Art. I1.—On the Structures and Distribution of the Genera of the Arciferous Anura,

By Epwarp D. Copr.

ARCIFERA.

Acromials and coracoids divergent, the former directed forward and connected
with the latter by a longitudinal arched cartilage, which is free from and overlapped
by the corresponding cartilaginous arch of the opposite side. Teeth on the upper
jaw ; tongue present. Tubse Eustachii not overarched so as to be prolonged towards:
the median line.

In this tribe the extremes of the series are more diverse than in the others, and
depend on the following features :

(1.) In that nearest the Aglossa, the vertebre are like those of the latter and of
the Salamanders, concave posteriorly and convex anteriorly: in the other extreme
the reverse. These features are not as irreconcilable as might at first sight appear,
as the intervertebral spheres do not become firmly attached to either centrum at
maturity in some individuals of Borborocaetes peronii, Pelobates fuscus (Stan-
nius) and Cultripes provincialis (Dugés). (2.) Those with opisthoccelian ver-
tebrae agree with the bulk of the tribe in possessing dilated sacral diapophyses,
whilst those at the other extreme exhibit them cylindrical. (5.) A few of the
former possess small ribs, and (4) approach the normal condition of the so-called
coccygeal vertebrx in possessing one pair of transverse processes; (5.) most of these,
with the adjoining less extreme forms, have a vertical or cat-like pupil. (6.) Many

* The material from which the observations in this contribution, and that on the special characters of the
Squamata (Proc. Acad. Phila. 1864, 224) were made, is that of the principal osteological collections of
Europe, and alcoholic collections of Washington, Philadelphia, Berlin, London, Paris and Vienna. Vide
Giinther Zoolog. Record, 1864, where an inaccurate report of the latter article is given.

I may mention here an inadvertent omission in the memoir on Squamata, of a known distinctive feature be-
tween the Lacertilia and Ophidia; they should be contrasted thus :

Lacertilia. Ophidia.
Continuity of parietal and sphenoid walls interrupted. Continuity of parietal and sphenoid walls complete.
Palatines united by suture with maxillaries and yomer. _Palatines not in contact with maxillaries and yomer.
Rami of the mandible united by suture. _ Rami of mandlble united by ligament.

68 ON THE STRUCTURES AND DISTRIBUTION OF THE

of the same group exhibit a degraded or obliterated auditory apparatus; but this
feature is not uniformly coincident with the preceding ones. (7.) The xiphisternum
is formed of divergent limbs; in the bulk of the tribe it is an emarginate cartilagi-
nous plate, and in the opposite extreme an osseous style, as in the Ranide.

Of these features, the first, third, fourth and sixth are agreements with, or approxi-
mations to the structures of the same elements of the Salamanders; the resemblances
are borne out in the physiology of the same types.

In the observed examples of the above types, that is, of the Discoglossidx, Pelody-
tide and Scaphiopodidx, the eggs are deposited in small clusters, (Pelodytes), a short
thick loop, (Pelobates), or in a series with a slender, tough, thread-like attachment,
(Alytes). In the family following that of the Pelobates, that is, the New World tree-
toads, the eggs are, in the only Old World species,—Hyla ar borea,—deposited in
globular masses, as among the Ranide, but much smaller; while in our Hyla
pickeringii the masses include but from four to ten eggs. In the first mentioned
forms, the male seizes the female in front of the arms, while in the remaining and
major number of species, as well as in the observed Raniformia and Bufoniformia,
she is seized round the axilla.

In respect to the deposition of eggs, the peculiarity mentioned is an approximation
to the mode observed by the Salamanders, which are deposited singly in the water
(Triton, Notophthalmus)* on leaves, or on the land, connected by a tough thread
(Desmognathus). Salamanders also seize the female in advance of the arms, but
with the Aind limbs; (Notophthalmus, Triton).

Additional peculiarities in the development of Alytes, Pelodytes,f Cultripes and
Pelobates are, that they spawn at two seasons instead of one, and that their larvae
attain a larger size than those of other Anura before completing their metamorpho-
sis. This latter feature is, however, repeated near the other end of the series—
among those with cylindrical pelvic supports, in the genus Pseudis. What the
significance of these peculiarities is, and what their codrdination with structural
characters, is not yet known.

The occurrence of a xiphisternal style similar to that of the Ranidx, may be re-
garded as an indication of superiority, not only in consideration of this affinity, but
as a greater degree of specialization and ossification of the part. It appears, how-
ever, not merely among the most Raniform Arcifera, but among some with proccelian
vertebrae, which have the salamander-like mode of reproduction, and also among
some of the opisthoccelian species.

* Notophthalmus viridescens lays its eggs singly on leaves, e. g., at the union of the capillary segments
of Myriophyllum, or along their length, pressing them together on the egg as it is deposited. They adhere
closely to its gelatinous surface, and serve to conceal it.

t+ Thomas, Ann. Sci. Nat, 1854, 290.

GENERA OF THE ARCIFEROUS ANURA. 69

The seven natural families are characterized as follows :
I. Sacral diapophyses dilated ; vertebrae opisthoccelian.
Ribs; xiphisternum of two divergent limbs ; usually fronto-parietal
fontanelle and coccygeal diapophyses; outer metatarsi separated
by web, : ‘ ; : ‘ : . Discoglosside.
No ribs or coccygeal diapophyses; usually complete frontoparictals,
and single coccygeal condyle: xiphisternum an osseous style; ex-
ternal metatarsi bound, . : : . : : ; . Asterophrydidee.
II. Sacral diapophyses dilated; vertebrae proccelian.
Terminal phalanges simple conic continuous; coccyx united by
condyles, be : : : é ; ; : ; . Pelodytide.
Terminal phalanges continuous conic; coccyx connate with
sacrum, . : 3 ‘ : d ; - : ; . Scaphiopodidee.
Terminal phalange with a swollen base and slender curved claw-
like termination, articulated beneath the penultimate; coccyx
united by condyles, ; F : : : ; . Hylide.
III. Sacral diapophyses cylindric ; vertebra proceelian.

