facet is less oblique with reference to the
"n axim bone, though more so than in Oreoim. This facet rs somewhat
sadSle-shaped. being ch.cave in the dorso-plantar f

transversely; the The dlutialarLet is unusually

63 JOUEN. A. N. S. PHILA., VOL. IX.

484 THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

tracted, much narrower than on the plantar side. The proximaUacets are of un-
e(|nal size, that for the calcaneuin being considerably the wider. The latter is con-
vex antero-postoriorly and is broad behind, narrowing toward the front, descending
lower upon the dorsal Dice than in the specimens figured by Kowalevsky (FI.
XXX VI 11, fig. 1), and separated by a distinct groove from the ascending process
which forms °the astragalar facet. The latter surface is divided into two facets,
dorsal and plantar, widely separated by a broad and deep sulcus. The plantar
surface of the cuboid is very broad and, in general, agrees with the shape found in
the European sjiecies, though dillering in some details. Kowalevsky says of Ins
specimens: “Looking at the cuboid from the posterior aspect, we perceive a very
broad and rough transverse ridge for muscular and ligamentous attachment, running
through the whole breadth of the bone. . . . This ridge does not reach the

level of the distal articular surface of the cuboid, which is the lowmst point of the
bone” (p. 57). “ Instead of the broad transverse ridge seen on the posterior sur-

face of the cuboid in the Hyopotarnus, the cuboid of the two-toed Diplopus has this
ridge prolonged downward in a beak-like process quite of the same shape as in the
common Hog. This posterior beak descends lower down than the distal articular
surface of the cuboid, and exhibits on its inner side an elongated facet, by which
this beak articulates with a corresponding cuboid facet on the outer side of the
posterior prolongation of the fourth metatarsal. ... In my specimens of
Hyopotarnus from Puy the posterior prolongation of mt. IV is not well preserved ;
but as there is no downward prolongation on the cuboid and no facet, the cuboid
seems not to have articulated with this posterior prolongation of the fourth meta-
tarsal, and it does not so articulate in Anoplotherium and Hippopotamus”
(pp. 58-59).

In A. brachyrhynchus there is a very massive but rather short posterior beak
which does articulate with the posterior prolongation of mt. IV, just as Kowalevsky
describes it in Diplopus, but internal to this the broad transverse ridge extends beneath
nearly the entire breadth of the navicular and above the posterior hook of mt. Ill,
and has a broad contact with the entocuneiform. On the tibial side the cuboid
displays two large facets for the navicular, which are separated by a continuation
of the same wide and deep sulcus that divides the astragalar facet into two parts.
The dorsal navicular facet presents internally, the plantar one superiorly. The
distal facets for the metatarsals do not dilfer notably from those of the European
species.

In Oreodon the cuboid is relatively lower and broader than in Ancodus ; the
calcaneal facet is not cut so deeply into the anterior face, and the astragalar facet
IS continuous, not being divided by a sulcus. The posterior beak is rudimentary

.7 r“, is excluded fram any

between tliei ri w f e t*eak of the navicular, which intervenes

“■““'I'-' ‘tan in

The mvicular is high and rather narrow, its greatest diameter being the antero-

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

485

posterior, whUe in Oreodon this is exceeded by the transverse width. The plantar
hook, which in the latter genus is long and well developed, is small, hardly more
than a rudiment. On the fibular side the facets for the cuboid correspond in size,
shape, and position to the navicular surfaces on that bone, already described. The
distal side displays separate facets for the cuneiforms. That for the ectocuneiform
is very large and occupies the whole dorsal half of the distal surface. There is a
second isolated hicet for the same bone, almost circular in shape, which stands be-
hind the principal surface and at a somewhat higher level. The mesocuneiform
facet is very narrow, and is confined to the tibial margin of the navicular, while
that for the entocuneiform is considerably larger, more concave and more oblique,
being continued down upon the tibial side of the rudimentary beak. This facet is
almost entirely plantar in position, and concealed w'hen the bone is seen from the
front.

The entocuneiform is of very remarkable shape, quite unlike that of any artio-
dactyl with which I have been able to compare it, though most resembling that of
the hippopotamus. It forms a high and very broad plate, not unlike a pisiform in
appearance, and had it been found isolated, would have been very puzzling. Antero-
posteriorly it is compressed and thin, but has a rugose surface. The proximal end
is contracted to form the navicular facet, which is transversely convex. Laterally
it articulates with the cuboid and anteriorly with the mesocuneiform, and extends
down behind the second metatarsal, with which it has an unusually long contact.
Distally it bears a facet for the rudimentary first metatarsal. In Oreodon the ento-
cuneiform has an entirely different shape, being high and narrow, articulating more
extensively with the navicular hook, but without facets for the cuboid or first meta-
tarsal. The latter occurs in Protoreodon [fide Marsh). This element has not yet
been identified for any of the European species of Ancodus.

The mesocuneiform is small and stands at a somewhat higher level than the
ectocuneiform. Though the specimen here described is of a young animal, m which
the epijihyses are still separate, an incipient cocissification of the meso- and ectocu-
neiforins is very plainly marked, and in the adult the two bones are doubtless as
indistinguishabiy ankylosed as in Oreodon. In the European species the ankylosis
of these elements is, according to Kowalevsky, subject to individual variation; m
some specimens the two have coalesced, while in others they are separate. n e
spcciine.i of A. mierUanus from tlie Metoiovnodoil-Ws the ect.> and mesocunei-
forms remain separiitc. How far this difference is characteristic of the species, and
how far subject to individual vari.ation. cannot be definitclj deeded at present

The ectccuHdform is liigher, aamnver, and deeper than in
that nenus tliere is a small lateral surface for the second metatarsal The proximal
side I'iears iwo facet, for the navicular, a large one in front „f snbtriangular shape,
and behind this a small circular and isolated facet. available the

It is somewhat difficult to

which this description is for the most part founded has no metatarsals

486 THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

with it, and of tlie tarsus only the calcaneum and astragalus. In a second fragmen-
tary skeleton the metatarsals and metacarpals are of nearly the same length, while
a third specimen, a beautifully preserved hind-foot, of which the calcaneum and
astragalus agree closely in size with those of the first-named specimen, the metatar-
sals much exceed in length the metacarpals of the latter. A more extensive series
of fore- and hind-feet associated together will be required to determine accurately
these relations. In the following description the isolated pes is made use of.

The metatarsals differ from those of Oreodon in the greater proportionate de-
velopment of the median pair and reduction of the laterals. The first metatarsal
is a small nodular rudiment of irregular shape, which is broadest proximally, taper-
ing distally to a blunt point, and is of roughly trihedral section. It is attached to
the distal end of the entocuneiform, but there is no clearly defined facet, and doubt-
less the joint was very imperfectly developed. No phalanges are connected with
the rudimentary metatarsal, and the hallux is thus far more reduced than is the
pollex, which is relatively larger than in the dogs. The rudiment is entirely plantar
in position, being concealed from the front by mt. II, behind which it lies.

The second metatarsal is long, much compressed laterally, and of trihedral
shape, expanded and somewhat thickened distally. The head is very narrow ; it
bears a small facet for the mesocuneiform, and abuts by a minute surface against
the tibial side of the ectocuneiform, beneath which the shaft is excavated to receive
an expansion of the head of mt. III. The postero-internal angle is cut away at the
proximal end, forming a long, oblique surface, overlapped by the wide entocuneiform.
The distal epiphysis has been lost from the specimen.

The third metatarsal is very long and, though much heavier in every way than
the laterals, is slightly shorter and considerably narrower than mt. IV, while in
Oreodon it is somewhat longer. The proximal end rises less above the head of
mt. IV, and has a smaller contact with the cuboid than in the specimen figured by
Kowalevsky (PI. XXXVIII, fig. 1) more so than in that figured by Filhol (PI. 25,
fig. 124), and the head is relatively narrower than in either. On the fibular side,
below the head, is a deep pit into which is received a corresponding projection
from mt. IV. By means of this and the mode of articulation with the tarsals
the median pair of metatarsals are very firmly locked together. From the plantar
side of the head arises a long and stout projection, which is held in place by the
cuboid proximally, the entocuneiform' internally, and mt. IV externally The
shaft IS more compressed antero-posteriorly, and has a more flattened dorsal face
than m OWOB. The distal trochlea is wider proportionately than in that genus,
but IS demarcated from the shaft in the same way by a deep pit on the dorsal face
of ‘he bone. In all the metatarsals the oarlna is entirely plantar,

not mneh e“ve d ‘'l' <>f i <*0^“

the proxi,:aTe„d.” B™ K “t’sSl d

the European species it is rather mt rnder^r^f^I^I.

are exclnswely w.th the cuWd, but are nevertheless quite 00^^ On Z

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 487

dorsal side the articulation is of the usual type, but the long and massive plantar pro-
jection is firmly wedged in between the corresponding projection of mt. Ill, and the
cuboid both proximally and externally, making a joint of great strength. Some-
thing of the same kind may he observed in Oreodon, though much less completely
elaborated, while the European species of Ancodus appear to be intermediate
in this respect between Oreodon and A. brackyrhynchus, the internal projection
from the plantar half of the cuboid being much stronger in them than in Oreodon.

The fifth metatarsal is somewhat longer than the second and of quite a different
shape. The shaft is more compressed and less trihedral in section, and though very
narrow, has considerable dorso-plantar diameter. The head has a long projection
from the posterior side, which extends beneath and appears to articulate with the
plantar hook of the cuboid. In Oreodon this projection is rudimentary and does
not touch the cuboid. The shaft is more compressed and less rounded than in the
last-named genus, and less expanded distally ; the trochlea is very similar in both
genera.

The phalanges of the pes are very different from those figured by Kowalevsky
xind Filhol, and, so far as the median digits are concerned, are much more like those
attributed to Diplopus. It is, however, uncertain whether the material accessible
to those writers enabled them to discriminate between the phalanges of the manus
and those of the pes. In the specimen here described there is fortunately no room
for doubt on this subject, all the bones of the hind-foot being preserved in their
natural position and connections by the matrix.

The first phalanx of the second digit is very much longer, more slender and
compressed than that figured by Kowalevsky and Filhol, and has considerable re-
semblance to the proximal phalanx of one of the median digits in the deer or ante-
lope. The proximal end is compressed, but thick (antero-posteriorly) with a shallow,
■concave facet for the metatarsal, which is grooved only on the plantar margin.
The shaft is much contracted in both directions, and the distal expansion is but
moderate. The distal trochlea is deeper than wide, is somewhat notched in the
median line, but not at all reflected over upon the dorsal side of the bone.

The second phalanx is hardly more than half the length of the first, but is
relatively much stouter. The proximal trochlea is divided by a low median ridge
into two shallow concavities, which are wider than the corresponding surfaces on
the distal end of the first phalanx. The shaft is short and stout and somewhat
unsymmetrical, being depressed and hollowed on the fibular side. The distal trochlea
has a relatively larger dorso-plantar diameter than that of the first phalanx, and

reflected more upon the dorsal side; it also is slightly asymmetrical.

The ungual phalanx is very like a median ungual of OreodonMi\i m size and
shape, but is more depressed, with a more regularly arched dorsal surface and blunter
distal end. The proximal articular surface is obscurely divided into two acets of
which that on the fibular side is smaller and more oblique in position with refer-
ence to the long axis of the bone. Hie

The phalanges of the fifth digit are essentially like those of the second, the

488

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

only noteworthy difference being that the second phalanx is distinctly narrower
and more slender. In spite of their very elongate proximal phalanges, the lateral
digits cannot have reached the ground, and must have formed mere dew-claws the
unguals extending only to the lower end of the proximal phalanges of the median
digits. This shortening affects principally the metatarsals.

Filhol’s drawing of the phalanges of the lateral digits oi A. velaunus (PI. 25,
fig. 124) shows them to have been different from those here described. The proxi-
mal one is much shorter and heavier, the second more slender, and the ungual much
smaller and more pointed. The relative lengths of the median and lateral digits are
about the same in both species, but in A. velaunus the lateral metatarsals are much
longer and the phalanges shorter, while in the American form these proportions

are reversed.

In the median digits the proximal phalanx does not exceed those of the lateral
digits in length, but is very much larger in every other dimension, and especially in
breadth. The general shape is not unlike that found in Or eodon, but the bone is
straighter, broader, less arched, less compressed antero-posteriorly, and the distal
trochlea, is less deeply notched in the median line. The phalanx is broadest and
deepest at the proximal end, and the articular surface is a shallow concavity, notched
on the plantar border for the keel of the metatarsal. The lateral processes for
ligamentous attachments just above the distal trochlea are better marked and more
prominent than in Oreodon, and the pits are correspondingly deeper.

The second phalanx is asymmetrical, though those of the two median digits
form together a nearly symmetrical pair; not entirely so, however, for the two are
not quite alike. This phalanx is shaped like the corresponding one of the lateral
digits, but is much larger and heavier. The proximal trochlea is very obscurely
divided into two facets, and the distal trochlea is oblique, inclining toward the
median line, as it passes dorsally ; it is reflected distinctly farther upon the dorsal
side of the bone in the fourth digit than in the third.

The ungual phalanx is much like that found in Oreodon, but is relatively
broader, more regularly arched on the dorsal surface, more depressed, of less dorso-
plantar diameter, and more bluntly rounded distal end. In spite of these differ-
ences, the unguals of the two genera are manifestly of the same type, a fact which is
not without morphological significance, because this type is not at all a common one.

The phalanges of the median digits in the European species, according to
Kowalevsky and Filhol, are m many respects quite different from those here described
an referred to A. brachyrhynchits. The proximal one is more slender and tapering,
as well as longer iri proportion to the metatarsals. The second is much less mas-

the ’.mini ' compressed, and pointed. In fact,

S JZt are more like those of Dtplopru than those of

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.
VI. EBSTORATION OF ANCODUS.

489

The general appearance of the skeleton of A. brackyrhynchus is not unlike
that of Sus scrofa, though with manifold differences of detail. The head is rather
shorter in proportion and of quite a different shape, the backward shifting of the
orbits in Sus and the elevation of the posterior part of the skull, giving to that
animal special peculiarities. Then, too, the absence of the great tusk-like canines
in Ancodus completely changes its physiognomy. The neck is longer and
more curved, but more slenderly and lightly built, with shorter and less massive
spines and processes on the vertebrm. So far as can be judged from the available
material, the trunk is relatively shorter, and the spines of the thoracic vertebr* not

490

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

and the chin is abruptly rounded and steeply inclined, while in Ancodus, on the
other hand, the muzzle is greatly elongated and very low, especially toward the
front; the chin is pointed and very procumbent. Another difference between the
two genera consists in the fact that in Ancodus the disproportion between the
length and weight of the fore- and hind-lirnbs is greater. The neck is also some-
what more elongated in the latter, though not very much so. In nearly all other
points the resemblance between the skeletons of the two genera is very close even
in minor details.

The proportions of A. americanus are quite different from those of A. brachy-
rhynchus. The neck is shorter and lighter, the trunk of almost the same length,
while the limbs are longer and lighter in joroportion to their length.

So far as can be judged from Kowalevsky’s restoration of Anthracotherium
(No. 4, PI. XV) the skeleton of that genus differs from that of Ancodus princi-
pally in the much greater elongation of the trunk and the shortness of the limbs.

VII. THE EELATIONSHIPS OF ANCODUS.

Ancodus is usually, and no doubt correctly, classed as a member of the An-
thracotheriidce, but our survey of its osteology has brought out numerous and sug-
gestive resemblances to the oreodonts. Both groups display many divergent speci-
alizations, but at the same time there is a fundamental similarity apparent in all
parts of the structure, which renders the reference of these likenesses to mere
parallelism an improbable one. The cranium is closely similar in the two groups
in almost every detail of construction, except the shape of the occiput, which in
Oreodon is higher and narrower and with the superior wing-like processes of the
supra-occipital much better developed. Agriocharus agrees more closely with
Ancodus in the character of the occiput than Oreodon does with either. The orbit,
which in the latter genus is completely encircled with bone, remains open behind in
Ancodus, as is also the case in Agriochoertis and Protoreodofi. The three genera
further agree in the absence of the lachrymal depression in front of the orbit, which
is so characteristic a feature of Oreodon. In the proportionate development of the
facial region Oreodon and Ancodus have diverged widely. In the former the face

uuii 01 rne race, nowever, varies
maximum in A. leptorhynchus,.

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

491

while in the American species it is generally less than in the European. The
longest-faced of the White River forms is A. americanus, in which the relative
length of the muzzle is nearly the same as in A. velaums, the shortest of the Euro-
pean species. The facial elongation is increased by a shifting of the orbits. In
Protoreodon, Oreodon and Agriochoerus the anterior rim of the orbit is above the in-
terval between “i and while in Ancodus, as also in Merycochosrus, it has re-
treated so as to be above As regards the length of the face, Agriochcerus is
intermediate between Oreodon and Ancodus, and it seems altogether probable that
in this respect it has been conservative, and represents very nearly the common
starting point whence the three lines diverged. As would naturally be expected,
Protoreodon is decidedly nearer to this type than is Oreodon, and it is a suggestive
fact that the anthracotherioids from the Titanotherium-beds, as yet but little known,
have the facial proportions, length of diasteinata, etc., very much as in Agriochcerus.

The mandible displays corresponding differences in the three diverging lines.
The condyle and angle are much alike in all, but Ancodus is peculiar for the re-
markable production of the angle below the level of the horizontal ramus, while the
angle is more thickened and the condyle more elevated in Oreodon. The develop-
ment of the coronoid process varies much within the limits ol the separate families,
in the American species of Ancodus it is high and recurved, with deep sigmoid notch,
while in the European species it is rather feebly differentiated, low and of triangular
shape. In Oreodon it is intermediate between these two extremes, and in Protore-
odon and Agriochoerus it resembles the shape found in the American species d An-
codus. Doubtless in this respect also Agriochcerus and Protoreodon represent nearly
the original condition. In all of these genera the masseteric fossa is ratlin small,

and situated high up on the ascending ramus, and is in most of the species quite

deeply impressed, least so in the European representatives of Ancodus. Ihe de-
velunmonl of the horizontal ramus varies in accordance with the e on gat. on of the
face in Oreodon it is short and deep, with abruptly trancated ohm and steeply
inclined symphysis; in Arou’.r it is very long and quite shallow (though m th s
latter respect there is much difference to be noted between the various sjKCiesh
AgHocl2rt,s is intermediate between the two
Butiposed Anihracotherium of the Titanothenmn-beds, as well

^ ^ The three lines display very striking divergences in the character of the den
1 • .1 of itiP sknll-structure, Agriochcerus, in some degree, com-

tition, and as in t le case ■ Protoreodon also have an inter-
bines the features of the other two. The teeth ot ^

mediate chameter between J ''

different sense. I" „„„ has assumed the form and functions of

upper canine is trihedral and 1 premolor. The premolars

irs:^rerLiy,hutLm^^^^^^^^

^he's: »

ingly like those of the existing brachyodont ruminant .

