GYACINVAWIDEA:
DEPARTMENT OF MINES
GEOLOGICAL SURVEY BRANCH

Hon. W. Tempieman, MINISTER ; A. P. Low, Deputy MInisTEr ;
R. W. Brock, Acting Director.

CONTRIBUTIONS

CANADIAN PALTZ ONTOLOGY

OU i TI j{Qrarto:

PART IV.-THE VERTEBRATA OF aE OLIGOCENE OF THE ;CYRKESS
‘ HILES, SASKATCHEW AN.

BY

/
/
LAWRENCE M. LAMBE/#.GS, FRSC.

Vertebrate Paleontologist.

OTTAWA
GOVERNMENT PRINTING BUREAU

1908
No. 1020.

This report on the Vertebrata of the Oligocene deposits of the Cypress hills forms the
fourth part of volume IIT (quarto) of Contributions to Canadian Paleontology. Part I by
Professor Edward D. Cope, on “ The species from the Oligocene or Lower Miocene beds of the
Cypress hills,” published in 1891, is descriptive of specimens obtained during the years 1883,
1884, 1888 and 1889. The present part by Mr. Lawrence M. Lambe, is based on the collec-
tion made by him in 1904, and on the material of the earlier collections; it consists of 82
pages of letter press, illustrated by text figures and eight photogravure plates.

R. W. BROCK,

Acting Director.
DEPARTMENT OF MINES,

GeEoLocicaL Survey Brancu,
Ottawa, January 5, 1908.

GEOLOGICAL SURVEY OF CANADA

THE VERTEBRATA OF THE OLIGOCENE OF THE CYPRESS HILLS,
SASKATCHEWAN.

By Lawrence M. Lamee.

INTRODUCTION.

The discovery in 1883 by Mr. R. G. McConnell of this Survey, of Tertiary beds in the
Cypress hills, of later age than any that had been found in the North West, was announced in
Dr. A. R. C. Selwyn’s Summary Report of the operations for that year.* These beds capping
the Cypress hills were assigned to the age of the Miocene by Mr. McConnell in his ‘* Report on
the Cypress hills, Wood mountain and adjacent country,”’** published in 1886. After
giving a general statement of the physical features of the country, Mr. McConnell in his report,
devotes himself (1) to a description of the geology in different sections of the district in turn,
and (2) to an account of tbe deposits of the formations observed of the Cretaceous, Tertiary,
and Quaternary periods. In the Cypress hills and vicinity the rocks seen were referred to the
Miocene, Laramie and Fox-hill—Pierre formations, of which the last three are conformable,
but the first lies unconformably on the Laramie,in places overlapping it and resting on the
Fox-hill. The Miocene beds “ cap all the more elevated parts of the range of uplands extend-
ing in a direction a little north of east, from the west end of the Cypress hills to the east end
of Swift-current Creek plateau; a distance of 140 miles. They have an average width of
fifteen miles, and cover altogether an area of nearly 1,400 square miles.”

The Cypress hills-are divided into two unequal parts—of which the eastern one is much
the larger—by the “Gap,” a valley of erosion, running in a north and south direction. The
Miocene deposits are best developed at the eastern end of the hills, where they attain a thiclk-
ness of fully 500 feet, and consist of conglomerate, usually formed of quartzite pebbles,
cemented together by carbonate of lime, associated with beds of sandstone, sands, clays, and
marls. West of the “Gap” the formation isrepresented only by asheet of hard conglomerate,
about 50 feet thick.

To quote from Mr. McConnell’s report: “the conglomerate which forms such a marked
feature of the Miocene deposits of the Cypress hills, is usually composed of quartzite pebbles
cemented together by carbonate of lime, but also appears under a number of other forms. In

* Geol. and Nat. Hist. Survey of Canada, Report of Progress, 1882-83-84 ; Summary Report of the operations of the geological
corps to 31st Dec, 1883 (published in Jan., 1884), p. 4.
** Geol. and Nat. Hist. Survey of Canada, Annual Report (new series), vol. 1, 1885, (1886), part C.

6

consolidated by a ferruginous cement. Beds several feet thick also occasionally occur, which

contain nothing but loose pebbles.” ‘Beds of pebble conglomerate, though more frequent
and larger near the base of the Miocene, are found at irregular intervals all through it, and

are of all thicknesses, from a single layer of pebbles up to beds fully 50 feet thick. In many
cases the formation consists of a single thick bed of this rock. Besides the pebble con-
glomerate, beds composed of angular pieces of clays enclosed in a matrix of hard sandstone,
and forming a species of breccia, are occasionally found.”

“ The sands of the Miocene sometimes form hard beds, from one to two feet thick, but
are usually only slightly indurated, and are nearly always affected by false bedding.”

The above deposits are best seen in Bone coulée which runs almost due north and south
about nine miles west of the eastern escarpment of the hills. In this coulée two streams have
their origin within a few hundred yards of each other, the north fork of Swift-current creek
flowing north-easterly, and Frenchman creek (Fairwell creek of Mr. McConnell’s report)
flowing in an opposite direction to the south.

It is in this main coulée and its tributaries, that the coilections of vertebrate remains
from this horizon of the Cypress hills have been principally made.

The first vertebrate fossils received from Bone coulée were obtained in 1883 by Mr.
McConnell whilst engaged in his geological exploration of that year. Later in the same
season Mr. I’. C. Weston visited this locality, and secured a collection ; but unfortunately all the
specimens then obtained were lost by the sinking in Lake Superior of the steamer Glenfinlas
on which the collection had been shipped for the east from Port Arthur. During the summer
of 1884 Mr. Weston revisited the eastern end of the hills, and obtained many mammalian and
other vertebrate remains typical of the Cypress Hills fauna. In 1888, and again in 1889, a
short time was spent by Mr. Weston in adding to the collections already made in Bone coulée.
In 1904 the writer spent some weeks in the eastern end of these hills making a supplementary
collection of the vertebrate remains.

The fossils collected by Messrs. McConnell and Weston in 1883, were submitted to
Professor Edward D. Cope, who published a preliminary list of the genera and species in the
American Naturalist, 1885, vol. XTX, p.165.* The result of hissubsequent study of the same
material appeared in 1886 as an appendix to Mr. McConnell’s report of 1886.** Further
eontributions to the American Naturalist *** by the same distinguished paleontologist,
followed in 1889, after Mr. Weston’s collection of 1888 had also been placed in his hands for
determination and description. Professor Cope’s final report on all the material from the
Cypress hills, including the specimens obtained by Mr. Weston in 1899, appeared in 1891 as
part I **** of this volume.

The White River beds of Swift-current river, North West Territory.
** Op. cit., part C, p. 79, appendix I. The Vertebrata of the Swift-current Creek region of the Cypress hills, by E. D. Cope.

1889. American Naturalist, vol. XXIII, p. 151, The Vertebrata of the Swift-current river, II; and p. 628, Verte-
brata of the Swift-current river, IIT.

**** The species from the Oligocene or Lower Miocene beds of the Cypress hills ; Geol. Survey of Canada, Contr. to Can.
Palwont., vol. ITI (quarto), pt. I. :

7

Cope, in his memoir of 1891, qualifies McConnell’s assignment of the uppermost beds of the
Cypress hilis to the Miocene by describing them as of Oligocene or Lower Miocene age.
Matthew would accord them a more definite horizon at the bottom of the Oligocene, and has
expressed the opinion that they are probably of approximately the same age as the Titano-
therium beds at Pipestone springs, Montana. This opinion appears to be borne out to some
extent by the list of species from Pipestone springs, published by Dr. Matthew in 1903,%*
and the collections from the Cypress hills, supplemented by the material secured in 1904. A
provisional list by the writer, of the genera and species included in the collection of 1904,
appeared in the Summary Report of this Department for that year.

That the Cypress Hills Oligocene deposits were the result of rapidly flowing water from
the west is evident. The thick basal beds of rounded pebbles represent the work of a strong
transporting force, such as would be supplied by a turbulent stream of considerable size carrying
eastward material fromthe Rocky mountains. The sands show false bedding as a result of
varying currents. With the accumulation of material eastward, and a consequent reduction
of the transporting force, beds of finer material were deposited at a higher level, and
probably on extensive areas of overflow.

Regarding the Cypress hills as an outlier of the Wood Mountain area, Mr. McConnell has
pointed out that, the part of the country ‘“‘ now covered by the Cypress hiils has been changed
from a depression in Miocene times into the highest plateau on the plains, which is its present
position, entirely by the arrest of denudation over its surface by the hard conglomerate beds
which cover it, whilst the surrounding country, destitute of such protection, has been gradually
lowered ; and so affords an index of the amount of material removed from the neighbouring
plains in the age intervening between the deposition of the Miocene and the glacial period.”
‘“‘The absence of any ridge connecting the Cypress hills with the mountains is somewhat
surprising, as one would naturally suppose that near their source the pebble-beds would be
thicker, and their constituents coarser and better able to resist erosion. This may be due,
however, to the fact that the valley of the transporting stream must have been more contracted
in its upper part than in the dilated portion in which the existing Miocene beds were deposited.
In such a case, its narrow shingle floor would be gradually undermined, and as denudation
proceeded would soon perish.”

During his expedition of 1904, the writer examined the exposures of the Oligocene
deposits along the eastern escarpment of the Cypress hills as well as on their southern slope
in the vicinity of Frenchman (Whitemud) river as far west as Fairwell creek, also in the valley
of this creek northward to Lone coulée, and for some miles along the upper reaches of the
north fork of Swift-current creek. Few fossils were obtained along the eustern, and southern
escarpments.

The greater part of the collection was made in Bone coulée and its numerous tributary
coulées, and in its southern extension for a few miles along Fairwell creek. Here the grass-
covered slopes are broken by numerous small and isolated weathered outcrops which at first
do not appear very promising from a paleontological standpoint. A careful and close search,
however, reveals an abundance of—for the most part—mammalian remains.

* The fauna of the Titanotherium beds at Pipestone springs, Montana; Bulletin Amer. Mus, Nat. Hist., vol. XIX,
article VI, 1903,

8

The most prolific beds are composed of a fine conglomerate that, on disintegration, has
freed the enclosed fossils. Associated beds of coarse sand, of arich brown colour, also yielded
some interesting remains. Very few fossils were found in the coarser conglomerates, and, as
might be expected, none at all in the beds of loose pebbles.

The generally fragmentary and dissociated nature of the remains at this locality
detracts much from their value as definite horizon markers. Many of the specimens clearly
show that they had been broken and often worn prior to being deposited in the beds where
they were found. Some excellently preserved jaws with continuous series of teeth were
obtained, and many separate and well preserved teeth, but bones of the feet were in all
cases dissociated.

Although the beds of the Cypress Hills deposits in question probably belong, in a general
sense, to the horizon of the Titanotherium beds of Montana, some of their upper members
may be synchronous with the Oreodon beds. Whether the time equivalent of the uppermost
division of the Oligocene (Protoceras beds) is present at all is problematical, The fossils in
the finer conglomeritic beds show in some cases evidence of having been transported from a
distance, and on this account it is possible that a certain admixture of remains from slightly
different horizons has taken place.

The Cypress Hills Oligocene faunal list has been considerably enlarged in the following
pages by the addition of a number of new species, and species previously known but not
recorded, hitherto, from this horizon in Canada, The majority of the additions to the fauna
have been supplied by the collection of 1904, but afew forms are represented by specimens
from the earlier collections, that apparently were not placed in Professor Cope’s hands.

The species described as new, with those not recorded, hitherto, from this locality, belong
to the three classes of fishes, reptiles, and mammals. New species of fishes of the families
Amiid and Lepidosteidxe are described. Among the reptiles are two chelonians, of which
one species is new; also lizards, snakes, and crocodiles representing the orders Squamata and
Crocodilia, both of which are additional to the fauna. The mammals preponderate in numbers
and variety and include a marsupial, ungulates, rodents, and carnivores. The artiodactyl
genera Ancodus, Anthracotherium ?, Agriochcerus, and Merycoidodon are now recorded from
the Cypress hills, as well as new species of horses, hyracodonts, rhinoceroses, and titanotheres.
A new species of Leptomeryx is described. Further evidence of the presence of Chalicotherium,
an ancylopod, is gigen. The rodents include four families of which three, the Ischyromyide,
Castoride, and? Sciurids, are new to the list. Two known species of the creodont
carnivores, three already described species of the Canidie, and one of the Felidz are also added.

The animals inhabiting this western tract of country during Oligocene times are thus
seen to have belonged to a variety of groups. That the number of individuals in some of the
groups was large is evident from the abundance of the fossil remains of some forms. Some
of the groups have since become extinct, others have undergone great changes and are with
difficulty recognized in their descendants of the present day; whilst a few are represented by
existing species that show but slight differences in form and structure.

9

Twenty-five vertebrate species in all, have, hitherto, constituted the Oligocene fauna
of the Cypress hills: this number is now raised to over fifty. The following is the fauna as
known to date :—

Class PISCES.
: Order ACTINOPTERYGII.
Suborder ProtosponDyYLt.
Family Amiide.

* Amia whiteavesiana, Cope.
* Amia macrospondyla, Cope.
+ Amia exilis, sp. nov.
AETHEOSPONDYLI.
Lepidosteide.
+ Lepidosteus longus, sp. nov.
NEMATOGNATHI.
Siluride.
* + Rhineastes rheas, Cope.
* + Amiurus cancellatus, Cope.
* + Amiurus maconnelli, Cope.
REPTILIA.
CHELONIA.
CrYPTopira.
Chelydride.
+ Anosteira ornata ? Leidy.
Testudinide.

* + Stylemys nebrascensis, Leidy.
+ Testudo exornata, Lambe.
TRIONYCHIA.

Trionychide.
* 4 Trionyx leucopotamicus, Cope.
+ SQUAMATA.
LaceRtiqia.
Anguide.
+ Peltosaurus granulosus, Cope.
OPHIDIA.

Palcophide.
+ Ogmophis compactus, sp. nov.

+ CROCODILIA.
Kusucuta.

Crocodilide.
+ Crocodilus prenasalis ? Loomis.
The signs before the names of species or groups signify as follows:—
* Represented in one or more of the collections made previous to 1904 ; but not in that of 1904.
+ Represented in collection of 1904; but not in previous ones.

* + Represented in the 1904 as well as in one or more of the previous collections.
12529—2

+++

+t++4++4++

++

++ +44

10

MAMMALIA.
+ MARSUPIALIA.

POLYPROTODONTIA.
Didelphyide.
Didelphys valens, sp. nov.
UNGULATA.
ARTIODACTYLA.
Anthracotheriide.
Ancodus (Hyopotamus) brachyrhynchus, Osborn and Wortman.
Anthracotherium ? pygmeum, sp. nov.
Elotheriide.
Elotherium coarctatum, Cope.
Agriocherida.
Agri cherus antiquus, Leidy.
Merychoidodon culbertsoni, Leidy.
Camelide.
Poébrotherium wilsoni, Leidy.
Tragulide.
Leptomeryx esulcatus, Cope.
Leptomeryx mammifer, Cope.
Leptomeryx speciosus, sp. nov.
Position uncertain.
Leptomeryx semicinetus, Cope.
Hypertragulus transversus, Cope.
PERISSODACTYLA.
Hquide.
Mesohippus westoni (Cope).
Mesohippus precocidens, Lambe.
Mesohippus propinguus, Lambe.
Mesohippus brachystylus, Osborn.
Mesohippus stenolophus, Lambe.
Mesohippus planidens, Lambe.
Mesohippus assiniboiensis, Lambe.
Hyracodontide.
Llyracodon nebrascensis, Leidy.
Hyracodon priscidens, Lambe.
Rhinocerotide.
Aceratherium mite, Cope.
Aceratherium occidentale (\.eidy).
Aceratherium exiguum, sp. nov.
Leptaceratherium trigonodon, Osb. and Wort.
Titano'heriide.
Megacerops angustigenis (Cope).
Megacerops selwynianus (Cope).

+++

11

Megacerops syceras (Cope).
Magacerops primitivus, sp. nov.
Magacerops assiniboiensis, nom. prov.
ANCYLOPODA.
Chalicotheriide.
Chalicotherium bilobatum, Cope.
RODENTIA.
SIMPLICIDENTATA.
? Sciuride.
Sciurus ? saskatchewensis, sp. nov.
Ischyromyide.
Ischryromys typus, Leidy.
? Castoride.
Cylindrodon fontis, Douglass.
Hutypomys parvus, sp. nov.
DUPLICIDENTATA.
Leporide.
Palcolagus turgidus, Cope.
Paleolagus haydeni, Leidy.
CARNIVORA.
CREODONTA.
ITycenodontide.
Hycenodon cruentus, Leidy.
Hycenodon crucians, Leidy.
Hemipsalodon grandis, Cope.
FIssIPEDIA, (CARNIVORA VERA).
Canide.
Cynodictis lippincottianus (Cope).
Daphenus felinus, Scott.
Protemnocyon hartshornianus (Cope).
Felide.

Dinictis felina, Leidy.

PISCES.
ACTINOPTERYGII.

AMIA WHITHAVESIANA, Cope.

Amia whiteavesiana, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills. Geol. Survey of Canada, Contr. to Can. Palreont., vol. III (quarto),
pt. L p. 2, plate I., figs. 1, 1a and 10.

No remains of this species were obtained by the writer in his expedition of 1904 to the
Cypress hills. The type of this species, as well as those of all of the species referred to or
deseribed in the following pages, are in the Museum of the Geological Survey at Ottawa.

AMIA MACROSPONDYLA, Cope.

Amia macrospondyla, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills. Geol. Survey of Canada, Contr. to Can. Palieont., vol. IIT (quarto),
pt. I, p. 2, plate I, figs. 2, 2a and 26.

Cope established this species on a single vertebra from the Cypress hills. No additional
material is included in the collection of 1904, to throw further light on the structure of
this fish.

AMIA EXILIS, Sp. nov.
Plate I, figs. 1-6.
A number of centra, found separately, represent an apparently undescribed species

of Amia, of small size as compared with A. whitewvesiana, Cope, and A. macrospondyla, Cope
both of which species are from the Oligocene of the Cypress hills.

All the fossil remains of North American species of Amia so far described are of Eocene
age, with the exception of the two Oligocene species above mentioned.

Amia exilis was about the size of Amia elegans, Leidy, from the Bridger Eocene of
Wyoming; but had vertebral centra of quite a different shape.

The centra on which Amia exilis is founded are mostly from the dorsal region, and vary
somewhat in size, being probably from a number of individuals. The one represented on
plate I, figures 1, 2, and 3, from the middle dorsal series, is one of the largest of the
specimens, and is about the best preserved (type), Its articular faces are oval in outline
with the major axis horizontal, the height being but slightly over two-thirds of the
breadth. Its thickness (length), is equal to about half the maximum height and there is a
perceptible flattening of the upper surface. The concave articular surfaces exhibit a few
concentric lines, but have the general appearance of being rathersmooth. A small notochordal
foramen, preserved in all the specimens, pierces the centrum at about mid-height. Above,
in the median line of the upper surface, the floor of the neural canal appears as a narrow,
oblong, transversely concave depression, with a shallowly excavated area, square in outline ,
on each side of it, marking the position of the base of the neurapophysis. The parapophyses
are placed slightly below the middle of the sides; they are circular in section and were

13

apparently very short. On the lower surface, one on each side of the median line and almost
touching, are two poorly defined very shallow oblong depressions—(well defined and com-
paratively deep in one of the small centra). The sides of the centrum are slightly
depressed between the raised margins of the articular faces; here the surface when preserved
is seen to be marked by short inosculating ridges directed antero-posteriorly. The structure
of the articular faces is dense; that of the remainder, which forms the greater part of the
centrum, is finely cancellous.

Measurements.

MM
Type specimen, Plate I, figures 1, 2 and 3 :—
Elerohtioficentrumisecene tele tr sepa Bivauih a eeleae lee ae DEES Prat eens Ber ye)
Bread thierereyec Seon R aT Reareseeineae eerie ES re oleracea leer mm aR teheTe 16°8
Theric Chives at esse ese aitesnaseb ecton naeaeneet ea ecnigtreose RSet pee beanie te er O gO
Smaller specimen: —
Flevohtroficentrum mers Geekery ae sence ceca) Ses rete aye hate comets Sancti aie ss bys 9-0
IB eal Ct ha eet ace Sees tea ese recat rece een ca NTR nC RG Alege 11:0
hen ethigsnesseeice: 3°8

A basi-occipital bone that apparently belongs to this species is shown on plate I, figures
4,5 and 6. Its posterior termination has the form of a vertebral centrum having a concave
surface for articulation with the first vertebra. The bone narrows slightly forward ; anteriorly
it is incomplete, but apparently only a small portion is missing. Seen from above, (fig. 4),
there is a deep excavation in the median line at some distance in advance of the posterior end,
representing the hinder basal part of the brain cavity. Above, posteriorly, is seen the floor
of the foramen magnum, extending backward from the brain cavity as a narrow smooth
surface, on each side of which is an area indicating the probable position of occipital arches
such as are found in the living Amia calva, Linn. Laterally, and directed upward and
outward, occur concave facets for the articulation of the exoccipitals. Inferiorly, (fig. 5), the
bone is flatly convex transversely, with a broad median longitudinal groove that does not extend
backward to the border of the articulating cup. On each side of the basal surface is preserved
the facet for the parasphenoid which evidently in this fossil form terminated posteriorly in two
branches as in the living species. A canal enters the basi-occipital at the side (c, fig. 4) and
finds an exit from the lower surface beside a similar opening of the corresponding canal of the
opposite side of the bone; this pair of foramina have their position in the median line of the bone
between the hinder ends of the parasphenoid. The posterior articulating cup, fig. 6, cor-
responds in general size and contour with the type centrum of Amia exilis, its breadth being
considerably greater than the height. Slightly above mid-height in the cup is a minute
notochordal foramen. As seen from behind, the outline of the cup is rather flat in the centre
below, and laterally subangular. The limits of the vertebra forming the posterior end of the
basi-occipital, being the third of the three vertebrx that are thought to enter into the com-
position of this bone, are faintly indicated in the specimen.

LEPIDOSTEUS LONGUS, sp. Nov.

Plate I, figs. 7, 8 and 9.

A species of Lepidosteus is represented by an opisthoccelous vertebra. A few thick,
smoothly enamelled, rhomboid scales, included in the collection, probably belong to the same
species as the vertebra.