Mandible bearing teeth, . ; . Hewiphractide.
Mandible edentulous; external metacarpals usually bound to-
gether, rarely free, . : : : : : : : . Cystignathide.

The only family features as above given, which seem to have a functional signifi-
cance, are the structure of the terminal phalanges as an adaptation to arboreal life
in the Hylide, and the increase of raptorial power by the addition of another set
of teeth in the Hemiphractidse. Yet for the first mentioned function how many other
arrangements are employed among other genera ?

We are at present acquainted with 265 species of this tribe, which represent 69
generic types: they represent the families in the following proportions and regions :

Gen. Sp. Distribution.
Discoglossidee, 5 6, 5 . RB. Palearctica.
Asterophrydidee, 4 5, R. Palexotropica, Australis.
Pelodytide, 2 2, ‘ . RB. Paleotropica; Palzearctica.
Scaphiopodidee, 5 o; , . _R. Paleearctica, Nearctica.
Hylide, baal iti 132, f . (R. Paleotropica) R. Palzearctica,
Nearctica, Neotropica, Australis.
Hemipbhractide, Be | 2, : . RB. Neotropica. |
Cystignathidee, sets) 109; i . R. Neotropica; Australis.

The generic forms are all peculiar to their zoological regions, except Hyla, found
wherever its family occurs, and Borboroceetes, common to Australia and the southern

portion of South America.
18

70 ON THE STRUCTURES AND DISTRIBUTION OF THE

The number of species so far known to inhabit these regions is as follows :

Regio Australis, 39, R. Palearctica, 2;
R. Neotropica, 176, R. AXthiopica, 0,
R. Nearctica, 25, R. Palxotropica, f(-

240, 16.
In two regions, lhe In two regions, 2.

The small proportion of species occurring in the old world, exclusive of Australia,
is evident, though they represent five families, while those of the new world repre-
sent but four.

The slight attachment of the integuments to the muscles is a well known feature
of the Batrachia Anura. The manner of this attachment presents many varieties in
the different groups. The typical arrangement is uniform among the Raniformia,
but reappears frequently among the other groups; it is as follows: A transverse
partition of connective tissue holds the integument along the acromials, and an-
other along the coracoids; a Jongitudinal band on each side of the back (frequently
marked externally by a glandular fold) and one below it on each side of the abdomen.
A band or line along the hinder inferior face of the thighs extending nearly to the
popliteal region, and a delicate one along the upper hinder face of the same, from
the groove between the superior and posterior muscles.

Among Bufoniformia the attachments are similar to the last in the Dendrobatide,
in Paludicola and in Brachycephalus. In Engystoma ovale the lateroventral line
is broad, or composed of several series of fibres and laminz, and in K. caroli-
nensis it is composed of two septa. In Pseudophryne the dorsolateral septum, as
well as the last mentioned, is widened; Phryniscus is similar, except that the dorso-
lateral is narrow posteriorly, but rapidly widening, meets its mate on the nape,
forming a broad transvere attachment. In Atelopus laevis the integument between
the dorso- and ventrolateral septa is attached, forming a broad lateral adherent band.
In Rhinophrynus dorsalis this lateral attachment is carried so far as to leave only
narrow free dorsal and ventral regions, while it is further peculiar in wanting the
coracoid septum, as in Discoglossus and Dactylethra. Epidalea, Bufo, Phrynoidis
and Peltaphryne, ia their numerous species, add to the Raniform structure the at-
tachment of the whole dorsal integument. The following table exhibits the other
attachments :

Belly broadly free, very narrow lateroventral attachment: B. haematiticus, lesche-
naultil.
Do., broad lateroventral attachment: B. americanus, lentiginosus, cognatus, chilensis,

boreas, vulearis, naricus, sp. Vera Paz, vallifrons.
+] oD + ’ )

GENERA OF THE ARCIFEROUS ANURA. 71

Do., posterior fourth or fifth abdomen attached : gracilis, speciosus, pantherinus.

Lateroventral attachment very broad, leaving but narrow free abdominal space: B.
coniferus, quercinus, intermedius, punctatus, alvarius, diptychus.

Ventral integument attached: B. coccifer, insidior, viridis, kelaartii (posterior half
attached.)

A considerable variety is exhibited by the families of the Arcifera. In the genera
of Discoglossidxe examined (Discoglossus and Bombinator) the attachments are as in
Ranide, except the absence of the coracoid septum, as in Dactylethra. On the con-
trary, in the Scaphiopodidx, the integument is more or less entirely adherent above
and below. The greater number, as well as typical forms of Hylidae, add to the
Raniform arrangement a close areolar attachment of the abdominal skin, while it is
characteristic of many species of Cystignathidze to possess one or two transverse,
simple posterior abdominal septa. For the many variations and exceptions, see
under the respective families.

Of the Aglossa, Dactylethra lacks the coracoid, and inferior femoral attachments ;
there is a double or treble but not wide lateral adhesion low down, which may be a
combined dorsolateral and dorsoventral, or broad dorsoventral only. In Pipa all the
attachments are wanting, except two closely approximated lateral lines, and a supe-
perior posterior and anterior inferior femoral.