64 JOURX. A. N. S. PHILA., VOL. IX.

492 THE STRUCTURE AND RELATIONSHIPS OP ANCODUS.

1„ AimJm Hie Incisors arc spaced well apart, and have large, spatulate crowns;
the calls are ordinarily smaH, except in J. Up<.kynchus, and the lower one
dillers hat little from the incisors in shape. The premolars are much snnpler than
those of Ore, dm,, not havins the ridges and tubercles developed on the internal
faces The upiwr molars are very different from those of the last-named genus ;
not only have they retained the pmtoconule, but the, have very broad, low crowns
with deeply concave outer crescents, which project far toward the median part of
the tooth, and with very prominent and tuberous external buttresses or styles. On
the lower molars the crescents are very much higher, somewhat thicker, more
conical and less completely crescentic in shape.

Agriochcerus combines some of the features of the other two genera with
characteristic peculiarities of its own. It agrees with Oreodon in the character of
the canines and caniniform first lower premolar, and in having lost the protoconule,
thus making the upper molars tetraselenodont. Aside from this, however, the
molar pattern is very much more like that of Ancodtis, though the cusps of the
lower ones are less elevated. The premolars are, for the most part, less compli-
cated than in Oreodon. Peculiar features are the more or less complete reduction
of the upper incisors, and the molariform pattern of the last premolar in each jaw.

Protoreodon nearly represents the common term from which all three types of
dentition may easily have been derived, and though it has already assumed too
many oreodout features to be actually the real starting point from which the later
genera diverged, it greatly reduces the gaps between them. The incisors and
canines are like those of Oreodon,, the premolars have the simple compressed coni-
cal form which recurs in Ancodus and Agriochcerus ; the upper molars still retain
a well-marked protoconule, like that of Ancodus, and the lower molars are almost
exactly like those of Agriochosrus. The particular interest attaching to Protore-
odon consists in the proof which it gives that the oreodonts were derived from an-
cestors with quinque-tuberculate superior molars, having the fifth lobe in the ante-
rior half of the crown, and this brings them into relationship with the anoplothe-
rioids, anthracotherioids, etc., as distinguished from the dichobunids and csenothe-
rioids, to which it seems probable that, as Sclilosser has suggested, the existing
lines of ruminants should be traced back.

1 he character of the vertebral column is very similar in both Ancodus and
Oreodon, es])eciii\\y if the species of the former which occur in the Protoceras-beds
be used in tlie comparison, the differences being merely such matters of detail as
are incidental to the great difference of stature. In the later species of Ancodus
(e. g. A. brachyrhynchus) the odontoid process of the axis is, like that of Oreodon
and Agriochcerus, neither conical nor spout-shaped, but half-way between the two
patterns. Ancodus americanus from a lower horizon, however, has a fully conical
odontoid, and this shows that the resemblance of A. brachyrhynchus to Oreodon in
this respect is a case of parallelism, and has been acquired within the limits of the
genus.

The scapula, which as yet is very imperfectly known in Agriochcerus, is alike

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS. 493

in the other two genera, both having the spine placed in the middle of the blade,
dividing It into subequal fossae. In some species of Ancodzis the blade is broader
in proportion to its height than in Oreodon, while in others the resemblance in out-
line IS exact, and in all the similarity is much greater to the latter genus than to
Anoplothermm. The character and position of the acromion are also alike in the
two genera.

' The humerus is much alike in Ancodus and Oreodon. In the former the inter-
condy lar ridge of the distal trochlea is narrow and compressed, while in the former
it is broad and hemispherical, and in both the internal epicoiidyle is very conspicu-
ous. In AgriocJmrus the distal portion of the humerus has its oreodont peculi-
arities so exaggerated as to closely approximate the creodont structure ; this is to
be seen in the breadth and lowness of the trochlea, perforation of the supra-
trochlear fossa, and the great prominence of the inner cpicondyle. In this way the
resemblance to the humerus of Mesonyx is made remarkably close ; indeed the
humerus of the latter is more ungulate in appearance than is that of Agriochcerus.

The radius and ulna are much alike in all three lines; the former has a slender,
subcylindrical shaft, which is most widened and flattened in Ancodus, while the
distal end in Agriochcxrus has become very creodont-like. The ulna is very little,
or not at all reduced, and has a very large olecranon, which in 07'eodon is very
high, and in Ancodus (juite low.

The carpus, again, displays in each of the three lines certain specializations
peculi.'ir to each, but with a general similarity throughout; in Agriochoertis we find
the widest departure from the common plan. In the oreodonts there is a strong
tendency in the magnum to shift altogether beneath the scaphoid and to retain
only a lateral contact with the lunar. This tendency, which is plainly incipimit m
Protoreodon, reaches its maximum in Merycochoertis and Merychyus.^ A similar
tendenev, though very much less marked, is observable in Ancodus, while in Agno-
c/icerus the displacement is in the opposite sense, the magnum shifting toward the
ulnar side of the hand. The individual carpal elements are quite alike in Ancodus
and Oreodon, and in all three genera the trapezium is present and of some func-
tional im}K)rtance. i- i i j

The manus is pentadactyl in all three lines, except in some of the later and
larger specimens of Agriochoerns, which seem to have lost the pollex. _ The first
digit iB rehatively best developed in Ancod,is. In all three the connections of
metacarpus will, the carpus are of the unreduced type, the third metacarpal being
excluded from the trapezoid by the contact of the second w.th the magnum In
Oreodon and Ancodus the phalanges are similar; the nng.mis are very char er-
istic and of a type not common among the artiodacty s. The European spec, es of
.. , n I fide fvne of ungual, giving a smaller and more

Ancodus seem to have modilied tins type ^ ^

pointed hoof than in the American foims. ^ 11^ TLfv nno-iials are

LtiodaetyU, recent or extinct, in the character of tts “J" ^

large, eon.pmssed, and claw-like, and the art.culat.ons »f
semble those of the A,uylopoda rather more thau those of the ungulates.

494

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

Tlie hind-leg of Ancodus is in all essentials like that of Oreodon. The proximal
end of the feinnr is more expanded transversely, and the shaft is relatively longer.
The patella is more massive; the internal malleolus of the tibia is less extended,
while the distal end of the fibula has moved somewhat more completely beneath the
tibia. The shaft of the libula is of about the same relative proportions in both
genera. In A^riochceriis the knee-joint has acquired a curious resemblance to that
of the carnivores, doubtless in correlation with the extraordinary character of the
hind-foot.

The tarsus of Ancodus is much more specialized than is the carpus; all its
elements are notably higher than in Oreodon (though this is subject to considerable
specific variation), and, therefore, much more so than in Agriochasrus. The special
cliaracters of the tarsus, however, resolve themselves principally into the remark-
ably complex and perfect articulations between the calcaneum and astragalus.
These peculiarities are much more strongly marked in the American forms of Ancodus
than in the European, and even among the former some species have these articula-
tions more perfectly differentiated than others. Another notable feature is the
great size and peculiar shape of the entocuneiform. There is a tendency, though a
variable one in both the European and American species, for the meso- and ectocu-
neiforms to ankylose, as in Oreodon. The tarsus of Agriochasrus does not differ in
any noteworthy way from that of Oreodon, except in the greater relative breadth
and height of its various elements.

The metatarsus is more or less peculiar in each of the three genera. In Agrio-
chnerus the pes is almost isodactyl, the median metatarsals not much exceeding the
laterals in length. In Ancodus the hallux is reduced to a nodular rudiment of the
metatarsal without phalanges, and the lateral metatarsals are so much shorter than
the median pair that the second and fifth digits cannot have reached the ground.
In Oreodon the hallux has entirely disappeared, but, on the other hand, the median
digits do not exceed the lateral pair so much as in Ancodus. Here, again, Protore-
odon serves to connect the two White River genera. In a recent paper (No 7 p
267) Marsh has pointed out that Protoreodcni {Eomeryx) possesses a nodular rudi-
ment of the first metatarsal. The tarso-metatarsal articulations are nearly the
same in all four genera, except that the second metatarsal, which in Protoreodon,
Oreodon and Ancodus has a small lateral contact with the mesocuneiform, is in
Agriocharus excluded from that element.

Fi-om this rapid corap.,rati,e survey of the osteology of Ar^odm .and Oreodon
the numerous .mportant reseraUauces between them become at once obvious, thougli
the oorrospondences are aocompanied and, to some extent, concealed by many Si
ences. I he similarities between Ancodus and the oreodonts are so nmnerons^aiid so
genera t at any reference of them to parallelism seems altogether ui.likl in the

toioinmiuHroTdeTcenr'’ Tr'* fundamental and point

of the pinbable European origin of .daWrrx, hut it Irt^em^b^rLT'a

495

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

common ancestor of the Bridger age is all that such a view postulates I have
elsewhere suggested that the Bridger representative of the oreodonts may be the
very imperfectly known genus Hdohyus. The same formation has yielded teeth
of a similar type, but considerably larger, which may well represent the ancestor of
Ancodiis. lhat the genus has not yet been reported from Europe is not surprising
in view of the very scanty Eocene fauna as yet knoAvn in that region. The indica-
tions, at present known, all go to show that Ancodus, Oreodon, and Agriochosrus
represent three divergent branches of the same artiodactyl stem, the starting point
of which will prove to be some middle Eocene genus with pentadactyl feet and teeth
of the type of Helohyus. Probably the agriochoerid and oreodont lines diverged
from each other somewhat later than Ancodus did from both, though, in view of
the extraordinary specializations which Agriochoerus exhibits, this view is uncer-
tain, and a decision upon it must await the event of future discoveries.

The possibility of an American origin of Ancodus must not be overlooked.
No one can imagine that we have yet obtained more than an insignificant fragment
of the Uinta fauna, and the number and variety of Bridger artiodactyls are far
greater than the described genera would lead one to expect; this is indicated by
numerous remains which, unfortunately, are too fragmentary for satisfactory iden-
tification. While the facts at present known all seem to point to the origin of
Ancodus in the Old World and its migration to America, in the interval between
the Eocene and the Oligocene (Uinta and White River), yet until the American
artiodactyls from the middle and upper Eocene are far better known than at present,
such a conclusion cannot be regarded as final.

496

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

lTp|>er iireniolar-niolur series, length
'• jireniolar series, length .

“ molar series, length
Ijower molar-preiiiolar series, length
“ molar series, length
“ preniolar series, length .

Skull, length from occipital condyles

" height from inion to angle of mandible
Cranium, length from for. mag. to front margin of
Kaoe, length from orbit to incisive alveolus
Sagittal crest, length
Premaxillary, “

Mandible, “

“ height at condyle

“ “ coronoid process

“ depth at 1113

“ " 1.3

“ breadth of angle, obliquely from m

Atlas, width . . .

Axis, length of centrum
Scajiulu, height .

“ greatest width .

Humerus, length (fr. ext tuberosity)

“ width of distal trochlea

Radius, length

“ width of distal end
Ulna, length

height of olecranon
Metacarpal 1, length .

“ III,’ “

“ IV, “

“ V, “ .

Metacarpal I, breadth of proximal end

“ lll| “

“ IV, “

“ V, “ “ o

Femur, length (from great trochanter)
breadth of proximal end
Tibia 1 distal end (fore-and-aft

“ width of proximal end
“ “ distal “

Calcaneum, length
Astragalus, length

‘ width of proximal trochlea
,, “ distal “

hletatarsal 1, length

“ II, “

“ 111, “

“ IV, “

“ V, “

iMetatarsal ^1, width of proxiinal end

“ III! " o !!

“ IV, “

“ V, "

Fiwt phalanx, II digit, length

!! !! “ “

Second phalanx, 11 digit, length

“ " IV “

“ V “ “

Ungual phalanx, II digit, length

;; “ IV “

V “

THE STRUCTURE AND RELATIONSHIPS OF ANCODUS.

1.

2.

3.

4.

6.

7.

8.

9.

LIST OF PAPERS QUOTED

- -i.

Ko^alenk,. ir-on th. 0..»logf of fc Hpp«..mid». PM.,,.*,,

Society of London, 1873.

Monographie der Gattung Anthracotherium, etc. Pakontographica, Bd. XXII,
1873.

Leidy, J.-Tlie Extinct Mammalian Fauna of Dakota and Nebraska. Joum. Acad. Nat. Sci.
Phila., 1869.

Marsh, 0. C.— Notice of New Tertiary Mammals. American Journal of Science, 3d Ser., Vol.
XXXIX, 1891.

Description of Tertiary' Artiodactyles. Ibid., Sept. 1894.

Osborn. II. F., and IFortwian, J. A.— Fossil Mammals of the Lower Miocene White River Beds.

Bulletin American Museum of Natural History, New York, Vol. Ill, 1894.

ScoU, W. R.— The Manus of Hyopotamus. American Naturalist, Feb. 1894.

EXPLANATION OF THE PLATES.

Plate XXIII.

Fig. 1. Ancodus hrarhyrhynchus t — Skull, from the right side, I natural size.

Fig. 2. Ancodus americanusf — Base of skull, I natural size.

Fig. 3. “ “ Occiput, J natural size.

F'ig. 4. Ancoduasp. — Plantar view of part of pes, showing rudimentary mt. I, f natural size.

Plate XXIV.

P'10. 5. Ancodus brachyrhynchusf — Right humerus, front view, I natural size.

PTo. 6. “ “ Left ulna and radius, from outer side, f natural size.

P'lO. 7. “ “ Left nianus, anterior view, f natural size.

Fig. 8. “ “ Right femur, distal end, s natural size.

Fig. 9. Ancodus sp. — Right pes, anterior view, f natural size.

THE OSTEOLOGY OF HYiENODON.

499

THE OSTEOLOGY OF HY^ENODON.

By W. B. Scott.

(Investigation aided by a grant from the Elizabeth Thompson Fund of the A. A. A. S.)

In a paper published in the Journal of the Academy of Natural Sciences of
Philadelphia in 188 i (No. 6) I gave an account of the osteology of this genus so
far as the materials then available would permit, but those materials were very
imperfect and left much room for conjecture. The Princeton Expedition of 1894
was especially fortumite in collecting specimens of Hycenodon, Mr. Hatcher having
found several more or less complete skeletons representing a number of different
species. I am no\v in a position, therefore, to supplement the earlier account and
to give a restoration of the skeleton of this very curious and remarkable animal.

For the sake of completeness a description of the parts of the skeleton already
known is added to those wdiich are here described for the first time. The rapid
increase in our knowledge of the creodonts which has taken place in the last seven
years makes it necessary' to go over this ground again from a somewhat different
point of view, in order to make clear the systematic relationships of the genus.

No less than six species of Hycenodon have been identified in the White River
or Oligocene beds. These may be conveniently arranged as below. This tabular
carrangement, however, is not intended to express the mutual relations of the species.

I. Upper premolars three, H. pauadens 0. .

II. Upper premolars four.

A. Palatines in contact throughout; pterygoid ‘i

plates of alisphenoids meeting below, H. leptocephalus Scott

B. Posterior nares between palatines, pterygoid plates separate.

a Postorbital constriction in advance of

fronto-parietal suture, H. cr^uians Leidy

b. Postorbital constriction at or behind fronto-parietal suture.

1 Size very' large ; frontal sinuses much

inflated, P2 with posterior cusp, H. horridus Leidy

2 Size moderate; sinuses less inflated,

P2 without talon, H. cruentus

3. Size minimal, P-” = 58 mm., H. m^istehnus sp. nov.

HY.*:NOr>ON MUSTELINCS sp. UOV.

This species is characterized by its small size,
known, the uniform size of the upper premolars
6.5 JOUEN. A. N. S. PHILA., VOL. IX.

less than that of any other yet
(except F), the acuteness of the

500 the osteology of hy^nodon.

tritocone on and P^, the slenderness of the canines and the shallowness of the face^
T of tl.e racial portion of the skull and many fragments of

the ekrieto'u, including a nearly complete hind-foM. It was found by Mr. Hatoher
in the lower l>,-otoceras-beds (upper part of the While River horison).

In the following descriptions, account will be taken of the peculiarities of each
species so far as these are known. The specific differences refer principally to
variations of size ; in important structures there is great constancy.

T rvxjT? riT^XTTTTTOISr

The structure of the teeth has long been accurately known and needs no de-
tailed account. The incisors and canines are entirely of the carnivorous type, the
external upper incisor much enlarged, and the second lower crowded back out of
line with the other two. The upper premolars are very simple, essentially com-
pressed cones, with more or fewer additional cusps. In N. crzientus p2 has no pos-
terior cusp, which is present in the other species. In the former, and in H. horri-
dus, this tooth has an exceptionally high crown. On the tritocone is always
present. The fourth premolar has all the elements of the carnivorous sectorial ;
but the deuterocone, though supported on a large fang, is itself but little developed,
and the tritocone is too small to form an efficient shearing blade. In the smaller
species, H. crucians, H. pmicidens^wyH H. mzislelinus, is a small antero-cxternal
basal cusp. H. pancidezzs is altogether excejotional in lacking Pi and in having
placed very obliiinely to the line of the jaw. The upper molars arc highly cliarac-
tcristic. The protocone is lost, though its fang is retained. The para- and meta-
cones are very closely approximated, and on “2 are in distinguish ably fused together ;
a long and trenchant posterior ridge forms a very efficient shearing blade, especially
on which is much the larger of the two.

The lower premolars are likewise of very simple construction. The first has
always a very low crown, but is much elongated from before backward. In H. erzt-

entzis p2 and pS have no talon (rnetaconid), which is present on p4 ; in H. pazicidens
the talon is present on p3 as well as fi4, and in H. cruciazis and H. horridiis it is
present on all the premolars except the first. In H. pazicidezis pi is smaller than
in the other species, and p3 has the same oblique position as in the upper jaw. The
first molar is one of the smallest teeth in the lower series; its crown consists of
three cusps m the same antero-posterior line, a high protoconid and lower para- and
hypocomd, the rnetaconid having disappeared. The second molar is composed of

compressed proto- and paraconids form an

httri„rth T ■“»« offirient and more simplified,

ditio. ” - "'lylh however, is sometimes retained in a rudimentary con-

sC" r-T f “PP- “■'<1 lowoh fs the

of all the cheek teeth.'™* ~ "“o> 11“ trenchant form

THE OSTEOLOGY OF HYiENODON, 501

1 he Milk Dentit707i. 1 he canines, and in all probability the incisors also, have
representatives in the temporary dentition. As Wortman has suggested, the first
premolar in botli jaws appears not to be changed. The temporary second upper
premolar is a very simple tooth ol compressed conical shape, much elongated from
before backward at the base, and with a cingulum on the inner side. While dp2 is
very much like its permanent successor, ipS is unlike any of the permanent series;
it consists of four cusps in the same fore-and-aft line, an anterioi' and two posterior
basal cusps, with the protocone, and considerably resembles a premolar of Tcnino-
cyon. The last milk-tooth, is constructed like “l, but the two antero-external
cusps, corresponding in position to the para- and metacones of the molar, are of
more nearly equal size and less closely approximated, the posterior trenchant ridge
is less elongated, and the whole crown is lower. There is no trace of an internal
cusp (deuterocone), though the tooth is carried on three fangs.