14

The vertebral centrum is from about the middle of the dorsal series, and is long in pro-
portion to its breadth and height. In end view the articular surfaces are six-sided, the
anterior surface is slightly convex : the posterior one as slightly concave. The parapophyses
are given off at the mid-height of the centrum a little in advance of the mid-length, p, fig. 9.
Beneath each parapophysis is a deep fossa, iong in an antero-posterior direction, occupying
the lateral inferior face of the centrum and separated from its fellow by the narrow, flat
inferior surface which is broadest at either end, where it is also most deeply impressed by a
longitudinal median groove. The surface between the parapophyses and the neurapophyses,
n, fig. 7, is deeply eycavated. The floor of the neural canal channels the upper surface of
the centrum, the depression being greatest at mid-length. There is also a small fossa above,
a little behind the parapophyses. Thesurface of the centrum throughout is quite smooth.

A conspicuous character of the above centrum is its length as compared with its height
and breadth ; length of centrum, along median line, inferiorly, 10 mm.; height of posterior
articular face, 6°S mm.; breadth of same, 8°3 mm.

The name longus is here made use of for the fossil gar represented by the Cypress
Hills specimen.

RUHINEASTES RHZAS.
Plate I, figs. 10-16.

Rhineastes rheas, Cope, 1891. The species from the Oligocene or Lower Miocene beds of the
Cypress hills. Geol. Survey of Canada, Contr. to Can. Palieont., vol. III (quarto), pt. I,
p. 3, pl. I, figs. 8, 83a and 36. :

A few broken vertebrze are apparently referable to this species. In comparison with the
type material, the internal structure of the centrum in the present specimens is seen to be the
same, viz., close set vertical laminze parallel to the articular surfaces.

The vertebrie mentioned in the original description of the species consist of a median
abdominal vertebra (the type spec.men), and a second centrum that is referred by Cope to this
species not without some doubt. There is with this material a third vertebra, not mentioned
by Professor Cope, and possibly not seen by him, which is slightly larger, and more perfect than
the type. This specimen, with little doubt, belongs to this species, but calls for remark in that
it is definitely flattened below, and is without a fossa beneath the base of the diapophysis.
In the type the inferior surface is broken away.

In the 1904 collection are a number of bases of pectoral spines, serrated on both the
anterior and posterior borders, probably referable to Rhineastes rheas. In the genus Amiurus,
to which the other Siluroid remains in the collection belong, the pectoral spine is serrated on
the posterior border only, whilst in R4ineastes this spine may be serrated on one or both
borders.

All the pectoral spines are imperfect distally, and show a considerable range in size.
One of the most perfect is small, but gives the details of ornamentation well. The sides are
covered with low narrow longitudinal ridges which often inosculate. There is no sign of
tuberculation here; such as is found in conjunction with longitudinal ridges on the spines
of Arius egertoni of the middle Eocene of England, and Belgium. On the anterior border
there isa median serrated ridge bounded on either side by a well-marked narrow groove.

15

There are nine outwardly directed serrations. in a space of 3mm. A similar ridge likewise
occurs on the posterior border with slightly larger serrations, about six of the latter occurring
in a space of 3 mm. These posterior serrations shuw a tendency to point backward, and they
are not continued so far toward the base of the spine as are those of the anterior border.
The measurements of this specimen are as follows:—length (distal half missing) 13 mm.,
greatest height at proximal end 6 mm., antero-posterior diameter at broken distal end about
2°8 mm., with a vertical diameter distally of about 16mm. The pectoral spines in the col-
lection are of various sizes, from 4 up to 16 mm., as measured in a vertical direction across
the base, with the more anterior part in proportion.

The serrations in the majority of the specimens have been worn down, and in some cases
almost entirely removed, although indications of them cam still be seen. In the largest
specimen (16 mm. across the base) the number of serrations in a space of 3 mm. is about six
on both borders. In all, the ornamentation of the sides is the same.

A few dorsal fin spines, with sculpture similar to that of the pectoral spines, are, probably,
also referable to this species. They are broken across at some distance from the base, and
the distal end lost. One, of small size and somewhat worn, is serrated on both borders. In
a second, a large spine, figs. 14, 15 and 16, the anterior border is rugose, and no satisfactory
evidence of serrations can be made out ; posteriorly its surface is deeply grooved proximally
as in the smaller spine, and the specimen is broken off behind where the serrations would
probably begin. The measurements of this large spine are—length of specimen 30 mm.,
breadth across proximal end 18 mm., antero-posterior diameter at fractured distal end 8 mm.
transverse diameter distally 6°5 mm.

A number of fragments from the distal end of spines are, probably, also referable here
They are longitudinally striated, and three are serrated on both borders. Another is serrated
at least on the posterior border ; whilst one bears on its posterior border comparatively long
backwardly curved barb-like denticles (figure 13).

These spines appear to approach closely, in detail of ornamentation and shape, to those of
R. arcuatus, described by Cope from the Bridger Eocene of Wyoming. In the Oligocene
specimens the serrations of the borders, and the ornamentation generally, are on a smaller
scale.

AMIURUS CANCELLATUS, Cope.

Amiurus eancellatus, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills. Geol. Survey of Canada, Contr. to Can. Paleont., vol. III (quarto),
pt. I, p. 8, pl. I, figs. 4, 4a—b. 5, 5a—b.

This species, founded on two vertebral centra from the Cypress hills, is one of two species
of the genus described from this region.

In the 1904 collection are a few centra, with parts of others, that, judging from their
form and structure in comparison with the type specimens, are apparently referable to Cope’s
species.

In the type specimens the dense tissue of the articular surfaces is succeeded within by
vertical laminze forming two thin layers which are connected by tissue, disposed for the most
part longitudinally, in which are many openings of variable size having their longer axes in

16

an antero-posterior direction. This open structure occupies the greater part of the thickness
of the centrum.

The 1904 specimens have this general structure, with a considerable variance as to the
number, size, and disposition of the openings inthe inner tissue. Superiorly there is a central
excavation or fossa, with one more or less developed on either side of the centre. Laterally a
fossa is present beneath the base of the diapophyses, and on the lower surface there is a
median, single, or double fossa.

AMIURUS MACONNELLI, Cope.

Amiurus maconnelli, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills. Geol. Survey of Canada, Contr. to Can. Paleont. vol. III (quarto),
pt. I, p. 4, pl. I, figs. 6, 6a—b, Ta-b.

The vertebrze of this species differ from those of the preceding principally in having the
inner longitudinally disposed tissue more compact. This tissue, in which there is a conspicuous
absence of large openings, is made up of slender longitudinal strands with secondary connect-
ing ones at right angles to the former, leaving small interspaces. As in A. cancellatus, there
are vertical laminee beneath the dense articular surface layer of tissue, but they occupy a
greater thickness and consequently restrict the innermost cancellous tissue to a narrower
area,

Cope, in describing the two centra on which this species is based, states that they are
without a fossa on the inferior face. This is no doubt an error of observation, as in the larger
of the two type specimens there is a single deep fossa below, and in the smaller centrum there
is also a single median inferior fossa.

A few imperfect centra and large vertebral fragments belonging to the collection of 1904
are probably referable to this species.

The lower or proximal ends of a few dorsal fin spines, differing from those that have been
provisionally assigned to Rhineastes rhaas, are in the collection of 1904.

These spines may have belonged to one of the two species of Amiurus here referred to,
or possibly both species may be represented. They differ considerably in size, and were
apparently without tubercles, or longitudinal sculpture ridges on their sides. From the
specimens it is impossible to state whether serrations were present along the anterior, and
posterior edges, or not. ‘The sides of the spines were apparently smooth, but the specimens are
either slightly worn or weathered so that, any delicate markings, if they were present, have
been obliterated. The largest specimen, figures 14, 15 and 16, has a maximum transverse
diameter at the base of 13 mm., the smallest does not exceed 45 mm., measured similarly.

The largest spine is one that has been broken off farthest from the proximal end. It is
subtriangular in section above the base, and is excavated longitudinally behind by a deep
groove. Above, the ridge bounding the posterior groove on one side persists, on the other
side it disappears, so that the spine is not bilaterally symmetrical. The lateral surface of the
spine, on the side on which the posterior ridge continues, is convex, the opposite side is slightly
concave. In the centre of the angular anterior surface is a longitudinal, shallow, but well-
defined, narrow groove. The basal perforation is about 3 mm. wide. Seen sideways the
anterior surface curves backward, the posterior outline is almost straight. Measured from
back to front, near the distal end of the specimen, the diameter is 12 mm., the transverse
measurement at the same height from the base is about 7 mm.

lef

Compared with a dorsal spine* of Arius egertoni, var. belgicus, Leriche, from the Eocene
of Belgium, the Cypress Hills spine is much more robust above, although the proximal end ard
the basal perforation are of about the same size in each.

REPTILIA.
CHELONIA.

ANOSTEIRA ORNATA? Leidy.

Plate I, figs. 17, 18 and 19.
Anosteira ornata, Leidy, 1871. Proc. Acad. Nat. Sci. Phila., p. 102.

A marginal plate of a turtle from the eastern escarpment of the Cypress hills (collection
of 1904) bears so striking a resemblance in general form and ornamentation to those of Leidy’s
species from the Bridger Eocene -of Wyoming, that it is, for the present, referred to that
species.

The plate is triangular in section, the free edge being sharp and smooth, the inner surface
excavated (figure 19). It is apparently the eleventh plate from the right side of the shell.
The sculpture beneath, fig. 18, consists of distinct, discontinuous, radiating ridges of varying
length with a few tubercles at the centre. Theupper surface, fig, 17, is somewhat similarly,
but more rugosely ornamented,the tubercles here predominating ; although toward the margins
of the plate they tend to coalesce into short divergent ridges. A furrow across the middle
of the upper surface marks where contiguous epidermal shields met. This groove is continued,
though very faintly, on the under surface of the plate. Leidy was doubtful asto the presence
of shields in this species. In his description** he mentions that the shell “appears to be
devoid of the usual outlines more or less strongly expressed, of the investing scutes.”

A second marginal plate from the same locality bears a slightly different sculpture. The
upper surface is granulose throughout, without the formation of definite ridges, although the
tubercles frequently coalesce. The lower surface would be quite smooth but for an indistinct
granulation near the free border. The plate is wedge shaped, shallowly concave above, but
convex beneath, and grooved on the inner border. A sulcus also in this plate denotes the
presence of epidermal shields. The anterior marginals in the type are stated to be smooth
beneath, and it is probable that this plate belongs to that part of the shell anterior to the
axillary notch.

In Bone coulée, Cypress hills, was found another specimen probably belonging to the
species represented by the eastern escarpment marginals. It is a lateral marginal, probably
the fifth of the right side, and is definitely sculptured in agreement with the type of A. ornata,
This specimen also bears scute impressions.

More material is needed to more definitely determine the Cypress Hills species, which,
from the evidence now available, and so far as a comparison can be made, apparently very
closely resembles the Eocene species described by Leidy. Additional specimens, however,
will probably prove the Cypress Hills species to be distinct from A. ornata, bringing to light
a form representative of the Oligocene deposits.

* Mémoires du Musée Royal d’Histoire Naturelle de Belgique, t. ILI. Les Poissons tocénes de la Belgique, par Maurice
Leriche, 1905, p. 143, pl. LX, figs. 4 and 5.
** 1873. Contr. to the Extinct Vertebrate Fauna of the Western Territories. Report U.S. Geol. Survey Terrs., vol. I,
p. 175, pl. XVI, figs. 1-6.
12529—3

18
STYLEMYS NEBRASCENSIS, Leidy.

This species has already been recorded by Cope, (this volume, pt. I, p. 5) from the head-
waters of Swift-current creek in Bone coulée (collection of 1884), who considered that certain:
fragments from this locality were not distinguishable from Leidy’s species from the Oligocene
of South Dakota and Colorado. The 1904 collection includes parts of the shel! of a tortoise
which is also, apparently, referable to the same species.

TrEsTUDO EXOKNATA, Lambe.
Plate I, figs 20, 21 and-22. —
Testudo exornata, Lambe, 1906. Ottawa Naturalist, vol. XIX, p. 187, pl. 3, figs. 1, 2 and 3.

Among the chelonian remains of the Cypress Hills Oligocene collection of 1904 are parts
of a number of costal plates that were described in 1906, as appertaining to a new species
of Tes/udo, under the above name,

The specimens were found separately, but were considered to belong, evidently, to the same
- species. The three figured are the proximal end of the left first costal, the distal half of the
left fifth costal, and the proximal end of the left sixth costal.

All the specimens show decided groove markings. The distal end of the fifth costal
plate, (figure 20, the type of the species), is particularly narrow and thick, but its outline indi-
cates that the bone when entire had a considerable breadth proximally. Its upper surface
presents a number of parallel shallow furrows in the direction of the length of the carapace.
It is thickened along its posterior articular border where it joined the similarly thickened
anterior border of the sixth costal, thus forming a stout ridge for the reception of the inguinal
buttress.

The specimen shown in figure 21, is apparently the proximal end of the left sixth costal
plate. This costal when complete was evidently much broader toward its outer end. Deep
sulci on the upper surface mark the position of the fourth vertebral, also the third, and fourth
costal shields, Distinct grooves also cross this plate from side to side nearits inner end, where
the sutural surfaces for articulation with the sixth and seventh neural plates are preserved.

The third specimen, figure 22, is the inner end of the left first costal. On its surface are
concentric grooves indicating an epidermal shield pattern such as is found in some of the
modern species of the genus.

These specimens show that the costal plates were alternately narrow and broad distally,
and broad and narrow proximally : a common character of species of Testudo. .

Measurements.

MM
lst Costal plate. Plate I, figure 22 :—
Maximum thickness at centre of proximal end............... Soe EAU 7
Thickness of specimen at anterior suture............. 0 --...-- oh Satanic os)
ss ss SSPOSLELION s Som teeta Slecias Specie moe SR Die 6% 4
5th Costal plate. Type. Plate I, figure 20 :—
Thickness at proximal end of specimen......... a Wee TCE Mean eee t 0 )
a near distal end at anterior suture .... 4 scene | saeco oes Seater a)
& distally near posterior suture.... ... nate piscacoE ARES oni 8

6th Costal plate. Plate I, figure 21 :—
‘Thickness/at;proximal¥end. -.2. 2 yt: sees os ee ee eee 8

19
This species is peculiar on account of the extrerne narrowness and thickness of the 5th

costal plate. The surface of the carapace bore a distinct pattern of grooyes which were,
anteriorly at least, arranged concentrically within the boundaries of the epidermal shields.

TRIONYX LEUCOPOTAMICUS, Cope.

This species was described by Cope in 1891*. The material on which it is based consists
of part of a costal bone from Bone coulée, Cypress hills, (Mr. T. C. Weston’s collection of 1884)
and some well preserved fragments from the White buttes, Dakota.

In the collection of 1904 from Bone coulée are a number. of fragments of shell, prin-
cipally broken costals, that are evidently referable to this species.

Other fragments may be assignable to 7. punctiger, Cope, from the Oligocene (White
River) of South Dakota, but the material is too poor to admit of a satisfactory determination.

SQUAMATA.
PELTOSAURUS GRANULOSUS, Cope.”
Plate 1, figs. 23, 24 and 25.

Peltosaurus granulosus, Cope, 1872. Paleontological Bulletin, No. 15, p. 5.
g & Cope, 1874. Annual Report U.S. Geol. and Geog. Survey Terrs.
for 18738, p. 513.
Peltosaurus granulosus, Cope, 1884. The Vertebrata of the Tertiary Formations of the
West, U.S. Geol. Survey Terrs., vol. III, p. 778, pl. LX, figs. 3-11.
Peltosaurus granulosus, Lambe, 1905. Geol. Survey of Canada, Summary Report for 1904,
p. 366.

With this species are identified part of a left dentary (fig. 23) and the posterior half of a
right maxilla (fig. 24), in both of which specimens a number of the teeth are preserved. A
worn portion of a second dentary from which the teeth have been abraded, probably, also
belongs to this species.

The type specimens described by Cope are from the Miocene of north-eastern Colorado ;
the Canadian specimens were obtained by the writer from the Oligocene beds of Bone coulée,
Cypress hills, in 1904.

In the dentary shown in figure 23, the teeth are pleurodont, of fair size, chisel-shaped, and
apparently in all particulars agreeing with those of the type specimens. There are four
of the largest teeth in a space of about 5mm. The mandibular groove, seen in the inferior
surface of the specimen, is of large size, and the dentary canal is well shown, piercing the bone
midway between the surface of attachment of the teeth and the exterior surface of the speci-
men in which occur a few small foramina.

In the maxilla there are eight teeth preserved, diminishing in size toward the back.
Exteriorly the bone curves slightly outward behind, and above posteriorly is seen the surface
for the articulation of the jugal. The teeth correspond in size with those of the dentary.

The Cypress Hills specimens are smaller than the corresponding bones on which the
species is based, but there is no evidence to indicate that they belong to a different species.

* The species from the Oligocene or Lower Miocene beds of the Cypress hills. Geol. Survey of Canada. Contr. to Can.
Palzont., vol. IIT, (quarto), pt. I, p. 5, pl. I, figs. 8 and 9.

20

A dermal scute, fig. 25, from Bone coulée, possibly referable to this species, may be men-
tioned here. It is quadrangular in shape, flat, longer than broad, and broadest behind, with
straight sides, and a convexly curved, sharp-edged posterior margin. It attains a maximum
thickness of 0°5 mm. in front and thins gradually to the rear. No overlapping surfaces are
seen. Above it is finely tuberculated, the turbercles being distinct from each other, and close
set, about three in a space of 1 mm. A well defined median ridge is developed in the
direction of its length. Thisscute differs from those of this species described by Cope, in that
it is keeled, and the granulation, apparently, more distinct.

OGMOPHIS CoMPACTUS, Sp. nov.
Plate I, figs. 26-30.

Ophidian vertebre, Lambe, 1905. Geol. Survey of Canada, Summary Report for 1904, p. 366.

Four dorsal vertebree apparently belonging to the same species were found separately.
They are all of different sizes, and, probably, are from different individuals. The maximum
breadth is across the zygapophyses, which are broadly expanded laterally; it apparently
exceeds the maximum height (unobtainable on account of the abrasion of the neural spine in
all the specimens) and greatly exceeds the length measured so as to include the pre- and,
postzygapophyses. A marked character is the shortness of the centrum. The cup is wider
than high with a well defined sharp rim, and is directed very slightly downward. The ball is
as slightly inclined upward. The zygosphene is broader than the neural canal is wide, and has
a plane upper surface, and a straight sharp front margin that slightly overhangs the upper
rim of the cup. The neural spine starts as an angular ridge behind the upper surface of the
zygosphene. The neural canal is subtriangular in cross section, the angles being rounded
with the apical one the most obiuse; its sidesare slightly incurved. A low rounded ridge
occupies the centre of the floor of the canal longitudinally, corresponding in shape with the
hypapophysial keel of the lower surface of the centrum. An angular interzygapophysial
ridge is feebly developed, the surfaces above and below the ridge being shallowly concave,
The front margin of the neural arch between the postzygapophyses is, in outline as seen from
above, deeply emarginate, restricting the space available for the base of the neural spine. The
facettes of the zygapophyses and of the zygosphene and zygantrum are inclined at a slight angle
to each other, those of the zygapophyses being the less removed from the horizontal. The costal
tubercle is not prominent ; its articular face in all the specimens is a little worn, but sufficiently
well preserved to show thatit is single. Its face is higher than broad, and is directed obliquely
outward and downward from beneath the prezygapophysisat a level corresponding with that
of the cup. In the largest vertebra (No. 3) the articular face is seen to be convex above and
slightly concave below posteriorly. A rounded ridge is developed near the base of the
tubercle, and passes backward almost to the side of the ball at its mid-height. This ridge
leaves a longitudinal depression on either side of the hypapophysial ridge which passes from
the ball to the cup, and is-well rounded and distinct but not prominent. There are slight
variations in the above vertebrie but their general proportions are similar. The vertebra
figured on plate I is No. 2 of the table of measurements given below.

Measurements in MM.

Length of Breadth of vertebra. Height of vertebra.

centrum. ant. post. ant. post.
Nos eyspeetetionvosteess Bese aeeneeerete 4°3 9-5 8-0
INO: oe ee attr StS eee fa 5-0 7°75 6-0
No. 3. 11-0 6-75

Nowe eo erate: vs nee 4:3 6-00 6-4

21

This species is distinct from O. angulatus described by Cope* from the White River
(Oligocene) beds of north-eastern Colorado. The vertebrie of Cope’s species approach more
closely in general form those of the Cypress Hills species than do those of other described
species of the genus. O.arenarum, Douglass,** from the Flint Creek beds (Miocene) of Mon-
tana, differs in important particulars.

CROCODILIA.
CrocoDILUS PRENASALIS? Loomis.

Crocodilus prenasalis, Loomis, 1904. Two new river reptiles from the Titanothere beds ;
Amer. Jour. Sci., vol. XVIII, p. 427, figs. 1-9.

Few crocodilian remains were found in the Oligocene deposits of the Cypress hills in 1904,
and none had been secured previous to that date. The writer obtained in 1904 the following
specimens :—two vertebral centra, two keeled scutes, a fragment of a pitted bone from the
head and a tooth. These specimens were found separately, but probably belong to the same
species.

The vertebree are from the dorsal region. They are concave in front, and prominently
convex behind, and in each case the base only of the neural arch remains. One specimen is
much smaller than the other, and, probably, belonged to a young individual, as the suture
between the neural arch and the centrum is strongly marked. The dermal scutes have
numerous deep, rounded pits in the upper surface, are prominently keeled longitudinally, and
their margins bear no evidence of having been in contact with other scutes. The under
surface is even and flat. The tooth is elongate conical and curved slightly inward, and back-
ward ; its surface is quite smooth. The inner face is defined in front, and behind, by a well
developed ridge that extends from near the base to the apex. The base of the tooth is deeply
excavated.

Measurements.

Large vertebra :— MM.
Maximum length at mid-height of centrum................--. t.+-+2.--+. 35
iElersht ofanterionlanticullartaceyy sec aecran epee eens eye late ones acs 20°6
Maxrmum'bneadthyotesam etemnnar sil cneenn a cepa nyt, Ame alas Renee nc us alr 22
inlerg htrotsposterionarticulaymalces, wayse sg ge sects repre Poa enters siete eile 18-2
Maximum breadth of same............... Guru cial acngs tn Siar unre taut 17-8
iken'othrot oomotmeunrallicana les see sean ace ane cece ny cree See oe 28-5
ikenothrofaunferion suriaceeam as ces ic tie Neve a ea SRA Caene te aoe 22)°5

Small vertebra :—

Maximum length at mid-height of centrum.....................-2....0.. 25
Height of anterior articular face......:........... Pa St vlane i ute ern Pre ek a 15
Miaxamumppreadthsol same tears cre aac omnnrs site eae ce cael 18
Height of posterior articular face... BT cen ene eal ont ane) le 15
Maximumebreadtheotisam ear cena eer tect ge yl ean esl aag tetera ce 15
Length of floor of neural canal... ....... Rios cope eee Wane Run card tReet GAN tun 18
eng thyotunteriorssurtaceaysps06).e es ee ENGIN ECPM ASS eN Cu mneste seats ge lls) 3b)

* Report U.S. Geol. Survey Terrs,, vol. III, Tertiary Vertebrata, book I, 1884, p. 783.
** Annals of the Carnegie Museum, 1903, vol. II, Art. X, p. 171.