The species of Arcifera, so far as known, exhibit some peculiar structures during
the breeding season; either an extension of the natatory membrane, or the develop-
ment of corneous plates or spurs, as aids to prehension. There is more variety and
efficiency displayed in this pomt than among the Bufoniformia, but is in especial
contrast to the apparent absence of all but the weakest modifications among the
Raniformia. It is perhaps in compensation for the structure of the sternum, whose
lateral halves being movable, offer a slighter basis of resistance for the flexor and
extensor muscles of the fore limbs.

In the Discoglossidze, Bombinator extends the natatory membrane in the male, but
does not develope horny plates. In Discoglossus two file-like oval plates cover the
superior surfaces of the short second digit, and the tubercle-like first, or thumb, which
is here developed as in no other anurous batrachian. Dermal rugosities on the upper
and under surfaces, including the gular region, are armed with corneous tips, as in
Telmatobius. No peculiarity has been noticed in Alytes. The Asterophrydide are
unknown.

In Pelodytes file-like plates are developed, one on the second and one on the third
digit, one much larger on the forearm, one slightly smaller on the inside of the hu-
merus, and a small one on each side of the breast.

Among Scaphiopodide the American species develope elongate laminz on the

1
bo

ON THE STRUCTURES AND DISTRIBUTION OF THE

superior inner face of the inner (second) third and even fourth digits. No peculiari-
ties are recorded as appearing in the European species.

Many Hylidx,—Agalychnis, Trachycephalus—develope a corneous shield on the
inner superior aspect of the inner metacarpal, which is prolonged on the digit.

While no appendages of the season have been observed in some Cystignathide, in
several genera two acute spurs appear on the superior aspect of the thumb, and
rarely spur-like tubercles on the breast ; the body is sometimes shielded with hardened
points on the rugosities, or the lip surrounded by an arched series of corneous ruge.
In one species the arms themselves increase remarkably in thickness and bulk, espe-
cially the brachium.

With regard to the differences in the arrangement and structure of the internal
organs, a great deal remains to be observed. Henle (Anatomie des Kehlkopfes)
points out some inconsiderable differences in the form of the cartilages of the larynx.
The size and number of the pulmonary cells vary considerably. Among Hylide,
especially those species with a loud voice, they are fewer and larger than in Disco-
glossidx and Scaphiopodide. The forms of the sinus, auricles, ventricle and bulbus
arteriosus, the three aorta bows, of which the median form the aorta roots, etce.,
appear quite identical externally in the Discoglossus, Scaphiopus, and Phyllomedusa.
Internally the two former present the known characters of the Anura, 7. e., the union
of the distinct ducts of the 1st (pulmonary) and 2d (aortic) aorta bows throughout
much of their length, the separate union of the two former and continuance on the
left side of a high free septum of the bulbus, till they are finally turned over the
right division toward the right, and have a common issue from the ventricle. A
conic pocket valve is at the origin of the bifurcation of the ductus communis of the
second and third aorta bows, but none in any part of the course of the pulmonary.

The form of the liver does not differ from the usual type in any of the various
species examined. In the alimentary canal there appears to be little variety in im-
portant points. The stomach has generally a more longitudinal position than among
Bufoniformia, except among Scaphiopodide and in Ceratophrys, where it is equally
transverse. No intestinal valves were observed in Pelobates, Hyla, Phyllomedusa,
Ceratophrys, but a strong pyloric muscular constriction in Pleurodema, and one at
the extremity of the small intestine in Cystignathus pachypus.

The testes are single in examples of all the types examined, and not strictly
symmetrical; they are variously situated with reference to the kidneys. Thus in
Ranoidea aurea, and Trachycephalus lichenatus they are elongate and at the
middle of the length of the kidneys, while in Hyla boans and Scytopis venulo -
sus they are oval and one or both at the anterior extremity of the latter. In
Phyllomedusa scleroderma they are more than half the length of the broad

=I

eo

GENERA OF THE ARCIFEROUS ANURA.

kidneys, the right originating at the anterior extremity of the latter, the left but
little behind it; both have their posterior apices in close contact, at the posterior
fourth of thé length of the kidneys, which are in close connection for their posterior
third. In Discoglossus, the testes are oviform, well separated, and anterior, and
during the breeding season attain a remarkably large size. During the same
in Cystignathus pachypus, they are not materially enlarged, are elongate, and
only in contact with kidneys for a small posterior part of their length.

The ovaries and oviducts do not essentially vary among the Anura; when the
latter are fully occupied by eggs in an advanced stage they are folded, but differently
in the same species. The oviducts are remarkably slender in Hyla nas uta (Litoria
Gtinther), and in Scytopis venulosus. The fontanelle is on each side behind the
partial diaphragm, at the superior anterior outer angles of the liver; in several
young female specimens of Ranoidea aurea of the size of Rana silvatica, in
which the frontoparietal fontanelle is not closed, the oviducts do not extend further
anterior than the ovaries; in adults, with the cranium complete, they have the usual
extent. In Gnathophysa ocellata* and gigas the “uterine” sacs at the exit
of the oviducts are of great size and at certain seasons distended with an albuminous
gelatine, when they present several convolutions. In spirits they occasion the
presence of a large convoluted coagulated mass. In one specimen on one side this
lay for the greater part of its length outside the abdominal muscles and above the
lateroventral septum.

The tribe Arcifera was first defined and its extent and distribution indicated by
the author in the Natural History Review, 1865, though explained a year previously
at a meeting of the Zoological Society of London. The sternal feature characteriz-
ing it has been noticed by Steetzen, Cuvier and others in isolated cases, but its
general significance not perceived: Dugés (Recherches, 64) attributes it to the tree-
toads, the toads, and the Bombinator, Alytes and Pelobates. In Stannius’}+ Zooto-
mie der Amphibien (73), it is assigned to the Aglossa and Bufo, as distinguished
from Rana and Cystignathus. The characters of the last genus must have been
taken from the Old World Cassina (formerly called Cystignathus), as the structure
in Cystignathus and its allies is that of the true Arcifera.