Tlie lower milk dentition has been described by Wortman (No. 4, p. 226), and
I can add little to his account. The first premolar appears to have no predecessor,
while dp2 1 have not seen, as it is replaced at such an early stage by p2. The crown
of dpk has a very high and acute protoconid, with a long, posterior basal expansion,
upon which a small cusp appears. The last milk tooth, di>4, has elements corre-
sponding to those of ml, but somewhat differently developed and not forming a
shearing blade; the protoconid is high and conical, while the anterior and posterior
basal cusps (para- and metaconids) are much lower and of more nearly equal size.
In the specimen described by Wortman, which apparently is referable to H. mus-
telinus, dpt resembles ml much more closely than in the one which forms the basis
of the foregoing description, a skull of a small species which is of uncertain refer-
ence. In this specimen the upper jaw contains, besides the canines and mcisors,
the following teeth: Pi, aud “1; in the lower jaw are pi, 2, dp3,4, ml, 2. An-

other mandible, belonging to H. cruentus has the same teeth in use. It is evident,
however, that ml has been in use much longer than m2, and that at an early stage
the sectorial teeth are ^ and ml, which imitates the arrangement found m the
permanent dentition of the carnivora, though not in the temporary set, m which

the last milk premolars operate as sectorials.

Tlie pcraanent canines would appear to be erupted after all the premolars and
molars are in place. At le,,st this is true of one large specimen oi a skull belon,-

*1 Imvrimt been able to detect the change in the incisors of either jaw.

IMie oniv otherci-eodont families whose dentition is at all similar to hat of the
^ I /--> onfl flip Provtvcwid^. In theformei, the premo

Hycenodontidcc are the Oxy^^tdee. ^pich is especially strong

bars of the upper jaw i^ve e\ l ,^q,qtion of a large proto-

THE OSTEOLOGY OF HYiiNODON.

L„„ w.,lch ....y be » the — ‘ The”"!"

The premelare are very simple I™/. “^"“ the para, and metacones

arc- umlirniiiislied in number, 0 ‘Jj (tj„g ridge may be observed.

and in Smopa, as in Hymwdon, ml is much the smallest of the
Measurements.

Upper luolar-premolar series, length
“ prcmolar series, length
“ molar series, length .
Diastema behind upper canine
Upjter premolar 1, length

“ “ si “

“ “ 4, “

“ molar 1, “

Dower molar-premolar series, length
“ premolar series, length
“ molar “ “

“ premolar 1, length

“ “ 2, “

“ “ 3, “

“ “ 4, “

“ molar 1, length

“ “ 3| “

6-

u

a

j H. HOERIDUS,

No. 2.

H. CRUENTOS,
No. 1.

j H. CKUCIANS.

p

<

H. MUSTELI-
NUS.

M.

0.127

0.137

0.106

0.072

0.062

0.058

.081

.092

.068

.046

.035 ‘

.037

.046

.045

.038

.026

.026 ,

.021

.005

.005

.002

.008

.002

.014

.011

.009

.006

.019

.015

.017

.011

.0125

.009

.022

.020

.018

.011

.013

.011

.019

.020

.020

.012

.011

.009

.016

.015

.017

.012

.011

.010

.031

.030

.023

.014

.01.35

.Oil

.118

.082

.077

.066

.060

.047

.044

.036

.062

.058

.03.5

.03.5

.030

.011

.008

.009

.005

.017

.015

.010

.011

.006

.020

.016

.011

.0125

.(K)7

.019

.017

.012

.0115

.010

.014

.008

.009

.020

.010

.011

.009

.030

.015

.014.5

.011

' Sitecimeu figured by Leldy,

II. THE SKULL.

The skull is in many ways peculiar, with considerable variation among the
species, and certain almost constant differences between the American and European
forms of the genus. Schlosser (No. 5, p. 175) points out that among the latter, two
types may be distinguished. In one the mandible is elongate, with shallow hori-
zontal ramus, its lower margin is curved throughout its length, and the symphyseal
region rises very gently. In the other type the horizontal ramus is deep and'mas-
sive, with almost straight inferior border, and steeply inclined symphysis. In the
latter tl.e teotli are closely crowded together, 5i has usually a single tang, and JS is
place.1 oblaiuelj to the long axis of the jaw, while in the former the two anterior
preniolars ate elongated and isolated. All the known Americnn species are of the
long and slendcr-jawed type, but H.pmuUem distinctly approximates tile short-
laced group and the general aspect of its dentition is very suggestive of tl.at of the

Eumpean yackyrhynch. the obliquely placed tooth, however, is tl.e third
preinolar instead of the second.

THE OSTEOLOGY OF HY^NODON. 503

The »kell „f is thoro.ghly creedoet i„ character, as may be seen

D til c™7v|"”"’T’h in^pacious cranium, the short distance betwee/the occi-
pita condyles and the postgleno.d process, the high sagittal crest, the deep post-
orb.tal constrichon, and the relatively short preorbital region of the face The
upper profile of the skul hes in almost the same plane from the nose to the occiput,
but this appearance is largely due to the sagittal crest, which becomes very lligh
at Its junction with the lamMoidal crest, the roof of the cranial cavity inclining
.Steeply downward and backward from the postorbital constriction, and reaching a
very low level at the occiput.

The basioccipital is short, but very broad and thin, concave on the dorsal sur-
face and slightly concave on the ventral, which has a short, feebly marked keel in
the median line. The other occipital elements early coalesce into a single mass, so
that even in young specimens it is by no means easy to determine their limits. As
a whole, the occiput is usually very high (it is lower in H. paucide7is) and of sub-
triangular shape, with broad bcuse and lanceolate apex. The width of the basal
jmrtion is largely due to the transverse expansion of the exoccipitals, which form
a convexity in the median line to receive the vermis of the cerebellum, and on each
side of this is a shallow depression. The paroccipital processes are short, narrow,
and antero-posteriorly compressed and flattened. The condyles are rather small,
low, and depressed, but quite strongly divergent from each other; the foramen
magnum is small and subcircular in shape. The supraoccipital is high and almost
pointed at the summit, though its shape varies in the difierent species; its upper
portion is diploetic, filled with cancellate tissue, and develops a bony tentorium.
The exoccijiitals are separated from the lambdoidal crest by a broad surface of the
peri<jtics, terminating distally in small rugose mastoid processes, which, like the
parocci])ital processes, stand but little in advance of the condyles. The tympanic
is loosely attached to the skull, and is very generally missing from the specimens;
when present, it is a small and moderately inflated bulla. The external auditory
meatus is iniperi’ectly ossified, and forms but a partial tube.

The basisphenoid is quite long, broad at the suture with the basioccipital but
narrowing forward. The presphenoid is narrow and but little of it is displayed,
even when the palatal tube is broken away, since it is largely concealed by the
vomer. The alisphenoid is quite large, but forms only a limited part of the side
wall of the cranium ; near its anterior edge is an oblique overhanging ridge, winch
runs forward and upward, and is continued upon the frontal, until it passes into the
po.storhital process, d'he pterygoid process of the alisphenoid is large and ap-
proaches near to its fellow of the opposite side, being in most of the species sepa-
rated only bv the narrow cleft of the posterior iiares. In H. kptocephalus there is
a sutural union between the two processes, concealing the pterygoids and causing
the posterior iiares to open backward rather than downward^ The limits of he
orbit', splienoids are not clearly visible in any of the specimens, but it is obvious that

these bones must have been small. „p,.phral

The panetals are very long and form almost the entire roof of the ceiebral

THE OSTEOLOGY OF HY.ENODON.

504

chamber. Their breadth varies in the different species, being least in H. horridus.

itn vanes in Lue uincjcm- o

greatest in H. crucians and H. leptocephalus, while H. cruentus is intermediate m
this respect. In front of the squamosals the parietals become much broader and
articulate with the alisphenoids. The sagittal crest is long and very thin and,
for most of its length, high, especially toward the hinder end, where the obliquity
of the cranial cavity leaves space for it. The postorbital constriction is at or belnnd
the fronto-parietal suture, except in H. criicians and H. leptocephalus, \uyc\\\d\ it is
in advance of that suture.

The squamosal is very large, making up most of the side of the cranial wall,
and forming with the supraoccipital the sharply compressed and prominent lamb-
doidal crest, which the exoccipital appears not to reach. The height of the squa-
mosal varies in the different species, being, of course, the converse of the parietal
width, and is, therefore, greatest in H. horridus, and is least in H. crucians. The
root of the zygomatic process is placed very low down near the base of the cranium ;
it is heavy and massive, and projects well out from the side of the skull, but the
anteriorly directed portion is short and remarkably light. The glenoid cavity is
broad and concave in both directions; the postglenoid process is highest internally
and continues as a low ridge for nearly the full width of the cavity ; the preglenoid
ridge is but feebly indicated, and in the small species not at all. The jugal is long,
slender, and nearly straight, not arching upward, but continuing back in the line
of the peculiar maxillary alveolar process ; it passes beneath the zygomatic process
of the squamosal, and extends as far back as the glenoid cavity, but external to it.
The jugal attains its greatest vertical depth at the point where it reaches the max-
illary, from which point it tapers anteriorly and forms a very narrow suture with
the lachrymal. There is no postorbital process on the jugal. As a whole, the
zygomatic arch is remarkable for its length, slenderness, and straightness, and for
its low position on the skull, the high, compressed, and isolated posterior region of
the maxillary forms a part of it, and thus the last upper molar appears to be im-
planted in the zygomatic arch. The very curious physiognomy of the Hycenodon skull
IS largely due to the peculiar character and position of this arch. In view of the
large and powerful teeth and the profound masseteric fossa of the mandible, this
weakness of the arches is exceptional.

As in the creodonts generally, the lachrymal is largely expanded on the face
in ront of and beneath the orbit. In most specimens the lachrymal bears a shal-
low int, or depression bounded behind by the elevated orbital margin. Tlie fora-
men IS within the orbit and single.

cove/ lozenge-shaped bones. In most of the species they

H. crucians and b LmhigUii mrf o^fHirs

ence of large frontal ainuso,, the rvel«t of

species, beins greatest in H. and H. JltZ, L7ZZ

THE OSTEOLOGY OF HY^NODON. 505

.pedes ^ Tl,c f„,„tcepa,-ietal suture i. ,„ite straight, end tie ..gittal crest is con.
tnrued lertvard lor some d.stauoe upon the frontal., where it bifurcates to form the
supraorbital ridges, dies* are best marked in H. cruc,a«: inthe other species they
are tnconspicuous. The postorbital process is quite prominent, but leavi the orbit
widely open be hind Anteriorly the fmutals diverge to mceivo the nasals between
them, but usually there are no long and pointed nasal processes, though such pro-
cesses occasionally occur in H. horridus.

Tlie fiasals are very long, broad and transversely convex. Posteriorly they
are wedged in between the diverging frontals, and attain their greatest breadth at
the Ironto-niaxillary suture. The differences exhibited by these bones in the vari-
ous species of the genus alLect chiefly the length of the portion enclosed between the
frontals ; this is greatest in H. horridus mdi least in H . leptocephalus ; in the latter
the broadening at the fronto-maxillary is but slight, while in H. paucidens it is very
marked. The free end of each nasal is deeply notched and the approximated
median projections extend over the edge of the narial opening. The mesethmoid
is exceedingly large, even more so than in the carnivorous marsupials; its size is
most marked in the vertical dimension, owing to the great height of the nasal
chamber, which, however, varies in the different species, and is relatively greatest
in //. horridus. The vomer is long and high, and the ethmo-turbinals are well
developed and complexly folded ; the maxillo-turbinals are not displayed in any of
the 8j)ccimens.

T'he preniaxillaries are shaped much as in the CanidcB, and enclose a narial
opening of similar form and relative size; the alveolar portion is thick and heavy,
but short, the incisors forming a nearly straight transverse row. The ascending
ramus is narrow, and does not reach the canine, which is entirely within the limits
of the maxillary. The nasal process of the premaxillary is quite short in most of
the species, but in H. horridus and H. crucians it is elongate and very slender,
though, owing to the shortness of the nasal process of the frontal, the two are much
mort“ widely separated than in Canis. The palatine processes have but a very
limited extent, and the incisive foramina are small, hardly encroaching upon the

maxillaries. , , , , „ ..

The maxillaries are of great size, and make up nearly the whole of the side-

• wulls of tlie face and nasal ch,miber; their height is greatest at the orbits and
diiiiinislies gradually to the front. The two dental senes

ri.,;.„risadee,con,press^^^^^^^^^^^^^^^^^^^

Wide interval, and seems to belong to tlit zy^, nmiscrmence of this

an arrangement which is quite orbit and, when the jaws

the last lower molar extends behind the bony ^ome special modifi-

are closed, rises well above The palatine processes of the

cation of the soft parts to provide toi t P

-Qg the osteology of HY/ExNODON.

maNilUrie, are very long, and anteriorly are quite narrow and broadening poste-
riorly, they reach their greatest width at Pi, behind wh.ch they are
row strips by the palatines. The elevation of the alveolar borders makes the hard

palate somewhat concave transversely. . . , ,

Tlie palatines are broad in front, where they unite in a semicircular suture with
the maxillaries; behind this expansion they contract to form a long, narrow tube,
and the two bones are suturally united for most of their length, notched only at
their hinder extremities by the narrow, slit-like posterior nares. In H. leptocephalus
the palatines are in contact throughout, and the canal appears to have no inferior
opening at all. Such an extreme degree of backward shifting of the narial aperture
is very rare among inainiiials, and is equalled only by the condition attained in the
edentate genus Myrniecophaga. The pterygoids are but little exposed, as they are,
to a great extent, covered up by the pterygoid processes of the alispheiioids. They
are low, short, and curved, so as to continue the tubular shape of the palatines, and
interiorly are separated only by the posterior nares, which are somewhat broader
here than between the palatines. In H. leptocephahis the two pterygoids would
apjiear to be in actual sutural contact. There are no distinct hamular processes,
their place being indicated merely by rugosities.

In all the American species the mandible has a long and shallow horizontal
ramus, the lower border of which is gently and regularly curved from beneath the
masseteric fossa to the incisive alveolus. H. cmicians and H. paucidens form par-
tial exceptions to this st.atement; in the former species the lower border beneath
the masseteric fossa is straight, the curvature beginning further forward, while in
the latter the face is shorter, and the symphyseal region of the mandible more
steeply inclined than in the other American species. In all the sjmiphysis is nar-
row and very long, extending back to p3, and at an early period the two rami are
firmly ankylosed in this region. The differences to be noted between the various
species appear chiefly in the posterior part of the mandible and in the ascending
ramus, l.i H. Imrridtu the coro.ioid process is high and pointed, slightly recurved,
with a concave posterior border, and with the summit placed far in advance of the
condyle (gee Leidy, No. 2, PI. IIIl; in H. cruentm the process is similar, but has a
broader summit ; In //. paudi,ns, H. c-ucian,, and H. kptocephalm tl,e summit is
still wider, the postenor border is straight and nearly vertical, and rises very
to'riil The lira, seteric fessa is large and deep with beriers parallel

sin “rh a r T, T - '‘“P. but rather

small ve tica y. The condyle ,s much extended transversely and placed verv low

hook, which is best developed .and descends fBrlh”t*i! 1 ^ **'‘’“*^

^rder of the tamns in /f.i»f„,Teasfs„ “t? '''''

O-annl Pora,nina. The optic foramen is placed quite far back of the orbit

THE OSTEOLOGY OF HYiENODON. 507

and is Idllowcd after a short interval b, the foramen laceram anterius, and this after
a similar s,,ace, l,j the foramen rotmidnin. These tliree foramina are of neariv the
same s„,e and are all enclosed in the groove formed by the oblique ridge alL,
mentioned which runs downward and backward from the postorbital process aemss
he fron ta , orhito- and allsphenoid. pauddens diffeis from the other species in
the tact that the foramen lacerum anterius and the foramen ovale are very closely
approximated and open almost side by side. The foramen ovale is separated by a
wide interval, both from the foramen rotundum and from its fellow of the opposite
side. Tliere is no alisphenoid canal in any of the American species. The foramen
lacerum medium and foramen lacerum posterius are situated much as in the dogs, at
the front and hind edges of the tympanic bulla; the carotid canal appears to be
fused with the latter; at all events, I have seen no specimen in which it is distinct.
The cimdylar foramen perforates the basioccipital well in front of the condyle. The
postglenoid foramen is distinct, as is also the stylo-mastoid, and the supraoccipital
is perf'orated by two venous forfimina. The posterior palatine foramina perforate
the palatines, in each of which are three openings, a larger one which opens near
the ina.xillary suture, and behind it two much smaller ones, just such as Schlosser
has described in the European species: “Die Gauraenbeine weisen zwei grtissere
Durchbriiclie auf, dahinter noch je z.wei kleinere Foramen” (No. 5, p. 175). The
infraorbital foramen is a high, narrow oval, and placed above P^. According to
Filhol (No. l,p. 19) there are some important difiereiices in the arrangement of the
cranial foramina found in the European species, at \Q'\s,i\\\ H. bracJiyrhy7ichus,{mm
that above described. The foramen lacerum posterius is distinct from the carotid
canal and perforates the basioccipital, and an alisphenoid canal is present. These
are tlie most significant differences regarding the foramina between the species of
the (lid and New AVorlds.

Measure.wents.

Skull, leiigtli from occipital condyles to Incisive alveolus
“ “ from for. mag. to front of orbit

“ “ of face from orbit to incisive alveolus

“ breadth across zygomatic arches
“ length of sagittal crest . . • •

“ height of occiput . . . • ■

“ breadth of weiput at mastoid processes .

Mandible, length from condyle . . • •

“ height of coroiioid jirocess
“ ‘‘of condyle . . • ■

“ depth at “8 . • • ■ '

“ “ at P2 . . • • •

w

M

H. HORRIDUS, 1
No. 1. 1

D

5 .

P

w

D

.

P

w

<

p

s

w

H. PAUCIDENS.

M.

L , „

0.209

0.290

'0.310

0.232

0.172

0.170

.121

.144

.172

.130

.114

.101

.092

.140

.143

.108

.067

.073

.114

.140

.072

.103

.117

.091

.077

.071

?.060

.067

.064

.100

.079

.054

!i66

.270

.280

.203 i

.148

.1.33

.058

.077

.060

.054

.047

.028

.030 1

.050

.034 ,

.020

.022

.042

.055

.038 ‘

.027

.025

.037

,056

.028

.021

&

%

.055

.017

.015

66 JOURN. A. N. S. PHILA., VOL. IX.

r,08. THE OSTEOLOGY OF HY/ENODON.

III. THE VERTEBRAL COLUMN.

The atlas is short and broad ; the anterior cotyles for the occipital condyles are
very deep extending lar back into tlie cavity of the neural canal, but they are not
so strongly concave as in many of the recent carnivores. The neural arch curves
upward very decidedly, giving relatively great vertical diameter to the bone; its
antero-posterior breadth is rather small, but its thickness is unusually great. This
arch has a nearly smooth dorsal surface, without ridges or any trace of a neural
spine, but perforated by foramina for the first pair of spinal nerves. The inferior
arch of the atlas is narrow from before backward, hardly more than half as wide
as the superior; it curves downward as strongly as the neural arch does upward
and thus the opening of the atlas is nearly circular. A rudimentary, backwardly
directed spine represents the hypapophysis. The posterior cotyles for the axis are
large and transversely curved, the two together describing nearly a semicircle. The
transverse processes are straight and not very largely developed, especially from
before backward, though they give great width to the bone. The vertebrarterial
canal perforates the hinder edge of the transverse process, and after a short course
opens into a depression on the ventral side. (In my former paper it was incor-
rectly stated that this canal was not present.) The forward extension of the trans-
verse process converts the atlanteo-diapophysial notch into a foramen. The pro-
cesses project outward with hardly any recurvature, and this fact gives to the atlas
its characteristic shape, quite diflerent from that found in most of the carnivores.