Larger dermal scute :—

heng theese Patines io Oh Backs Se AMO OGG Dla eo ol Go mo sues 20

Breadthie na tanis cistiioe notes Sais Sees Sg heia fatal OMe inh nad Sa GAR gs CoA TLE O a Eee OATES 14

Maximumheishitjorsthicknessia-p temiates sche erste ret cere U8)

Average. Giameter: Of pits, > sists soto stele oe neta ce sch one pee ee 3
Tooth :—

EDWIN UD asa herac ss ccketer te taove te eye tet ome teeth ae orem ty eh ere Re a 17-5

Antero-posterior qiameterat. basses a sie asm ereen ec eeneeg eens ira 9°2

The above crocodilian remains are referred provisionally to the species lately described
by Dr. F. B. Loomis, from the Titanothere beds of South Dakota. The larger vertebra from
the Cypress hills agrees well in size, and general proportions with the South Dakota dorsal
centrum (p. 428, fig. 3, of Dr. Loomis’s paper), whilst the larger dermal scute closely
resembles the Dakota plates in the disposition and size of the surface pits.

MAMMALIA.
MARSUPIALIA.

DIDELPHYS VALENS, sp. nov.
Plate VIII, figs. 1-7.

An upper right molar from Bone coulée, Cypress hills, is provisionally referred to this
genus. The tooth in crown view, is triangular in outline, has three prominent V-shaped
cusps, and a strong external style-bearing cingulum. Of the three cusps, the internal
one (protocone) occupies the apex of the triangle, the other two (paracone and
metacone) form an antero-posterior pair somewhat removed from the external face of
the tooth by the strong development of the cingulum. The three primary cusps are
compressed antero-posteriorly, the protocone to a less extent than the other two; all have
their external slopes well excavated. The protocone is the stoutest, and is of about the same
height as the paracone, which is the smallest ; the metacone is conspicuously higher than the
others. At the base of the posterior spur of the protocone, is a decided though small fourth
cusp that may represent the hypocone. Three principal stylar cusps occur in the cingulum.
Of these, the most prominent occupies a position only slightly posterior to the mid-length
of the cingulum : it is compressed transversely, and has a vertical external face with a some-
what rounded internal slope; its height is nearly equal to that of the paracone. Of the other
two stylar cusps one is at either end of the cingulum, the anterior one being the larger of the
two. The demarcation between the anterior style and the large one posterior to it is very
decided, and is accentuated by a furrow in the vertical external face of the cingulum. On
the anterior slope of the central stylar cusp are two inconspicuous secondary styles. The
cingulum is continued round the anterior base of the paracone as a narrow shelf. ‘The crown
is borne on three short roots.

This tooth, plate VIII, figures 1-4, probably the second or third upper molar, is consider.
ably larger than (slightly more than one-third as large again as) the corresponding molars
of Didelphys (Peratherium) fugax, which exceeds in size the other species of the genus
described by Cope from the Oligocene of Colorado. “For the species represented by the
Cypress Hills tooth the name valens is proposed. Collection of 1904.

23

Measurements of type specimen. MM.

Or

(Gencthtotexternalstace ofecnowimers. cine settee ee apace isey-te eyeieyey vel ane)
ERPANSV.ETSE4C IAIN LET ti vege ae hayes cay piece liars eos os hes epic ta steer hatrherich «epucttasesoe mateo oy
enebh ofumberno-posterlor faCey ey. sos sie )ever-ts)/-tsielete ates chant

Ww
ec ww ob
oo

(=)

Maximum height of crown (height of metacone).....................- ah scoow ile

The presence of an incipient hypocone isa decidedly progressive character, and one that
has been considered by Bensley* in the Australian genus Perameles as an indication of a
change from an “insectivorous to an omnivorous condition.” The hypocone appears not to
be present in the molars of Didelphys, and suggests that the Cypress Hills tooth may repre-
sent a distinct genus. Under the circumstances, however, with eo little evidence to go on, a
provisional reference to the above, mainly Oligocene genus is at present adhered to.

Another small tooth, plate VIII, figures 5-7, from the same locality as the above, deserves
attention. It possibly represents an undescribed genus of marsupial of the polyprotodont
section, but the one small tooth found is quite insufficient for any definite determination. The
crown is triangular in cross section, and consists of a high, apical, principal cusp, subpyramidal
in shape, with two less elevated, conical, subequal cusps occupying the base of the triangle.
The tooth has one root which would suggest an anterior premolar, but the crown is molariform,
and presumably a posterior molar is represented. Regarding the tooth as a lower molar, the
principal apical cusp is the protoconid, the smaller pair being the metavonid and paraconid
occupying internal posterior and anterior positions respectively. A cingulum is continuous
round the base of the crown except internally. Anteriorly, and externally, the cingulum is
feeble, but posteriorly it becomes accentuated, and ends abruptly beneath the posterior slope
of the metaconid in a minute tubercle. On the internal face of the crown a vertical furrow
occurs between the bases of the two smaller cusps.

Measurements. MM.

Maximum antero-posterior diameter of crown.... . 0... 2. eee. sees eee eee 1-20
£6 transverse diameter Of Crown . 20-2250. ..e chee ote eee peel ba}0)
Heichtobvexternal cusps (Provocomid))s is. Uwase or ftin nists evens sare eee ()
Ai internal cusps (metaconid an paraconid) Fae A INO ar ene a 0°85

The second lower molar of Notoryctes typhiops*, Stirling, has a cusp arrangement very
similar to that of the Cypress Iills tooth, suggesting that the dentition of this living Australian
marsupial may be primitive in some of its characters rather than specialized. In the Cypress
Hills tooth, however, the talonid is only indicated by a minute tubercle, or enlargement of the
cingulum at the base of the metaconid, proportionately much smaller than the definite sub-
sidiary cusp of Notoryctes.

It is possible that this tooth, and the upper molar above described, both of the collection
of 1904, may belong to the same animal.

* On the Evolution of the Australian Marsupialia ; with remarks on the relationships of the marsupials in general, by B.
Arthur Bensley, Ph. D., University of Toronto ; Trans. Linnean Society, vol. LX, part 3, 1903.

* This tooth is described and figured by Dr. Bensley in his memoir of 1903, p. 119, pl. 6, figs. 17 a-b, i

24
UNGULATA

Awncopus (HyoporaMus) BRACHYRHYNCHUS, Osborn and Wortman.

Plate II, figs. 1-9,

Hyopotamus brachyrhynchus, Osborn and Wortman, 1894. Fossil Mammals of the Lower
Miocene White River beds. Collection of 1892; Bulletin Amer. Mus. Nat. Hist., vol.
vi, article vii, p. 220, fig. 6B.

This genus was not known from Canada prior to the publication of the writer’s list of fossil
remains from the Cypress hills in the Summary Report of the Geological Survey for the
year 1904. Unfortunately, separate teeth are the only evidence that we as yet have of the
existence of this artiodactyl in this country during Oligocene times.

A well preserved right upper third molar, fig. 1, belonging to this genus, is included. in
the collection of 1904, and is thought to be referable to A. brachyrhynchus, Osborn and Wort-
man, from the Protoceras beds of South Dakota. In this species there is a greater develop-
ment of the cingulum in the upper premolars and molarsthan in A. americanus, Leidy, from
a slightly lower horizon. The cingulum in the Cypress Hills molar is conspicuous, and in this
respect as well as in its general proportions this tooth agrees better with the corresponding
one of brachyrhynchus than with that of ~mericanus. Inthe Cypress Hills tooth the mesostyle
is prominent in the ectoloph, and apparently more protrudent than in brachyrhynchus ; the
protoconule is well defined and throughout the cingulum is moderately developed.

Measurements. MM.
/Antero-posterior Giameter..j: 22 <4 sie sey s Syotin a pti teesta.n cero oe ee eee 29
Anterior transverse diameter ....... PEE serach? CaP ESA RSG eb ThG OOS 31°5
iPosterioritransverse diameterzeas jes lessee oetcie eee Visiateleas Sheen seven 26
Leight) of para cone serie. oy clays eet stats ohn citer herds ch tome Mea nee enc ateret on acne bo lair)
Height of protocone: 7.) 2s. -< se. see ua) Sig Umea as ove ste cumen aieeraaee 12°5

Within a very short distance of the above tooth, and at the same level, were found four
other teeth that appear to belong to this genus, and are probably referable to this species.
These teeth are determined as follows :—a left lower first incisor, a right lower third incisor,
a right lower canine, and an upper left third premolar, all figured in plate II.- The premolar,
fig. 2, is slightly smaller than the same tooth in brachyrhynchus, but is otherwise very similar,
particularly as regards the shelf-like, interno-posterior expansion of the cingulum, which
greatly increases the breadth of the tooth behind. As seen from below, fig. 3, the outline
of the tooth is triangular, with the inner posterior angle obtusely rounded. The cingulum is
continuous throughout, and is conspicuously prominent internally.

The lower canine agrees in shape with the corresponding tooth of the Hyopotamus from
the Lower Miocene of Ronzon, near Puy-en-Velay (Haute Loire), France, as figured by
Kowalevsky in the Philosophical Transactions of the Royal Society of London, 1873, vol.
163, pl. XX XIX, figs. 3, 3'. Its crown, viewed from the side, is nearly triangular, sharply
pointed above (unworn), with its height slightly in excess of the basal breadth. Its anterior
and posterior slopes are sharp-edged, the former curving inward below. The exterior sur-
face, fig. 5, is convex, somewhat flattened behind. Internally, fig. 4, it is excavated, with a
median vertical rib breaking the general concavity.

25

Of the incisor teeth, the supposed lower third, figs. 6 and 7, is very similar in shape to the
canine, but is smaller, less pointed above (worn), and the breadth of the crown below is greater
than the height. The crown is set obliquely to the root. The left lower incisor, figs. 8 and
9, probably the first, is considerably worn above where the greatest breadth occurs. Its
cutting edge forms an almost straight line across, and the later margins slope gently inward
to the root, without the abrupt basal constriction observed in the third incisor. Internally
the crown is concave, with a median longitudinal rib.

ANTHRACOTHERIUM? PYGM UM, sp. nov.

Plate VI, fig. 6.

A right upper molar of very small size indicates an artiodactyl with dental characters
suggestive of an Anthracothere. As the tooth is imperfect, lacking some of the parts most
essential for its exact determination, a description of it is given, in the hope that at some
future date, better material may be forthcoming. For the present it is referred to Anthraco-
therium, but it is probable that an undescribed genus is represented. For the species the name
pygmeum is proposed.

In crown view the outline of the tooth is quadrangular, with the antero-posterior diam-
eter internally greater than the anterior transverse diameter, so that the tooth is longer than
broad. In Anthracotherium and Ancodus these proportions are reversed. The margin of the
tooth is perfect anteriorly and internally, but externally and posteriorly it is damaged. The
specimen lacks the mesostyle and the posterior slopes of the metacone and hypocone. The
four main cusps are crescent shaped and there is a distinct but small protoconule.

A deep transverse valley separates the anterior from the posterior cusps, a comparatively
shallow longitudinal valley occurs between the protocone and the paracone, but a correspond-
ing valley does not exist between the hypocone and metacone. The protocone is larger and
more elevated than the hypocone, but both are prominent with steep inner slopes. A broad,
median rib occupies the outer, otherwise slightly concave slope of the former. The paracone
is low (in the specimen much worn), but the metacone rises nearly to the height of the
hypocone, whose outer slope is short, and descends but little to meet it. The outer slope
of the paracone (judging from the small portion of it preserved) resembled that of the proto-
cone. The anterior spur of the protocone reaches to the protoconule, which is close to a well-
defined anterior cingulum. The posterior spur of the protocone is long, crosses the median
transverse valley, and rises on the anterior slope of the hypocone nearly to the apex of the
metacone. The basal cingulum occurs on the anterior face of the crown, and in the inner end
of the transverse valley The anterior spur of the hypocone connects with the posterior spur
of the protocone almost at the apex of the metacone. The specimen shows the junction
of the anterior spur of the metacone with the posterior one of the paracone, but the mesostyle
is missing. The parastyle is very feebly developed.

The approximation of the posterior cusps in this tooth is a character probably sufficient
to distinguish the species generically from any of the known genera of Anthracotheriide.
The selenodont form of the main cusps, and the presence of a protoconule, makes it most
probable that this species is properly assignable to the Anthracotheriide. The tooth pattern
indicates a closer relationship to Anthracotherium than to Ancodus.

12529—4

26

Measurements of type specimen.

MM.
Imternaltantero-posteriory diameters <r.5- een eee ee ee 9-00
Anterior bransverse\ diame tecen nas sack cae ree een eee 8-00
EHeightiofsprotocone serene ie dae eis Ss Re oe eee ae 4-70
icleightrofihypoconesnn acer eee Roo SBE Sh Ee cSns 3°80

Locality :—Bone coulée, Cypress hills. Collection of 1904.
ELoTHEeRIUM COARCTATUM, Cope.

Plate II, figs. 10-15, and plate III, figs. 1-6.

This species, based on the greater part of a left mandibular ramus discovered by Mr. T. C.
Weston in the Cypress Hills deposits during the summer of 1888, was first described by Pro-
fessor Cope in the American Naturalist, vol. XXIII, p. 628, July 1889, in his third article
on the * Vertebrata of the Swift-current river.” Cope’s fuller description, with illustrations
of the type specimen, appeared in 1891 in part I of this volume. ;

The original description of 1889 is worded as follows :—‘ Hlotherium coarctatum, sp.
nov.—Represented by a left mandibular ramus with condyle, which supports all of the molar
teeth. The species differs from the H. mortonii, with which it agrees nearly in size, in having
all the premolars in a series uninterrupted by diastemata, except a very short one between
pm. iii andiv.* The second premolar is the most elevated, and the third and fourth are
abruptly smaller. The fourth has one compressed grooved root. The molars are peculiar in
having the two anterior cusps elevated above the three posterior ones, as in Mioclenus sp.
The posterior, or fifth tubercle, is well developed, especially on the m. 111.”

‘*‘Tength from condyle to edge of canine alveolus, 295 mm.; do. to last molar, 125; do.
of true molar series, 67 ; do. of m.i, 22; width of do., 13; elevation of pm. ii, 21; length of
base of crown do., 28; depth of ramus at m.i, 55.”

An upper molar, obtained by Mr. Weston at the Cypress Hills locality in 1884, and
assigned to Hlotherium mortoni, Leidy, by Cope in his earlier references** to the Survey
collections, was, in 1891, referred to EL. coarctatum in his final description of the species.

This upper tooth, plate IT, fig. 10, is regarded as m! from the right side. It has six
low tubercles arranged in two rows transversely, of which the inner posterior tubercle
(hypocone) is apparently not separate from the cingulum. The two outer tubercles (paracone
and metacone) are well developed, the paracone being the larger of the two. Both the inner
tubercles in this specimen are injured, but the protocoue has been apparently of fair size. The
protoconule and metaconule are well marked but do not attain the height of the outer cones,
The cingulum is conspicuous on the anterior and posterior faces of the crown, The tooth has
three roots.

Another right upper molar, fig. 11, belonging to the writer’s collection of 1904, is referred
to this species. It is the posterior tooth of the series and is of about the same size as the
first upper right molar just mentioned. It resembles the last upper molar of EH. mortoni, as

* The usual premolar enumeration from front to back is here reversed.

** American Naturalist, 1885, vol. XIX. The White River beds of Swift-current river, North West Territory, p. 163
(Entelodon mortoni, Leidy); and Geol. and Nat. Hist. Survey of Canada, 1885, vol. I, new series, appendix I, p, 84 C
(Elotherium mortoni, Leidy). :

9
a

bom oI

described by Leidy in 1853 in “The Ancient Fauna of Nebraska,” plate VIII, fig. 1, but the
six tubercles are more distinctly marked in the Cypress Hills tooth. The cingulum is con-
tinued round the entire crown, except for a short distance at the base of the inner slope of the
protocone; it forms a broad shelf anteriorly, and is prominent posteriorly. Seen from above
the crown in outline is unequally four-sided ; it is transversely much narrower behind than
in front. It ie low with six conspicuous tubercles, of which the outer and inner anterior ones
(paracone and protocone), are about equal in size and larger than the others. Of the three
tubercles forming the transverse posterior row, the inner one (hypocone) is connected with
the cingulum. ;

Two fragments of the lower jaw of this species were also obtained in 1904. These are
a part of the left ramus with molars i, ii, and iii, and a small portion of the right half of the
jaw holding the first molar. The teeth agree in all particulars with the corresponding ones
of the type specimen.

Two teeth, the upper third and fourth premolars of the right side, collected in 1904, are, on
account of their large size, referred to E. coarctatum with some hesitation. They were found
together, and probably belonged to the same individual. If they properly belong to this
species, and they are apparently not referable to any other described species from the
Oligocene, they will indicate that in H. coarctatum the upper third and fourth premolars
are considerably stouter in every way than the corresponding teeth of the lower jaw. Of these
specimens, the third premolar, figs 12 and 13, is a simple robust cone, elongated antero-
posteriorly, and supported on two roots, of which the hinder one is the thicker but shorter
of the two. A cingulum passes round the base posteriorly and is present, but feebly developed,
anteriorly. The enamel is roughened by short vermicular markings, which, toward the base,
above the cingulum, pass into conspicuous wrinkles. The crown shows signs of wear toward
the inner side behind and along the front slope. The fourth premolar, figs. 14 and 15, is a very
strong, three-rooted tooth, with a transverse diameter greater than its maximum antero-
posterior diameter. The crown consists of an outer conical cusp with a smaller, less elevated
one on the inner side. A strong cingulum is present except at the centre of the base of the
external slope. This tooth is also considerably worn on the front and back slopes of the
crown, more particularly on the former. Except where worn the surface above the cingulum
presents the same style of surface marking observed in the third premolar.

Measurements.
MM.
Upper right m. iii, plate IT, fig. 11 :—
Transverse diameter of crown, maximum.......-.....5.0.200 000005 A arene eee
Antero-posterior ‘ Me ess Oin ohs eB UGE a RB eck Obra bigs Rane OAH Ora ONO wi ho eo
Upper right m. i, plate IT, fig. 10 :—
AMEN CE CHATMEKGP Or CON Ne cocusnen abo poges bob GuoeL.duoo Sd>ouaduoaD 21

Antero-posterior ‘ Ria iy Gaon eo BE Neca coINRO Ub aire Oe 20-5
Upper right pm. iv, plate IT, figs. 14 and 15:

MransverserGiameter, OL Crowns atOASCnajseiss rece ehiele eiciers eye cieierata ee cis reh ersten ao

Antero-posterior ‘ se ee JED MAMI G 6 eo no BaoK MAO Aou MeN aoe oAe CASO

Herohtror crown wextornalcerr psy iichepuioten eae tor eco Rrstsilckorohon ashes yotcniek 23

Upper right pm. iii, plate II, figs. 12 and 13 :—
to} ? ’ ton)
Transverse diameter of crown at base, maximum ...... EAR Reiter Reve SA Heid es
’

Antero-posterior ‘“ a SS Sree eS Sant Rone ho ua NeLe EOD

27

Height of crown, external .....

28

.

The reader is referred to part I of this volume for Professor Cope’s description of the
type of this species.

Five separate teeth from Bone coulée may be mentioned here as apparently belonging to
Elotherium, They resemble incisors in form, and may represent more than one species, as
four of them are nearly of a size, whilst one is much smaller. Two of the larger specimens
are shown in plate IIT, figures 1, 2, 3 and 4; the small one is shown in figures 5 and 6 of
the same plate.

In his memoir on the Cypress Hills fauna Professor Cope alludes to the fewness of the
remains of Oreodonitde in the collection studied by him. The only specimen mentioned by
him is a left lower first premolar which was not assigned to any genus.

In 1904 a few additional separate teeth were obtained by the writer; these are noticed
as under.

AGRIOCHERUS ANTIQUUS, Leidy.
Plate II, figs. 16 and 17.

Three imperfect posterior upper molars, one from the left side and two from the right,
represent one or more species of Agriochwrus. Comparing these teeth with the posterior
molars of Agriochwrus antiquus, Leidy, from the Oligocene of South Dakota, as described and
figured in the “‘ Ancient Fauna of Nebraska” (Smith. Contr. to Knowledge, 1854, vol. vi) p.
24, pl. 1, the same general form of low cusps, pertaining to this genus, and distinguishing it
from Oreodon, is observed. Of these molars, one is of about the size of the corresponding
tooth of Leidy’s figured types, the other two are slightly larger.

One of the above specimens (an upper right third molar, imperfect internally) may with
little doubt be referred to A. antiqguus; its dimensions slightly exceed those given by Leidy
forthis species. In thisspecimen the form of the external median buttress (mesostyle), seen also
in a molar to be mentioned presently, is low and flattened from without, quite unlike the high
antero-posteriorly compressed mesostyle of Oreodon. In the other posterior right molar the
agreement in form with the teeth figured by Leidy is close, so far as can be judged ; the
ectoloph is missing and a full comparison is not possible. Its breadth is about the same, and
the shape of the inner cusps is similar. This tooth is also referred to A. antiquus. The third
specimen (plate IT, fig. 16), the left posterior molar, has a greater proportionate as well as
actual transverse diameter, and may represent a species distinct from A. antiquus.

Besides the three above mentioned specimens, there is in the collection of 1904 another
left upper posterior molar (plate I], fig. 17). The low rounded form of the mesostyle is here
well shown. The tooth exceeds in size the corresponding one of A. antiquus, and the pro-
portions of the cusps are somewhat dissimilar; the flatness of the outer slope of the metacone
(postero-exterior cusp) is particularly noticeable. In the absence of better material this tooth
is provisionally referred to A. antiquus.

29
MeERYcOIDODON CULBERTSONI, Leidy.
Plate IT, figs. 18-26.

A second genus of Agriocheride (Oreodontide) is represented by separate teeth from
the Cypress hills, included in the collections of 1884, 1889 and 1904. They are referred to
Merycoidodon eulbertsoni, Veidy, of the Oligocene of South Dakota, and consist of the
following specimens:—The left lower caniniform premolar, mentioned by Cope in part I of
this volume, but not assigned by him to any species (Weston, 1884), a left upper canine
(Lambe, 1904) and a right lower second molar (Lambe, 1904).