These arches extend behind the so-called acromials to the extremity of the scapu-
la; they have the same form and structure as during the earlier portion of the larval
life of the Raniformia. In the latter, in maturing, they unite, and contract to a slen-
der median rod, which gives with the superior transverse portions, a T-shaped
element. Dugés has regarded this cartilage and its halves as equivalent to the fur-

* Rana ocellata L, R. pentadactyla of Laur., not Cystegnathus ocellatus of later writers.
+ A work which should be in the hands of all students of comparative anatomy.

19

74 ON THE STRUCTURES AND DISTRIBUTION OF THE

cular clavicle of birds, Monotremata, and Lacertilia, (where it is often called meso-
sternum,) which view possesses much in its favor ; but the presence of the arched
cartilages connecting coracoids and acromials, in addition to the presence of the
furcular and true clavicles in Lacertilia, opens the position to objection, and renders
it quite possible that neither kind of clavicle exists among the Anura.* The question
is therefore open to further investigation.

That the type of Arcifera is inferior to that of Raniformia, the structure of the
sternum renders clear; it is also proven by the most usual undeveloped condition of
the cranium in the former, its completeness in the latter, and the usual imperfection
of what exists of the sternum, 7. e., the manubrium and xiphisternum, in the former,
contrasted with its developement in the latter.

The Bufoniformia extend still lower, adding to the inferior sternum, the larval
character of want of teeth; in many of the types, however, the sternum approaches,
but never equals, the form of the Ranidze, and offers a mark of superiority equivalent
to the presence of teeth in the Arcifera.

C. Bruch, in an article on the Anura,j contends that’ the Bufones are the most
elevated of this order, on account of their greater intelligence of movement, persist-
ency of object, and adaptability. But this cannot weigh against developmental con-
siderations, and is moreover a common order of things. The superior Quadrumana
have every appearance of inferior intelligence to the dog or elephant; the Corvide
are much more intelligent than the superior Turdidz, and Woodward complains that
the Matid crabs are psychically much inferior to the Cancrid family, which are
structurally below them. Perhaps this “intelligence” is only tmpressibility and
educability, features which distinguish the young from the adult man as well, and are
not consistent with that stamp of peculiarity fixed upon types by the greater length
of their developmental scale.

DISCOGLOSSID 2.

Vertebre opisthoccelian.{ Diapophyses of sacrum dilated. First coccygeal verte-
bra united as usual with the second or style, but furnished with posteriorly divergent
diapophyses, and attached to the sacral by two cotyloid cavities (with one exception).
Short ribs articulated to the anterior diapophyses.§ Ossa fronto-parietalia, enclosing
a fontanelle (in existing genera). External metatarsi more or less separated by a
web. Terminal phalanges continuous, simple. Xiphisternum of two slender postero-

* Vid. Natural Hist. Rev., l. c., where I have taken this view. '

¢ Which contains much of interest, and advanced views on the systematic-position of the European Arcifera.
See Wurtzbiirger Wissenschaftliche Zeitschrift, 1862, 222.

t Observed by Dugés and Gervais in Alytes.

2 Noticed by Duges in Alytes and Bombznator, and Dumeril in Discoglossus.

GENERA OF THE ARCIFEROUS ANURA.

exteriorly diverging fibro-cartilaginous or cartilaginous styles. Tongue round,
entire, and little or not at all free behind. Males without vocal vesicle.

If we cominence the series of the Arcifera with the great family of the Cystigna-
thidx, we will end it with the families Asterophrydidw and Discoglosside, which are
perhaps equally connected with that which precedes them—the Seaphiopodide. The
former leads to Dactylethra through Paleobatrachus; the latter, as far as our
present knowledge indicates, finds its completest development in the extinct genus
Latonia, established by Von Meyer on the L. seyfriedi from the miocene of
Oeningen. A species also occurs in the freshwater deposits of Sansan, L. rugosa,
whose salamander-like vertebrae have been noticed by Gervais.* These animals
were nearly related to Discoglossus, and had, like it, short posteriorly-directed pro-
cesses on the ribs, as in the genus Salamandra; they were, however, much larger,
had the frontv-parietal bones completely ossified, and the whole of the cranium
roughened externally by a dermo-ossification. On this account the genus has been
compared with Ceratophrys, which belongs to the family of Cystignathide. This
dermo-ossification occurs in various families, especially in the New World.

In the remaining and recent genera, the structure of the sternum is worthy of note.
In old individuals of Discoglossus, it is sometimes fibro-cartilaginous, as in Pipa.
The xiphisternum, proximally homologous with the xiphisternum of the Lacertila,
consists distally of the united hemapophysial cartilages of the anterior ribs. Jn
the genera in question,t this part is divided nearly up to the point of attachment to
that preceding, each moiety being directed outwards and backwards, and tapering
into a lateral linea semilunaris. Between these and the pubes there are in Discoglos-
sus the usual three pairs of line semilunares, connected on the median line by a
strong linea alba.