The axis is a rather remarkable bone. Its centrum is of only moderate length,
but broad and very much depressed, with distinct ventral keel ending in a hypapo-
pliysial tubercle behind. The dorsal surface of the centrum, forming the lloor of
the neural canal, also bears a strong median ridge. The atlanteal facets are low
and wide, of oval shape, and with convex surfaces. Like the corresponding facets
of the atlas, the outlines of the two together describe nearly a semicircle, very much
as in the badger {Meles) to the axis of which, indeed, that of Hycenodon bears a
close general resemblance. The odontoid process is very long and prominent, and
of irregularly conical shape, tapering to a blunt point. 'The transverse processes
are sliort compressed and slender; they are directed backward and but little out-
ward and arc |mrforated by the relatively large vertebrarterial canals. The neural
canal ,s higher and narrower in front, broader and lower behind. The pedicels of the
arch are thick and heavy, but narrow antero-postcrlorlj, leaving considerable open

EietlwH 7" r", 7 “ '“SO, tldn,

hatchet-shaped p ate, which, though not very high, is of great fore-and-aft extent

aygapopi.;:e^:f;fax::

.ow and wide, and the dorsal surface of .he ir ntdy Z

509

THE OSTEOLOGY OF HYiENODON.

and especially the anterior pair, are very widely separated and present almost ver-
tically. ilie neural spine is very little developed, the great overhfinging spine of
the axis leaving hardly any space for it. The transverse process forms a thin, com-
pressed plate considerably longer than the centrum, from which it diverges at a wide
angle. The fourth vertebra is like the third, with all its peculiarities exaggerated;
it is shorter, heavier, with faces more oblique to the long axis of the centrum ; it
has a lower, broader neural arch, and more widely separated zygapophyses. The
free margin of the transverse process is strongly concave, instead of straight, and
hence the process is partially separated into anterior and posterior portions. The
neural spine is slightly higher than on the third. The fifth and sixth cervicals
dilTer only in minor details from the fourth, the principal changes being the gradu-
ally increased height of the neural spines and the narrowing of the neural arch and
canal. On the seventh vertebra the spine becomes relatively very high ; the cen-
trum is short, broad, and depressed, the transverse process heavy, straight, and im-
perforate.

As a whole, the neck of Hymiodoti is surprisingly short and light, when com-

pared with the size of the head, the skull considerably exceeding the neck in length.
The small size of the processes on the cervical vertebrae is evidence that the neck
could not have been so heavy and muscular as in most of the recent Carnivora.

I'he thoracic vertebrce number fourteen and, like the cervicals, are proportion-
ately small and weak. In the anterior region the centra are short, gradually in-
creasing in length as we pass backward. The first thoracic vertebra has very
prominent transverse processes, which bear very large, concave facets for the tuber-
cles of the first pair of ribs. The second thoracic has similar, but somewhat smaller
processes, and on the other vertebne they become of the ordinary size, though con-
spicuous on all, except the last two. The size of the spines vanes m the differen
species ; in H. horridus they are relatively very heavy, while in the
they are light and delicate. In height and in backward niclinatmn^
nosteriorlv the 11th being the anticlinal vertebra, while the 12th, 13th and 1

have lowViiines of the lumbar type, inclining forward. The change in the charac-
iKiv e low spines oi l ..grtebra; those of the posterior thora-

entire column. Ihe onl} comp c c sei lumbars. There is no reason

mined species, and in this hi H. horridus the lumbars

to assume a diflerent numbei oi , gg^^ed slio-htly opisthocoelous and pro-

have very large centra, which are broad, dep-- ^ ..g but not

vided, except the last one ,g,,i,ate in a point. The spines

510

THE OSTEOLOGY OF HYvENODON.

that of the last vertebra is nearly erect. The prezjgapophjses are exceedingly
concave curving far over, and into them lit the convex, nearly cylindrical postzyga-
pophvses. The metapoph vses are small, and on the last three vertebrm riidinien-
tarv.^ In this species the loins are not for from being as heavy and powerful as m
the" wolves. In the small, undetermined species the liimbars are relatively smaller
and lighter, the neural spines are low, compressed and thin; the zygapophyses are
more cylindrical in shape, and interlock more perfectly than those of the posterior
thoracic vertebra) of the same specimen, but less so than in the lumbars of H. hor-
ridiis ; the aiiapophyses are largest on the 1st vertebra, becoming rudimentary on
the 4th. and are absent from the last three. In H. criientus the lumbars are inter-
mediate in character between those of the two species above described. On the
last lumbar, however, occurs a peculiar structure, which may be only an individual
variation; the transverse process is short, but much extended antero-posteriorly,
and abuts against the ilium, forming functionally a part of the sacrum, though no
ankylosis with it exists. The process on the left side is much larger than on the
right, and has a more extended contact with the ilium; a deep notch divides the
j)rocess into two parts, the hinder one of which bears a large concave facet for the
sacrum, which also is confined to the left side.

The sacrum in young animals consists of only two vertebrm, to which in the fully
adult form a third is added. The 1st sacral has a broad, depressed centrum with
very large pleurapophyses, which carry the ilia almost entirely, the 2d vertebra
having but a very limited contact with those bones. In H. horridus the 1st sacral
has long and heavy transverse processes, which are quite distinct from the pleura-
pophyses, and are directed obliquely Ibrward ; in H. cruentus these processes are
much smaller, but still blunt and massive. The prezygapophyses of the 1st verte-
bra are of the same pattern as those on the lumbars, but much louver; the neural
canal is also very low, though quite as capacious as in the last lumbar. The spine
is well developed and erect. The 2d sacral has a much narrower centrum than the
1st and all its processes are less developed, except the neural spine, which in some
cases IS larger and heavier than that of the 1st. In H. nmstelinus the spines of
the eaormn arc rudimentary. The M vertebra h.aa a shorter and wider centrum

is'^ill « horridm, tl,e spine

The caudal veriar,c are seldom preserved in any considerable numbers One
speemren, Imwcvcr, beleng.ng to the American Museum of Natural Ilislory h“
several verlcbrm from all parts of the tail, which rive an excellent idea f I
p..rtions. Those show that Hymnadan had a tail of relativolv Lhl ‘^d ’Y

the charnctcrof the vortebno is of distinctly carnivorous tvne ^ ^ ’

cats, though oil a very much smaller scale The t ■ ^ Oy^tnbling those of the

Pliyses are rudimeu.ar, -1; hratre

THE OSTEOLOGY OF HY^NODON.

511

,„uc . more slender and eyhndrical in shape, contraeted in the middle and more e.
pandod at the ends, without neural arches and with all pr«esse, rudire^ry t
the tnriainal region the centra become exceedingly elongate and slender ey Wers

Measurements.

AtluH, leriKlh (in mctiian line) .

“ width

A.\iM, leiiKtli of centrum

“ “ of odontuid |)ro(,-e»»

“ “ of Hpine (antero-|M)8terior)

'I'liird cervical, length of centrum
Fourth “ •' “

Fifth

Sixth ‘‘ “ “

Seventh “ " “

Fir«t thorardc, length of centrum
“ “ width, iMwterior face

Tenth thoracic, length of centrum
Fourteenth “ “ “

SecontI lumliar, length of centrum
“ “ width “

“ “ height of Hpiiie

Fourth “ length of centrum

Seventh ‘‘ " “

Sacrum, lengt h (1’ vertebne)

Anterior caudal, length of centrum
" “ width “

Median caudal, length of centrum
“ width “

PoHtcrior caudal, length of centrum
‘‘ “ width “

M.^

0.018

.022

.033

.017

.017

.016

.016

.021

.016

.020

.022

.019

.014

.025

.022

.034

.029

.026

.031

.028

.102

.039

.027

.028

.024

.029

.035

.026

.028

.032

.031

.047

.019

.016

0.017

.081

.029

.015

.056

.023

.021

.019

.019

.021

.021

.025

.020

.024

.028

.022

.037

.015

.013

.022

.010

.019

.006

* //. horridm, No. .3, is the fragmentary Hkeleton belonging to the Museum of Comparative Zoology,
Oanibridge, Muaa., dcscrilied in my first pajier.

IV. THE RIBS AND STERNUM.

The anterior ribs are very broad and bat; this flattening is marked as far as
the ()th, beliind which they become nmcli more slender and rounded. The 1st rib
is especially broad and flattened, and in H. cruentus is very much curved as well;
the ttibercle is exceedingly large and convex, it rises high above the neck and fits
into the very prominent transverse process of the 1st thoracic vertebra. The .
has a siniila; hut smaller tubercle. The other ribs have less conspicuous and some-
what saddle-shaped tubercles which diminish m size posteriorly, and on the lAh

become obsolete. . p . j, r +

The firm scgnieiit of the storiiiini, or in,n.iubrium, is of decided y “ VP-

It is very lone slender, coii.l, reused, .end of trihedral shape ; the dorsal su.fime is
Ibatteiied and narrows in ndvaiice of the rib-facets to the bluntly “

end ; the ventral side is nearly straight ,aiid forms a sh.arp ^

surfaces are wider than the dorsal and are slightly concave. The facets

512

THE OSTEOLOGY OF HYiENODON.

pair of sternal ribs form large, prominent, and rounded tubercles j the anterior end
projects far in advance of them and they are considerably in front of the joint
between the presternuin and the first segment of the mesosternum. Among the
recent Carnivora with which I have been able to compare this manubrium, that of
the viverrine genus Merpestes shows the nearest resemblance to it. The segments
of the mesosternum are short and heavy; somewhat contracted and of cylindrical
shape in the middle, expanded, massive and of more quadrate shape at the ends.
The number of these segments is not known at present.

V. THE FOBE-LIMB.

The scapula is remarkably small, not only in proportion to the size of the skull.

Fig. l.—Hymmdon cruentus ; Left scapula,
i natural size.

F'ig. 2. — The same, seen in profile from the
anterior side.

but_ also relatively to the length of the vertebral column, and it has certain pecu-
liarities wliidi do not occur in any of the recent Carnivora. In general shape the
scapula of Hycenodon is most like that of the dogs ; its outlines are all curved and
more or less sinuous, somewhat as in Plverra, which it also resembles in its relative
an'ehrrr ' ° somewhat feline in shape, and forms

than the anterior, and its hio-hest point i ^ 1!^^ descending more rapidly

Slit-—

and of

THE OSTEOLOGY OF HYiENODON. 513

peculiar sl.ape when viewed in profile from the front. Looked at in this way, it is
seen to rise gradually from the suprascapular border, maintains a uniform height
for most of Gs course, and then curves up {i. e., toward the external side, when the

bone is in its natural position) to form the prominent and curious acromion. The

latter is a compressed and plate-like projection, which extends externally and dis-
tally, though not reaching or overhanging the glenoid cavity. There is no trace of
a inetacromion, and the acromion is not in any way flattened, depressed or retro-
verted ; it thus difl’ers very markedly from the type of structure found among the
true Carnivora. Ihe spine, as a whole, is slightly recurved, which gives it a convex
anterior and concave posterior face; distally it extends nearly to the glenoid cavity.

Thii-httmerus is short and weak in proportion to the size of the animal ; aside
from this it is distinctly canine in character. The head is relatively large and

antero-posteriorly is nearly hemispherical, though much less
strongly convex in the transverse direction ; it presents back-
ward almost as much as proximally. The external tuberosity

is high, rugose and massive, but does not extend across the
entire anterior face of the bone. The internal tuberosity is
small and laterally compressed, with a roughened face, while
the bicipital groove is widely open and not very deeply in-
cised. The proximal portion of the shaft is laterally com-
pressed, but of great fore-and-aft depth; distally it contracts
to an almost circular section, below which it is moderately ex-
fr,‘insvpr.selv. The development of the deltoid ridge

American aim rmroppan -

served in many other parts of the s'ee on.

514

THE OSTEOLOGY OF HY/ENODON.

The bones of the fore-arm display a considerable degree of variation among the
different species. In H. horridus the ulna is relatively short, but massive and not
at all reduced. As is so very generally the case among the creodonts, the olecranon
is very high ; it projects quite strongly backward and terminates in a heavy, rugose,
and club-shaped swelling, which overhangs somewhat toward tire internal side ; it
is not grooved bv a tendinal sulcus. The sigmoid notch is high and deep, and the
coronoid process is very prominent. The notch is somewhat oblique with reference
to the long a.xis of tlie bone, inclining downward and inward. Except proximally,
the humeral surface is confined to the inner half of the sigmoid notch, but there is
a small distal external facet for the humerus, which presents upward. The radial
facet forms an uninterrupted concavity, the ends of which project beyond the sides
of the shaft; the projection on the outer side is much the more prominent of the
two. The shaft is laterally compressed, but very stout, rounded and convex on the
inner side, deeply channelled on the outer. Its principal diameter is the antero-

posterior one, which gradually diminishes downward, while

1

1

THE OSTEOLOGY OF HYiENODON. 515

with one another and marked only by a change of shape. Of these facets the
largest is the internal one, which is convex transversely and concave antero-poste-
riorly ; the median one is a shallow, rounded pit for the intercondylar protuberance
of the humerus, while the external facet is small and nearly plane. Such an elbow
joint as that here described cannot have allowed any greater degree of pronation
and supination than exists among the dogs. The ulnar facet of the head is a single
broad, convex band, uninterrupted by any sulcus. The bicipital tubercle is so in-
conspicuous that its position is somewhat uncertain. The proximal portion of the
shaft is wide but very thin, gradually increasing in thickness and decreasing in
width downward, until it becomes nearly cylindrical in shape. The distal portion
of the shaft is much heavier than the proximal and of more trihedral section, having
a 8har[) edge on the external or ulnar side, and on the inner side is a broad and deep
tendinal sulcus. As a whole, the radius has an irregular double curvature, both
anterior and lateral. The carpal surface is a simple concavity, which shows no sign
of a division into facets for the scaphoid and lunar ; it is deepest on the outer side,
contracting toward the inner, and the inner angle is prolonged into a recurved hook,
which jm)jects over the tendinal sulcus already mentioned. The radius is relatively
heaviest and best developed in H. horridus ; in the smaller species it is more slender
in proportion, and in H. mustclinus is exceedingly so, much less heavy than the

ulna. The slenderness of the radius and the large
size of the ulna in Hycenodon are in notable con-
trast to the proportions which are to be found in
the recent Carnivora.

The carpus of the American species of Hyce-
nodon has some constant differences from that of
the European species. In the latter the scaphoid,
lunar and central appear to be always united,
while in the American forms they are as constantly
separate and show no tendency to ankydosis. In
my former paper I stated that de Blainville’s draw-
ing [Taxotherium parisiense, Ostdographie, Subur-
sus, PI. XII) seemed to show the impression of a
distinct lunar. Since writing that suggestion,
however, I have had an opportunity of examining
the original specimen in the Paris museum and
find the supposed lunar to be a displaced magnum.
Of the American forms I have seen the carpus in
H. horridus and H. crueiiius and, except 111 the
matter of size, find no noteworthy difference be-
tween the two species. , - .

The scaphoid is wide and thick in the dorso-

palniar direction, but very low vertically; seen from -^etds Tow

67 JOURX. A. N. S. PHILA., VOL. IX.

Fig. 5. — Hi/wnodon horridus; Ijcft
maiius, from the dorsal side, s, sca-
phoid ; I, lunar; cn, cuneiform ; (771,
trapezium ; t, trapezoid ; ti, unci-
form. The central appears between
the lunar and trapezium. One-half
natural size.

the osteology of HY/ENODON.

where the height of the scaphoid reaches its maximum. This facet occupies or. ly
r Zt of the lu-oximal srrrface of the scaphoid ; on the palmar srde of rt rs a broad
shelt-like expansion with a roughened surface. On the distal side are thice is-
tiiictly separated facets, for the trapezium, trapezoid and central respectively, the
magnum having no contact with the scaphoid. The facet for the trapezium is very
lar--e mucli tlie largest of the three, of irregular shape and nearly plane. That for
tl.f i» inucl, tl.e smallrat, and deaennda in front to a. lower level than the

others, rising somewhat toward the palmar side, and is of triangular shape. The
surlace for the central is much larger than the trapezoid facet, on the palmar side
of which it comes in contact with that for the trapezium; it is very oblique in
position, presenting almost as much toward the ulnar side as distally ; in front it is
narrow', becoming broader and more concave behind. These three facets do not
occupy the entire distal end of the bone, though they take up more of it than the
radial facet does of the proximal end; behind them is a similar, but smaller, rugose
expansion. On the ulnar side of the scaphoid is a large and slightly convex facet
for the lunar, which is cut aw'ay behind by that for the central.

The lunar is a small bone, inferior to the scaphoid in every dimension except
the vertical, in which it considerably exceeds the latter. The radial facet is very
strongly convex in the dorso-pahnar direction and is reflected farther down upon
the dorsal face of the bone than in the scaphoid, but not extending very far tow ard
the palmar side. Behind this radial facet the proximal surface of the lunar descends
steeply toward the palmar side, and is quite rugose. The lunar has no distinct facet
for the cuneiform, but on its internal side is a concave facet, into which the scaphoid
fits, interlocking the two bones very firmly. Distally the lunar bears three facets,
for the central, magnum and unciform respectively, all of which are narrow and
concave in the dorso-palmar direction. The facet for the central is widest in front,
narrowing posteriorly, and is lateral rather than distal in position. The magnum
facet is very narrow and somewhat oblique with reference to the dorso-palmar axis
of the bone, inclining toward the radial side as it passes backward. The unciform
surface is slightly the largest of the three and much the most decidedly concave.
The lumar is of almost uniform breadth throughout, in height it increases somewhat
to the ulnar side.

I lie cuncifmt is a large square bone, considerably exceeding the lunar in size,
broin the extaaial border it gives off a strong, recurved, hook-shaped process. The
proxniial siirlaco kars a groove-like facet for the ulna and on the palmar side is a
large laeet lor the pisiform The distal end is occupied by the facet for the unci-
oii , this IS siiildlc-shaped, being broad and concave on tbe radial side, becoming

Tr ! iii," I™”'* “r »f tl.e ciinei-

at?71rt opti aX^ t ‘“'d bears two distinct facets, which meet

two and is sligbUy convex, ^hk tint

coming very high, rugose and thick.

THE OSTEOLOGY OF HYiENODON.
not very thick, hut of great vertical diameter; toward the free end i

it expands, be-

517

occui.ied by the large facet for Hie scaphoid, which is quite convex transversely, and

descends low upon the radial side of the trapezium. On the external or ulnar side
are^ two tiicet.s, obscurely separated by a faint ridge. Of these the proximal one,
which is the larger and more concave, articulates with the trapezoid ; the distal one
is r.-shaped and articulates with the head of the second metacarpal. On the distal
side of the trapezium is a large, oval and concave facet for the head of the first
metacarpal ; this facet presents obliquely downward and inward and indicates an
unusual freedom of movement, perhaps even some degree of opposability, on the
part of the first digit.