The premolar, plate II, figs 18 and 19, agrees closely in size and form with the corre-
sponding tooth of the female skull of J. culbertsoni, described and figured by Leidy in ‘The
Ancient Fauna of Nebraska.” This premolar shows signs of wear, in front on the outer side,
and behind on the inner side, where it closed against the upper canine and the upper first
premolar.

Measurements of lower first premolar.

MM.
Hxberio“ hel shtOrcrow NM (WOLM)) yy ars deieVelo wees alas sei Sete ioe sly isso 13
Antero-posterior diameter of crown at base..... Sei ec A Colo ao oe pone cogs 15
Mransverse. diameter Ol CrowMeatyWASe nk stiuy siete ce ce oe ele oesis sees sisters Siete tenet at 75

The left upper canine, figs. 20-23, is long, curved, and subtriangular in transverse section
throughout its length. The posterior surface, fig. 21, is flattened, and the exterior and
interior surfaces are nearly flat, the former being slightly more convex than the latter, fig.
20, in which a low, longitudinal median ridge is developed in the fang above the crown. In
the exterior surface a shallow groove is noticed in a corresponding position. The forward
angulation is evenlyrounded. The crown of the tooth is worn flat posteriorly, where it came
in contact with the lower first premolar, and its side angles are sharp. The immediate
extremity of the crown is broken off but it seems to have been bluntly pointed. The enamel
of the crown extended upward from the point, about 20 mm., measured along the forward
angulation. The antero-posterior diameter of the tooth throughout its entire length exceeds
the breadth of the posterior flattened surface (max. transverse diameter), otherwise the
resemblance of the Cypress Hills tooth to that of M. culbertsoni is strong. In describing the
upper canine of this species, Leidy, in his above mentioned memoir (p. 42), states that the
posterior side “isa little larger than the other sides,” that is the transverse diameter
exceeded the antero-posterior diameter.

Measurements of upper canine.

MM.
Total length of specimen along anterior curve.......... 0.2.0. ce ce eee eee eee 58
Max. transverse diameter at base of crown....... Sancti icc UO Rarsicc a atesr aN nen O,
Antero-posterior diameter at base of crown...........2-- +12 esse ect e ese eter 10°5
Antero-posterior diameter near upper end of fang.......-............----2+:- 12
Transverse diameter £6 fe é ore alia nek 141 Se erie at oe Ohara a Rees eg 10

The remaining tooth, referred to M. culbertsoni, is a lower right second molar, figs. 24,
25 and 26. Comparing the specimen with Leidy’s figure of the corresponding tooth (op. cit.
pl. IIT, fig. 4) no difference is noticed, except that the Cypress Hills molar is a little the
larger of the two.

30
PoEBROTHERIUM WILSONT, Leidy.

Plate VIII, figs. 8 and 9.

This species, made known by Leidy in 1847 (Proc. Acad. Nat. Sci. Phila., vol. III, p. 322),
from the greater part of a skull from the Oligocene (White River) of Nebraska, is represented
in the 1904 collection from the Cypress Hills beds by two separate lower last temporary molars,
one of which remains in a portion of the jaw. These teeth are composed of three double
lobes decreasing in size to the front. The jaw fragment in which the molar is preserved, has
a depth agreeing with that of the lower jaw of the type skull, fully described and figured by
Dr. Leidy in 1854* in his classic “ Ancient Fauna of Nebraska” (Smith. Contr. to Knowledge,
vol. VI). In advance of the molar in this specimen are the alveoli for the tooth next in front.

Jleasurements.

MM.
Lower right last temporary molar :—
>) -Antero:posteriondiameterasa-n)--eieiria-c) Meera ene ae eee 12-3
Posterior transverse: 26) iiy..Nac.e7<ccispeioe ete ei ee eee She ER 7:0
Anterior se LE Sea ORLOne EHSAN UUs Behe BEA Varies octraa ae)
Lower left last temporary molar in jaw fragment :—
(Plate VIII, figs. 8 and 9.)
Antero-posterior diameter......... wy Fh siai Sealer sais ep cya) Seaton ce Tea ome UO eae pa Oe)
osterior transverse!) SO sees yee) a eee ieee eae Diets 2 6-0
Anterior c Met llaisisveren te ersueleys Shi deeb nesS Ss ETO SAE ee LO
(epthiof ramusjbeneathmolarta..-- -saseare oe oe eee see 13-0

LEPTEMERYX ESULCATUS, Cope.

No tecth from Bone coulée belonging to the 1904 collection can with certainty be referred
to this species, which is based on a worn upper, right molar of which the posterior half of the
ectoloph is broken away. In size the type of L. esulcatus is between one-third and one-fourth
smaller than the molars of L. evansi, Leidy. The lower teeth figured by Matthew in his paper on
the fauna of the Titanotherium beds, 1903, p 223, fig. 15, and referred provisionally to L.
esulcatus, belong evidently to a species considerably larger than the one represented by the
type of L. esulcatus.

LEPTOMERYX MAMMIFER, Cope.

2 Leptomeryr mammifer, Cope, 1885. The White River beds of Swift-current river, North-
West Territory, American Naturalist, vol. XIX, p. 163; name only.

Leptomeryx mammifer, Cope, 1885. Geol. and Nat. Hist., Survey of Canada, vol. I, new
series, part C, appendix I, p. 84.

Leptomeryx mammifer, Cope, 1889. The Vertebrata of the Swift-current river, II, American
Naturalist, vol. XXIII, p. 154.

Leptomeryx mammifer, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills; Geol]. Survey of Canada, Contr. to Can. Palont., vol. III, (quarto),
pt. I, p. 22, pl. XIV, figs. 6, 6a, 7, 7a.

Leplomerysz mammifer, Matthew, 1899. A provisional classification of the Fresh-water
Tertiary of the west, Bulletin Amer. Mus. Nat. Hist., vol. XII, article III, p. 61.

* For this species see also, 1869. The Extinct Mammatian Panna of Dakota and Nebraska; Jour. Acad. Nat. Sei! bilan
second series, vol. VII, p. 141, pl. XIII.

31

Leptomeryx mammifer, Matthew, 1902. The skull of Hypisodus, the smallest of the Artio-
dactyla, with a revision of the Ifypertragulide., Bulletin Amer. Mus. Nat. Hist., vol.
XVI, article XXII, p. 315.

Leptomeryx mammifer, Matthew, 1903. The fauna of the Titanotherium beds at Pipestone
Springs, Montana, Bulletin Amer. Mus. Nat. Hist., vol. XIX, article VI, p. 224, figs. 16
and 17.

Leptomeryx mammifer was founded on lower molars, from Bone coulée, by Cope, who,
at a later date, arbitrarily associated with them upper molars from the same locality. The
best preserved of these latter, the one figured in 1891, may be regarded as the cotype of the
species. There are in the collection of 1904 separate upper molars that agree closely in size
and form with the cotype, and are, therefore, regarded as belonging to this species. An upper
fourth premolar, obtained in 1904, is also thought to be referable to L. mammifer.

It has been pointed out by Matthew (1902) that one of the characters of 1. mammifer
relied on by Cope as a distinguishing one, viz., the presence in the lower posterior molar of a
“peculiar column intercalated between the heel and the posterior internal column,” is in
reality the small antero-internal cusp of the heel found in other species of the genus.

No lower molars are recognized in the collection of 1904 as belonging to L. mammifer.

LEPTOMERYX SPECIOSUS, Sp. NOV,

Plate VIII, figs. 10-15.

A species of Leptomeryx is represented by a large number of separate teeth, of which the
upper molars are much larger than the type of L. esulcatus, Cope, considerably larger than
those of L. evansi, but not reaching the size of those of ZL. mammifer. This species is
apparently distinct from any of these three species.

In the upper molars the proportionate development of the mesostyle, the anterior (para-
style), and posterior (metastyle) styles, and the ribs of the external face are much the same as
in L. evansi. The styles are quite different from the gibbous styles of L. mammifer, as seen
in the cotype of that species.

In the upper molars a moderately strong cingulum is generally present for a short distance
at the base of the anterior slope of the protocone, and, in a number of specimens there isa slight
indication, as well, of a cingulum on the posterior slope of the hypocone. In two fourth
premolars a cingulum is present for a short distance on both sides (anterior and posterior) of
the inner crescent. Ina majority of the upper molars a median internal cusp is present,
smaller than that of the molars of L. evansi.

The lower molars referred to this species, relying on their size principally for their asso
ciation here, agree in size and general shape with the mandibular teeth referred provisionally
to L. esuleatus by Matthew in 1903, (op. cit, p. 222, fig. 15). The Cypress Hills lower molars
have a slight anterior and posterior cingulum in the majority of cases, and there is also in
most of the specimens a small median external cusp having about the same degree of develop-
ment as the median interval cusp of the upper molars. No mention is made by Matthew of
a cingulum, nor of a median internal cusp in the Pipestone Springs lower molars, which, how-
ever, in other respects, and as regards exact size, agree with the Cypress Hills specimens,

32

Measurements.
MM.
Upper molar, plate VIIT, figs..10, 11. Type :—
Maximum) transverse diameters: em. yon oe serene terse hanes 10°20
a antero-posterior diam eterms\ sews ciare re eee) eee en tO)
Lower molar, plate VIII, figs. 12, 13 :—
Maximum@transyerse diameters erty ioe seer ae or ae ae rea 5-30
Antero-posterior, diameter ...2.5...+..2-:..- Vase ae a segeeaith ouces Clas aageR Rote 8-00
Posterior lower molar, plate VIII, figs. 14, 15.
Antero-posterior diameter.......... AREA BOE an te Voto cioae Ml) a0)
Upper molar of LZ. esuwlcatus (type) :—
Maximum" transverse diameter -saceniyse sees ieee cic a eons So emer aeaet 6-00
Antero-posterior diameter, approx. ..........1 ..... DAH cal tla eye ioeeg os OSS
Upper molar of LZ. mammifer (cotype) :—
Maximum transverse diameter. ...... 222.2 --0es ness: EUR a Seno oINIEe YO)
ws antero-posterior: diameter passe tia seiner eee eae 9°50
Lower posterior molar of LZ. mammzfer (type specimen) :—
Antero:posterior) diameter,sapproxie. »-:sjscascacios is si areeie ele eens ieee)

The name speciosus is proposed for this apparently undescribed species of Leptomeryx.
Locality :—Bone coulée, Cypress hills, collection of 1904.

LEPTOMERYX SEMICINCTUS, Cope.

Leptomeryx semicinetus, Cope, 1889. The Vertebrata of the Swift-current river, II, American
Naturalist, vol. XXIII, p. 154

Leptomeryx semicinctus, Cope, 1891. The species from the Oligocene or Lower Miocene
beds of the Cypress hills; Geol. Survey of Canada, Contr. to Can. Palzeont., vol. III
(quarto), pt. I, p. 23, pl. XIV, figs. 8, 8a.

Leptomeryx semicinctus, Matthew, 1902. The skull of Hypisodus, the smallest of the
Artiodactyla, with a revision of the Hypertragulidie, Bulletin Amer. Mus. Nat. Hist.,
vol. XVI, article XXIII, p. 314.

This species was founded by Cope on two upper molars, and part of a third, from the
Cypress hills. Additional upper molars were obtained in 1904, by the writer, in Bone coulée.
This species is for the present referred to Leptomeryx; without the full dentition its
generic affinities cannot be satisfactorily determined.

HYPERTRAGULUS TRANSVERSUS, Cope.

Hypertragulus transversus, Cope, 1889. The Vertebrata of the Swift-current river, II,
American Naturalist, vol. XXIII, p. 154.

Hypertragulus transversus, Cope, 1891. The species from the Oligocene or Lower Miocene
beds of the Cypress hills; Geol. Survey of Canada, Contr. to Can. Palzont., vol. IIL
(quarto), pt. I, p. 22, pl. XIV, figs. 4, 4a.

Hypertragulus transversus, Matthew, 1902. The skull of Hypisodus, the smallest of the
Artiodactyla, with a revision of the Hypertragulide, Bulletin Amer. Mus. Nat. Hist.,
vol. XVI, article X XIII, p, 316.

No teeth in the 1904 collection are recognized as belonging to this species. Matthew
(1902) is of the opinion that the two worn upper molars from Bone coulée, described by Cope,
under the above name, are probably not referable to the genus Hypertragulus.

MESOHIPPUS WESTONI, (Cope.)
Plate III, figs. 10, 11, 12 and 13.

Anchitherium, sp. indet., Cope, 1885. The White River beds of Swift-current river, North
West Territory ; American Naturalist, vol. XIX, p. 163.

Anchitherium westonii, Cope, 1889. The Vertebrata of the Swift-current river, II; idem, vol.
XXIII, p. 153

Anchitherium westonii, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills ; Geol. Survey of Canada, Contr. to Can. Palzeont., vol. III (quarto),
pt. I, p. 20, pl. XIV, figs, 1, 2 and 2a.

Mesohippus westoni, Osborn, 1904. New Oligocene horses; Bulletin Amer, Mus. Nat. Hist.,
vol, XX, p. 169.

Mesohippus westoni, Lambe, 1905. On the tooth-structure of Mesohippus westoni (Cope) ;
American Geologist, vol. XX XV, p. 243, pl. XIV.

Mesonippus westoni, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills, Assini-
boia; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 44, pl. II,
figs. 1, la, 1b, and Ie.

The type material of this species, from Bone coulée, Cypress hills, consisting of a right
upper molar, and two right lower molars in place in a fragment of the mandible, is in the
Museum of the Geological Survey at Ottawa.

A right upper molar belonging to the collection of 1904, has been referred by the writer
to this species. The upper molar described by Cope is imperfect, the outer slope of the
ectoloph is missing and the anterior part of the tooth, including the protoloph, is much
damaged.

The crown of the molar obtained in the summer of 1904 is practically perfect and had
been subjected to little use during the life of the animal; it is most probably the second
molar and is shown in figures 10-13 of plate III. This tooth is brachyodont, with well
developed low cross crests (protoloph and metaloph). The crown, seen from be'ow, is
suboblong in outline, transversely broader in front than behind and relatively narrow in an
antero-posterior direction. The outer border (ectoloph) rises higher than the cross crests.
The latter are unequal in length, the protoloph being longer and better developed than the
metaloph. The intermediate cusps (protoconule and metaconule) are both well defined,
although the protoconule is larger than the metaconule, and more distinctly separated from
the protocone than is the metaconule from the hypocone. The protocone is slightly larger at
its base than the hypocone, but both have about the same height. There is no hypostyle.
The parastyle is large, and adds considerably to the crown’s anterior transverse diameter.
The mesostyle and metastyle are distinct, and the ribs distinguishable, the anterior ribs
being the better defined of the two. The cingulum is well developed and passes from the
metastyle entirely round the inner side of the crown to the parastyle without interruption,
except for a short distance on the front inner slope of the protocone; it connects in front

12529—5

34

with the parastyle, with which the outer end of the protoloph shows a marked tendency to
unite. Outwardly the cingulum rises on to the parastyle, but does not cross it.

M. westoni, judging of its dental characters principally from the molar obtained in 1904,
approaches closely to M. latidens,* Douglass, in tooth-structure, but its molars are distin-
guished principally by the presence of an internal cingulum, by the less pronounced parastyle,
and a proportionately greater antero-posterior diameter, with the protoloph more nearly equal
in length to the metaloph, as well as by other characters. MV. celer, ** Marsh, and M. mon-
tanensis, *** Osborn, are two other nearly related, but apparently distinct species, from the
Lower Oligocene. The presence of the highly developed internal cingulum is one of the
most interesting characters in the dentition of M. westoni. This character, together with the
absence of a hypostyle, points to this species being probably the most primitive of the known
horses of Oligocene age.

A lower second premolar and a lower molar, are included in the collection of 1904.
Figures of the two lower molarsobtained by Mr. Weston are given in Cope’s memoir of 1891.

Measurements in mm. Measurements Measurements
of upper molar of W/.° of type molar of M1 (type) of
weston? obtained of M. westonias M. montanen-
in 1904, given by sis as given
Osborn. by Osborn.
Transverse diameter............ : 13-0 12+ 14-0
Antero-posterior diameter......... 10°2 9-5
Height of protocone...... sta 4°5 10-5
Height of hypocone dyieeee 4°5 4—
Leight) ofsectolophin.... 5 s-.- aa 6:2 o+

Mr. Gidley has expressed the opinion that, the tooth collected in 1904, approaches more
closely to MW. montanensis than to J. westoni, and would be inclined to refer it to the former
species with some degree of doubt. In comparing it with JZ. montanensis he has noted the
somewhat less elevated inner cones and the presence of an internal cingulum, regarded by
him as differences of perhaps not more than varietal value, which may be explained by cailing
the tooth a premolar instead of a molar.

Judging from the characters of the teeth and their size, it is evident that the two species
M. westoni and M. montanensis approach each other closely. The type of M. westoni is not
as well preserved (nor as accurately figured in the original description) as is desirable, and the
absence of the ectoloph and the anterior margin, including the front slope of the protoloph,
precludes the taking of exact measurements. That the tooth of 1904 (figures 10-13) comes
from the same locality as the type of JZ. westoni, and that it has a particularly well defined
internal cingulum, are facts worthy of every consideration in determining its specific affinity.

MESOHIPPUS PRECOCIDENS, Lambe.
Plate ITI, fig. 14.

Mesohippus precocidens, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills,
Assiniboia; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 46,
pl. II, fig. 2.

* 1903. New Vertebrates from the Montana territory by Earl Douglass ; Annals of the Carnegie Museum, vol. II, p. 161,
fig. 7.
1874. American Journal of Science, vol. VIT, p- 251,
*** 1904. Op. cit,

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Left upper molar (imperfect). Type.
Measurement in mm :—
Height of protocone...... 4-7.
The left upper molar, on whick this species is founded, lacks the ectoloph and the pos-
terior border with the hinder slope of the hypocone, but is otherwise well preserved.

This tooth is about the size, or possibly smaller than J. westoni, but is more progressive
in every way. There is an entire absence of an internal cingulum, the cross crests are better
developed, and relatively higher, with steeper slopes. The protoconule is relatively larger, and
the metaconule, although defined, scarcely breaks the continuity of the metaloph, which unites
in a decided manner with the ectoloph. The protoconule is distinctly defined in the proto-
loph, and connects closely with the forward slope of the paracone. The hypocone has about
the same height as the protocone. Theanteriorcingulum is strong, Mr. Gidley has informed
the writer that he ‘would expect to see the hypostyle well developed, were that portion of
the tooth present.”

MESOHIPPUS PROPINQUUS, Lambe.
Plate III, figs. 15 and 16.

Mesohippus propinquus, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills,
Assiniboia ; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 47, pl.
II, figs. 3 and 4.

2nd right upper premolar, worn (figure 16).
2nd left upper molar, unworn, (figure 15). Type.
2nd right upper molar, unworn.

The above teeth have been regarded by the author as characterizing a species of
Mesohippus distinct from M. bairdi, Leidy, although closely allied to it and most resembling it.

They are of nearly the same size as those of WV. bairdi,if anything slightly larger, and on
the whole more primitive. Their general proportions are somewhat different.
Measurements in mm.

(0? Clef Peacoat WO CY tie cess. 13:5.
m2 left Ap... 12 by tr.......15°5, height of protocone...... 5.
height of protocone...... 5°17, height of ectoloph....8.

m2 right. a.p..... 12°2 by tr.....15.

In the unworn tooth, figure 15, (left upper m2), the ectoloph is well elevated above the
cross crests, in which the protocone and hypocone are conspicuously higher than the conules.
The hypocone exceeds the protocone in height. The protoconule is well defined and distinctly
breaks the continuity of the protoloph. The metaloph is fairly continuous and shows a
disposition to unite with the ectoloph, which, however, it does notreach. The hypostyle is
connected at its inner end with the posterior cingulum and outwardly abuts against the
ectoloph ; it is of fair size. In the ectoloph the mesostyle is conspicuous, the parastyle is
flattened and connects with the protoloph, and the ribs are faintly shown. There is no trace
of an internal cingulum.

Mr. Gidley has drawn the writer’s attention to the interesting fact that the protocone
in these teeth ‘‘is peculiar in having the slope of its anterior face about equal to that of its
posterior face, while in M. bairdi, and all the middle and upper Oligocene horses, the anterior
face of the protocone is always much more abrupt than the posterior one.”

36

A right upper molar, presumably the third, arbitrarily associated with the foregoing, is
considerably larger than the corresponding tooth of M. bairdi. A flatness of the ectoloph is
principally noticeable, as well as the smallness of the hypocone, otherwise its characters are
very similar to those of the left upper second molar already mentioned.

MESOHIPPUS BRAOHYSTYLUS, Osborn.
Plate III, fig. 17.

Mesohippus brachystylus, Osborn, 1904. New Oligocene horses; Bulletin Amer. Mus. Nat.
Hist., vol. XX, p. 175, fig. 6.

Mesohippus brachystylus, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills,
Assiniboia; Trans. Royal Soc. of Canada, second series, vol. XI, section LV, p. 48,
pletion 5:

4th left upper premolar, worn.
Measurement in mm.
[De (le (Oe decd PG.

A fourth left upper premolar is referable to this species. Theinternal cingulum is slightly
more accentuated than in the corresponding tooth of the type, but the general proportions and
the size seem to be the same. In the Cypress Hills specimen the greater part of the ectoloph
is unfortunately missing, but enough remains of its anterior end to show that the parastyle
was rounded and of a relatively largesize. There are certain slight differences of detail to be
noticed but nothing apparently of importance.

The type of I. brachystylus is from the Upper Oligocene, Leptauchenia beds of the
Cheyenne river, South Dakota, U.S.A.

MESOHIPPUS STENOLOPHUS, Lambe.
Plate IIT, figs. 18, 19 and 20.

Mesohippus stenolophus, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills,
Assiniboia ; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 48, pl.
II, figs. 6, 6a and 60.
1st left upper molar, unworn.
3rd right upper molar, unworn. (figures 18,
19 and 20). Type.
Measurements in mm.
(DY Cs Foaccoa 14.
G08 Os Dn-cceor IVS) WptieacacllGy

This species of Mesohippus is larger than W. brachystylus, but resembles it in some
particulars of its dentition. The differences are: (1) The greater relative size of m*, with a
more pronounced obliquity of the cross crests in these teeth, (2) the greater length of the
metaloph, which in m* is connected with the ectoloph, and (3) the intimate connexion of the
hypostyle with both the posterior cingulum and the metastyle. The resemblances are (1)
somewhat similar general proportions, with about the same degree of development of the pro-
toconule and a like suppression of the metaconule, (2) the parastyle and internal cingulum
similarly developed.

A special character of J. stenolophus, seen in m%, is the oblique crossing of the parastyle
by the external cingulum, which rises rapidly from without and appears very distinct on the

37

upper anterior surface of the style (figures 19 and 20). The cross crests are narrow in propot-
tion to their height, a feature suggested in the name that has been given to the species,

MESOHIPPUS PLANIDENS, Lambe.
Plate III, fig. 21.