In Discoglossus the prefrontalia are strongly developed, being in contact for most
of their length, sometimes touching the fronto-parietalia. In Alytes they are also in
contact throughout, but are transverse and do not reach the fronto-parietals; the
fontanelle is larger, and the ribs without processes: the whole animal is weaker. In
this genus, as well as the preceding, the pupil is a vertical slit; elsewhere found
in Hylorhina, Platyplectrum, Limnomedusa, Pelodytidxe and the Scaphiopodide. A
species, A. troschelii,{ has left its remains in the miocene Braunkohle along
with Palaobatrachus. Bombinator is similar to Alytes in its osseous structure,
except that the prefrontalia are in contact anteriorly only, and that the sacrum
presents but one condyle for the articulation of the coccyx, as is typical of the Aste-
rophrydidw and Aglossa. Along with Alytes and Dactylethra it has true ossa

* Paleontologie Francaise, p 494.

+ Duges has given a figure of it in Bombznator, pl. 3, fig. 24.
} Rana troschelit (Von Meyer, Paleontographica, iii. p. 138) is undoubtedly an Alytes.

76 ON THE STRUCTURES AND DISTRIBUTION OF THE

nasalia, which bound the external nares exteriorly, thus explaining their anomalous
position in Breviceps, where they are inferior. In this genus there is no cavum
tympani or auricular ossicles, and the tube Eustachii are rudimentary or wanting.
This character is said by Tschudi and Bruch not to be exceptionless in adults, and
that the tube and tympanum are always present in the young of both this genus and
Pelobates. All European.

Cephalic integument involved in cranial ossification, which completes

the o. o. fronto-parietalia. Two coccygeal cotyli and diapophyses ;

ribs with posterior process, . ; :; . LATONIA.
Cephalic integument involved in cranial ossification; an open fronto-

parietal fontanelle ; no coccygeal diapophyses, two condyles. Tem-

poral fossa roofed over, . : : é : : : . ZAPHRISSA.
Cephalic integument free ; a small fronto-parietal Fmtanelle: (sometimes

apparently closed by the ethmoid.) Prefrontalia largely in contact.

Two coccygeal cotyli; ribs with posterior process. Pupil round.

Cavum tympani present. No parotoid glands, ; . DiscoGLossus.
Cephalic integument free; a fronto-parietal fontanelle. Prefrontalia

in contact throughout. Two coccygeal cotyli. No rudimental digit.

Tympanum and cavum tympani distinct. Pupil erect. Parotoid

glands present, ; : : ; . ALYTES.
Cephalic integument free from cranium; a fronto-parietal fontanelle ;

prefrontalia in contact anteriorly. One coccygeal cotylus. No inner

digit developed. No tympanum or cavum tympani; Eustachian

tubes rudimental or wanting. Parotoid glands none, . : . BomBrn ator.

LATONIA.

Von Meyer, Saugethiere Vogel u. Reptilien von Oeningen, p. 18.
L. seyfriedi von Meyer, l.c. Tab.
Habitat. Oeningen, Baden.

L. rugosa Cope, Nat. Hist. Review, 1865, 105. Rana rugosa Lartet (Notice sur la
Colline de Sansan, p. 41); Gervais Palsontologie Frangaise, p. 494. Tab.
? Rana gigantea Lartet, 1. ¢.

Habitat. Sansan, Southern France..

On account of the great brevity of Lartet’s descriptions, it is not possible to deduce
any characters by which to distinguish this species from the last. In both the tem-
poral fossa is overarched, as in Cultripes, but in neither is the sacral diapophysis as
much dilated as in this genus and Pelobates. The L. rugosa may, however, differ

-1
-]

GENERA OF THE ARCIFEROUS ANURA.

in many points, since of the remains we possess, the humerus offers some distinctive
marks. The latter exhibits two opposite proximal alee, and one internal distally ;
all very strong. These are not represented in Von Meyer's figures of the largest of
theseyfriedi. Inthe rugosa the front is a little swollen; there is no median
superior process on the coccyx.

The remains of a vertebral column with sacral diapophyses much more dilated
than either of the preceding, probably pertains to one of the species described by
Lartet as Rana sansaniensis or R. laevis. Whether this be another Lato-
nia, or an animal allied to Pelobates, is not easily determined. In the Natural
History Review for 1865, No. 1, I stated that a large species of Pelobates occurs in
the miocene Braunkohle of Rott, near Bonn, Rhine-Prussia. A further study of a
single specimen has convinced me that the species must be referred to the neighbor-
hood of the genus Latonia; the sacrum is more dilated than in the known species,

and resembles that of Pelobates. This is

ZAPHRISSA m.

Z. eurypelis sp. nov.

The general form is well displayed by an inferior view of the whole skeleton. The
extremities, especially the feet, and the pelvis of this species, are elongate. The
terminal phalanges were short conic; the exterior or long metatarsals are closely
juxtaposed, the outer the shorter of the two. The tarsal bones are preserved; the
cuneiform was small and little prominent. The length of the astragalus and calca-
nium is little less than half the tibia: the latter is relatively slender, flattened and
grooved at both ends. The ilia are slightly incurved, slightly compressed distally,
and as long as the femora. The impression of the coccyx does not display a strong
dorsal keel; its position corresponds with the axis of the sacrum, although other
portions of the skeleton have been much disarranged; the traces of a small sacral
condyle indicate the union with the sacrum by double condyle, as usual in this
family.

The sacral diapophyses are remarkably expanded, almost as in Pipa or Cultripes :
they articulate with the proximal three-fifths of the ilia. The remaining vertebrae
have been much disarranged ; they were probably eight in number. The atlas is dis-
tinct, without processes, necessarily much expanded anteriorly for articulation with
the large and separated occipital condyles, and about as long as wide. The diapophy-
ses of the second, third and fourth vertebra are the only ones preserved; those of
the second are longest, and articulate without constriction, with a cylindrical costal
appendage. The terminal portion of this is lost, but it has not probably exhibited a

posterior process, nor been much dilated. The third pair of diapophyses are the
20

78 ON THE STRUCTURES AND DISTRIBUTION OF THE

shortest, and are rather depressed at their articulation with the ribs, which are the
longest, nearly straight and slightly widened distally. The fourth diapophyses is
equal to the third, but heavier and directed anteriorly ; its rib is transverse, heavier,
but shorter than the last.