The /rapezoid \s, a rather small bone, though relatively somewhat larger than
in the dogs. Its largest area is the dorsal face, from wdiich it tapers to the palmar
side, where it terminates in a blunt point. The proximal surface is unequally
divided between the facets for the scaphoid and central; the former is small, of
triangular shape and slightly convex, the latter much larger and concave. On the
radial side is a large facet for the trapezium, but the trapezoid does not extend to
nearly so low a level as does the latter. On the distal side is a saddle-shaped sur-
face for the second metacarpal, which is convex transversely and less decidedly con-
cave in the antero-])osterior direction.

The viagnutn is not preserved in any of the specimens, but its shape and con-
nections may be confidently inferred from the facets of the surrounding bones. It
had no articulation with the scaphoid and was connected proximally only with the
lunar and central, more extensively with the former than with the latter. Later-
ally it articulated with the trapezoid and unciform, distally with the third meta-
carjial and by a very small facet with the second. In size the magnum must have
Lofiii <»f’ file siTinllest bones in the carpus.

the osteology of HYiENODON.

1 ..nilv hrmfleniti<^ behind; the latter forms a high
smaller and is very steeply toward the ulnar side, where

convexity on the radia si e, u _ o reduced.

Un tlie rauiai siinat fPi.kness of the unciform, the distal one very

"vLLpelurllinod t„ the dors.l borfet. The fecet for the uttciform
prlicoie of the thiril metacarpal h small. On the distal s.de are large facets for the
fourth an.l liaii metacarpals, that for the latter being somewhat the smaller and
more concave of the two. The palmar hook of the uneiform is reduced to a mere

rongli tubercle. . , , o mci

The carpus of Oxycena, which has been described by Osborn (iNo. d, p. iUb,

fi-r. !)), presents niatiy decided differences from that ^iHymiodon. ^ The scaphoid is
even lower and has a more evenly .curved distal border. The lunar is larger, and rests
by facets of nearly equal size upon the central and unciform, while it appears to be
altogether excluded from the magnum. The cuneiform is much smaller, and has
not developed the strong, hook-shaped process from the ulnar border. The trape-
zium is very much smaller and has a differently shaped facet for the first nieta-
carjial. The central is not displaced toward the radial side and has facets of nearly
equal extent (at least on the dorsal side) for the scaphoid and lunar, trapezoid and
magnuin, and thus its dorsal face is diamond-shaped. The unciform is much higher
and narrower and the cuneiform facet is much more oblique ; the hone thus is de-
cidedly more like that of the fissipede Carnivora. The peculiarities of the Hyanodoii
carpus are, then, as follows : (1) Tlie large size, especially breadth, of the cmieiforni
and its ulnar hook ; (2) the radial shifting of the central and the consefiuont
articulation of the lunar with the magnuin ; (3) the great enlargement of the
trafieziiim ; (4) the breadth and lowness of the unciform.

The metacarpus consists of live members. The first metacarpal is the shortest
ot the series, but is heavy and massive, particularly at the proximal end. The head
hears a very large and strongly convex facet for the trapezium, the only carpal
element with which it conies into contact. Below the facet the head is widened
transversely and very thick antero-posteriorly, with a prominent rugosity on the
ulnar side, which has no facet for me. 11. Distally to this the shaft contracts, ex-
panding again slightly at the distal end. The trochlea is narrow, asymnietrical
and oblique and has hut a low carina. The rugosities for ligameiitoiis attachment
above the trochlea are low, but the lateral pits, especially the one on the ulnar
SK e, arc large and deej). Tlie pollex appears to have diverged somewhat from the
direction taken by the other metacarpals, and to have possessed some fiicility of
adduction and abduction. .

Tl,a «c,«,,l metacarpal ie the etouteet of the series .and much longer than the

iZiie, ‘ Wt", file head carries a saddle-

Doi^r L -C tl “ tl-msverscly and convex ai.tero-

■irticulatioiiof ® >i'i“l » large facet for the trapcriani. This

.irt.culat,o,i „i me. I[ with the trapezium is very general among the Oamivoiva, but

THE OSTEOLOGY OF HYiENODON. 519

in none of tl.e a-cent fo,.,,., it so extensive as in //jWo,, just as in this venus
the faiKsatn,.. „ of very except, onall, Urge site. There is 1 long and promt”
nmgiiu,,, prcicesson me. II, which bears a Urge facet for that carpal. The contact
of ,.,c. II with the niagnum is more extensive than that of me. Ill with the iinci-
lor,,., and „ rclati.m ly larger than is to be found in any of the recent earnivoms,
except the cats. Below the magnum projection is a concavity, into which tits the
head of me. III. The shaft is stout, particularly its distal portion, and in the proxi-
mal part 18 of subqnadrate section. The trochlea is low, but wider, more symme-
trical and with a heavier and more prominent carina than that of me. 1.

The third metacarpal considerably exceeds all the others in length. The
proximal end is rather narrow but much extended in the dorso-palmar direction
and carries a facet for the magnum, which is extended and convex in the same
direction, narrow and slightly concave transversely. On the radial side of the head
is a convex facet for me. II, which is confined to the dorsal border, while the articu-
lation with me. 1\' is by means of two facets which occupy the whole dorso-
palmar thickness of the head. Of these facets the dorsal one is large and concave,
the palmar smaller, plane and situated at a higher level, becoming confluent with
the magnum surface, from which the dorsal facet is divided by the unciform process.
The latter process is .small, not at all comparable to the size which it attains in the
cat.s ; it e.xtends but little over the proximal end of me. IV, and is confined to the
dor.sal half of the head. In the figure of the manus of H. horridus given in my
former pajier (Xo. 0, IM. VII, fig. 5) this process is restored as much too large, for
1 was misled by the damaged condition of the head of me. Ill in the Cambridge
specimen. The better preserved individuals now at hand show that tbe unciform
process of me. HI is much smaller than in Mesonyx, or even than in Oxyxna, and
smaller than the magnum process of me. II, which is not only more prominent, but
extends across the entire thickness of the head. The shaft of me. Ill is long and
rather slender; its proximal half has the angular, subquadrate form seen in the
dogs, while tbe distal is more oval in section and considerably broadened at the end,
though the lateral ligamentous processes are much less prominent than m the cats
The tloclllva in iMwiid „„d ayniNielricil, the oariiia being in the media., line and
better deveUiped than on ,„c. I and II, The trochlea is but moderately convex,

„ .|„. ouicm. The Lad

i;::.:r:,eL:i:t-rh;::tndg^^

a lower level, allowing t ;:S.ai

While the palmar lacet ^ V ^ tbe same plane. On the ulnar

articular surfaces ol me. Ill and 1 facet for me. V, which extends

side of me. IV is a .single low an

iu-ross the full thickness of the hem . heavier and of less

but curved, with the do not form asymmetrical pair, as they

distinctly quadrate section. Me. 1

520

THE OSTEOLOGY OF HY^NODON.

un-

the

<1„ !,. Mestnyx, Oxy^na, Cmis, Hyxm, etc., and tlie trochlea of the latter is
equally divided by the oarina, ivbicli is slightly nearer to the radial than to

Tlie liftli metacarpal is very short, only slightly exceeding the first m lengtli,
to which it bears a close resemblance in shape and appearance. The proximal end
is considerably expanded, and carries on the ulnar side a prominent rugosity tor
ligamentous attachments. The facet for the unciform is narrow transversely, but
much extended antero-posteriorly, and very strongly convex ; it articulates only
with the distal side of the unciform and does not extend up upon the ulnar side.
The facet for me. IV is of crescentic shape, the dorsal horn being convex and pro-
jecting, while the palmar horn is flat. The shaft is stouter than that of me. I, more
arched and more strongly compressed antero-posteriorly, while the distal trochlea
is much broader, especially on the palmar side.

The metacarpus of Oxycena is decidedly different from that of Hytenodon. The
bones are even shorter, weaker and more slender in proportion to the size of the
skull. The digits are disposed more symmetrically. III and IV forming one pair of
nearly equal length and weight and, apparently, II and V another pair. In Hyce-
nodem^ on the other hand, the metacarpals are all of different lengths, the order being
III, IV, II, V, I, and they are arranged so as to diverge from one another more than
in Oxycena, though much less than in Patriofelis. The carpal connections are also
dillerent in the two genera, hi Oxycena me. II has an extensive articulation
with the trapezium, but does not reach the magnum, while in the White River
genus the magnum process is very prominent and the facet large. The unciform
process of me. Ill is in Oxycena rather small, but decidedly larger than in Hyce-
nodou, while the head of me. V has a concave facet for the unciform, and embraces
both the distal and external sides of that bone. The only^ other creodoiits, the
structure of whose manus is completely known, axQ Mesonyx ?cnd Palriofelis ; in the
former the manus is of an entirely different type, approximating more to the condi-
tion assumed by the hyrnnas, while the latter is not notably diflerent from Oxycena.

The phalanges of the various digits in Hyeenodon differ from one another only
m size and in the degree of curvature which they display. The proximal phalanx
IS of only moderate length, but broad, heavy and depressed. The proximal end is
broad and thick, with a shallow articular surface for the metacarpal, which is deeply
notched at the palmar border; a notch which would seem to be wider and deeper
than necessary for the metacarpal carina which it accommodates. The shaft is
briwul, stout ami strongly arolied toward the dorsal side. The distal trochlea is of
rather small dorso-palmar diameter and but imperfeetl, divided into two facets by a
h!d ir ‘ '>»“ >i°t encroach ufmii the dorsal face of tlie bone,

t i, „l I "'a 0 There is some resemblance between

n ore sle r d “L“”yP“"<‘“S Caniy but the latter is more elongate,

deeply dTptLt. .^Lddlt “ “

The second phalanx is short and depressed, but very broad. The pmximal

621

THE OSTEOLOGY OF HYJ5N0D0N.
articular surfkee is distinctly divided into twr. i ,

I lie iiiiguiil phalanx has a single proximal articular surface, ivhich is deeply
concave ,n the dorso.,,al,nar direction, but without curvatnre transversely. On St
paltnar side below the trochlea, is a large, rough tubercle for tei.dinoifs and liea.
meiitous nttaehineiits the subungual process. This phalanx is broad and thick
tapenng very gradually to the free end. As is so very generally the case in the
creoilonts with the exception of the Mkddo!) the iingnal is very deeply cleft at
the tip and is altogether similar to that of Oxy^ena and Patriofelis.

Mkasurejients.

•Sca|>ula, height ....

“ KrvatcHt width

‘‘ lieiKht i)f ucruniiuii

“ untero-jMiHtcrlor diameter of glenoid cavity

traiiHverm; diameter of gleuoid cavity .

1 1 iiineruH, length (from head)

“ tliaineterof |>ruxinial end (ant. post.) .

“ breadth of trochlea

rina, length ... ...

“ iieight of olecranon from Iteak
" diameter of shaft at radial facet (ant. post.)

“ “ “ distal expansion (ant. p

ItudiuH, length . . ...

“ breadth of pro.xinial end .

“ “ distal end

Carpus, breadth . . ...

“ height . • .

Metju-arjial I, length . ...

“ 1, breadth of ifroximal end

“ 1 1, leugtli ....

“ 1 1, breadth of proximal end

“ III, length . ...

“ I II, breadth of proximal end

“ IV, length . . . •

“ IV, breiMith of proximal end .

“ V, length . • •

‘‘ V, breadth of proximal end .

First phalanx, digit III, length • ,

" “ “ “ breadth of proximal end

.Second “ “ " length . • ,

“ •• " " breadth of proximal end

Third “ “ " length . ■ ,

« “ o o breadth of proximal end

§ ■

£ •

as 0

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PS O

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a

H. CRUENTUS,

No. 1.

H. CRUENTUS,

No. 2.

D

g

P

D

S

B

M.

0.122

.067

.019

.037

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i .160

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SiKH-imeii iieloiigiiig to tire .American Museum of Natural History.

622

Kia. d.—Iff/amodon cruentus ; Left os in-
nomiiiatuiii, J natural size.

THE OSTEOLOGY OF HYJ5N0D0N.

VI THE HIND-LIMB.

Tl„ /.Ms of Hysrnodon i» not otpociolly croodont in character approximating-
more the^condition round in certain of the Carnivora. In the earlier and less dif-
ferentiated creodonts, as likewise m the insec-
tivores, the ilium is more or less distinctly
prismatic and trihedral in shape, while in
Hyanodon it is flattened and expanded into a
plate, though less so than in some of the re-
cent large genera. So far, complete specimens
of the pelvis have been found only in H. cru-
which will therefore be used as the basis
for the present description. Fragments be-
longing to some of the other species indicate
that certain differences obtain between them
regarding the shape of the ilium. In H. crti-
entus the neck of the ilium is short, deep, and
thick ; the ischial border rises abruptly to form
a quite moderate anterior expansion, with a
somewhat concave gluteal surface. The rugose area for the attachment to the
sacrum is placed very far back, its posterior margin coinciding with the commencing
expansion of the iliac plate. The latter thus extends considerably in front of the
sacrum and, when viewed from the side, almost completely conceals the last lumbar
vertebra, against the transverse process of which the ilium partly rests. The iliac
surface is quite broad posteriorly and somewhat oblique in position ; anteriorly it
becomes narroAver. The acetabular border describes a slight curve, with the con-
cavity downward, which is much less pronounced than in Canis, but decidedly more
so than in the cats or mustelines. The pectineal process, which among the creo-
donts is so generally well developed and prominent, is in Hycenodon reiu'esented
by a mere tubercle. The acetabulum is quite large and deep, and its articular sur-
face is but little reduced by the sulcus for the round ligament.

The ischium is rather short, compressed and plate-like. It does not lie in the
same veitical plane as the ilium, but is posteriorly somewhat twisted upon itself and
everted, though this eversion and depression are much less marked than in the dogs,
and the tuberosity is much less prominent and massive than in those animals.

I he pubis IS short, straight, broad and very thin. The symphysis, formed
partly by the pubis and partly by the ischium, is elongate. The obturator foramen
IS a long, narrow oval, with its principal axis directed antero-posteriorly. The
foramen is considerably more elongate proportionately than in the dogs, which is
due to tlm greater width o the descending process of the ischium in the latter.

not a cefd Zt' T ZT border does

not ascend so abruptly to form the anterior expansion, which is narrower- the

acetabular border IS less decidedly curved and tbLlni. i 7

cavated. ^ ^ gluteal surface more deeply ex-

THE OSTEOLOGY OF HYJSNODON. ' 523

.„..t „f t„e t„,e ea,.„ivo.. L,, . :tir:sr

ofcatlj , less so than is the case in most of the Canidte. The
head IS small, hemispherical, projecting strongly toward the
mesial side, as well as proximallj; it is set upon a very dis-
tinct neck and has a remarkably small pit for the round
ligament. The bridge connecting the head with the great
trochanter is narrow and compressed. The great trochanter
is ma.ssive and roughened, but low, not rising as high as the
head and enclosing a sniall but deep digital fossa. The
second trochanter is developed to an unusual degree ; it
forms a prominent, heavy and rugose pyramid, which is
much more pronounced than in the recent carnivores and
is more closely connected with the great trochanter by
means of an elevated ridge. The third trochanter, which
in most of the creodonts is very distinctly developed, has
in IlycEtiodon become rudimentary and is not so well marked
as in the early dogs and cats; e. g., Daphmms and D midis.
The e.xternal linea aspera, with which the third trochanter
is connected, is also but feebly marked. The proximal end
of the shaft is not so much exp.anded transversely as in
the Canida: and, aside from the large size of the second
trochanter, the whole upper part of the femur is decidedly
more feline than canine in appearance. The shaft is flattened on the posterior face,
rounded on the other sides and relatively very slender. In the latter respect, how-
ever, tli(*re are considerable differences between the species, the larger forms having
relatively stouter bones, and even in the same species marked differences occur,
whicli inav. |HThi,|,». W of a sa.vaal nature. The shaft of the femur h.as a double
cirvaltliv.'arehiug Ih.|Ii foi-ward and oultv.trd. so timt the inner profile, when viewed
from the Ironl, is ilistinctly concave and tlie outer convex. The distal end is
nUKlcratcIv widened traiisvci-sely and very thick antero-posterioy , in which dimen-
sion it |,n,|,ortio, lately inucli exceeds tlie femur of the wolf The .yular trochlea
i. not like that found in the recent carnivores , it is narrow and Y*“P- "
coinpreeae.!. shar,, and elovntod horders, and is reflected far np "f” ‘'’t, “ *

face of the shaft The internal Imrder is higher than the extern. , ""d “
structure has a iKU-issudactyl ofter mii

arc rather small, but project strongly to t 1 „ating the condyles is

slightly exceeds tlie inner one m brc.uU .

slightly narrower proportionately than m j for a sesamoid bone,

vores. therc^ is a small facet on the 1--^ ' thinning is especi-
The patella is of oval shape ami ol no gieat c
ally noticCble in the smallest of the »FCies, H. nmslelmm.

68 JOURN. A. N. S. PHILA., VOIa. IX.

Kio. 7. — II}/<rno(lon enun-
tun; latyft fciiiiir friini the
rront, i natural ni/.e.

524

THE OSTEOLOGY OF HYxENODON.

Tl,e tx. is sl,ort. decidedly shorter than the femur, and in gener.al character
most n-seinbles that of such recent plantigrade genera as Procyott. The condj es

are rather small, nearly plane transversely and slightly convex antero-posteriorly

The posteroexternal angle of the outer condyle forms a broad, overhanging shelf,
on the distal surface of which is a large, plane facet for the head of the fibula. The
cnemial crest is only moderately developed and is much less prominent than m the
CixnidiC ; it extends, however, quite far down the anterior face of the shaft. The
proximal portion of the shaft is quite heavy and of trihedral section ; it has a double
curvature, like that of the femur, arching forward and toward the mesial side; the
distal portion of the shaft, on the other hand, is of rounded form and nearly straight.
The distal end is but moderately widened and thickened and has nearly equal
transverse and autero-posterior diameters. The articular surface for the astragalus
is quite w.ell grooved and distinctly divided into two facets, the inner one of which
is nari'ow and deep, the outer one broad, but slightly concave and placed at a very
acute angle with the long axis of the shaft. Except at the anterior margin, the
intercondylar ridge is low and inconspicuous. This ridge is better developed in
H. horridus than in the smaller species and the astragalar facets are more deejily
impressed. In all the species the malleolar process is prominent and thick antero-
posteriorly, though not very long; its distal end bears a facet for a pit on the neck
of the astragalus, a character which is very common in the creodonts. The distal
fibular surface is not a distinct facet, but merely a groove on the outer side of the
tibia.

T\\<i fibula is relatively little reduced, even less so than in the Procyonidc?, except
in H. crucians, in which, according to Wortman (No. 4, p. 225) it is very slender.