Mesohippus planidens, Lambe, 1905. Jossil horses of the Oligocene of the Cypress hills,
Assiniboia ; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 49, pl.
ptosis

1st and 2nd left upper molars, worn. Type.
Measurements in mm.
mi m2..... 31

These teeth indicate a species of about the size of M. intermedius, Osborn, from the Upper
Oligocene, Protoceras beds of South Dakota, but smaller than JM. validus, Osborn, from the
same horizon and state. They differ from those of M. intermedius in the greater obliquity
of the protoloph and metaloph, in which respect they resemble those of J. obliquidens, Osborn.
The teeth are brachyodont, and are devoid of an internal cingulum. Externally, the ectoloph
is noticeably flat, with only a slight development of the parastyle and mesostyle, the ribs are
absent or but feebly indicated, and the metastyle is particularly inconspicuous. The hypostyle
is of fair size, curved and attached at either end to the posterior cingulum. ‘The cross crests
are oblique to the ectoloph, well elevated, and moderately continuous, the metaloph more so
than the protoloph. The protoconule slightly interrupts the protoloph, and unites with the
parastyle. The metaconule scarcely breaks the continuity of the metaloph, which is sharply
separated from the ectoloph and develops a rudimentary crochet. The protocone and hypo-
cone are not so elevated as the ectoloph.

The specific name has reference to the flattened condition of the ectoloph.

MESOHIPPUS ASSINIBOIENSIS, Lambe.

Plate III, figs. 22, 23 and 24.

Mesohippus assiniboiensis, Lambe, 1905. Fossil horses of the Oligocene of the Cypress hills,
Assiniboia; Trans. Royal Soc. of Canada, second series, vol. XI, section IV, p. 50, pl.
II, figs. 8, 8a and 80.
2nd right upper premolar, unworn. Type.
Measurements in mm.
[De Os 40s cone 18:5 by tr.....17, height of tritocone....10°5.
height of tetartocone....8.
This species is larger than M. intermedius, Osborn and Wortman, and apparently than
M. validus, Osborn, from the Leptauchenia beds of 8. Dakota. It resembles M. brachystylus,
Osborn, from the Leptauchenia beds of 8. Dakota, inthe great development of the parastyle,
which is, however, more distinctly separated in the Cypress Hills species.

In the above tooth (p2) the antero-posterior diameter is greatly increased by the separ-
ation and large size of the parastyle. The cross crests are short, steep-sided and set almost at
right angles to the ectoloph. The two inner cusps (deuterocone and tetartocone) are strongly

38

and about equally developed. The protoconule* (anterior intermediate cusp) is very
much smaller than the metaconule (posterior intermediate cusp), and passes posterior to, and
beyond the inner end of, an inwardly directed spur from the protocone (antero-external cusp
of the premolar, adopting Scott’s nomenclature). The ectoloph has a distinct mesostyle, a
broadly rounded and well detached parastyle, and strong ribs, of which the anterior one is
particularly rotund. ‘The hypostyle tends to separate from the posterior cingulum, to which
it remains connected by a stout bar. The cingulum is robust, high and sharp edged behind,
low and forming a narrow shelf abutting against the base of the parastyle in front, and is
entirely absent within. The external cusps (protocone and tritocone) rise considerably higher
than the internal ones (deuterocone and tetartocone).

This species, known only from the second premolar, in which the size of the parastyle
would be expected to be accentuated, appears to approach most nearly in tooth development
to the much smaller MW. brachystylus. It exceeds M. intermedius and ? WM. validus in size,
but apparently, more closely resembles the latter. It is distinguished from the last two
species by (1) the greater development of the protocone and deuterocone in this species,
(2) the slight development of the protoconule, {3) the more complete separation of the para-
style, and (4) the intermediate height of the ectoloph.

The foregoing species of Mesohippus are related to, or resemble, previously described
species of the genus from Montanaand Dakota as follows :—

M. westoni, (Cope.) More primitive than J. latidens, Douglass, and JZ. montanensis,
Osborn, from the Lower Oligocene, Titanotherium beds.

M. precocidens, Lambe. Nearly related to and more advanced than IW. westoni (and
? M. montanensis of the Titanotherium beds).

M. propinquus, Lambe. Nearly related to and more primitive than J. bairdi, Leidy,

of the Middle Oligocene, Oreodon beds.
M. brachystylus, Osborn. The type of the species is from the Upper Oligocene, Lep-
tauchenia beds.

M. stenolophus, Lambe. Approaches closely J. brachystylus of the Leptauchenia beds.

M. planidens, Lambe. Approaches in size MW. intermedius, Osborn and Wortman, from
the Upper Oligocene, Protoceras beds.

M. assiniboiensis, Lambe. Some resemblance to, but larger than J/. validus, Osborn, of the

Protoceras beds.
It would seem probable then, that the species from the Cypress hills, in their relative
degrees of progressiveness, are to be assigned to the horizons of the Oligocene in the following
order :—

M. weston 2 are .

mete \ Lower Oligocene, Titanotherium beds.
M. precocidens j =

M. propinquus Middle Oligocene, Oreodon beds.

M. brachystylus \
M. stenolophus {
M. planidens \
M.assiniboiensis

Upper Oligocene, Leptauchenia beds.

Upper Oligocene, Protoceras beds.

* It has been pointed out by Scott (The Evolution of the Premolar Teeth in the Mammals, Proc. Acad. Nat. Sci. Philadel.
vol. XLIV, 1892) that the anterior and posterior intermediate conules of the premolar tooth are not homologous with the proto-
and metaconules of the molar although they correspond in position.

39
Hyracopon Neprascensis, Leidy.

Aceratherium pumilum, Cope, in part, 1885. The White River beds of Swift-current river,
North West Territory ; American Naturalist, vol. XIX, p. 163, name only.

Aceratherium pumilum, Cope, 1885. Geol. and Nat. Hist. Survey of Canada, vol. I, new
series, part C, appendix I, p. 88, specimen IIT; and 1891, this volume, part I, p. 19,
specimen IT, pl. IV, fig. 4.

Hyracodon nebrascense, Osborn, 1898. The Extinct Rhinoceroses. Memoirs Amer. Mus,
Nat. Hist., vol. I, pt. III, p. 188, fig. 28.

The principal specimen from the Cypress hills, representing this species, is the portion of
mandible, holding teeth, described by Cope under the name Cenopus pumilus, (specimen 2).
This specimen, as pointed out by Osborn in 1898, is part of the right ramus of a young
individual of H. nebrascense. A tooth, belonging to the collection 1904, is referred to this
species; it is from the right side of the lower jaw, and is apparently a deciduous third pre-
molar.

Hiyracopon priscrpeNns, Lambe.

Plate IV, figs. 1, 2, 3 and 4.
Hyracodon sp., Lambe, 1905. Geol. Survey of Canada, Summary Report for 1904, p. 368.

Hyracodon priscidens, Lambe, 1905. A new species of Hyracodon (H. priscidens) from the
Oligogene of the Cypress hills, Assiniboia; Trans. Royal Soc. of Canada, second series,
section IV, vol. XI, p. 37, pl. I, figs. 1, 1a.

Another species of Hyracodon is represented, in the collection of 1904 from the Oligocene
deposits at Bone coulée, Cypress hills, by an upper jaw with teeth, giving the complete pre-
molar-molar series. Three teeth are missing, viz., the fourth premolar from the left side,
and the second and third premolars from the right. As the form of the tooth in each case
is seen in the corresponding one of the opposite side, the details of structure of all the cheek
teeth are presented. The ectoloph of the right third premolar remains. The teeth are in an
excellent state of preservation and, as they are only slightly worn, evidently belonged to a
young animal. The last molar on either side has not protruded from the jaw to its fullest
extent. Both jugals are preserved, and, on the right side, part of the squamosal also.

The specimen to which the following remarks apply consists for the most part of the
two maxillary bones holding teeth. These bones are imperfect in their lateral upward
extension. The right maxilla is broken off slightly in advance of the first premolar, but, on
the left side, the full extent of the diastema, separating the first premolar from the canine, is
preserved. The lower margin of the orbital opening on either side is intact.

This specimen (type) indicates an animal of about the size of Hyracodon nebrascensis,
Leidy, from the Oligocene of Nebraska, South Dakota and Colorado, from which, however,
judging from its tooth structure, it differed specifically. The species has been ‘described
under the above name.

Hyracodon priscidens, as compared with H. nebrascensis, exhibits the following charac
teristics :—(1) The teeth are shorter or more brachyodont, (2) in the premolars the protoloph
is continued in a curve round the inner end of the metaloph, the tetartocone being confluent

9

with the deuterocone and arising from the protoloph, (3) in the last molar, m®, the ectoloph

40

is relatively much shorter, with a concomitant greater development of the metaloph, (4) the
exterior cingulum is developed only on the posterior half of the base of the ectoloph in the
seven teeth, and the internal cingulum is absent in p!', (5) the parastyle in the premolars is
only slightly developed, (6) the skull is apparently flatter and relatively more elongate, the
lower margin of the orbit being less distant from the alveolar border, and the jugal less curved
upward in the posterior halt of its length, (7) the diastema in advance of p! is proportion-
ately longer and its margin is not so arched.

For this species of Hyracodon the name priscidens has been proposed, indicative of the
less advanced stage of its dentition as compared with H. nebrascensis. Jn the form of its
premolars it is decidedly primitive, and implies a position in a direct line of descent from
Hyrachyus. A progressive character is seen in the squareness of the premolars which in
Hyrachyus are triangular; also in these teeth the metaloph is much advanced in comparison
with the Eocene genus.

In H. priscidens, as in the type species, m? is much the largest tooth, and m! is larger
than pt. The molars occupy about the same space antero-posteriorly as the premolars.

In the premolars there is a progression toward the molar pattern, but the advance has
been slow. The anterior premolars are more progressive than the posterior ones in some
respects. This is shown in the tendency to the separation of the tetartocone from the deutero-
cone seen in passing froma pt forward. In p! the tetartocone and the deuterocone are very
closely united, but in p’, although still connected to the protoloph, the tetartocone has moved
farther toward the posterior border ot the crown, lengthening the anterior loph, and also
effecting a junction with the metaloph.

In p! the cross lophs are unequal in length, the protoloph, in which the tetartocone is
very intimately united with the deuterocone, not passing beyond a point in line with the
inner end of the metaloph, which is short and curves slightly backward. In p? the protoloph
is increased in length by the shifting backward of the tetartocone, with a tendency to separate
from the deuterocone. The two lophs remain distinct, the anterior one passing slightly
beyond the inner end of the metaloph, which in this tooth is developed to about the same
extent as that of p!, with a like backward obliquity. In p? the protoloph is still further
increased in length, and curves round the inner margin of the crown considerably past the
metaloph toward the posterior border of the tooth. The metaloph curves slightly forward
and unites with the protoloph at a point some distance in advance of the latter’s postcrior
termination. The increased length of the protoloph is due to the further recession of the
tetartocone from the deuterocone, although the union of the two remains complete. In pl
the protoloph is separate from the metaloph, a narrow but distinct sinus dividing them, and
the tetartocone arises from the metaloph which in its inner half presents a concave surface
forward. A variation is noticed in the right first premolar of the Cypress Hills specimen. In
this tooth the sinus, seen in the left first premolar, in advance of the metaloph, does not occur,
in which case the tetartocone would still be said to arise from the protoloph which, com-
mencing at the ectoloph, behind the parastyle, forms a high continuous wall curving round
the inner border ot the tooth for some distance past its union with the metaloph, giving to
the protoloph a length proportionately still greater than the corresponding loph of p?. The
left first premolar, above described, resembles the corresponding tooth of H. nebrascensis as
figured by Leidy in plate XIV, figure 5, accompanying his description of the type species in
“The Ancient Fauna of Nebraska,” 1852, (Smithsonian Contributions to Knowledge). The

41

other premolars in this figure denote a stage of evolution much in advance of the correspond-
ing teeth of H. priscidens.

In the premolars of H. priscidens the deuterocone arises from the protoloph, as in p? and
p! of Hyrachyus agrarius, Leidy, of the Bridger Eocene of Wyoming and Utah; also, in the
second, third and fourth premolars, the general outline of the tooth is quadrangular instead
of triangular as in Hyrachyus. The transverse diameter of p* is relatively greater than that
of either p® or p?. The second, third and fourth premolars are provided with a well defined
cingulum that is continuous round the entire base of the crown, except at the base of the
tritocone ; at the base of the parastyle the cingulum is feebly shown, with increasing faintness
in passing from p! to p?. In the first premolar the exterior cingulum is developed only in
the posterior half of the ectoloph, the posterior cingulum is strong, the anterior cingulum
extends but a short distance from the parastyle, and there is no internal cingulum.

In the molars the cross lophs are nearly equal in length, the protoloph being slightly the
longer, the hypocone is strongly developed and of the size of the protocone, from which it is
separated by a deep anterior valley (medisinus). A crista, strongest in m!, is developed from
the ectoloph, and an antecrochet, of fair size in m!, smaller in m? and incipient in m°, is given
off from the protoloph. In p+, in addition to a small crista, and an indication of an
antecrochet in the form of a decided tubercle, there is a delicate crochet* which is of interest
as a decidedly progressive character. In the molors there is no internal cingulum, but posteriorly,
anteriorly, and externally the cingulum is as in the premolars, except that externally it is
scarcely more than suggested at the base of the parastyle. Asalready mentioned, the ectoloph
in m3 is short as compared witb that of m? and m!, principally on account of the reduction in
size of the metacone, which does not extend, as in the other molars, far posterior to its junction
with the metaloph, but is curtailed at this point, in consequence of which there is only a slight
indication of the formation of a posterior valley (postsinus) that in H. nebrascensis has reached
a more advanced stage.

The order of premolar transformation in H. priscidens is apparently an exception to the
usual metamorphosis of the Hyracodont premolars, which, as stated by Osborn in his memoir
on “ The Extinct Rhinoceroses” 1898, p. 90, is presented in three successive stages of evolu-
tion toward the molar pattern in the second, third and fourth premolars, the last premolar
(p’) being the most advanced.

In H. priscidens the fourth premolar is the least advanced, as regards the relation of the
lophs to each other, although in other respects, viz., in the presence of secondary crest folds
(“crista,” ‘“‘antecrochet” and “crochet ”’), a decided advauce has been made, and it may be
considered in this regard as more progressive than p!, p? and p?.

* Professor H. F. Osborn in his memoir on ‘‘ The Extinct Rhinoceroses” (Memoirs of the Amer. Mus. of Nat. Hist., vol. I,
part ITI, p. 89, 1898), has mentioned that the ‘‘crochet” is ‘‘ peculiar to the true Rhinoceros molars” and is ‘only feebly
developed, if at all, in the Amynodonts and Hyracodonts.”

42

Measurements.
H. priscidens. _H. planiceps** —_-H. nebrascensis**
MM. MM. MM.
Upper molar series, length..............+++ 62 103 70
Upper premolar series, length.............. 62
IMS wii ithe brs) easembccsscece secistelsener ee tee 23°2 BD) 26
M2 « Seon o spas coe SouuUoedoooaBoRNGEES 24°5 36 28
M3 « Eesnewe store oaete Eee Sood 24 BM 26
IMislenc thw (azps)iieerscssssuersenesaeeccesceses 22
M2 « Sroosesent ss So eadeSaesennaseates 23 3) 27
Ms xc wa Nasceeeeicces Sop Rada osboraiheo 19°5 40
Piiwadthu((tr) ie tees -cececcst sects stsies 13°5
1 ee Meeeh acorn erece fivhspeett : 20
Poe eae laa eee se ae cbactes pod D 0 bSb 21:7
Eee Girt 2 Laine Merry Sees eis ect Sonose Sore 23
Jee Ike aetdlann( 0) ) soasssgqdino ascaadaoaaddoonon 12°3
Be eT a) tsek panini counter wets hectic 16
WPS CE Wp hee aaoee Ssesreicecee ce aeerie saree 16°8
Pe ean ke asote cee ntensonvee piece see 17:3

The anterior end of the mandible of a Hyracodon, obtained in 1904 from the Bone Coulée
beds, is of special interest ; it is provisionally assigned to this species.

The specimen (plate IV, figures 3 and 4) consists of nearly half the left ramus with that _
part of the right ramus anterior to the second premolar. Premolars 2, 3 and 4 are preserved,
as well as the roots of the canines, and of the three pairs of incisors. The alveolus of the
second premolar is partly seen on the right side.

A striking feature is the long diastema, between the canine and the second premolar,
nearly equal to that of Hyrachyus (H. agrarius) in proportionate as well as actual length, and
about twice as long as that of Hyracodon nebrascensis, Leidy. A basal cingulum is continuous
round the entire crown of the premolars, except for a short distance internally, in the second
and fourth teeth, posterior to their mid-length.

Measurements.

MM.

engeth of premolar "series 5 o/s 5 ss ain aS ni ciee civto Saye (alo nu era at eee ee ee ee 44
Premolar 2:—

Anitero-posterior diameter <5 5.0 ee ect cheng a Sera oe se eres ee 13

MranSVerse (CiaMetersec.:..<..00 veo otysvaecke ae Sas ee FIRE Ee oe Ree 10
Premolar 3:—

Antero-posterior diameter: <a). .5 <2 66) 5 ier arose Gus dole be eee eee eee 15

Transverse(diameter’. :..\0 fo. 2:28. SSueiage ee neice oie ee eee 12
Premolar +:—

Antero:posterioridiameter:. <0, .a-)- 3. Steines cet eee 16°5

Transverse diameter......... mgs Age she degen sha) Absit ee oye sek sage meter snch er pareee 13°5
Depth} oframusiin'frontiofipremolan's). | 35. ase a oe ener 28-5
Maximum thickness of ramus beneath same tooth.............-- ...---+-++-+---- 15
ensthi of diastemay behind canines -25 o..ah a5 45. eee eee eee Ailes) An
Breadth of mandible at mid-length of diastema............-.-..-:-+--+-++-+--=- 21
henge thiok’symphysis= <<). 7. Nea eis ee eee BO tee: Nee eR veers Peieaced)
Thickness of mandible near posterior end of symphysis ............----+--2+++-- 14

** The measurements of the teeth of H. planiceps and H. nebrascensis are taken from the ‘‘ Preliminary account of the
Fossil Mammals from the White River formation, contained in the Museum of Comparative Zoology” by W. B., Scott and
Henry F. Osborn, 1887, p. 171, Bull. Mus. Comp. Zool., Harvard College.

43
ACERATHERIUM MITE, Cope.

Plate IV, fig. 5.

Aceratherium mite, Cope, 1874. Annual Report U. 8. Geol. and Geog. Survey Terrs. for
1873, p. 493.

Aceratherium mite, Cope, 1885. The White River beds of Swift-current river, North West
Territory, American Naturalist, vol. XIX, p. 163.

Aceratherium mite, Cope, 1885. Geol. and Nat. Hist. Survey of Canada, vol. I, new series,
part C, appendix I, p. 83.

Cenopus mitis, Cope, 1891. The species from the Oligocene or Lower Miocene beds of the
Cypress hills, Geol. Survey of Canada, Contr. to Can. Paleeont, vol. III (quarto), pt. I, p.
UG) Falls IL 5 alien, AX,

Cenopus pumilus, Cope, in part, 1891. Idem, p. 19, specimen No. 1, pl. IV, figs. 3, 3a.

Aceratherium mite, Osborn, 1898. The Extinct Rhinoceroses, Memoirs Amer. Mus. Nat.
Hist., vol. I, pt. II, p. 136.

In his 1891 report Cope assigned certain remains of Aceratheres from the Cypress hills
to this species. They consist of parts of two lett mandibular rami, and are referred to as
specimens Nos. 1 and 2. The first specimen is a section of a left ramus holding the roots of
the last two molars, and extending back beneath the base of the coronoid ; the fragment is
87mm. long. The second is part of the anterior half of another left ramus, with premolars
3 and 4 preserved, the roots of premolar 2, and the inner end of the alveolus of a procumbent
canine. A figure was given (pl. IV, fig. 2, pt. I of this volume) of this second specimen
viewed from above.

A symphysis of a mandible, also from the Cypress hills, described and figured by Cope
in 1891, under the name Cenopus pumilus, in the same publication as the above, is regarded
by Osborn (op. cit. 1898) as properly referable to A. mite. The second of the two specimens
on which C. pumilus was founded (pt. I, this volume, pl. IV, fig. 4) has been shown by Pro-
fessor Osborn (op. cit. 1898) to be part of the lower jaw of Hyracodon nebrascensis.

In the type ramus from Colorado, described by Cope in 1874, the space occupied by the
first three lower premolars (2, 38 and 4) is 80 mm. as given in the original description. A
similar measurement, taken from the “type lower jaw” (and therefore presumably from the
same specimen), is stated by Osborn (op. cit. p. 139) to be 55 mm. In specimen 2 from the
Cypress hills (A. mite) the three premolars together measure in length 58 mm, and in the
symphysial specimen (C. pumilus) a like measurement gives 43 mm. In one only of the
three Cypress Hills specimens referred to A. mite, are premolar crowns preserved, and in the
type ramus the crowns of the three premolars are imperfect.

A very perfect lower jaw from the Protoceras beds of South Dakota is referred doubt-
fully by Osborn (op. cit. p. 139) to this species. The premolar series in this last specimen
occupies a space of 47 mm.

An upper left third molar tooth, obtained by T. C. Weston at the Cypress Hills locality
in 1884, is probably referable to this species. Its dimensions are :—antero-posterior diameter,
25 mm., transverse diameter 28 mm.

44

A much larger tooth, plate LV, fig. 6, an upper right posterior molar of the 1904 collec-
tion, compares favourably in size and general proportions with the third molar of Leptacera-
therium trigonodon, Osb. and Wort. Its diameters measure, antero-posterior, 31 mm., trans-
verse 37 mm.

ACERATHERIUM OCCIDENTALE (Leidy).

Plate IV, fig. 7.

Rhinoceros occidentalis, Leidy, 1851. Proc. Acad. Nat. Sci. Phila., vol. V. p. 276.

This species is recorded by Cope (this volume, pt. I) froma the Oligocene of the Cypress
hills. A number of lower jaw fragments, belonging both to the collection of 1904 and to the
earlier collections, apparently represent species distinct from A. mite and A. occidentale, but
they are too imperfect for determination.

An inferior left posterior molar (collection of 1904) evidently belongs to this species. In
it the basal cingulum is developed in front and behind but not on the exterior and interior
surfaces. Diameters—antero-posterior 32 mm., transverse 21 mm.

ACERATHERIUM EXIGUUM, Sp. nov.