The cranium is broad, with its whole surface roughened by the development of
numerous minute, inosculating ridges, forming a coarser pattern than in any recent
species, and leaving a nodular relief. The temporal fossa was overarched by a
thick lamina, as portions remaining indicate, and the ossification formed a supra-
orbital ala beyond the brain case, as in Latonia sey friedi and Ceratophrys. The
impression of the fronto-parietal bones is interrupted medially by an elongate oval
elevation of the matrix. This is bounded before by the concave border of a smooth
bone, whose impression is of the usual form of the superior ethmoid plate. I cannot
conceive this to be anything other than an indication of a frontoparietal fontanelle,
though I know of no form combining this feature with dermoossification, or the
overarched temporal fosse. The impressions of the prefrontals are very distinct ;
the greater part of the substance of one remains. Their form bears some resemblance
to that in Pelobates; their common anterior suture does not measure one-half their
longitudinal extent. The superior ethmoid plate presents a narrow posterior con-
cavity for the fontanelle; it has left no rugose impression in the matrix. The
frontoparietals exhibit a broad lateral wing, as occurs in Latonia and Pelobates,
which passes into the postorbito-temporal arch. The latter is broad, and continues
into a strong posterior dilatation of the ‘“ temporo-mastoid,” which includes with the
end of the quadratum a deep sinus.

The anterior limb is elongate. Scapula and supra-scapula preserved, undivided : hu-
merus broad proximally, and with a right anterior outline, which is probably a bicipi-
tal ridge; no apparent posterior ridge. Distally more transversely compressed than in
Pelobates fuscus, at the base of the prominent condyle. Forearm with two distal
longitudinal grooves. The impressions of the carpals are very distinct; that of the
lunare larger than that of the cuneiforme; and that of the unciforme representing a
bone larger than any other, but not prominent. The impressions visible are three
proximal, two distal. The fingers are elongate.

The sternum and one arm were pressed across the cranium, and are mutilated ;
hence the important point as to whether the xiphisternum is bifureate or styloid
remains for a more fortunate observer. Measurements are as follows :

In. Lines.
Length from end muzzle to posterior margin ethmoid, ; 5 : 5)
cc ss level of occipital condyle, ‘ : 12°5
Interorbital breadth (behind middle), : f ; : : : . 5:3
Breadth of temporal arch, 4°35

GENERA OF THE ARCIFEROUS ANURA. 79
In. Lines.
Thickness of temporal arch, ; : 4 : : : F ; 8
Breadth between extremities of quadrata, as crushed, : ; val 75
Transverse extent of third vertebra with appendage, ; 8
a cs fourth ‘ cs : : : 8
3 Se sacral cs a o'8
Length of sacral diapophysis, 8
“of ilium, : , : : : . ; ; ; salt 3°6
c.f rcoccyx, )
“ of femur, ; : ; : : . ; ; ae 2
sof tabta;, : : é : ‘ : : . { eal 2
“of tarsus, : : : : ‘ E 2 : : : f
“of fifth metatarsus (exterior), . : ; : ; ‘ . Axe)
“ of fourth oo f : é : : : ‘ , a9
“of first cs : : : ; ; : , 2 2
“ of third digit from tarsus, é : ; ‘ f ‘ if
“ of humerus, . : F : : ; ; ‘ ; 10
“ of ulna and radius, igo
“of third metacarpus, ‘ : } : ‘ , : 32

This species was the cotemporary of the Morelia papyracea, the Palewobatrachi
Ranx and Cyprinidae of the period and place of deposit of the Braunkohle of

Rhine-Prussia.
ASTER OPHRYDID Al

Vertebre opisthoccelian. Diapophysis of sacrum dilated, of first coccygeal
vertebra wanting; the latter attached by but one cotyloid cavity (except in one
genus). Ribs none. External metatarsi not separated for a web; terminal pha-
langes continuous, simple. O. fronto-parietalia not strongly ossified medially, but
without fontanelle. Superior plate of the ethmoid well developed anteriorly. Kar
perfectly developed. Xiphisternum a slender osseous style (first two genera not
examined).

Genera: Cryptotis, Gthr.; Asterophrys, Zsch.; Megalophrys, Aufl ; Xenophrys,
Gthr.

The Palxobatrachide differ from this family in the conversion of their seventh,
eighth, and ninth vertebral centra and diapophyses into a sacrum, instead of the
ninth only; and in the osseous covering of the cavum tympani and tuba Eustachii.

Cryptotis, the only Australian genus of the family, possesses two sacral condyles
for the articulation of the coccyx ; it has a long tooth-like process on the os dentale,

similar to that seen in Rana macrodon, and R. kublii.

80 ON THE STRUCTURES AND DISTRIBUTION OF THE

The other genera belong to the Malayan Islands, except Xenophrys, which has
only been found in the mountains of India. There are no arboreal or aquatic forms

embraced in this family. The whole number of species known is five.

a. Toes free.