Ihe proximal end is very heavy and is expanded both in
breadth and thickness ; it articulates by a large, plane facet
with the lower side of the overhanging external condyle of
the tibia, which has been already described, and on its outer
face IS a deep tendinal sulcus. Somewhat below this enlarged
a..d most contmeted, but it stx...
aud libula of young and gradually, though not regularly, increases in

animal, natural «ize. diameter toward the distal end. The double curvature of the
t.bia produces a wide interval between the two le-boncs
whether seen from the front or the side, and though the shaft of the fibula i:neari;

Jir 1;:^

1 1 • I t, X. fiighly characteristic of the o-enus It is

enlarged m both the transverse and antem r x “

latto,-; on the outer side is a broml „d , r • !"" espocially i„ the

which forms a tendinal groove- on the imTer^'^!l ’ process,

ex, face, for the extcrual WUm !"

lie calcaneum. Tlie ntilpono.,! r„„„x x, ^ distal side is a facet

for the calcaneum. The calcaneul fnoot , «u uie aistal side is a facet

neea (fore-ai.d-aft) „f the Kbular'ead No e'oetiM™’ ““‘’1''*
sive and elaborate articulation between the'k.d, 7°";

Hy^noden. nor I, it found in „tber known creod„.“

THE OSTEOLOGY OF HY.EN0D0N. 525

Tlie tarsus m not at nil characteristicnlly crcodont in structure ,md altliou"h
nivora a* in any of the cX

I'l't- in all the American species of Hy^mdon displays certain con-

fof . ?r'"“n ?"■ - ‘ (*■* No 9, n. 684. fij.

587, tie ISIainvlIle, Osteographie, Subursus, PI. XII), the most important of which

are the greater obliquity of the external calcaneal facet
and the much greater length of the neck in the former.
The amount of grooving exhibited by the trochlea varies
according to the species. In H. cruentus the groove is
deep, for a creodont astragalus, less so than in the recent
digitigrade carnivores, but decidedly more so than in
such White River genera as Dinicfis, Hoplophone^^s or
Daphmius. In the little H. mustelinus the trochlea is
more flattened, while in H. horridus the grooving is
better marked than in the existing cats. Between these
extremes the contrast is very notable. The degree of
symmetry of the astragalar trochlea also differs in the
different species. In H. horridus and H. cruentus the
external condyle but slightly e.xceeds the internal in size,
wdiile in the small undetermined species (marked H. sp.
in the tables of measurements) and in H. miistehnus it
does so considerably. The fibular facet of the astraga-
lus is large and slightly concave; distally it becomes
confluent with the external calcaneal facet, from which
it is elsewhere separated by a deep sulcus. The facet on
the inner side for the tibial malleolus has but little dorso-
plantar depth, but extends well distally, where it termi-
nates in the characteristic pit or fossa which occurs in so many creodonts. The
neck is long, especially in H. mustelmus, and strongly everted toward the mtm-nal

^ 1 ..1 it* K/V1 f\

Kio. ». — Ifi/tr.iwdonsp. Right
j)c» : a, astragalus, el, lalca-
iieiiiii ; cb, cuboid ; c', e",
e"', ent<>-, lueso- and ectocu-
neiforniH. j natural size.

side, so that there is no contact, or none

but the most limited, with the cuboid.

Tire head bears a rounded, simply convex facet for the navicular; there is no facet
for the cubtiid (Zittel’s figure is incorrect in this regard) and, apparently^ the wo
bones do not meet at all. The head is depressed and flattened, the transveise

The external calcaneal facet is large

diameter exceeding the dorso-piaiuai unc. -uuv. w ...
and ilunply concave ; its position is obliqne with reference “ ^

plnntnr and prlvimonlisUl a.ve» of the astragalus, ^lis ^

slightly convex and is everywhere sepanated from the outer calcaneal facet by

the osteology OF HY^NODON.

narrower, less depressed and has no such extensive articulation with the cuboid, if,

indeed, it has any at all. , . . . , i j

The calcancum has a r.ather long tuber, which is deep and compressed, some-
what thickened and rugose at the free end, which is without any distinctly marked
ten.linal sulcus. The donsal margin of the tuber is slightly convex and the plantar
concave, arching downward to a rougliened surface vertically below the fibular facet,
whence the border rises to the distal end. The greatest dorso-plantar diameter is
thus at the lihular iacet; it is a little more distal in H. cmenhis than in H. ho7'-
ridiis. In //, mustelimis the tuber is relatively shorter than in the large species,
'fhe process for ligamentous attachment which arises from the external side near
the distill end is quite prominent, especially in H. Iwrridus and H. mustelinus,
though not so nnich .so as in some of the European species (e. g. H. bj'achyrhynchus) .
The sustentacnlimi is not very strongly developed and carries a concave, nearly
circular astragalar facet. The outer astragalar facet is large and convex and pre-
sents more toward the internal than toward the dorsal side; its junction with the
(ilmliir facet, which lies in a somewhat different plane and presents distallj’ and
dorsally, forms an inconspicuous ridge. The fibular surface is very" large and promi-
ueiit, most exceptionally .so for a flesh-eater, and gives to this region of the calca-
neuiii quite an artiodactyl aiipearance; this facet is elongate and convex and rises
very" steeply from the body of the calcaneum. So far as can be judged from the
pulilished (ignres, the fibular facet is not so extensively developed in the European
species as in the American and the sulcus between the external astragalar facet
and the sustentacnhim is more deeply incised. The cuboidal facet is quite oblique
to the long axis of the calcaneum, inclining distally and to the external side; it is
slightly concave in both directions and more or less warped and saddle-shaped.

1 he calcaneum of Oxycejta has a relatively shorter and heavier tuber than that
of Hycetiodon, a much larger and more prominent sustentaculum and a more ob-
h.piely-placed cuboidal facet. The most important difference between the two
genera, however, consists in the fact that in there is no distinct surface for

he fibula, the a.stragalus extending so far over the dorsal face of the calcaneum as
to exclu.le the latter from any contact with the fibula. In the whole creodont-

large ,,„„e . its greatest diameter is the vertical or

the hreadtl, and thiekness are ne.rl, equal to Zl other

obiiq„ei„p»itio„. beh,g highe; at

both the dorsal and external sidL If

lus, whicli seems unlikely, it is not sufficient to astraga-

ntal end ot the „„b„id L thus el« dlrlT" l’™"'

Palrio/el,!, where the cuboid posse^es^facets for tlir f”*

^eari, equal site. These two U meetr": rl^ ^d C tt

THE OSTEOLOGY OF HYiENODON. 527

the cuboid a highly characteristic appearance, which is not reproduced in Hyceno-

don In the latter the tibial side of the bone displays proximally a large flat facet
for the navicular, and distal to this two small, round projections for the ectocunei-
form, which are separated from each other by a wide and deep sulcus. The plantar
hook-shaped process is not long, but very broad and heavy and extends around both
the external and plantar surfaces. The distal side has a large, triangular and con-
cave articulai surlace, which is obscurely divided into facets for the fourth and
filth metatarsals; in II. cruenlus the latter is very small and somewhat oblique in
])osition ; in //. horridus it is larger and more entirely distal.

1 he navicular is low and narrow, but with considerable dorso-plantar exten-
sion. The astragalar surface is simply and deeply concave. On the fibular side is
a large and nearly Hat surface for the cuboid, the proximal ends of the two bones
lying in nearly the same plane. On the distal side are the usual three facets for the
cuneiforms, the only noteworthy feature of which is the narrowness of that for the
entocuneiform. The plantar hook is quite prominent; in H. sp. it is 'straight and
knob-like, while in the larger species it is longer and more decurved.

T'he entocuneiform is high and thick antero-posteriorly, but very narrow and
compressed ; it is broadest on the plantar side, thinning to an edge on the dorsal,
and the distal end e.xceeds the proximal in every dimension. The navicular facet
is very small, while that for the first metatarsal is considerably larger and strongly
concave in the dor.xo-plantar direction. On the fibular side is quite a large facet for
tlie head of the second metatai’sal.

The niesocuneiform is low, but exceeds the entocuneiform in the other two dimen-
sions ; its distal surface stands at a higher level than that of the tarsals on each
side of it, as is very generally the case in both the creodonts and carnivores. The
bone is wedge-shaiied, but in the opposite sense from the entocuneiform, the dorsal
surface being the wider. The lateral facets are small and obscurely indicated.

T’he ectocuneiform is much the largest of the three, except in vertical height,
which is less than tliat of the internal element, though much greater than in the
median one. On the plantar surface is a heavy, prominent knob, shaped very much
like that on the navicular. On the tibial face are two facets, a proximal one for
the niesocuneiform and a distal one for the second metatarsal. The cuboid facets
are both proximal; they are small, rounded and separated by a wide sulcus, but
are not projecting and shelf-like, as are the corresponding facets on the cuboid.
The distal facet for the third metatarsal is not much wider than that on the raeso-
cuneiConn lor the second metataral; it is much extended from before backward
and is (luite deeply concave in the same direction.

The consists of nve fully developed members; thy are rather more

slemlor than the metacarpals and exceed then, bnt little .u leyth. Th.ys
usual ,„-o|K,rtio„ a.uong the lleshu,alera in which the hn.d- foot .. >^0^

ably IninrcM- lliail the Ihre-font. lioth are short, we.ak and slender m lelat on the
siinf the animal, thongh in the larger specimens of HJ^ndus the feet are not
^^uite so disproportionately weak.

528 THE OSTEOLOGY OF HYvENODON.

.j;s;

un.l abuts aguinst the ectocuneifbnn. for which it has a facet. The proximal por
tion of the shaft is laterally compressed, but of considerable thickness antero-poste-
riorly ; it soon becomes slender and subcylindrical. The distal trochlea is narrow,

of asymmetrical shape, with prominent carina. xx, i, j r-

Owing to the small proximo-distal diameter of the mesocuneiform, the head of
nit. II rises to a considerably higher level than those of mt. I and mt. HI, and is
wedged in firmly between the ento- and ectocuneiforms, with the latter one of which
it has an extensive articulation. On the fibular side the head is excavated to re-
ceive that of lut.lll. The shaft at first pursues an oblique course, its proximal
|)ortion being inclined outward as well as upward, but then turns and most of the
shaft runs more nearly parallel with those of the other digits. Something of the
same sort may be observed in Lutra, but the curvature of the proximal end is less
ill amount and in the opposite direction. In HycBnodon the shaft of mt. II is weak,
slender and relatively short ; the distal end is but moderately expanded and thick-
ened ; the trochlea is asymmetrical and somewhat obliquely placed.

'File third metatarsal is the longest of the series and, except mt. IV, the heaviest.
The head is narrow and convex from before backward, terminating on the plantar
side in a rough knob, which is especially large and rugose in H. horridus. On the
fibular side of the head is a deep cavity into which is received a rounded articular
projection from the head of mt. IV. A second concave facet for mt. IV extends
posteriorly to the end of the plantar knob already mentioned. Mt. Ill and IV arc
thus very firmly interlocked, while the connection of the former with mt. II is looser.
The shaft is slender, nearly straight and of trihedral section, the apex of the tri-
angle being tlie plantar edge. The distal end is more expanded than in mt. II and
the trochlea is wider and more symmetrical, with the carina nearly in the median
line. The lateral ligamentous processes above the trochlea are quite prominent.

The fourth metatarsal is somewhat shorter and slightly stouter than the third,
but otherwise similar to it. It is closely interlocked with both the adjacent meta-
tarsals, having on the head a deeply concave facet for mt. V and a prominent articu-
lar convexity for mt. III. I he heads of these three metatarsals stand at nearly the
same level, each of them articulating with a single tarsal element. The shaft and
trochlea ol' mt. IV are very much the same as those of mt. Ill, with which it forms-
an almost symmetrical pair.

Tlie liftlimi.tiitarsal i.s considerably longer and heavier than the first; the head '
IS distingiiis heel by an inmsually large process for ligamentous attnchinent. which
.appoars ,m the hbubir side. This proeess is much larger and more massive than in

till side'nim ta.' ‘-“"i «-

The //m/««g.,r„rthe pes differ little from those of the manns. They are only

529

THE OSTEOLOGY OF HYiENODON.

«>nu.wl,a( ,M„re .lender and elongate, but are relatively shorter tl,a„ in most recent
carnivores.

^ In the American representatives of the genus there is veiy little

variation in the structure of the hind-foot. The preceding description is founded
upon well-preserved si»cimens of no less than four of the species, vis., H. horriim
//. crucnlus,ll. mmtdinus and H. sp., and the only tangible differences between them
are Hiose ol siz-e, aside from the few minor variations which have already been
mentioned, such as the deptli of the astragalar groove, the size and massiveness of
the various processes for muscular and ligamentous attachments and the like. In
the small species also (e. g. H. sp. and H. mustelmus) the metapodials are somewhat
more slender in proportion than those of the larger and more robust forms, but the
(lifleieiice is not a strikingly obvious one. The agreement with the European spe-
cies is closer in the pes than in the maims, for in the latter the condition of the
carpus is (piite dill’ereiit in tlie two groups of species. In the pes the shoi’tness of the
astragalar neck, the greater prominence of the external, distal ligamentous process
of tlie calcaneum and the somewhat smaller size of the fibular facet, are almost the
only divergences to be noted. Schlosser’s figure (No. 5, PI. V, fig. 47) of the hind-
foot of //. compressus is, it is true, not very like that of the American species in
appearance, but the dilTerence is, doubtless, partly due to the fact that his speci-
men is built up from many individuals. Comparing the pes of Oxyatia Patrio-
fclis with that of Hyceyiodon, the principal difference to be noted consists in the
shape of the cuboid, its extensive articulation with the astragalus and the conse-
(juent divergence of the metatarsals, and also the absence of any calcaneo-fibular
articulation. Hycrnodon has attained the ditfereiitiation of pes which is found in
the Carnivora, though without any reduction in the number of digits.

Measurements.

Pelvis, leiiKtli ....
Ilium, “ . . .

“ Kreutest width

Isehiiiiii, length

Obturator foramen, fore.and-aft diameter
Femur, leiif^th (from head) .

“ lireadtli of iiro.xiinal end .

“ thickness of distal end

“ widtli of rotulargnxive
Tibia, leiiKth ....

" breadth of jiroxiinal end

“ “ of distal “

Fllmla, length

“ thickness of proxinial end
“ “ of distal end

K .

c4

K .

a c

P o

S O

I ^

w

:

1

1

K

B

: B

K

i W

JM.

0.150

.089

.028

.061

.0,37

.165 ;

.169

.040 '

.041

.047

.041

.044

.013

.015

.133

.146 {

.031

.038 !

.038

.017

.025

.018

.021

.024

.123

.015

.014

.017

.014

.016

530

THE OSTEOLOGY OF HYiENODON.

Measurements — {contimied) .

Ctilcuueuiii, length . . . ■

" dorsD-plantar depth at free end
“ “ •' “ at libiilar facet

AHtruKahiH, length

“ width of trochlea

“ " of head .

TarsuH, i)roxini(Mlistal height (fr. astragalus to mt. Ill)
Metatarsul 1, length

“ I, hreadthof proximal end

“ II, length

“ II, tireadth of proximal end

“ III, length

“ III, hreadth of proximal end
" IV, length

“ IV, hreadth of proximal end

“ V, length

“ V’, hreadth of proximal end'

Phalanges of III digit, length

a

&

Q .

io

B

D

H .

§ o

td

H. CBUENTUS,

No. 2.

o

B

j H. MUSTELINUS.

M.

.055

.053

.029

.018

.013

1 .009

.023

.032

.024

1 .014

.028

.037

.028

.032

.018

.013

.017

.013

.015

! .009

.013

.016

.01.3

.013

.008

.038

.060

.047

.027

.043

.010

.007

.004

.063

.010

.008 1

.005

.057

.070

.066

.008

.011

.010 !

.006

.056

.069

.065 '

.006

.009

.008

.005

.040

.054

.048 !

.008

.011

.011

.045

VII. RESTORATION OF HY^NODON.

As a wliole, the skeleton of Hycenodon presents a curious and remarkable ap-
petirance. As compared with any of the recent Carnivora, the head appears large

Kio.lO -Rostoratiouofl/yreaodoacraeatos. The skull o.nt a rv,
venebne, ^-apula, ulna, radius and part of carpus fern ’ t ^’ ^horactc, 4 lumbar, 2 sacral and 2 ,
individual, and were excavated from the same bl^ Tho ^ ^

supplieri from a siiecimen in which the

i JIE OSTEOLOGY OF HYiENODON.

531

out of all proportion to the Wy and limbs, the neck short, the back, especially
the lumbar reLnoiw>r it. nn fa i^nr. ^ v

Kj± vviiiuii io veiy

low down .... the s.des of the skull; in fro.it the maxillary alveolus forms a part of
the /ygoma, winch thus seems to carry the sectorial molar, a very exceptional
arrange.ne.it. The region of the cranium back of the glenoid cavity is very short,
a featin-e winch .s usual among the creodonts. The low position of the zygomatic
ai’ches inc-eases the appai-ent depth of the fiice, which, independently of this, is
very considerable. Other chai-acteristic features of the head are the great length
of the inaudible, which very' neai’ly equals that of the skull itself, its slenderness
an.l the regular curvatui'e of its inferior horde.’. When the jaws are closed, the
lower teeth, e.xcept the anterior ones, are concealed fi’om view, the upper molars
extending over tlie sides of the mandible.

I he neck 8ei*m.s vei’y short and slender to cari’y the weight of the large head,
its length being liai’dly moi-e than two-thirds that of the skull. The axis is the
only cervical vert.’hra which is sti’ongly developed and possesses a large spine; the
olhe.’s iire weak.

The tliorax i.s small, when compared with the skull, but measured by' any other
standiird, it is (|uito large and capacious. The vertebral spines are developed much
as in the Cai’iiivoi’a and the ti’ansverse processes and rib-tubercles are v'ery' conspicu-
ous. The lumbar I’egion is long and powerful, the vertebrm having massive centra
and long heavy spines, transverse processes, etc. These features are most marked
in //. /lorridns, the smaller species having much less massive loins and evidently
feebler muscles. The wluile back, fi’om the neck to the sacrum, is strongly arched
upward and its parts are articulated together with unusual flexibility' and strength.
The sacrum partakes of the character of the lumbar region, with prominent spines,
while the tail is rather short .and slender, h.aving about the s.ame proportion.ate de-
veloj.ment as in the r.aecoons.

The scai.uhi is I’emarkably small and, with many peculiarities, is shaped not
unlike that of the dogs. The hn.nerus is short and slender and the fore-arm bones
still iiioix* so, though the ulna is stout .and h.as, as in nearly all the creodonts, a very
p.'onunent olecranon. The inanus is relatively sm.all, short and broad, with spre.ad-
ing digits and short phalanges, teriiiinatod by' heavy chaws.

The pelvis is of moderate size, with expanded, flattened ilium, and is carnivorous
rather than creodoiit in character. The femur considerably exceeds the humerus
in length, but it is proportionately light and slender .and Ims ne.arly lost the third
trochanter. The tibia is short, though much longer than the radius and the fibula
stout, esiiecially .at the ends. The pes is small .and weak, not greatly exceeding
the nm,,,.., in l..ngth. It in very difflenit t.. decide whether Hym.odon wan digit,.
grade or jdantigrude in gait and several struetiirai characters may e a uce

6i» JOURN. A. N. S. PHILA., VOL. IX.

the osteology of hy^nodon.

„r fitter view. I., favor of the plantigrade poritioo may be mentioned the
,,r„ .orlim... hclween the arm and foie-arm, ae well M those between the thrgh and
le... the clnmlfter of the carpus, tl.e absence of any tendinol sulcus on the free end
oalie oalcaiieiiiii, tlie large size of the pollex and hallux and the fact that the digits
do not form svimiu'trical pairs, but are all of different lengths. On the other hand,
the back ward’ projectio.i of the head of the humerus and its position with reference
to the line of the shaft, the height of the humeral trochlea, the character of the
rotular trochlea of the femur and the position of the femorcul condyles, the deep
grooving of the astragalus and the length of the tuber calcis, all seem to indicate a
di'Mtigradc gait, hi the restoration herewith given a semi-plantigrade position, such
as occurs in many imistelines and viverrines has been selected as the most proba-
ble. Hut for the lact that so many of the bones drawn belong to one individual, I
should feel groat hesitation in publishing this grotesque figure.