Plate V, figs. 3, 4 and 5.

A mandibular symphysis, collected by the writer in Bone coulée, Cypress hills, in 1904,
has entirely different proportions to the symphysis (Cwnopus pumilus, Cope) from the same
locality, already referred to A. mite. This specimen consists of almost exactly the same parts
of the jaw preserved in the symphysis of C. pumilus, viz., the anterior end of the left ramus,
and a short length of the right ramus united with it so as to show the extent and form of the
symphysis. No crowns of teeth are preserved, but in the left ramus the roots of premolars 2
and 8 remain. ‘The alveoli for the canine and for one incisor in each ramus are preserved, as
well as the alveolus for premolar 2 in the right ramus, and the anterior half of the alveolus
for premolar 3 in the left.

Comparing it with the symphysial specimen of C. pumilus, the following differences are
apparent :—a narrower and longer symphysis, having increased depth behind ;a more rapid
deepening of the ramus from in front backward, with a corresponding increase in transverse
thickness ; a greater space occupied by the first two premolars; and very much larger canines
as indicated by their alveoli. The greater depth of the ramus beneath the first two premolars
is very noticeable.

In this specimen, belonging to the 1904 collection, the diastema is of about the same
length as that of C, pumilus. .The alveoli for the vanines are 8 mm. apart in front, and close
together at a lower level are those for two incisors, one on each side of the median line.
Premolar 2 was a tooth of fair size with two well separated roots.

A small species of Acerathere, slightly exceeding A. mite (pumilum) in size, is here
represented, to which the name exiguum is given. The jawismore robust than in A. pumilum,
its main characteristics being the contracted and lengthened symphysis and the enlarged
canines.

45
Measurements.

Aceratherium exiguum compared with A. mite (pumilum).
c A. criguum. <A. mite.

MM. MM.
Length of eR oe Sere Ee Bi Seen Iai tos en ea 58 40
Depth in front. . See cg ea Gen un RU RR ue Beaten ono mee Te IAS 18
De pthrioe lain cle cae Cae rennrnyestade rte iat ances ideas need Lae senate, sete rete 26 21
Distancesapurtiotipremolarsy2ir sss c.se rican as ee ttachae «) Mets/aleoersieto =i 27 32
Space occupied by premolars 2 and 3. SAMs malay see aus arate teens teres ste OO) 23
Antero-posterior diameter of premolar 2 Chere Biad SS OEN a cae ete en | a5) 9
Breadth of jaw transversely across alveoli forcaninés’ ee 49 33
Height of alveolus for canine. FAlirs cM ppaRine 1 yee eeeiRe aE H acc engamen 12 7
Width « g teat Geen Etsy eons ee Me LO. 10°5
Depth of ramus below posterior end of diastema..... Aerie rns cisernmee rts AS) 32
Depth “ SO Cee LEM OAT soy sacauane. secreesnay seek oesk a te ees w aie. lov enene suena 46 39

MEGACEROPS ANGUSTIGENIS (Cope).

- Menodus angustigenis, Cope, 1885. Geol. and Nat. Hist. Survey of Canada, vol. I, new
series, part C, appendix I, p. 81.

Haplacodon angustigenis, Cope, 1889. The Vertebrata of the Swift-current river, fale
American Naturalist, vol. X XIII, p. 153.

Menodus angustigenis, Cope, 1891. The species from the Oligocene or Lower Miocene
beds of the Cypress hills; Geol.. Survey of Canada, Contr. to Can. Palont., vol. ITI,
(quarto), pt. I, p. 13, pl. V, figs. 1 and 2, pl. VI, figs. 1, 2, 2a, pl. VII, figs. 1, 1a, 1b,
pl. VIII, figs. 1,2, 3 and figures of leg and foot bones.

Titanotherium angustigenis, Osborn, i896. The Cranial Evolution of Titanotherium, Bulle-
tin Amer. Mus. Nat. Hist., vol. VIII. p. 184.

Megacerops angustigenis, Osborn, 1902. The Four Phyla of Oligocene Titanotheres, idem,
vol. XVI, p. 99.

This species apparently approaches closest to M. coloradensis, Leidy, founded on
coéssified nasals with horns attached. In the Cypress Hills species the horns are much farther
apart, with a flatter surface separating them. Also the nasals, besides being shorter, expand
laterally in front instead of narrowing rapidly as in MW. coloradensis.

Cope, in the American Naturalist, 1889, p. 153, made this species the type of Haplacodon,
a generic term discarded by him in his later writings.

The species, of which the full description with figures is given in part I of this volume,
is based on two maxillary bones from the same individual, a separate left ramus, and the
symphysial part of another jaw. With these were associated, as probably belonging to the
same species, an imperfect cranium, and certain separate leg and foot bones. One of the
maxillary bones, the left ramus, and the nasal bones with horns and part of the frontal, were
figured in plates V, VI, VII and VIII. In plate VI, figure I, a view from above was given
of the codssified nasals shown in side and front view in plate VIII, and belonging to the
cranium mentioned above. Through an error in the explanation of plate VI, these nasals
(fig. 1) were ascribed to Menodus ? americanus, Leidy, instead of to Menodus angustigenis. This
error has been repeated in Professsor H. F. Osborn’s paper ‘‘ The Cranial Evolution of
Titanotherium,” Bull. Amer. Mus. of Nat. Hist., 1896, foot note p. 175.

46

FIG. 1 FIG. 4
x4
FIG. 2

HE
W
Ye

FIG. 6
aN

/ |

Saas i‘ a

(ara

x2 x}

Coissified nasals and horns of Megacerops angustigents as seen from above (fig. 1), from the front (fig. 2), and from the left

side (fig. 3), for comparison with the nasals and horns of Megacerops coloradensis similarly viewed (figs. 4, 5 and 6 after Leidy)}.
One-fourth the natural size. Figs. 1-3 after Cope.

47

MEGACEROPS SELWYNIANUS Cope).

Menodus selwynianus, Cope, 1889. Vertebrata of the Swift-current river, III, American
Naturalist, vol. IIT, p. 628.

Menodus selwynianus, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills; Geol. Survey of Canada, Contr. to Can. Palxont., vol. III (quarto),
pt. I, p. 17, pl. V, figs. 3, 8a and 8b.

Titanotherium selwynianus, Osborn, 1896. The Cranial Evolution of Titanotherium ; Bulletin
Amer. Mus. Nat. Hist., vol. VIII, p. 198.

Megacerops ? selwynianus, Osborn, 1902. The Four Phyla of Oligocene Titanotheres, idem,
vol. XVI, p. 99.

The coossified nasal bones of one individual constitute the type of this species. They
are long and narrow, abruptly rounded in front and bent downward at the sides. Tne lower
surface is deeply excavated in a longitudinal direction. Professor Cope’s full description, with
figures, will be found in part I of this volume.

FIG. 7

IE SS
f
{ )
i

a
xt
FIG. 8

Codssified nasals of Megacerops selwynianus, fig. 7 viewed from above, fig. 8 from the left side. One-fourth the natural size.

48
MEGACEROPS SYCERAS (Cope).

Menodus syceras, Cope, 1889. American Naturalist, vol. X XIII, p. 628.

ss “ Cope, 1891. The species from the Oligocene or Lower Miocene beds of the
Cypress hills; Geol. Survey of Canada, Contr. to Can. Paleont., vol. ITI, (quarto), pt. I,
p. 18, pl. VII, fig. 2, pl. VIII, figs. 4 and 5.

Titanotherium syceras, Osborn, 1896. The Cranial Evolution of Titanotherium ; Bulletin
Amer. Mus. Nat. Hist., vol. VIil, p. 198.

The type material of this species consists of the codssified nasal bones of three individuals,
with a right horn, preserved in one of the gee Cope’s description, with figures,
appeared in part I ‘ot this volume

A separate left horn collected by T. C. Weston in 1884, closely resembles in shape the
right horn with attached nasals, and is assigned to this species. The transverse subangulation
of the surface between the horns, and the basal flattening of the horn on its antero-exterior
surface, are well marked.

FIG. 10

xt

Nasals and horns of Megacerops syceras, fig. 9 viewed from above, fig. 10 from the front, fig. 11 from the right side. One-
fourth the natural size ; figs. 10 and 11, after Cope.

MEGACEROPS PRIMITIVUS, Sp. nov.

Plate VI, figs. 4 and 5.

In 1904 the writer was fortunate in securing, from the Oligocene deposits of the Cypress
hills, a mandible of a Titanothere that is of considerable interest. It is the most perfect
lower jaw obtained so far from this locality, and is the type of the above named species.

The specimen consists of both halves of the jaw. The left ramus is perfect, with the full
number of teeth preserved ; the right ramus lacks the fourth premolar, and the molars, with
that part of the alveolar border that held these teeth.

The mandible is of fair size, and belonged to an adult individual. It presents the follow-
ing dental formula: I;, C;, Py, Mz. There is a diastema behind the canine, a character
which, taken in conjunction with the presence of three incisors and four premolars, is
indicative of a somewhat primitive species. The chief characters displayed are: incisors, in
three pairs,with a space between the inner pair; canines, of small diameter, apparently short ;
a diastema between the canine and the first premolar; first premolar, small; third premolar,
becoming molariform, fourth premolar, molariform; symphysis, long ; symphysial surface
between canines, narrow; jaw contracted at the diastema; external cingula, moderately
developed ; internal cingula, wanting ; mental foramen, beneath the second premolar; coronoid
process, short.

Megacerops avus (Marsh), from the Oligocene of South Dakota, has three pairs of inferior
incisors but only three premolars below on each side, and there is a short diastema behind
the lower canine. Its dimensions are greater than those of M. primitivus. These two
species are apparently the only ones of the Oligocene Titanotheres in which there are three
pairs of incisors in the lower jaw. :

In the Cypress Hills specimen the crowns of the incisors are of a depressed spherical
shape, with a tendency to come to a rounded central point.above. The second incisor is the
largest, and the first is slightly smaller than the third, which is the most upright. The first
is more procumbent than the second. Between the inner pair is a very decided interval,

leaving a space of 6°5 mm. between the crowns of the two teeth The crowns of the canines
12529—7

50

are broken off (that of the right tooth being restored in fig. 5 of plate V1), and the right first
premolar is lost from its alveolus.

Compared with Megacerops angustigenis (Cope), (this volume part I, p. 13, plate V,
fig. 2 and plate VI, figs. 2, 2a, M. primitivus differs in the following respects :— There are
six incisors instead of four, and the breadth of the jaw between the canines, which are of
smaller diameter, is relatively greater; the diastema between the canine and the first premo-
lar is twice as long ; the symphysis is of greater length, reaching back toa point almost in line
with the posterior edge of the fourth premolar (in angustigenis in line with the anterior root
of the corresponding tooth); the exterior cingala are much less developed ; the coronoid
process is shorter. In both species the premolars have reached about the same stage of

development toward the molar pattern, and the molars have very much the same propor-
tions. In angustigenis the internal cingula are partially developed. In primitivus the man-
dible is shorter, proportionately deeper, and not so thick in the neighbourhood of the alve-
olar border posteriorly.

Keeping in mind the differences due to sex in Titanotheres generally, and the apparent
variability, both specific and individual, of certain dental characters, such as the degree of
development of the cingula, the presence or absence of the first premolar, the size of the
canines, and the number of the incisors, M. primitivus is apparently a well marked species,
characterized principally, so far as known at present, by the breadth of the mandible
anteriorly (as compared with MM. augustigenis), and the presence of the full number of teeth,
with a comparatively long diastema behind the canines.

This species, for which the name primitivus is used, is regarded as representing a rather
early stage in the development of the Titanotheres. The general character of the dentition
suggests the appropriateness of referring the species to the genus Megacerops. That the
species is already represented by cranial fragments from the Cypress hills, found separately,
is quite possible, and further material will probably prove the identity of some of the species,
from this locality, described under different names.

Measurements of mandible of M. primitivus.

MM.

ben gthofiramus i occs5 3 hos pt CRE ASO te Eee Pperdant 51/13)

Depth of same at posienoy end of fourth IMO engacossodrodooooa Sd odo. 74

oe SECONG + MOAT 1 5.<. hese gs eis seeders wi Cree Ee 81

is “from tip of coronoid process to lower border.......... afereyNetens 247

Maximum thickness of same beneath third molar... .. oka DLR ae Ae eenae 46

Length of'symphysis. ss. q-q0ceee st oauciusssiae seen sa ciate ee eet 144

Distance apart of inside surface of base of canines*......,,......2005 0-000 31

Leng thiof Sprentolar series sr: S)-s.1 soe oveve.ctesssea ote oer ea cneeniee eS Pacman. lS)

ss MOAT -SELIES Es os ar oe Sih cats Forbes eis ore ee one 183

: : : {antero-posterior =. .1)- cul: ce Soke eerie 18
Diameter of canines at base.. / | ‘PS

| transverse..... PM Sree oo OOo z 16

< hh 9

° : antero-posterlore- 2 cae foe Onn eee 26

Diameter of second premolar... F :

) bLADSVELSE oei.oo enmsha era er eee eet se eet 18

; marc antero-posbeLlOnas scene eee Cee 32

Diameter of third premolar. .. ) P 59

PIM So oan Gamo Dopo Ss BOOS obo BaD Lo

~ 315 ric (cantero-posteniole eee alee ee oe 35

Diameter of fourth** premolar < ° P Orr

)Sitransverse tse ea oe ie a eee 27

*In the mandible of Mf. angustigenis (No. IT) figured by Cope, op. cit., this measurement Is ¢ Aiea 18 mm., Fil in the
symphy sis of the jaw (No. I, also figured) a like measurement given, by the same authority, as 27 mm., should read 22 mm,

* First pre Eanes in Cope’ s description of M. angustigenis.

51

Se : AMIR NOAA wo consoans opoduuccocDO UE 8
Diameter of first molar....... J eae ass
litransvierser jycrscec theta Cran: te na epee eacte erect 29

: NAIK NOMIMOP. gai ndoo odon oube sboeuio” 58
Diameter of second molar... .. J a ¢
IRCEANSVELSEsrunienscteanceecid atm erate tease baaeea rs 33

; : AMTTOR NOS AOO ns ote Gerado sooodom. ogone 82
Diameter of third molar.. : f asa ° BG
WitranSVGrSeue nw pint cea cence cnr re cere ore 39

MEGACEROPS ASSINIBOIENSIS. Nom. prov.

Plate V, fig. 6, and plate VI, fig: 3.

A robust, short, left mandibular ramus, belonging to the 1904 collection, indicates a
species distinct from M. angustigenis and M. primitivus. In this specimen the three molars
and the fourth premolar are preserved, with the roots of the third premolar. The posterior
end of the ramus is missing, as well as the anterior end in advance of the third premolar. A
part of the right ramus next to the symphysis remains.

The jaw is much deeper, thicker and relatively shorter than in angustigenis and primitivus,
and the teeth are much larger than in these species, It is narrow anteriorly, and the symphysis
extends back to a point in line with the division between the fourth premolar and the first
molar. The bone is massive and heavy throughout. The mental foramen is placed beneath
the posterior root of the third premolar, farther back than in M. primitivus.

The cingula are very slightly developed. The external cingulum is present for a short
distance only, on the anterior face of each of the four teeth, and in the third molar in
advance of the heel. The only trace of an internal cingulum is to be seen in the third molar
on the posterior slope of the heel.

The fourth premolar is fully molariform. The teeth are stout, and of about the size of
the corresponding ones in M. marshi, Osborn, but the jaw is relatively shorter than in this
species.

From the material available, the species, for which the provisional name assiniboiensis is
proposed, cannot be definitely characterized.

Measurements of ramus. Type.

MM

Depth of ramus at posterior end of fourth premolar .....,............ 22000. 80
fe ag third Wmolaris.rsqoeca eect aces 156
Thickness of ramus above lower border beneath posterior end of first molar.,.. 55
Vertical thickness of symphysis a little in advance of its posterior termination.. 53
Vertical thickness of symphysis in line with front root of third premolar..... . 31
Space occupied by fourth premolar and the molars,........... 0 ...eesseeeee 260
Diameter of fourth premolar (lanitero=posterionenr sc se= ceca kee aera e orale 41
\itransverse.<t Aor eee ean ae wea mene ceaerneere 31

Diameter onbrctmolae ffantero-posterlormnwiss eee seac eel Renee aor 55
Sikes MEPATISVIEESES Ac. bue RVna uate Os iors arora arene Poet sts 36

Daateoheeccna tiGlane. | LROWNKO TOMO’ hn Soca aubo 1 SeS0b BooDbS gpO> at
GEMMA ase ouGos obo nabens Sou ped bout eblloDe 41

Diameter /ofithird mola Ganbero-posterloniowerugers ee ivers iets ferer rors arte 99
Wael LRA SVETSEyA cies eksk oper am koesy ae Pater ioe ee ae eRe Tas 45

Space occupied by roots of third premolar (antero-posterior)............-+..+5 34

Space between fourth premolars (twice the distance of fourth premolar from
vertical plane through symphysis)........+..........00- potersie ties e-5) sicmeegen OO

52

With the left ramus, above described, is arbitrarily associated, as probably referable to
the same species, the abbreviated coossified nasal bones figured in plate VI, fig. 3, (collection
of 1904). The specimen includes the bases of the horns which are seen to have been placed
far forward and some distance apart. The horns apparently pointed laterally outward and
upward, as in M. angustigenis and M. coloradensis, but were much farther forward than in
either of these species. These nasals are entirely different from those of W. selwynianis, and
M. syceras ; they are short, thick, and broadly obtuse in front where they are but slightly
bent downward. The front and lateral margins are thick and rounded, and the former is
deeply notched in the middle. The lower surface is, as a whole, shallowly concave, a low
longitudinal median ridge marking the line of union of the two bores. The concave surface
between the horn bases is shallowly and evenly curved. The horns at the base appear to
have been longitudinally oval in transverse section, but a definite statement in this regard
cannot be made, as the horn bases are imperfect posteriorly. The specimen is, on the line of
coossification of the two bones, 70 mm. back from the front margin, 44 mm. thick.

The shortness and general robustness of the nasals, with like characters noticeable in the
proportions of the above ramus, makes it appear probable that these specimens represent a
single species.

FIG. 12

a

Coissified nasals of Meyacerops assiniboiensis, fig. 12 superior aspect, fig. 13 left lateral aspect. One-fourth the natural size.

The two species, angustigenis and syceras, have the general form of horn foand in the type
of the genus Wegacerops, viz., M. coloradensis, Leidy. In the other three species frora the
Cypress hills the horns are not known. In tour of the five species, however, the nasals are
known and show a wide variation in shape, all differing from those of the type.

53

A comparison of the nasals and horns of M. coloradensis, with those of Cypress Hills
species, is set forth in the table given below :—

Nasals. Horns.

M. selwynianus. Long and narrow, obtusely rounded Unknown ; probably short.
in front, under surface deeply ex-
cavated, lateral margins produced

downward.

M. angustigenis. - Thick and rather long, expanded Short, far apart, flattened at
antericrly, front margin very ob- base on anterior outer sur-
tusely pointed, under surface face, and cylindrical above,
moderately excavated. directed decidedly outward.

M. coloradensis. Of moderate length, thin and bent Of moderate length, cylindri-
downward anteriorly. cal above, flattened on pos-

terior outer surface at base,
directed obliquely outward
and upward.

M. syceras. Rather short, evenly rounded in Lengthening, close together
front, stout, shallowly excavated and upright, more rounded
beneath. in section near base than in

M. angustigenis.
M. assiniboiensis, Very short and thick, ending square- Placed very far forward and
ly in front,under surface only slight- rather far apart; probably
ly concave. long.

A series seems to be represented here with selwynianus and assiniboiensis as extreme
forms, and coloradensis occupying an intermediate position. Compared with the type species,
selwynianus has long and narrow nasgals, whilst those of assiniboiensis are broad and very
short. In angustigenis the nasals are rather long and the horns short. In syceras the reverse
is the case, the nasals are rather short and the horns are lengthened. Coloradensis has both
nasals and horns of medium length. A lengthening of the horns appears to have accompanied
a shortening of the nasals, and itis probable that selwynianus had short horns and assiniboiensis
long ones. Selwynianus, primitivus and assiniboiensis are, for the present, referred to the
genus Megacerops.

A portion of a right maxilla, holding the second, third and fourth premolars, and a separate
left horn, are mentioned by Cope in the first part of this volume, under the name Menodus
americanus (Leidy), dimensions and figures of the horn being given. Two separate horns,
also belonging to the Cypress Hills collection of 1884, were referred by the same author in
the same publication to Menodus proutii (O. N. and E.). These two species are not determi-
nate, and the specimens referred by Cope to them do uot present characters sufficient for
their identification with described forms. The horns evidently represent two species distinct
from Megucerops angustigenis and M. syceras. It is possible that, with the advent of new
material, they may be found to be assignable to two of the other three species of Megacerops
from the Cypress hills, viz., MW. selwynianus, M. assiniboiensis and M. primitivus,of which the
horns are not known.

54
CHALICOTHERIUM BILOBATUM, Cope.
Plate III, figs. 7, 8 and 9.

Chalicotherium bilobatum, Cope, 1889. The Vertebrata of the Swift-current river, II,
American naturalist, vol. X XIII, p. 151.

Chalicotherium bilobatum, Cope, 1891. The species from the Oligocene or Lower Miocene
of the Cypress hills; Geol. Survey of Canada, Contr. to Can. Palont., vol. ITI,
(quarto), pt. I, p. 8.

The type specimen of this species has been described and figured by Cope in part I of
this volume. It consists of the coossified anterior ends of the mandibular rami, of which the
left is preserved backward a short distance beyond the posterior end of the symphysis, and
displays the alveoli of the second, third and fourth premolars, and of the first molar, with
part of that of the second molar. In advance of the second premolar are the remains of
alveoli for the canine, and three incisors. The bone is here slightly abraded, the alveoli
appearing as distinct but shallow depressions. Of those for the incisors, the first or inner-
most is the largest and deepest, and the third is the least distinct. That for the canine is
narrow transversely and twice as long as wide. A smooth surface to the bone passes out-
ward between the second premolar and the canine, representing a narrow diastema. It is
probable that the canine and incisor teeth were not present in the adult avimal. There
is no indication of a first premolar. The roots of the three premolars are partially preserved.