Two coceygeal cotyli. O. dentale with a dentiform process. Vomer-

ine teeth; no parotoids; palpebra simple, . : : ‘ . CRYPTOTIS.
One coccygeal cotylus. No dentiform process. Head large angular ;

upper palpebral border with cutaneous appendages. Vomerine

teeth. Tongue entirely adherent. Tympanum hidden, perfect, ’ ASTeROPHRYS.
No dentary apophysis. Head ordinary, no dermal appendages. No

vomerine teeth. Tongue broad, but little free. Tympanum

distinct, . , : ; ‘ : : : : . XENOPHRYS.

aa. Toes partially webbed.
Very much depressed ; cleft of mouth large. Vomerine teeth little
developed. A superciliary dermal appendage. Tongue broad, free
behind: (tympanum concealed), : ; : : : . M&GALOPHRYS.

PELODYTID EZ.

Vertebre proccelian ; no ribs or diapophyses of coccyx. Sacrum united with the
coceyx by condyle, its diapophyses thin and largely dilated. Xiphisternum an
osseous style, with terminal disc. External metatarsi bound together.

The species of this family are of weak organization ; the fronto-parietal bones are
undeveloped in one of the two genera embraced by it, and they are very weak in the
other. Their affinities are altogether between the Asterophrydidze and Scaphiopo-
didx. Their vertebre only distinguish them from the former, and their distinct
bicondyloid coccyx from the latter. In both genera the auditory apparatus is
developed, and the cephalic integument is free; in neither is there a metatarsal
shovel.

Fronto-parietal bones complete; no vomerine teeth ; one sacral con-

dyle for coccyx: tongue partially free, é : : : . LEPTOBRACHIUM.
Fronto-parietal bones embracing a large fontanelle ; vomerine teeth ;

two sacral condyles for the coceyx; a weak parotoid gland; pupil

elliptic erect; tongue partially free. Atlas and axis confluent, . PELopyres.

SCAPHIOPODID i.

Vertebre procoelian ; no costal elements or coccygeal diapophyses; diapopbyses of

ninth vertebra much dilated, thin and triangular ; coceygeal style without condyloid

GENERA OF THE ARCIFEROUS ANURA. 8

articulation, its axial portion restricting that of the sacrum and connate with it:
external metatarsi bound; distal phalange continuous, simple. Manubrium carti-
laginous. Tongue rounded, nearly entire.

The small number of species embraced in this family are of stout toad-like
habit, and furnished with a shovel-like development of the cuneiform bone and a
coriaceous posterior digital palmation, to aid them in removing earth while making
their subterranean abodes. Many of them very seldom come to the surface of the
earth, and then only in darkness; for this habit the vertical cat-like pupil is an

adaptation, a peculiarity not exhibited by the toads, which are crepuscular.

Group I. Cavum tympani and tympanum wanting. Xiphisternum with an ossified
proximal style. Cuneiform bone and sheath well developed. Pupil erect.
Toes webbed.

Derm involved in cranial ossification. Temporal fossa with a strong roof.

Vomerine teeth: no parotoid glands, ‘ : ; : : . CULTRIPES.

Derm involved in cranial ossification. No roof over the temporal fossa,

or parotoid glands. Vomerine teeth, : } : : . PELOBATES.
Derm distinct from cranium, which is undeveloped above) two lateral

fronto-parietal bars enclosing a median fontanelle. Vomerine teeth.

No parotoids, : : : : 5 ; . Dipocus.*

Group IT. Cavum tympani and tympanum present. Xiphisternum en-
tirely cartilaginous. Cuneiform bone and sheath well developed.
Toes more or less webbed. Pupil elliptic erect.

Derm involved in the cephalic ossification, which is complete. Parotoid

glands and vomerine teeth, —. - : . , : . SCAPHIOPUS.

Derm distinct from cranium, which is only ossified superiorly in two
superciliary bars. Parotoid glands and vomerine teeth, . : . SPEA.{

The extreme of divergence of the series of this family is, then, that representing its
type in a preéminent degree. This is seen in the genus Cultripes where the ossifica-
tion of the superior cranial walls is especially thickened, obliterates the sagittal

* Type Rana calcarata Michahelles Isis von Oken, 1830, 160. In the lack of a good series of specimens
of Cultripes provincialis, I should have hesitated to separate this species generically from the latter, re-
membering the very late period of completion of the cranium in Ranoidea aurea of Australia. But Dugés’
“Rech. Ost. et Myol.,” ete., p. 93, says that the parasphenoid and frontoparietal bones are simultaneously
and early completed, and illustrates in a figure the confluence of the latter while quite young. Dumeril,
Erp. Generale, viii. 484, states, moreover, that the temporal roof is developed before the tail of the larva has
disappeared. ‘In our specimen, which is fully developed, though not of large size, the temporal muscles
are only enclosed by the usual fascia. The species occurs in southern Spain. See my forthcoming memoir
in the Smithsonian Contributions.

7 Type Scaphiopus bombifrons Cope; embraces S. hammondii Baird, and 8. multiplicatus

Cope.
21

82 ON THE STRUCTURES AND DISTRIBUTION OF THE

suture, and is extended in an arch over the temporal fossa. The anterior ossification
of the coccyx is applied by its axial portion beneath the axis or centrum of the sacral
vertebra, and becomes consolidated with it shortly after its commencement, furnishing
a structure not rare among burrowing Anura. This character is maintained in the
descending scale by Pelobates, Didocus, Scaphiopus and Spea, though none of these
have the temporal fossa overarched. Cultripes, with Pelobates and Didocus, exhibit
an ossified basal xiphisternal piece, while in all below it is cartilaginous, as in most
Arcifera: the extreme position of the former is also maintained by the obliteration of
many portions of the auditory apparatus. The succeeding forms Scaphiopus, Spea
and Helioporus, resemble the first group in the toad-like form, and in the strong
cuneiform shovel and webbed feet, but in the last the usual bicondyloid articulation
of coccyx brings us within the limits of the Cystignathide, and with Spea, an
incomplete cranium marks a descent. The more elongate Cystignathid form of Chiro-
leptes maintains the Scaphiopod foot, with a strong cranium, while in the same family
the superficially similar Hyperolia exhibits no longer the cuneiform shovel, or any
true mark of affinity.