In the following table comparative measurements of Hycstiodo7i crue7ihi.s and
Cinis occideulalis are given to display the different proportions of the various parts
of the skeleton in the two genera. In both cases the length of the skull is taken
a.s 100 and the relative lengths of the different bones calculated to the nearest in-
teger. There is some room for error in the measurements of Hyesnodon, because
the skeleton is made up from several individuals, though the skull, neck, nine
thoracic and four lumbar vertebrm, the sacrum, scapula, ulna and radius, carpus,
femur, tibia and fibula are all from one specimen. In addition to this it should be
noted that the different specimens contain many parts in common, so that the vari-
ous proportions may he calculated from one to the other without any great risk of
serious error. Thus, the small, undetermined H. sp. has the skull, vertebral col-
umn complete to the sacrum, tibia and fibula and hind-foot; a second specimen of
//. cruenliis consists of the mandible, axis, humerus, ulna, pelvis, femur; a third of
the skull, many vertebrm, femur and pes, and so on. The wolf-skeleton has been
selected ^ lor the purpose of comparison, because the actual length of the skull is
not lar Irom being the same as that of H. cruentus, and it is therefore well adapted
hu- bringing clearly to light the altogether different proportions of a modern car-
nivore from those of even a highly differentiated creodont.

1 , ^ TU'te possible that, as Filhol has suggested, HycBnodon was of aquatic
habits; ,f so, this would partly account for its extraordinary proportions.

C. OCCIOENTAUS.

Length of skull ,

“ of neck . ' ’

“ of thoracic region
of lumbar region
“ of scapula

“ of humerus

“ of radius

o phalanges

“ of femur

“ of tibia . ■ ■

of isis, without phalanges !

100

97

139

93

63

100

67

127

.62

29

65

633

the osteology of HYiENODON.

VIII. THE UELATIONSHIPS OF HY^NODON.

It has been customary of late to include Hycenodon and Pterodon with

Tontr. Xo"?) Tl^ " ^ «« the creo-

donts (.No. 0. The propriety ot such reference will depend upon the significance

.dnch IS assigned to the tainily groups. In the classification of recent anhnals the
family is einployed to include all the genera which agree with one another in the
possession of certain dehnite structural characters, and it thus often embraces mem-
bers ot many collateral lines. This principle is useful in grouping the recent forms
and gives e.xpressioii to the relationships of animals existing together at any mven
period ot tl.e earth’s history. In the plan of fomily classification adopted by Os-
born and bchlosser, on the other band, the tainily represents a single phylogenetic
hue or branch, which may include short side-branches not leading to permanent
modifications. This method is useful to express the relationships obtaining between
the various succes,sive faunas which have been discovered. Each of these methods
thus possesses certain advantages and each is exposed to the necessity of more or
less arbitrarily separating allied genera. Schlosser’s method, however, is much
better adapted to the needs of paleontological inquiry; indeed, it is almost impos-
sible to use the other with any degree of satisfaction.

Thanks to the researches of Osborn (No. 3) and Wortman (No. 8) the struc-
ture of Oxycena and Patriofelis is now well understood and a detailed comparison
ot these genera with IlycPfwdon may be made. As the result of such comparison
I have no hesitation in adojiting Wortman’s suggestion of a return to Cope’s origi-
nal scheme and separating the Oxyanidce from the Hyce7iodontid(e . That these
two families are nearly' related to each other and were derived from a common stock
is clear, hut with all their resemblances, they represent diverging lines. In the
Oxycenidtr the face is much shortened, with a consequent reduction in the number
of teeth. This reduction affects the molars principally, the formula being m^, but
in effect is almost lost, as well ; it is very small and forms a transversely directed
tubercle, while is much the largest of all the cheek-teeth. The fourth upper
preinolar is a well-developed sectorial, with large posterior cutting edge, or tritocone,
and in .some species with antero-external cusps. In the lower jaw mi is large,
though somewhat smaller than ni2- which with forms the principal pair of sec-
torial teeth, while Jha has disappeared. In Patriofelis the reduction of teeth hag
proceeded still farther .and gives the formula, ™ both genera there are

but two pairs of lower incisors. In the Hyceiwdontidce the emphasis of develop-
ment, so to speak, is differently placed, the principal pair of sectorials being m2 and
ni3, which are much the largest teeth in their respective series; a second and less
important pair is formed by' and ni2. while ml is very greatly reduced in size and
smaller than most of the preinohars. The last upper premolar is not sectorial in
form, the tritocone being but little developed.

,Si„,il„r divergences .appenr in the skull. The face in the Oxy^md^ ,s short
•and abruptly truncated ; the zygomatic arches are enormously developed and curve

53^ THE OSTEOLOGY OF HY^NODON.

oi.t strongly from the sides of the skull, as well as arching decidedly
Ixdng iioUhe least tendency toward the assumption of the peculiar conditions foil
i„ Ihuenodm and, to a much less marked degree, in Plerodon. The lachrymal is
not cNpanded on the face {fide Wortnian) and the mastoid processes are very largely
develoiHHl. In the Hymiodontidce, on the contrary, the face is not shortened, but
rather elongated and tapering ; the zygomatic arches are straight, slender and placed
very low down on the si.les of the skull, while anteriorly they are contmued by the
alveolar portion of the maxillaries. This unique arrangement has attained only an
incipient stage in Pterodon. The lachrymal forms a large facial plate m front of
the orbit and the mastoid process is rudimentary.

The extremities display divergences of at least equal significance. In the more
ancient family the scapula is large, with broad, flattened acromion and largely de-
veloped metacromion. The humerus is short and massive, with enormous deltoid
and supinator ridges. The ulna is very massive and has a remarkably high ole-
cranon. In Oxycena the carpal bones are of moderate width and of the form usual
among the Carnivora, while in Patriofelis they have more the width found in Hyee-
nodon ; me. 11 has lost its connection with the magnum. In Hyesnodon the carpus,
especially' the cuneiform, has greatly widened and me. II has an extensive connec-
tion with the magnum, while that of me. Ill with the unciform is much I’educed.
Even more important are the dillerences in the pes.

In the Oxytenidee the astragalus is depressed, flattened and hardly at all
gr(K>ved ; it has a stout neck and the head articulates extensively with the cuboid,
the proximal end of which thus receives a highly characteristic shape. The calca-
neum has a short tuber and does not articulate with the fibul.a while the metatar-
sals have a strongly divergent position, almost like the sticks of a fan. In the
I lyernodotUidce the pes has become entirely carnivorous in type ; the astragalus does
not articulate with the cuboid, but the calcaneum has developed a very large and
prominent facet for the fibula, such as occurs in no other unguiculate. The meta-
tarsals do not diverge strongly from one another, but pursue an approximately paral-
lel course.

1 lie group to which both the Oxycenidee and Hyeenodontidez may be traced
back is undoubtedly the family Proviverridce . The skull-structure of such genera as
Cy fiohycenodon and Smopa {Stypolophus) is of a kind from which that characteristic
of tlie Oxyuemda, on the one hand, and of the Hyeenodontidee , on the other, might
readily be derived; even the remarkable character of the posterior narcs found
in the latter is perhaps in an incipient stage. The dentition also is of the type
which we should expect to find in the ancestral form; this is particularly seen in
the reduced size and transverse direction of ”1'^, the very close approximation of the
par.i- and metacones on the upper molars and the development of a trenchant pos-
terior riflge behind the latter. This type of molar-structure is already indicated in
Puerco tunes and if this feature alone be regarded, the genera Deltatherium, Sinopa,
Oxyana, Plerodon, Hycenodoii, form a complete series of transitions from the tri-
tubercular to the exclusively sectorial pattern of crown. Various considerations,

the osteology of HY.EN0D0N. 535

however, slunv that the "enera inpnOr,n£.ri a. ^ v

lower molars, thoiigli still hi a very |)viinitive''ti l”"” 1

the premolars, canines and incisors of both jaws iiiTlie “•'"8''’ “

which might easily be modified into those of the other

present a partienlar resemblance to the H,„od,ntid^ Ztlkt

skeleton of favors the same view of its relationship to tlic other families

at libnla” “* with the coWd and the calcanenm with

So far as is yet known, tile Oxymiids: are an American family, the supposed
members o it which have been found in France being inferred to it with very doubt-
ful pi opiu'ty. Hie group tnust have originated in the interval between the Puerco
and asatdi formations from some Piierco genus not jot identified, but which, in
all probabditj. was hut little removed from Deltatherium. The Hya-nodontid<s', on
the other hand, arose in the Old World, appearing first in the upper Eocene (or lower
Ol.gocene) and hj a later migration reaching North America, where they are not
known before the (upper) Oligoccne, or White River beds.

Pterodon apparently did not accompany Hycenodon in this migration, though
it is represented by tlie very closely allied genus Pemipsalodon, which differs only
in tiie character of the talon on nis- It is a significant fact that this genus has been
found only in the Titaiiotlierium-beds of Canada (lat. 49°, 35' N.) which contain a
fauna in several respects difl'erent from that of the regions farther south and one which
in many ways is more distinctively allied to the Oligocene fauna of Europe. These
differences are doubtless owing to climatic and geographical factors rather than to
any discrepancy of geological age. Assuming, as we may safely do, that Hctni-
psalodoH came from the Old World, the Cypress Hills region would probably repre-
sent its sontherninost range.

Any attempt to comstruct a series of genera leading to Hyeenodon Avould be
premature, though Proviverra, or some very similar form, will doubtless prove to be
one of the genera through which the line of descent passed.

LIST OF PAPERS QUOTED.

1. Filhot, IT. — .Memoires stir qiielques Maramiferes Fos.«iles. Toulouse, 1884.

2. Leidy, J. — The E.Ktinct Haninialian Fauna of Dakota and Nebraska. Philadelphia, 1869.

3. Osborn, H. F. and Wortman, J. X.— Fossil Mammals of the Wahsatch and Wind River Beds

Bull. American Museum of Natural History, New York, Vol. IV, 1892.

4. Fo.ssil Mammals of the Lower IMioceue White River Beds. Ibid, Vol. II, 1894.

5. Schfosser, .V.— Die Atfeii, Leinureu, etc., des europaischen Tertiars. Th.I. Reitriige zur Palseon-

tologie Oesterreich-Eiigarus, VI Bd. Vienna, 1887.

6. Scoff, W. R-On some new and little known Creodonts. Jourii. Acad. Nat, Sci. Phila., Vol. IX,

No. 2, 1887.

7. A Revision of the North American Creodonta. Proc. Acad. Nat. Sci. Phila., 1892. ^

8. iroz-Xmii, .7. L.— Osteology of Patriofelis, a Jliddle Eocene Creodout, Bull. Amer. Mus. Nat.

Hist., \'ol. VI, 1894.

9. Ziffdil, K. r.— Haiidhuch der Rahcontologie, I Ahth., IV Bd. Munich A Leipsic, 1890-189.^

70 JOUKN. A. N. S. PHILA.. VOL. IX.

APPENDIX.

After the foregoing paper on Ancodus was completed, the Princeton Museum
received an umisuiilly large and line skull appertaining to this genus from the White
. River bad lands of South Dakota. The specimen was found in the Metamynodon
division of the Oreodon-beds, and appears to represent the same species as that re-
I'erred by Osborn and Wortman to the A. americanics of Leidy. (Bull. Amer. Mus.
Nat. Hist., New York, Vol. VI, p. 219.) Leidy ’s species, however, was found in
the Titanotlierium-beds, which affords a pi’esumption against its being identical
with the specinien before us. As in the skull-fragment described by Osborn and
Wortman, the first upper premolar is wanting, an evidence of the constancy of this
character. The principal differences from A. americanus which may be observed
in the dentition are two: (1) has a imich better developed cingulum, especially
upon the inner side of the crown. (2) In the upper molars the external buttresses
or styles are decidedly less conspicuous, the median buttress (mesostyle) is divided
by a deeper cleft and has a tuberculated or crenulated edge.

The differences from A. brachyrhynchus are very distinctly marked. (1) VI is
absent and the muzzle is much more elongated. (2) The palatal notches are much
more deeply incised and extend farther forward. (3) The posterior nares are not
displaced so far backward and have a (piite different shape, the palatines forming a
long and pointed median projection from the anterior border. (4) The size of the
animal is greater. Imleed, this skull is distinctly the largest of this genus that
has yet l)een reported iroin the White River formation.

1 be mandible has a very shallow, though quite thick, horizontal ramus, with
a long and narrow symphysis, the chin expanding into a spatulate shape at the in-
cisive alveolus.

llie new species may be called Axconus kostratus; in apipearance it ap-
proaches most nearly to the European species, A. velaunus. It is altogether likely
that the large hind-foot, described and figured in the foregoing paper under the
name Ancodus sp., belongs to A. rostratus.

MEA.su HEM ENTS.

Skull, extreme length

“ length from oeciiiital eomlyles ! .

“ of cranium

‘ “ of face . . .

Diastema between canine and nil '
Uength of ui)|)er iiremolar-molar series .

“ premolar series ....

Length of upper molar series ....

Hard palate, length

Diastema between canine and pi . .

. .090

“ “ pi and . . .

Length to ms, Inclusive

. .120

“ of lower molar series ....

. .0.51

Depth of mandible at mS . . .

( 536 )

INDEX TO GENERA, ETC.

Acaiithodii, -481
AccipitnjH, »»1, 416, 4.'.0
AchiiMKKloii, 271
Afimtliiu, HI
Ai-liatiiivlla, 43

Aoliyrodoii. 1H7, IHH, 199,201, 225,
24(1, 240, 247
A< tiiit»ptc*ryKia, 441
ActrLMMiemn, 121
/I'k-lltllophorUH, 396, 397
AKelalUH, 41H

AKri'H'hciTiiM, 470, 490, 491-495
Alx, 405
Alfldu*, 397

All.xlun, IH7, 212, 217, 218, 251-253
Allothorla. 213
AlvflliilH, 147

Ainl)li)t»UTlidH-, 236, 237, 247, 248,
251

AinMutluTiiiin, 187, IHK, Krj, 104,
lt«>-202, 2(M, 226, 236, 242, 247,

257, 202

Aiiilily<>|MKlu, 321
AinniiHilii, 181
Ani|K.‘liH, 4 19

AmphlkwtfM, IW-IW, 224, 225,
227, 228, 2-10, 211, 243, 247
Aillplllicniillii*, 228, 230, 2il
AmphllhiTldiv, 230, 231, 232, 237,
241, 242, 244, 24.i, 247, 248, 251,

258. 259

Am)diitheriniii, 187, 190-193, 199,
231, 21(1, 242, 245, 247,250, 256
AmphytyluH, 187, 188, 190, 192-
194, il«», 228, 210, 219, 247, 257
AmyiKHluii, 271
Allan, 403. 4(M, 406
Aiiatina, 122
AlKiidiia, 461-495
Ai)('yi<>|MHla, 272, 493
AndniiiiiHla, 153
AiK)|>l(>lhpriuin, 470, 473-475, 484
Anoer, 4(81^08
AiiR'iva, 394. 402
Anthrapothoriuni. 465, 490, 491
Apia, 25

AptpryKidH', 4.50
Aptoryx, 4-50
A.iuila, 416-418
Area, 119, 121 ,145

Areha-opteryx, 423
Architeotouica, 121
Aroo|x;nm, 147
Aretwyon, 1.56
Ardea, 411
ArjfilloruiH, 4-51
Arteininia, 390
Ai^-iiatla, 392
Aapidorhyuchidai, 441
Atwimiuea, 9:1, 107, 110, 111
AMlarte, 122, 152

Aathenodou, 187, 237, 238, 244,
247, 248, 250, 251, 261
Athrodoii, 187-189, 208
Atlantonaurus, 187
Atnipia, 93-99, 106, 110
Aturla, 121

Auricula, 17, 89, 90, 91, 112
Auria, 67
Avlculu, 121, 151
Aythya, 405
Axliiica, 147

llarentHia, i:i, 15
HftUuigia, 262
Itimin, 4.5*
nianfordia, 98

Ilolialon, 186, 187, 188, 210-213,
216-229, 2)2, 25:4
Bol.Klontida*, 213, 218, 219
Ik>ua<<a, 415
Hos, 4.')6-4.59
Hrai'hionun, 14
Bnuita, 406-408
Bubo, 418
Buwiiium, 148

Buliinua, 17, 43, 46, 47, .53, .56, 57,
58. 62, 65, 66, 67, 72, 76, 78
Bulinim, 65
Bulmiiiuii, 47
Busycou, 148

farj-a, 145
C'aloK'hloris, 24.5, 261
C'aniptolirauB, 402
t'aiiipylorliyuchua, 419
C’auli*, .391, 392, 4.53, 505, 520, .522
Cardita, 122, 129, 131, 138, 14.5,
147, 148, 151, 1.52
Carditnniera. 122, 1:38
Cardiuiii, 1:38, 145, 147, 148

Cariacus, 468, 469
j Cariuifex, 391
; Caryatis, 121
Caryophyllia, 131
Cafisidaria, 14.5, 148
I Cassidula, 90
Castor, :492
Catostomus, 392
Ceauothus, 153
Cecomorpha;, 4.50
Centetes, 260
I Ceutrocercus, 415
' Chalicotheriidie, 273, 276
, Chalicotherium, 272, 273
Chama, 119
Charitouetta, 406
Cheii, 406, 409
ChenoraorphiB, 4.50
Chirogidie, 219

Chirox, 187, 213, 219, 220, 252, 253
Chu‘ropus, 258
Chondreiiehelys, 436
Chondrella, 106, 110, 111
Chrysochloridse, 235
Chrysoehloris, 210, 235, 256, 261
Cidaris, 131
Cionella, 81

Cladodus, 427, 428, 429, 434
Cladoselache, 429, 430
Clangiila, 406
Clavelithes, 148
Cliola, 392
Coccyges, 4.50
Collodus, 447
Colymbus, 396, 397
Coiioviilus, 89, 90
Conus, i:34, 145, 148
Corbula, 122, 145, 147, 149, 151
Cormis, 145
Corvus, 419
Corvphodon, 328
Craasatella, 121, 122, 125, 145, 147,
152

Creecoides, 412
Cra)douta, 243, 257
Cristellaria, 118, 137
Creasida, 24, 25, 26
Crossopterygia, 438, 440
Crotalus, .391
Crjnuophilus, 413

538

INDEX TO GENERA, ETC.