In his observations on the genus, following the specific description in the American
Naturalist (p. 152), Professor Cope proposed the order Ancylopoda for the reception of the
two genera Chalicotherium and Ancylotherium. These remarks, which do not appear in
the Contributions to Canadian Paleontology, were as follows :—

“« Although this is the first announcement of the discovery of the genus Chalicotherium
in America, it is not the first discovery. Professor Scott showed me a series of superior
molars from the Loup Fork formation of Kansas, from the Agassiz Museum, which he
identified as belonging to this genus. The present species is of larger size than the Kansas
form, and is apparently equal to the C. goldfussi of the Upper Miocene of Europe. The
occurrence of this form in the Lower Miocene (White River), as well as the Upper Miocene
(Loup Fork), of this country, is a noteworthy fact, but is parallel to its history in Europe.
Described from the Upper Miocene by Kaup, it was afterwards found in the Middle Miocene
(C. grande) by Lartet, and in the Upper Eocene (C. modicum) by Gaudry.”

“The remarkable character of this genus, as discovered by Filhol, has been already
mentioned in the Naturalist.* It has little relation to the family of Perissodactyla, to which
it has given the name, and which it so resembles in molar dentition. It must form a family
by itself, and the genera with which it has been associated must form a family to which the
name Lambdotheriidae may be applied. The anterior ungual phalanges of Chalicotherium
are of prehensile character, and not ungulate, but rather unguiculate. The phalanges
resemble those of the Edentata, but the carpus and tarsus are, according to Filhol, diplar-
throus in structure, while the Edentata are taxeopodous. We have in the Chalicotheriidae
the antithesis of the Condylarthra. While the latter is ungulate, with an unguiculate carpus
and tarsus, the former is unguiculate, with an ungulate (diplarthrous) carpus and tarsus.

* “ Osborn on Chalicotherium, 1888, p. 728.”

Thus the Chalicotheriidae must be referred to a distinct order of unguiculate Mammalia,
which I propose to call the Ancylopoda, with the above definition. Two genera belong to
the single family, the Chalicotheriidae, viz., Chalicotherium Kaup, and Ancylotherium
Gaudry. Inthe former, the phalanges are distinct; in the latter, the first and second are
coossified (Lydekker). Marsh has not yet shown how his genus Moropus differs from
Ancylotherium. The species described by Marsh under this name are from the Loup Fork
bed of Kansas.”

A separate lower left premolar of a Chalicotheroid (collection of 1904) is probably referable
to this species. The tooth (plate IiI, figs. 7, 8 and 9) is regarded as the third premolar, and
has an antero-posterior diameter about equal to the space for the corresponding tooth, of which
the roots are preserved, in the above (type) mandible. Professor W. B. Scott, of Princeton
University,has kindly examined this specimen, and, although agreeing with the writer that it
is the lower premolar of a Chalicotheroid, considers it unlikely “ that the genus Chalicotherium
should be found in the Titanotherium beds, for that genus is typical of the Middle and Upper
Miocene of Europe.” He is of the opinion that “much more probably the species of Cope

will prove to be referable to one of the genera of the French Oligocene, such as Schizotherium.”

The Cypress Hills species needs to be studied from better material before its true generic
affinity can be determined.

RODENTIA.

Scrlurus ? SASKATCHEWENSIS, sp. nov.

Plate VIII, figs. 16, 17.

A species of rodent, most nearly allied apparently to Sciwrus, is represented by a molar
tooth. As enough characters are not supplied by the single tooth for the proper definition
of the undescribed genus seemingly indicated, a provisional reference to Sciurus is made for
the present. The species is described as new.

The tooth is apparently an upper left molar. The crown, which is borne on three roots, is
subquadrangular in outline as seen from below, with the antero-posterior diameter slightly
less than the transverse diameter. The maximum antero-posterior measurement (length) is
near the outer side. Of the three roots, one is internal and is much the largest, the other two
are external and subequal. The height of the enamelled surface of the crown is twice as
great internally as externally.

The tooth is only slightly worn. The pattern consists of an external median enamel
inflexion, extending inward nearly across the crown, and two fossettes, one anterior, the other
posterior. The enamel inflexion has a depth greater than half the height of the external face
of the crown but the two fossettes are not so deep. Of these latter, the posterior one is the
larger and is complete, the anterior one is closed outwardly but communicates inwardly with
the median inflexion. A narrow marginal ridge is continuous round the crown except where
it is interrupted by the external enamel inflexion. This ridge is most prominent internally,
anteriorly and posteriorly it sinks to a lower level, rising again to enclose the fossettes
externally.

56

The inner face of the crown is not strongly tumid as in Sciurus typically, but approaches
the marginal ridge as a moderately convex slope, in contrast to the other faces,which contract
toward the base. The anterior cross crest is formed of two distinct cusps, recalling the sub-
division of the crests described by Matthew in Sciurus (Prosciurus) vetustus*. A minute
style occurs in the marginal ridge external to the posterior fossette, breaking the continuity
of the ridge to a slight extent. No style is present at the outlet of the median enamel
inflexion.

From the above description it will be seen that the tooth pattern implies a nearapproach
to Sciurus, but the radical differences apparent preclude its definite reference to that genus.
The comparative prominence of the marginal ridge in front and behind is probably a primitive
character.

Measurements of crown of type specimen :—Antero-posterior, 2°30 mm., transverse
diameter, 2°70 mm.

Locality :—Bone coulée, Cypress hills, Saskatchewan.

Iscuyromys typus, Leidy.

Plate VIII, fig. 18.

A slightly worn molar is referred to this species described, originally, in 1856, from the
Oligocene of Nebraska. The Cypress Hills tooth is apparently a second lower molar from the
right side, and was mentioned in the writer’s preliminary list of species contained in the 1904
collection (Summary Report for 1905) as probably referable to this species. Its tooth pattern
agrees fairly well with that of the corresponding tooth, figured by Leidy, in his “ Extinct
Mammalian Fauna of Dakota and Nebraska,’ 1869, pl. X XVI. In size the Cypress Hills
tooth is slightly smaller. The antero-posterior diameter of the crown measures 3 mm. and is
about equal to the transverse diameter.

Bone coulée, Cypress hills. Collection of 1904.

CYLINDRODON FONTIS, Douglass.
Plate VIII, figs. 19, 20.

Cylindrodon fontis, Douglass, 1901. Fossil Mammalia of the White River beds of Montana ;
Trans. Amer. Philos. Soc, vol. XX, p. 15, pl. IX, figs. 9, 9a.

Cylindrodon fontis, Matthew, 1903. The Fauna of the Titanotherium beds at Pipestone
Springs, Montana; Bulletin Amer. Mus. Nat. Hist., vol. XIX, article VI, p. 212, figs.
7 and 8 A, B,C, D.

Douglass established this genus and species on two parts of right mandibular rami, with
well worn teeth, from the Pipestone beds (Oligocene),near Pipestone Springs, in south-western
Montana. The variation of the tooth-pattern through wear has been worked out by Matthew
from a series of lower jaws, and an upper jaw, from the same locality.

In the writer’s provisional list of the fauna of the Oligocene beds of Cypress hills, as
represented by the collection of 1904, part of a left mandibular ramus was referred to a species
of Steneofiber distinct from S. nebrascensis, Leidy, This specimen is now seen to be properly
referable to Cylindrodon fontis, Douglass.

* The Fauna of the Titanotherium beds at Pipestone Springs, Montana, 1903.

57

The Cypress Hills fragment of lower jaw is from the middle of the left ramus, and holds
one tooth, the first molar. Anterior to the tooth is part of the alveolus for the fourth pre-
molar, and behind it thealveolus for the second molar, and the remains of that for the posterior
or third molar. The tooth is only moderately worn, and has reached the stage of wear shown
by Matthew in his figure 8 B. Of the three fossettes in the worn surface of the crown, the
anterior one is closed internally, a slight inflexion of the enamel remains to the posterior one,
but there is still a very decided inflexion to the median one. When further worn the
posterior fossette becomes complete internally, and later the median one also. The crown
of this molar measures, antero-posteriorly 2°25 mm., transversely 2°20 mm. The full depth
of the ramus is not preserved, but enough of the bone remains to show that the jaw was deep.

Matthew places the species with some doubt in the Castoridx. It is interesting to find
this small species included in the 1904 collection, thereby adding to the number of species
common to the faunas of the Cypress Hills and Pipestone Springs Oligocene beds.

Locality :—Bone coulée, Cypress hills, Province of Saskatchewan.

EvutypoMys PARVUS, Sp. noy.

Plate VI, figs. 1 and 2.

A single molar represents this species. In the Summary Report of the Geological
' Survey for the year 1904, the writer specially mentioned this tooth as being worthy of notice
on account of the large number of isolated enamel loops or lakes present in the worn sur-
tace of the crown, and in a foot-note, added whilst the report was being printed, the opinion
was expressed that it was probably referable to Matthew’s then newly established genus
EHutypomys.

The Cypress Hills tooth, thought to be she lower third molar of the left side of the jaw,
closely resembles, in tooth pattern, the teeth of H. thomsoni, Matthew, the type species of
the genus* from the Oligocene (Lower Oreodon beds of the White River formation, Cheyenne
river) of South Dakota. It is considerably smaller than the lower teeth of the type, and indi-
cates a proportionately smaller animal.

Seen from above the crown is subtriangular in outline, the transverse diameter in front
being greater than behind; the antero-posterior diameter exceeds the maximum transverse
diameter. A view of the worn surface of the crown is given in plate VI, figure 2, in which are
shown the numerous isolated lakes characteristic of the genus. In all about twenty lakes are
seen. The tooth is constricted behind its mid-length exteriorly, the crown being well rounded
and tumid on each side of the constriction or valley, in which are three or four shallow infold-
ings of the enamel below the level of the worn surface. On the inside, at mid-length, the
crown is slightly inflected above, but the decided constriction of the external surface is want-
ing. The tooth is two rooted, the anterior fang being much the stouter of the two. The
anterior surface of the crown is flattened, and has the appearance of having been preceded
by a tooth in front. Posteriorly, however, the surface is rounded, as if no tooth pressed
against it from behind; these considerations, together with the somewhat triangular shape
of the tooth, suggest its being the last of the series.

*Notice of two new ’genera of Mammals from the Oligocene of South Dakota; Bulletin Amer. Mus. Nat. Hist., vol.
XXI, p. 21.

12529—8

58

Measurements of type specimen.

MM
Motaléhershtyofstoothyposteriorlyares yesh reer ia at Renan Jen tine2S
iHleichtiokicrownspostenior lives escer crite ee eet nee ee ace re eereeees 16
Antero-posterion diameter of Crows ce).ettte | sie ssn yes iene ache is eee eae
JAmnteriorsbransyv.erse diameter, Of Crown 4. nes cent ctesie se tact ae eerie 23
OSberioratransvierse diameter Ofacrow eer und eee ee eee ike rene 18

PaLXOLAGUS TURGIDUS, Cope.

A left mandibular ramus from the Cypress hills was referred by Cope, in 1891 (part I,
this volume, p. 5, pl. XIV, figs. 9, 9a), to this species. The specimen lacks the upper part
of the anterior lobe of P; and the upper end of the incisor. The posterior molar is missing,
but its approximate size is given by its alveolus. The other lower teeth are perfect.

Comparing the specimen with the rami of this species figured by Cope, in his “ Tertiary
Vertebrata,” 1884, pl. LX. VII, it is seen that the space occupied by the molar-premolar series
is slightly greater, but the depth of the jaw is the same, as is also the size of the diastema
behind the incisor. The teeth appear to have the same relative size to each other, and the
internal enamel inflexion, apparently, has a like development. Matthew has placed this
specimen, described by Cope in 1891, in his species P. brachyodon (op. cit., 1903, p. 217)
which is of the size of P. turgidus, but differs from it, as the name implies, by being more
brachyodont. Other characters ascribed to P. brachyodon as distinguishing it from P. tur-
gidus are P* smaller and more conical, m* apparently larger, the internal enamel inflexion
less persistent. In lower jaw P; shorter, more conical, and the inflexion disappearing earlier
than in P. turgidus. These distinguishing characters are not apparent, to the writer, in the
Cypress Hills specimen, which is here left under Cope’s name.

Measurements of Cypress Hills specimen

MM.
Molar=premolar' series! 32-075 2 acrsieweet.fantcract Gls Sets lei ore Qtoke by Rise teereeeene 18-0
Third premolar :
Antero-posterior diameter,” . 2). assess cle functors eee eens See 3° 4
Transverse HG, VRrUebIS o. ontaiamORea are En orbs aa Schana co 2-4
Height above alveolar rim...... ..... D+
Posterior molar :
‘Antero;posterior diameter. -).<).4 shes eee os sede oe eee 2°8
Transverse Hee LE aackolae @ roe BGs Isdoe ote bod sono oUDH OO OnS 2
Wength’ of diastema, behindlincison 2 v.15... 4/2 se eee eee nee sal 222
Depthvot ramussbeneathwbz... 1 cee ae te eee ener Te irnn aeons: MS

PALHOLAGUS HAYDENI, Leidy.
Plate VITI, figs. 21-25.

Another speciesof Palwolagus, distinct trom the preceding, is represented by teeth, from
both jaws, included in the collection of 1904. These teeth agree in size with those of P.
haydeni, the type species of the genus (Oligocene {White River) of Nebraska, South Dakota,
&c.), established by Leidy in 1856; they are tor the present referred to that species. On
plate VIII, are figured three of these teeth, an upper premolar, an upper molar, and a
lower molar, from which the following measurements are taken :—

a9

Measurements. :
MM

Upper left premolar, ? fourth premolar (plate VIII, figs. 22 and 23) :—
Antero-posterior diameter of grinding surface......................0-- 2°0
Dransverse diameter of grinding, surface. 2. ...-2...... sees es sees sens 2°8

Upper right molar, ? first molar (plate VIII, fig. 21) :—

Antero-posterior diameter of grinding surface......,.... .......+..--- 2-0
dransverseidiameteron orindingsurfacem ace oer aces eee 2°6

Lower right molar (plate VIII, figs. 24 and 25) :—
Antero-posterior diameter of tooth above..............1.--++--+202++25 2°
Transverse diameter of anterior lobe above........... 0.002000 eee ee eee 2

bo ew

It is likely that more than two species of Palwolagus are represented from the Cypress
hills) Among the separate teeth, obtained in 1904, are a number of incisors of rodents,
some of which are probably referable to Palaolagus.

CARNIVORA.

Hynopon crvgntus, Leidy.

Plate VII, 1, 2 and 8.
Hycenodon cruentus, Leidy, 1853. Proc. Acad. Nat. Sci., Phila., vol. VI, p. 392.

#6 sé Leidy, 1869. The extinct mammalian fauna of Dakota and Nebraska ;
Jour, Acad. Nat. Sci. Phila., second series, vol. VII, pp. 47 and 369, pl. V, figs. 10, 11.

The anterior half of a left mandibular ramus is referred to this species, and represents
the second member of the Hyzenodontids to be recorded from this locality, the first being
Hemipsalodon grandis described by Cope.

This specimen shows the alveoli of the canine, of the four premolars, and of the first
molar ; the roots of these teeth, with the exception of those of the canine and first premolar,
being preserved. The alveolus of the canine indicates that the tooth was of large size,
directed well upward, and oval in transverse section, with its greatest diameter in an antero-
posterior direction. The first premolar, as shown by its alveolus, was single rooted, and
followed closely behind the canine. The roots of the first and second premolars passed down-
ward obliquely backward, those of the third and fourth as obliquely forward. The first molar
was of small size, its antero-posterior diameter being about equal to that of the second pre-
molar.

Although the crowns of the teeth are missing in the Cypress Hills specimen, it is appa-
rently properly referable to H. cruentus, Leidy, from the Oligocene of South Dakota and
Colorado, judging from its size and general proportions, and the relative spaces occupied by
the teeth, in comparison with the published figures of Leidy and Scott.

The anterior end of the specimen, inside the alveolus for the canine,is broken away,
and no trace of the alveoli for the incisors is preserved. Following the plane of the
symphysis forward, however, it is seen that there could have been little room for the incisors,
which must have been crowded. At the symphysis a small piece of bone, belonging to the
right ramus, remains attached to the specimen, and, along the line of junction, indicates a

60

rather thorough coodssification of the two rami. The hinder end of the symphysis is in line
with the front root of the third premolar. Two mental foramina are present, the larger of
the two beneath the anterior root of the third premolar, the other beneath a point slightly in
advance of the second premolar.

Measurements.
MM
hen'gth of specimens 2s ant saci aeiosiain cies Sena aes ete Se eee eee 89
Wensthrof premolariseriess 3h.) 4)sj- A ciel cae cosy esas ieee ee Ge ee nee 54
fowl Stepremolark cramer ccm aheiear eee 4
2nd Sn Sofia die Soo aha acs Ses i hoes EE EER: 11
Length of alveolar space of - 3rd Lente PRESSE CA ai FRR Henao Kern rib role 60 15°5
4th Oe selesrak Slee Surammcnitennst sachet rene ar eater . 16
Uistimolar .2cuestie motel, S Stee Re oe IS 11
Antero-posterior diameter of alveolus of canine......... .....+.-+.ee eee vee 10
Transverse diameter of same, approx ...... gd apc ani com = toga ca aes eee 7
Space between alveoli of canine and Ist premolar. Set er oe Sona TG erarel tee p18 0.6 3
& fe SS shrandy2ndi premolars... ee eer Rinetey Ese OO)
Depth of ramus at point between 4th premolar and Ist molar.............. +. 934
Depth of ramus at mid-height beneath same point ..:.........-. 0.2022 ee eee 12
Thickness of ramus at posterior end of symphysis .............. ALMA ecaaee ee

Collector T. C. Weston. Headwaters of Swift-current creek (Bone coulée), Cypress hills, 1888.

A left lower tooth, found separately in 1904, plate VII, fig. 3, has the proportions of the
second premolar of Hy«nodon. The alveoli (containing roots) of the second premolar of the
left ramus, mentioned sbove and referred to H. cruentus, indicate by their size that this separate
tooth is probably referable to this species.

Hymnopon cructans? Leidy.
Plate VII, figs. 4, 5 and 6.
Hycnodon crucians, Leidy, 1853. Proe. Acad. Nat. Sci. Phila., vol. VI, p. 393.

A second species of Hy«nodon is represented by a superior left fourth premolar (collec-
tion of 1904). The tooth is not quite as large as the corresponding premolar of H. crucians,
as described and figured by Leidy in 1869 in “The Extinct Mammalian Faura of Dakota and
Nebraska” *, but approaches closely to it in shape ; it is referred to this species provisionally.

In the Cypress Hills tooth the protocone is large and compressed, the tritocone (posterior
cusp) is small and slightly trenchant, the deuterocone (interior cusp) is fairly developed on
the inner side in line with the protocone. There is an inconspicuons protostyle (anterior
basal cusp) and exteriorly, at the mid-length of the crown, the basal cingulum is feebly
developed. - ;

Measurements.

MM.

Max. height of crown of tooth 7.1.90) esi et cem ore Son aye epet aoe 8 2
length us SON te hs Shea se pany en BRN Ie Seen eho Sela Oe ee OBNIG

t breadth “ 6 “ 7:8

The specimen represents a species of about the same size as H. ecrucians, Leidy, but
possibly distinct. ;

* The extinct mammi ain un fauna of Dak <ota and N Nebraska. Jour. Acad. Nat. Sci. Phila., second series, vol. VII, pp. 48 and
369, p

61

HT[EMIPSALODON GRANDIS, Cope.

Plate VII, figs. 7 and 8.

Hemipsalodon grandis, Cope, 1885. The White River beds of Swift-current river, North
West Territory, American Naturalist, vol. XIX, p.163; and Geol. and Nat. Hist. Survey
of Canada, vol. I, new series, part C, 1885, appendix I, p. 80.

Hemipsalodon grandis, Cope, 1891. The species from the Oligocene or Lower Miocene beds
of the Cypress hills; Geol. Survey of Canada, Contr. to Can. Palzont., vol. III (quarto),
pt. I, p. 6, pl. IL.

The material on which this genus and species were established consists of a right mandi-
bular ramus, a complete and well preserved right femur, and a left femur, of slightly smaller
size, from which the distal end is missing. Cope’s full description, with figures, is given in
part I of this volume.

Hemipsalodon is the representative, in North America, of the European Upper Eocene
Pterodon. It differs from the latier in the form of the enlarged posterior lower true molar.

Among the characters of H. grandis, which is the largest of all known creodonts, are to
be noticed the great depth of the mandible,the length of the symphysis, and the immense size
of the canine, which so crowds the incisors that the second of these teeth is behind the other
two. The symphysis reaches back to a point nearly below the middle of the fourth premolar.

Through an error, in printing probably, the length of the premolar seriesis given, in the
description on p. 6, of part I, of this volume, as 108 mm. This measurement should read
87 mm.

In the 1904 collection from the typical locality is a large canine tooth, plate VII, figs. 7
and 8, that apparently belongs to this species. Its dimensions, at the point of greatest thick.
ness, agree with those of the canine in the type specimen. In this separate tooth the upper
part of the crown is broken off, but the whole of the root is preserved, giving a length to the
specimen of 111 mm., with an estimated total length to the tooth, when perfect, of about
129 mm.

CYNODICTIS LIPPINCOTTIANUS (Cope).

Plate VII, figs. 9-14.

There are in the collection of 1904 four teeth that apparently belong to this species, of
which Cope was uncertain as to whether it was distinct from, or only a large variety of C.
gregarius (Cope), one of the commonest of the White River (Oligocene) carnivores described
from Colorado, Nebraska and South Dakota.

The teeth from the Cypress hills were obtained separately, and agree in size most closely
with those described by Cope under the name G'alecynus lippincottianus (see Cope’s Tertiary
Vertebrata, vol. III, book I, 1884, p. 919, pl. LXVila). They are, a left lower third pre-
molar, a left lower fourth premolar, and a right lower first molar of which the anterior cusp
is missing. Another tooth, slightly damaged, from the left side, is apparently a lower fourth
premolar.

62
DaPHZNUS FELINUS, Scott.
Plate VII, figs. 15 and 16.

Daphenus felinus, Scott, 1898. Notes on the Canide of the White River Oligocene ;
Trans. Amer. Philos. Soc., vol. XIX, p. 361.

The hinder part of a right maxilla, in which is preserved the sectorial tooth, is referred
to this species with a certain amoant of doubt. The specimen includes the alveoli of the
third premolar and of the three molars.