Ctfliiu-odoii, 187,-13-217, iW, 253
Ciu-iill(.*a, 121, 125, 12(1, 129, 154
t'yclai*, 147
C.volomiiriilia, 24, 92
Cyrlt>|>h<iruH, 24, 92
Cyt'loKtoinu, 92, 95, 98, 99, 100,
111

UyKiiiim*, 409
CyKiiiiH, 407
Cy moil la, 121
C’yiioofiihalua, 292
fyiioKalc, 171
Cynohya'iKxlon, 534, 535
(’yiihornia, 449-452
Cypnoa, 145, 148
Cyprlnlila-, 391
Cyntopliora, 323
Cytlion-a, 147, 148, 149, 151

Uallla, 404
Dapccliiilas 441
Dupliioinix, .524, ,525
DaaypiiH, 202
DaayiirUiif, 200, 259
I)u.syuru«, 202
Dfllotlim, 435
Delphinidio, 240
Dfltallierium, .534, .535
DumlraKapUH, 415
IH'iulrwyKiia, 40(i
Domlrophyllia, 131
IK-iitalium, 145, 148
Dlaiii-ma, 92, 110
Diatryina, 451
Dicoiiotloii, 3.53
OicotyleH, 471
UicnK’yiiiKlou, 203
l)i<ifli)hya, 207, 227, 258, 259, 262
DlilymictiH, 109, 172, 173, 243
DiiiytnuduH, 430
DImetrodon, 222, 240
Diiiiotis, .524, 525
DinolamtiH, 454, 4.56
Diiiornithida-, 4.50
Diphu^alon, 270-383
DipliK'.viKMlon, 187, 224, 2.31-243,
240, 242, 244, 245, 247, 248, 251,
203

Diplopua, 473, 474, 482,487, 488
DinHacim, 243
l)<K-«>don, 187, 232, 247, 248
DoliopHiM, 147

Diwima. 119 I

Dryolealca, 187, 225,235,248,244, i
245, 247, 201 |

Dryoleatidio, 240
Ilrimiotheriida', 222, 247, 251
Dromotheriiim, 186, 187, 222, 224,
225, 249-243, 247, 262
Uryaiidroidea, 145

Elmrneopecteu, 147
Echidna, 255
Echiuofyaiiuis, 1.31
Eheagnus, 153
Eliusmobranchii, 427
Klephaa, .392, 420, 452, 457
Eiidodonta, 37-42, 108
Eiiilopachys, 148

Enneodoii, 187, 242, 244, 245, 247,
248

Eomeryx, 494
Eporeudon, 469
EipiOB, 392, 457
Eriaiiiatiira, 406
Eachara, 131
Eachatius, 392
Euajjataugus, 118, 1.37
Eutamia, 391

Fagua, 154
h'aaciolaria, 122
Fella, 4.56
Ficua, 145
Fiaaurella, 122
Flabellura, 131, 145, 148
Folgoraria, 145, 148
Fulgnc, 122, 149
Fulica, 411, 412, 423

Gallime, 413, 450
Gallua, 413
Garrettia, 92
Gastornia, 451
Gaatridiura, 145
Geloeua, 470
Glaucionetta, 405
Goniodypeua, 131
Gorilla, 262
Gouldia, 147
Gralla, 4.50
Gymuura, 260

Halteetus, 418
Halmaturiis, 2.54
Haplacodon, 272, 276
Harporhynduia, 419
Helieina, 17, 100-106, 110-112
Ilelicopaia, 19, 21

Helix, 17-22, 24-31, 35, 37, 38, 39,
42, 46, 47, .57, 111
Heniipaalodoii, 535
Heptanchua, 430
Herodii, 4.50
Herodionea, 411
Heaperocichla, 391, 419
Heaperoi'iiia, 423, 451
1 leteroapondyli, 450
Hippoohrenea, 121
Hiatrioiiious, 406
Holomeniacua, 392
Hoplo))h()neu8, 525

Hvana, 160, 164, 520
Hyienodou, 156, 164, 173, 175-184,
499, 515-535

HytenodoutidEe, 184, .501, 535
Hydrocena, 18, 93, 94, 96, 98, 99,
100, 106, 107, 111
Hydroehelidon, 399, 400
Hydroidioerua, 457
Hyla, 391

Hyopotaiuus, 461
Hypsiprymnopsia, 190
Hypaipiymnua, 254
Hyrachyua, 281, 299, 302-367
Hyracotherium, 299, 373

Ichthotomi, 431
Ichthyornia, 423
Icteridpe, 419
Infundibulum, 131

Jugiaua, 153
Juuipeius, 390

Kurtodou, 208-210, 222, 225, 226,
234, 240, 247, 248, 250, 251, 257,
259

Kurtodontid®, 2.34, 241, 247, 248,
250, 251, 2-59

Laimodonta, 91 , 92, 110, 111
Lambdodus, 434
Lambdotheriidaj, 272, 273
Lambdotherium, 270-383
Lamelliua, 82
Lanina, 419

Laodon, 187 , 237, 238, 244, 247
Larus, 397-400
Latiarea, 126, 129
Laurua, 145
Leda, 145, 147
Lepidotida?, 441
Lepidotus, 441
Leptinaria, 81

Leptocladus, 187, 188, 201, 202, 225,
.238, 239, 247 , 250
Lepus, 391
Leiicophiya, 12
Leucua, 392
Leurocephalua, 269
Libera, 33-36, 41, 108
Limax, 17, 57, 88, 109, 111
Limicolie, 418
Limnocyon, 173
Listraeauthus, 434
Lithornia, 451
Longipennes, 394, 397
Lophudytea, 402
Loxolophodou, 271
Loxoaoma, 13, 1.5, 16
Lucina, 131
Lunulitea, 131

539

INDEX TO GENERA, ETC.

Lutra, 180, 3«2
LyiiiiiohyuH, 2(19-339
Liainohyo|iH, 2(17, 3.38-38.5

MutTepiHliUH, 441
Macr<»«elideM, 323
.Macro«eiiiiidu‘, 441
Macrotherium, 272
Mactru, 148
MadrejK>ru, 14.5, 149, 1.51
MaKtiolia, 14.5
MarHU|iluliu, 2.54, 256, 257
.MaxtiHiciii, 4.57
MegalifhIhyH, 438-4.38, 440
MfgalotlH, 172
.Mvgatlicrhiin, 4.57
McgeiK-ophaloii, 185
Molaiii|>iiH, H0-»l, KK), 111
.\k'laiieri>tti, 391
.McknigrlH, 4.51
Mek-H. 1.59

Mc-iuuMMlon, 187. 189, 230, 244, 247,

251

.MfidH.-<Ki«.UH, 187, 189, 214 , 217,
218, 25.3 2V.

.MclKHkiiilldii-, 273
.Meliodiia, 278
Merix'iiariu, 122
.Mfivlrlx, 149. 1.53
.MiTgaiiHiT, 40(1
•Mt-rtila, 419
MorychyiiM, 49:3

.MiTycNM-li.iTiia, 470, 477, 491, 493
MiKalia, 147
.Mmxkiii, 443, 444
MitwildppiiH, 470
.Miw)iiy.-hidii>, 109, 184
.Mwdiy.x, 1.5V1(19, ni, 180, 181,

182, 49:3, .517, 819
.McMoreiHlmi, 477
Metal heria, 257
Mia<-ldii-, 189, 173
.MiaelM, 172. 173

Micr.K-«)ii.Hlon. 188, 187, 222, 223,

225, 239, 240, 241, 243, 247
MienKTinuM, 131
MicnH-yHtiH. 18, 19, 2), 21, 108, 111
Mierolwdc**, 18(1, 187, 190, 212, 214,

21.5, 252, 253
MiniiiH, 419
Milra, 145, 148
Moii(K*lad<KUiH, 434
.Morio, 14-5
Mortotda, 131, 143
MoriiH, 14.5
MuHlela, 173
MiiHlell«lH‘, 170
Myadexti-a, 419
.Myduut*, 1.59
Myladentoa, .391

71 JOURN. A. N. & PHILA.. VOI

Myl(jdon, 392
Myloleucus, .391, 392
Myoconclia, 124
Myogale, 323

MyrniecobiuH, 255, 256, 258, 262
My«ia, 122
Mytlloconcha, 1.38
Mytilus, 122, 128
Nanina, 19-22, 24, 25, 26, 28
Natlca, 122, 148, 149
XautlluH, 121
Navicula, 14.5, 148
Neoplagiaiilax, 186, 187, 189, 214,
216

Nucula, 124, 131, 147
Numiniilites, 1,37
Xycticora.x, 411

OduntogloHSie, 410
Olea, 14.5
Oliva, 131
Olor, 406, 409

OniphalotropiH, 18, 92-95, 97, 98,
106, 107, 110, 111
OnuHtUH, 121
0|H.*reuliiia, 1.37

Orl.ilolde.*, 117-119, 1.34, 142, 145,
147, 1-50, 151, 1.54
Oreodtili, 4(35-495
OrnitliorhynchiiH, 254, 255
OroduH, 432, 4:33
OnmcoplCM, 391, 419

< IrthacantluiH, 4:36
Onte<Hle8, 145

OHtrea, 119, 121, 122, 125, 126, 129,
1.34, 1.36, 14:3, 145, 147, 149, 150,
1.51, 152
Otoeorio, 419

OxyaMia, 174, 184, .501, 518, .535

< Ixyieliidie, .501

Paehya'iia, 1.57, 1.58, 1.59, 160, 161,
I62' 16.3, 164, 16.5
I’alieowyDiliule, 267, 274 , 275
PaliiHiayoi*, 267-388
PalHM.tetrix, 415, 416
Palaiim, 24
Paludieclla, 5
Paliidieolie, 411
Paiiojiea, 125, 126, 145
Pantolheria, 256, 257
ParexuH, 430

Partiila. 17, IS, 43-80, 108, 111,
112

Partulu!*, 47, .50, 57, .58, 65, 67
Pa..<«.TeH, .391, 418, 4,50
Patriofelis, 501, 520, .525, 5.33
Patula, 2841.1, S'-JO. 108. ,

Paiir<.doi), 187, 233, 234, 24.3, 24,,
248, 257
IX.

Pecten, 119, 122, 124, 131, 134, 138,
143, 145, 147, 1.52
Peetunculus, 147
Pedieellina, 9, 11, 13, 14
Pediocsetes, 414, 416
Pelecanus, 401, 402, 451
Peralestes, 187, 188, 200, 202, 205-
207, 225, 227, 231, 23:3,234,242,
245, 247, 250, 251, 256
Peralestida;, 231, 23.3, 237, 240, 242,
245, 247, 248, 251, 259
Peramus, 187, 188, 202, 203, 205,
223, 225, 232, 247
Perameles, 258

Peraspalax, 187, 188, 200-203, 205-
207, 225, 226, 2.33, 234, 245, 247
Peratherium, 258
Perna, 128
Persea, 145
Petaloconchus, 119
Phalacrocorax, 400-402
Phalaropiis, 413

PhaseolesteH 187, 188, 192, 194,
199, 200, 202, 207, 225, 236, 237,
239, 247

Phascolomyidie, 234, 255
Pbaseolomyg, 210, 2.59, 262
Phasc'olotheriura, 187-189, 193-
195, 205, 223, 224, 225, 228, 239,
243, 247, 249, 257, 258, 262
Phascolotheriiuae, 229, 248, 250,
251

Phenacodus, 327, 323
Phoenicopterus, 410, 411
Pholadomya, 124, 126
Pholas, 125
Phorus, 121, 151
Pici, 4.50
Pinus, 133

Pithyg, 28, 29, 39, 40, 41
Pitys, 28-31, 34, 35, 39, 42, 108
Plagiaulacidre, 213-215, 21., 218,
221, 252

Plagiaulax, 187-190, 212-217, 219,
252-256

Plagiostoma, 145
Plaiioi'bis, .39
Plecotrema, 92, 110, 111
Pleuroeauthidw, 4.36
Pleuracaiithus, 436
Pleurctoma, 121, 151
i Pleurotomaria, 121
I Plicatula, 122
' Plioprion, 215
Plumatella, 6, 13
Podteps, 395, 396
‘ Podilynibiis, 395, 396, 397
Poebrotberium, 470
Polymastodou, 186, 187, 189, 213,
220, 221, 252, 2.55

640

INDEX TO GENERA, ETC.

I’olymiwtoduiitidie, 213, 221
Polypterus, 440
Populus, 14.5

Priai-odon, 187, -'29, 247, 24:8 , 249
Procyon, .524
I’nididelphia, 226, 247, 260
Protocardia, 121, 147
Protoi'cras, 469, 470, 481
Protodontu, 222, 247 , 2.51, 2.58
I’rotopnalis, 174

Protoreodon, 479, 485, 490, 491, 495

Proviverra, .53.5

Proviverridiv!, .501, 535

I’m nils, 153

Psaiiiniobla, 148

Psatuloliva, 148, 151

PsittiKd, 4-50

Ptemdoii, 174, 184, 533, 534
P[ilodu.s, ISO, 187, 214, 216, 2.53
Pupa, 18, 81,83,84
PyeiKidoiitidie, 443
PygopodeH, 394, 395, 396
PyiilUius, 121
I’yrula, 121, 151

<i,uereus, 145, 153

Katiliv, 450
H-alia, 93-100, 106, 107
Uhamiuis, 145
Uheidne, 4-50
llhi|)id()ptei',ygia, 436
UhinoceruH, 289-379
Uhus, 14.5

UliyncdiDdontid®, 441
Uingiciila, 151
Uonzolherium, 470
ItoHtellaria, 121, 145, 148

Kagda, 20

Salix, 1.53

.Salmi), 391, 430

Sapotaidtes, 1,53

.Sarcophiliis, 207, 2.50

♦Saurodontidie, 441

iSaxicava, 122

.Scalaria, 148

.Si-alinella, 99, 100, 110

.SceloporUH, 391

.Suolefophagus, 418

.Scuttlla, 131

Sclaehii, 431

.Sialia, 419

Siuopa, .534

.Smilodon, 454-4.56

.Spalacotheriimc, 229, 230, 248, 2.50

2ol ’ ’

Spalacothei'ium, 187-189,202,203, ^
I 205, 225, 228, 230, 243, 244, 245,
247, 250, 258, 260
Spatula, 404
Spermatodus, 43S-440
Spermophiliw, 391
Spha'rodontidie, 441
Sphoerella, 147
Spondylus, 143
Steganopudes, 400, 4.50
Steuogyra, 43, 84, 108, 111
Stereoguathus, 187, 188, 190, 212,
j 213, 218, 221, 253
Sterua, 399, 400
Strephenterus, 1.5
Striges, 418

Stylacodoii, 187 , 226, 23,5-238, 243,
244,245,247, 2-50, 251, 257, 260,
261

StylacodoutkUe, 224, 235, 233, 239,
241, 244, 247, 248, 250, 251, 260,
261

Stylodon, 187-201, 203, 204, 207-
210, 234, 236, 2.56, 257, 261
Stylodoutidie, 236, 441
Stypolophus, 156, 157, 173, 179,
243, .534

Styptobasls, 434
Sucdnea, 84-88, 109, 111
Surcula, 121
Su8, 489

Symmorium, 428, 430, 433
Synoplotberium, 1.58, 165

Taheitia, 100, 107, 110
Talpa, 260
Tamlas, 391
Tapirus, 289-385
Tarsi pes, 258

Taxotherium, 181, 183, 513, 51.5
Teleostomi, 436 ’

Tellina, 119, 122, 147
Telmatotherium, 267-,383
Terebra, 151
Terebratula, 121, 131
Teredo, 119
Termiiialia, 145
Thoinomys, 391, 392
Thracia, 121, 122

Tbylaeyuus, 1.55, 156, 158, 176, 177
^37, 256, 2.59, 262
Thylacule, 256

Thylocoleo, 186, 187 , 214, 216
'I'inamus, 423

Titiodou, 187, 189, 228-230, 243
247, 251

Titaiiotheriime, 274 , 275
Titaiiotberium, 272, 273, 275, 302,
353

Tornattdlina, 81-S;i, 109, 111
Toxodon, 457
Tralia, 90

Triawinthodoii, 187, 197-199
Trieonodon, 187, 188, 194-1<«), 20.5,
206, 224-229, 240, 243, 247, 251,
256-260

Triconodonta, 251
Tricoiiodontida*, 225-228,230, 2:31,
237 , 239, 241, 247, 248, 250, 251,
258, 259, 260

Triglyphus, 186, 187, 189, 21.3, 220,
221

Tringaii;, 413
Triplopu.s, 271

Tritylodon, 1.86, 187, 189, 213, 2 1 7,
220, 221, 251-2 )3
Tritylodoiitidie, 21.3, 220
Troi'hita, 145
Trochoiiiori.ha, 21-27, 108
Troidionauiua, 21,22, 108
Ttuella, 87
Truiicatella, 107
Turviuella, 122, 148
Tiirdus, 419

Tiirritella, 122, 129, 147, 151, 1.52,
154

TympauucliUH, 413, 415

Uintaeyon, 172
niitatheriuni, 329
Umbrella, 145
j Uraiioplosus, 445, 446
I Urile, 401
Urinatoridie, 396
Urnatella, 5-16
Ur-sus, 288, 5.53
Dta, 391

Veuericardla, 121, 129
Venus, 122, 123, 138
Vertigo, 18, 83, 84, 109, 111
ViverridiB, 171
Vivipara, 131

Voluta, 57, 121, 145, 147, 151
Volutilithes, 121

Xema, 399, 400
Xenacanthus, 429, 432, 436
Yoldia, 121, 122

Zeuglodon, 117, 134, 139, 145 147
1.50

Zonites, 22-26, 108

Jourri Acad.Nat.Scl.Philada. 2':''? SerVjLIX

-5 SYMMORIUM RENIFORME 6 -7. ORORUS' BASALIS.

'■'■-/'’-V' 'wW;

I 'fnA'lif'. ^

■ ;:V

Joum Acad.Nat.Scl.Philada. 2""^ SerVol.IX

l.MEGALICHTHYS MACROPOMUS . 2.MACREPIST1US ARENATUS . 3 . LISTPACANTHUS

iJc-i Philada,2^'^- SerVollX.

Plate XX.

URAMOPLOSUS lO.COELODUS 11-15. CEPHORNIS

i-5 STYPP'OBASIS 6DELTODUS 7MESODON 8-9

Joum Acad. Nat. Sci.Philada^ 2=:“^ SerVol.IX. , Plate XXl

1-13 . DINOBASTIS ' SERUS. 14-16. CANIS INDANENSIS.

Joum Acad. Nat. Scl.Philada. SerVbl.IX. Hate XXII

-^■.BOS CRAMPIANUS X3 -5-9. BOS SCAPHOCERAS

PI. 23

Journ.Acad Nat Sci.Philad 2"** Ser Vol.IX

1 ANCODITS PRACHTOHYNCHUS^ 2,3.ANCODUS AMERICANUS P4-. ANCODUS SP.

Journ.Acad. Na-t.Sci.Philad. 2Pf^Ser. Vol.IX.

Pi. 24

R»er.dd.

5.6.7 8. ANCODUS BRACHYRHYNCHUS? 9.ANCODUS SP.

V ..

Hayden Memorial Geological Fund.

Mrs. Emma W. Hayden has given to the Academy of Natural Sciences of Phila-
delphia in trust the sum of |2,500 to be known as the Hayden Memorial Geological
Fund, in commemoration of her husband, the late Prof. Ferdinand V. Hayden, M. P.,
LL. D. According to the terms of the trust, a bronze medal and the balance of the
interest arising from the fund are to be awarded annually for the best publication, ex-
ploration, discovery or research in the sciences of geology and paleontology, or in such
particular branches thereof as may be designated. The award and all matters connected
therewith are to be determined by a committee to be selected in an appropriate manner by
the Academy. The recognition is not confined to American naturalists.