In his “Oligocene Canidi,’”’ Hatcher* has made known the complete dentition of this
species, from excellent material from the Oreodon beds of Bad Lands creek, Sioux county,
Nebraska. In comparing the dentition of the Cypress Hills specimen, so far as its incom-
pleteness will admit, with that of the species as set forth by Hatcher in his description and
figures (plates XIV and XVI) it is seen that there isa fair agreement in the size of the
sectorial (fourth premolar), and the space occupied by the teeth from the third premolar to
the second molar, both inclusive, is almost the same, giving about a corresponding size to the
third premolar,and the first and second molar teeth. A ciearencel is noted in the position of the
alveolus of the third molar, which is placed farther outward in the Canadian specimen, being
in line rather with the exterior borders of the first and second molars than with the inner
margins of the same as shown by Hatcher. The alveolus of the third molar is very close
to the hinder berder of the second molar, and indicates a greater crowding of these teeth,
with a probably smaller antero-posterior diameter to the second molar. There seems also to
have been a greater backward obliquity to the outer border of the second molar. In the
sectorial tooth of the Cypress Hills specimen the antero-internal cusp (deuterocone) is longer
and narrower, and is directed more forward, so as to form with the base of the external cone
a decided fork, into which the posterior border of the third premolar fitted closely. The
deuterocone has a slightly convex upper surface (within the cingulum),on which is developed
a distinct longitudinal median ridge. The antero-external cone (protocone) and the posterior
cone (tritocone) apparently agree well with the corresponding parts of the sectorial of the
Nebraska skull. A basal cingulum is present; it is moderately developed internally, and
includes the anterior border of the deuterocone, but is rather weak externally.

Hatcher (op. cit., p. 67) has drawn attention to the difference in the position of the upper
third molar relative to the two preceding molars in the genera Amphicyon and Daphenus,
His remarks appeared as follows :—* The chief generic distinctions between Daphwnus, Leidy,
and Amphicyon, Lartet, in so far as they are at present known, are to be found in the relative
size of the premolars, structure of canines, and position of the superior third tubercular molar.
The canines of Daphenus are without either anterior or posterior cutting edges, while these
are present in Amjhicyon. The premolars are reduced in size in Amphicyon, while those of
Daphenus show little or no reduction. In Daphenus the superior third tubercular molar is
pushed inward and aligned with the internal cones of the preceding molars, while in
Amphicyon this tooth occupies a more external position.”

In the Cypress Hills specimen (1) the canine is not preserved, so that a comparison cannot
be made in this connexion, (2) the fourth premolar at least is not reduced in size (Daphanus)
and (8) the third molar is in line with the external cones of the preceding molar (Amphicyon).

Memoirs of the Carnegie Museum, Pitts ina eh, vol. ik No. 2 Sept., 1902.

63

From this it appears that the Canadian specimen combines characters that, according to
Hatcher, belong to both of the above genera.

The Cypress Hills specimen represents an animal of about the size of D. felinus, and it is
provisionally referred to that species, although there is not an exact agreement in the form of
the sectorial, and although a difference is noticed in the alignment of the molars. The
incompleteness of the specimen precludes a satisfactory comparison.

Locality :—eastern escarpment of the Cypress hills, nine miles due east of Bone coulée.
Lawrence Lambe, 1904.

PROTEMNOCYON HARTSHORNIANUS (Cope).

Plate VII, figs. 17, 18, 19 and 20.

A left upper fourth premolar (sectorial), belonging to the collection of 1904, is referred to
this species. The tooth, from which the inner anterior cusp (deuterocone) has been broken
off, is well worn, and probably belonged to an old individual.

This species is known from rather meagre material from the Oligocene of Colorado and
South Dakota. Cope has referred to his species Amphicyon har/shornianus* certain fragments
of jaws, holding teeth, that Leidy,in his memoir on “‘ The Extinct Mammalian Fauna of Dakota
and Nebraska,” 1869, included in his description of Amphicyon vetus (p. 32. pl. I, figs. 8, 4 and
6). The superior sectoriai, obtained in 1904 from the Cypress hills, agrees very closely in size
and form (without considering the inner anterior cusp which is missing in our specimen) with
the sectorial shown.by Leidy in his figure 6.

A second upper sectorial, also from the left side, obtained from the Cypress Hills locality
by Mr. T. C. Weston in 1884, may belong to this species. It isslightly smaller than the 1904
specimen but is otherwise very similar. The protocone is robust and has a broad anterior
face ; posteriorly it narrows to a sharp, steep edge directed obliquely inward. The tritoeone
is compressed laterally and forms a good cutting edge. The deuterocone is of fair size and
is well detached from the base of the protocone. A distinct cingulum encircles the entire base
of the crown. The posterior root is laterally compressed, its antero-posterior diameter proxi-
mally greatly exceeding the transverse one. The root supporting the deuterocone is likewise
compressed, but to a less extent.

Measurements.

cy

MM
Sectorial of 1884; plate VII, figs. 18, 19 and 20:
Length from posterior end to antero-external base of protocone.............. 12:5
Length from posterior end to antero-internal base of protocone.............. 13:0
Breadth anteriorly, avsbase of protocone.. cs .c- ew ess onesies ee ase
iWeightyot protocone, includiney cingulum), 205.0 \.qs gee. ss actenee ease 8-5
Sectorial of 1904 ; plate VII, fig. 17 :—
ibxbermalelenethinsrqg. crane eucrsterr s Maw OUGhOo Hons onooots deadananed: uel)
Internal glenathiesrceespccn ope eect coos meno ate eee Sines Pic g eee ts eens 13°6
iBreadtheanteniorlysiac actis« sas tenis tur titties Sater waive ie serenade wate STs 7-2
Breadthvanteriorly atsbase of. protocone.y.. «.....55 00. sods s-eeeee 0nd
Height of protocone, including cingulum . 8-2

*1884. The Vertebrata of the Tertiary Formations of the West. Report U. 8, Geol, Survey Terrs., vol. IIT, p. 783,

64

According to Hatcher, Daphenus hartshornianus is properly referable to his genus Pro-
temnocyon,* founded on excellent material from the Oligocene deposits of Hat Creek basin,
Sioux county, Nebraska.

Dintctis FELINA, Leidy.

Plate VII, figs. 21, 22, 23 and 24.
Dinictis felina, Leidy, 1856. Proc. Acad. Nat. Sci. Phila., vol. VIII, p. 91.

as “ Leidy, 1869. The extinct mammalian fauna of Dakota and Nebraska ;
Jour. Acad. Nat. Sci. Phila., vol. VII, pp. 64and 368, pl. V, figs. 1-4.

A right lower first molar,belonging to the 1904 collection, is referred to this species.
The three figures of it in plate VII will give a fair idea of its proportions. The two large
cusps, the principal one and the smaller anterior one, together form an admirable cutting
edge. The posterior cusp or heel is well developed, trenchant and larger than the heel of
the corresponding tooth in Hoplophoneus. A small postero-internal cusp is present, high on
the posterior border of the principal cusp, There is also a very small anterior basal cusp
or tubercle. The tooth has not been subjected to much wear, and its cutting edges are,
throughout, slightly denticulated.

Another tooth, fig 24, an upper canine, probably also belongs to this species. It curves
slightly backward and ends below in a moderately sharp point. In transverse section above
it is narrowly elliptical. The posterior border is denticulated and sharper than the anterior
one on which no denticles are seen. The surface of the specimen is weathered. Length
(imperfect above), 28°5 mm.; max. antero-posterior diameter, 14 mm.; max. transverse
diameter, 8 mm.

* Oligocene Canide. Memoirs of the Carnegie Museum, vol. I, 1902, p. 104.

LIND OX

Pace.
ILATROCINOHOIN Sea nano sO sp Ne Con Sooe orn De 5
Amia whiteavesiana, Cope .. ............ 12
Amia macrospondyla, Cope........... 12
PATI UORCLULUSHES Dis ON meets ste att 12
Lepidosteus longus, sp. nOV..........-..4.- 13
Rhaneastes rhwas, Cope... ......,....+..- 14
Amiurus cancellatus, Cope. ............-. 15
Amiurus maconn«lli, Cope.......- : 16
Anostetra ornata? Leidy. ..............- 17
Stylemys nebrascensis, Leidy. ............. 18
Testudo exornata, Lambe...... .........- 18
Trionyx leucopotamicus, Cope.........-- i)
Peltosaurus granulosus, Cope......-....-. 19
Ogmophis compactus, sp. NOV............--- 20
Crocodilus prenasalis? Loomis............ 21
Didelphys valens, sp. nov................. 22
Ancodus brachyrhynchus, Osborn and Wort-
MNEs cco pod0 nubu ecu Oooo D oe BHO m ae 24
Anthracotherium? pygmeum, sp. nov...... 25
Llotherium coarctatum, Cope.............. 26
Agriocherus antiquus, Leidy.............. 28
Merychoidodon culbertsoni, Leidy.. ....... 29
Poébrotherium wilson, Leidy...... . 30
Leptomeryx esulcatus, Cope..............-. 30
Leptomeryx mammifer, Cope..... 30
Leptomeryx speciosus, Sp. NOV.....-....-.5. 3]
Leptomeryx semicinctus, Cope.......... 2... 32
Hypertragulus transversus, Cope.... ....-. 32
Mesohippus westoni, (Cope) ..........-.. 33
Mesohippus preecocidens, Lambe.. .... . 34
Mesohippus propinquus, Lambe............ 35

Pace.

Mesohippus brachystylus, Osborn,.......-. 36
Mesohippus stenolophus, Lambe... ........- 36
Mesohippus planidens, Lambe... ........-- 37
Mesohippus assiniboiensis, Lambe ...... 37
Hyracodon nebrascensis, Leidy.......-..-- 39
Hyracodon priscidens, Lambe..........-.-. 39
Acerathertum mite, Cope..............-.. 43
Aceratherium occidentalie, (Leidy).... . 44
Aceratherium exiguum, sp. nov......:..... 44
Leptaceratherium trigonodon, Osborn and

Wiortimamtsa cto waters cicitenced ec 44
Megacerops angustigenis, (Cope)..... ....-. 45
Megacerops selwwynianus, (Cope) .... ...... 47
Megacerops syceras, (Cope). .... ....+-.-.> 48
Megacerops primitivus, sp. MOV...........- 49
Megacerops assiniboiensis, nom. prov.......- 51
Chalicotherium bilobatum, Cope..........-. 54
Sciurus ? saskatchewensis, sp. NOV.........- 55
Ischyromys typus, Weidy. ............--.- 56
Cylindrodon fontis, Douglass............-- 56
Eutypomys parvus, Sp. NOV...........1---- 57
Paleolagus turgidus, Cope ..........-- SaaS
Paleolagus haydent, Leidy...............-- 58
Hycenodon cruentus, Leidy. .............. 59
Hywnodon crucians, Leidy..............- 60
Hemipsalodon grandis, (Cope) ........---- 61
Cynodictis lippincottianus, (Cope)..... ..-. 61
Daphenus felinus, Scott...............-. 62
Protemnocyon hartshornianus, (Cope) ...... 63
Deans hse, ILC 53355460 Jono ko05 GbE 64

PwAYT EE:

gq" de 0g" 08 08" 0g 0G

.

PLATE I.*

Amia exilis, Lambe ; dorsal vertebral centrum, articular face. Type. Page 12.
The same specimen from above.
Lateral view of the same.
Amia exilis, Lambe ; basi-occipital, superior aspect.
The same bone, viewed from below.
The same, posterior view.
Lepidosteus longus, Lambe; vertebral centrum, superior view. Type. Page 13.
The same centrum, inferior view.
The same, lateral view.
Rhineastes rheas, Cope; pectoral spine collected by Mr. T. C. Weston, inner view.
Page 14.
11. Same specimen, outer view.
12. Same specimen, view from above.
13. ? Rhineastes rheas, Cope ; fragment from distal end of spine
14. Rhineastes rheas, Cope; dorsal spine, anterior view.
15. The same, posterior view.
16. The same, lateral view.
17. Anosteira ornata, Leidy ; marginal plate from the right side of the carapace, seen
from above. Page 17.
g. 18. The same plate viewed from below.
19. End view of the same.
. 20. Testudo exornata, I.ambe; distal half of left fifth costal plate, upper surface. Type.
Page 18.
21. Testudo exornata, Lambe: proximal end of left sixth costal plate, upper surface.

.

SPaANDoe RWW

—

22. Testudo exornata, Lambe; proximal end of left first costal plate, upper surface.

23. Peltosaurus granulosus, Cope; part of left dentary, interior view. Page 19.

24. Peltosaurus granulosus, Cope; posterior half of right maxilla, interior view.

25. ? Peltosaurus granulosus, Cope: dermal scute, upper surface ; twice the natural size.

26. Ogmophis compactus, Lambe; dorsal vertebra, superior aspect ; twice the natural
size. Type. Page 20.

27. The same, anterior aspect ; similarly enlarged.

28. The same, posterior.aspect ; similarly enlarged.

29. The same, from below; similarly enlarged.

30. The same, right lateral view; similarly enlarged.

In this and the following seven plates all the figures are of natural size unless otherwise stated.

I.

PEATE

GEOLOGICAL SURVEY OF CANADA.

/
s

\

L.M.LAMBE, Delt.

PLATE IT.

=

JS 0Q UG Dg OG

Fig.

So & go po

Senn

PLATE Ii.

Ancodus brachyrhynchus, Osb. and Wort.; right upper third molar, viewed from
below. Page 24.

Ancodus brachyrhynchus ?, Osb. and Wort. ; left upper third premolar, external view.

The same tooth viewed from below.

Ancodus brachyrhynchus ? Osb. and Wort. ; right lower canine, viewed from within.

The same tooth, viewed from without.

Ancodus brachyrhynchus ? Osb. and Wort. ; right lower third incisor, exterior view.

The same tooth, interior view.

Ancolus brachyrhynchus? Osb. and Wort.; left lower first incisor; exterior view.

The same, seen from within.

Elotherium coarclatum, Cope; right upper first molar, viewed from below. Page 26.

Elotherium coarctatum, Cope; right upper third molar, as viewed trom below.

Elotherium coarctatum ? Cope; right upper third premolar, outer aspect.

Same tooth, seen from below.

Elotherium coaretatum ? Cope; right upper fourth premolar, inner aspect.

The same specimen, viewed from below

Agriocharus antiquus? Leidy; left upper third molar, crown view from below.

Page 28.

Agriochwrus antiquus 2? Leidy ; left upper third molar, viewed from below.

Merycoidodon culbertsoni, Leidy; left lower first premolar (caniniform), outer
aspect. Page 29.

The same as seen from within.

Merycoidodon culbertsoni, Leidy ; left upper canine, inner aspect.

The same tooth, posterior aspect.

Outline of transverse section of same at a.

Outline of transverse section at 6.

Merycoidodon culbertsoni, Leidy ; right lower second molar, inner view.

The same tooth, viewed from without.

The same, viewed from above.
Abbreviations for cusps, ete., as in plate ITI.

GEOLOGICAL SURVEY OF CANADA.

72S.

PLATE

L.M.LAMBE, Delt.

Je eI RI JEIEIL,

WE TR 9 pe

SOB CO

PLATE III.

Elotherium sp.; incisor, lateral view. Collection of 1889. Page 28.

The same tooth, inner aspect.

Elotherium sp.; incisor, lateral view. Collection of 1904.

The same tooth, inner aspect.

EHlotherium sp.; incisor, inner view. Collection of 1904.

Same specimen, viewed from without.

Chalicotherium bilobatum, Cope; left lower third premolar, viewed from above.
Page 54.

The same tooth, inner aspect.

The same, outer aspect.

Mesohippus westoni, Cope; right upper second molar, viewed from below ; twice
the natural size. Page 33.

The same tooth, exterior aspect ; twice the natural size.

The same, inner aspect; similarly enlarged.

The same, anterior aspect ; similarly enlarged.

Mesohippus precocidens, Lambe; left upper molar, as seen from below. Type.
Page 34.

Mesohippus propinquus, Lambe; left upper second molar, viewed from below.
Type. Page 35. :

Mesohippus propinquus, Lambe ; right upper second premolar, viewed from below.

Mesohippus brachystylus, Osborn; left upper fourth premolar, as seen from below.
Page 386.

Mesohippus stenolophus, Lambe; right upper third molar, viewed from below.
Type. Page 36.

The same tooth, anterior aspect.

The same tooth, outer aspect.

Mesohippus planidens, Lambe; left upper first and second molars, seen from below.
Type. Page 37.

Mesohippus assiniboiensis, Lambe; right upper second premolar, viewed from
below. Type. Page 37.

The same tooth, outer aspect.

The same tooth, posterior aspect.

pa., paracone; me., metacone; pr., protocone; hy., hypocone; pl., protoconule ;

ml., metaconule ; ps., parastyle ; ms., mesostyle; mts., metastyle; d., deuterocone; fe., tetar-
tocone ; ?r., tritocone.

GEOLOGICAL SURVEY OF CANADA.

PLAT

m

L.M.LAMBE, Delt

ae Ae ve.

12529—10

—

PLATE IV.

Hyracodon priscidens, Lambe; left maxilla with premolar and molar teeth. Type.
Page 39.

The same specimen, outer aspect.

Hyracodon priscidens, Lambe ; anterior end of mandible, outer view from the left.

The same specimen, seen from above.

Aceratherium mite, Cope; left upper third molar, seen from below. Page 43.

? Leptaceratherium trigonodon, Osb. and Wort.; right upper third molar, as seen
from below. Page 44.

Aceratherium occidentale (Leidy) ; left lower third molar, view from above. Page 44.

pr., protocone ; d., deuterocone; ¢r., tritocone; ¢e., tetartocone; ¢., canine; Ps, second
premolar.

GEOLOGICAL SURVEY OF CANADA. PLATE IV.

L.M.LAMBE, Delt.

PATH Vv:

jor)

PLATE. V.

Aceratherium sp.; left upper first premolar, outer aspect. Cypress hills, 1904.

The same tooth, viewed from below.

Aceratherium exiguum, Lambe ; anterior end of mandible, left outer aspect. Type.
Page 44.

The same specimen viewed from above.

The same specimen viewed from the front.

Megacerops assiniboiensis, Lambe; left mandibular ramus, outer aspect; one-half
the natural size. Type. Page 51.

c., canine ; 7., incisor ; P2, second premolar.

PLATE V.

GEOLOGICAL SURVEY OF CANADA.

TRS FSR erent

L.M.LAMBE,, Delt

Jed SAN i ae WE,

PANN eivale

Hutypomys parvus, Lambe ; left lower third molar, as seen from above ; four times
the natural size. Type. Page 57.

The same tooth, outer aspect ; four times the natural size.

Megacerops assiniboiensis ? Lambe ; coéssified nasals, viewed from above; one-half
the natural size. Page 52.

Magacerops primitivus, Lambe; mandible viewed from the left; one-third the
natural size. Page 49.

The anterior end of the same specimen as seen from above; one-half the natural size.

Anthracotherium ? pygmeum, Lambe ; right upper molar, crown view ; twice the
natural size. Type. Page 25.

pl., protoconule ; pr., protocone.

GEOLOGICAL SURVEY OF CANADA. PLATE VI.

L.M.LAMBE, Delt.

JP JE II Ds WIE

Fig. 1.
Fig. 2.
Hig. 3:
Fig. 4.
Fig. 5.
Fig. 6.
Fig. 7.
Fig. 8.
Hig. 9!
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15.
Fig. 16.
Fig. 17.
Fig. 18.
Fig. 19.
Fig. 20.
Fig. 21
Fig. 22.
Fig. 23.
Fig. 24.

PLATE VII.

Hycenodon cruentus, Leidy; left manibular ramus viewed from without. Page 59.

The same specimen viewed from above-

Hycnodon cruentus, Leidy ; left lower second premolar, outer side view.

Hycnodon crucians ? Leidy: upper left fourth premolar, exterior aspect. Page 60.

The same tooth, interior aspect.

The same tooth, posterior aspect.

? Hemipsalodon grandis, Cope; left lower canine, inner side view ; one-half the
natural size. Page 61.

Outline of transverse section of same at s.

Cynodictis lippincottianus (Cope) ; left lower third premolar, viewed from without.
Page

The same as seen from within.

Cynodictis lippincottianus (Cope) ; left lower fourth premolar, exterior view.

Cynodictis lippineottianus (Cope) ; right lower first molar, external view.

The same, internal view.

The same, posterior view.

Daphenus felinus, Scott ; hinder portion of the right maxilla holding the fourth
premolar, viewed from below. Page 62.

Same specimen, external view.

Protemnocyon hartshornianus (Cope); left upper fourth premolar, internal aspect.
Page 63.

Protemnocyon hartshornianus (Cope); left upper fourth premolar, viewed from
within.

The same tooth, viewed from without.

The same tooth, from below.

Dinictis felina, Leidy ; right lower first molar, outer view. Page 64.

The same, inner view.

The same, view from above.

Dinictis felinu, Leidy ; left upper canine, external view.

e., canine ; d., deuterocone ; m., molar; p., premolar ; pr., protocone ; prs., protostyle ;

tr., tritocone.

GEOLOGICAL SURVEY OF CANADA.

771i

PLATE

L.M.LAMBE, Delt.

Vi

Je

fe ee AES Vs ele:

12529—11

PLATE VIII

1. Didelphys valens, Lambe; right upper molar, crown view ; four times the natural
size. Type. Page 22.

2. The same tooth, posterior aspect ; similarly enlarged.

3. The same tooth, anterior view ; similarly enlarged.

4. The same tooth, exterior view; similarly enlarged.

5. 2 Didelphys valens, Lambe ; lower molar, viewed from above ; enlarged four times.

6. Same tooth, inner aspect ; same enlargement.

7. Same tooth, posterior view ; same enlargement.

8. Poébrotherium wilsoni, Leidy ; part of a left mandibular ramus with last temporary
molar in place; outer aspect. Page 30.

9. Crown view of the molar shown in figure 8; enlarged three times.

10. Leptomeryx speciosus, Lambe ; crown view of right upper molar ; three times natural

size. Type. Page 31.

g. 11. The same tooth similarly enlarged, outer aspect.

12. Leptomerye speciosus, Lambe; right lower molar, crown view; three times the
natural size.

13. The same tooth, outer aspect; three times natural size.

14. Leptomeryx speciosus, Lambe; left posterior lower molar, crown view ; enlarged
three times.

15. The same molar, inner aspect; similarly enlarged.

16. Sciurus ? saskatchewensis, Lambe; left upper molar, crown view; four times the
natural size. Type. Page 56.

17. ‘The same tooth, posterior aspect ; similarly enlarged.

18. Ischyromys typus, Leidy; right second lower molar, crown view; four times the
natural size. Page 56.

19. Cylindrodon fontis, Douglass; portion of left mandibular ramus in which is
preserved the first molar ; enlarged three times. Page 56.

20. The same specimen, as seen from above ; four times the natural size.

g. 21. Pulwolagus haydeni, Leidy ; right upper first molar, crown view ; slightly over four

times the natural size. Page 58.

22. Paleolagus haydeni, Leidy ; left upper fourth premolar, posterior view ; slightly
over four times the natura! size.

23. The same tooth, crown view; similarly enlarged.

24. Palwolagas haydeni, Leidy ; right lower molar, outer aspect ; four times the natural
size.

25. The same tooth, viewed trom above ; similarly enlarged.

GEOLOGICAL SURVEY OF CANADA. PLATE VIII.

L.M.LAMBE, Delt.