The distribution of the species of the family is as follows:

R. Austr. R. Neotrop. R. Nearctica. R. Palearct. R. Aethiop. R. Paleotropica.

Cultripes, 0 0 0 al 0 0

Pelobates, 0 0 0 1 0 0

Didocus, 0 0) 0 1 0 0

Scaphiopus, 0 0) 3 0 0 0

Spea, 0 1 2 0 0 0
1 5 3

The inferior dermal attachments of seven species of this family are as follows :

Didocus calcaratus; belly more than half attached.

Pelobates fuscus; from half to two-thirds attached; same in larva, with long tail.
‘Femur one line below.

Scaphiopus holbrookii; free only opposite sternum; thigh attached only below on
basal half.

Scaphiopus couchii. Triangular free area to middle abdomen.

Spea hammondii, very wide lateral inferior attachments, which do not meet till
femora.

Spea bombifrons. Belly with a free median band; femoral lines, below and above
behind.

Spea multiplicata. A free dorsal line, very narrow in front, but wide as ilia behind ;

abdominal area with a broader free space.

GENERA OF THE ARCIFEROUS ANURA. $3

HYLIDAE.

Vertebre proceelian. Sacral diapophyses dilated, the simple coccyx articulated
to two condyles. External metacarpi bound together. Terminal phalanges articu-
lated inferiorly on to the extremity of the penultimate, globular or swollen prox-
imally, and giving rise, usually from a central emargination, to the curved, acute
distal portion which is of a more compact tissue. O. frontoparietalia shortened
anteriorly, usually embracing a fontanelle. Superior plate of ethmoid never covered
by frontoparietals, usually produced anteriorly, between frontonasals. Har perfectly
developed. Abdominal integument areolate.

This family embraces the tree-toads of Australia and America. It presents com-
paratively little structural variety, not containing as undeveloped types as the
Cystignathidx, nor as high ones: it possesses neither earless genera, nor fossorial,
nor really aquatic. ;

The adaptive modifications are: first, those which accompany a terrestrial habitat,
t. e., the diminution of the digital dilatations and palmation. These occur in
regularly increasing degree, in a small number of the species of the typical genus
Hyla, and are general in, and distinctive of, two other genera. Second, those which
adapt the extremities to grasping a limb by opposition of digits, instead of adhering
to a surface by expansion of them in one plane. This first appears in a species of
Agalychnis, and is permanent in Pithecopus and Phyllomedusa. Third, those which
restrict the light admitted to the retina, first, by the lateral contractility of the
pupil; second, by the rendering opaque of the inferior palpebra. The first
characterizes the three genera just mentioned, the last occurs in the first two, but is
inconstant in the second, and appears in two species of the genus Hyla. Fourth,
that which adapts the female during the breeding season to localities without water,
or where perhaps the water contains enemies, by the inversion of the dorsal integu-
ment so as to form a sack, in which the eggs are carried. This occurs in, and is
accepted as characteristic of two genera, of one species each , but as it occurs in but
one sex its value is questionable.

Another feature, which may have a functional value, is the union of the abdominal
integuments with the superficial fascia of the muscles by an areolar or fibrous net-
work, continuous with that of the usual latero-ventral band. The skin of the inferior
surfaces of these creatures, as in the Raniform tree frogs, has a thickening in nume-
rous close areols, the nature and function of which is like that of the digital dilata-
tions, and the derm of the tuber on the thumb of the male Rana, 7. e., to secrete an
adhesive fluid as aid in maintaining the peculiar positions assumed. In proportion
to the developement of these, is the extent of the abdominal attachment, and hence

may be supposed to be adapted for relieving the other areolar connections from the

84 ON THE STRUCTURES AND DISTRIBUTION OF THE

strain of the animal’s weight when in an appressed or vertical position. Its uniform-
ity in the burrowing genera of the Bufonide and Scaphiopodide, and especially on
their dorsal surface, rather confirms this view.

This connection is, however, evidently not necessary to the use of the abdominal
integument as an adhesive support, as this faculty is nowhere better seen than in
Acris, where the derm is free. This creature will adhere for days to a vertical glass
plate, not only by the abdomen and digits, but by the interdigital membranes, and
will light securely from a long leap on such a surface. Daudin and Duméril have
related the same adhesive faculty in Pelodytes punctatus, which is not known in
regard to the dermal attachments, but has not the abdominal areole present in Acris.
The extent of the attachment is least where the dilatations are smallest, as foliows:

Abdomen entirely attached ; 18 sp.
Phyllomedusa two sp. Pithecopus two sp. Agalychnis three sp. Trachycephalus
two sp. Nototrema one sp. Scytopis two sp. Smilisea baudinii.

Hyla albomarginata, boans, agrestis, krefftil, phyllochroa,

Posterior half or third of abdomen attached; latero-ventral band wide.
Triprion petasatus.
Hyla fusca, arenicolor,* gratiosa, versicolor, femoralis ; squirella, andersonii, cyanea.
Ranoidea aurea.
Chorophilus triseriatus.

Less than posterior third abdomen attached ; the latero-ventrals wide.
Hyla arborea, regilla, lateralis, cadaverinat miotympanum; pickeringli.
Chorophilus nigritus.

Abdomen entirely free.

Hyla leseurei, curta, gracilipes. Acris gryllus.

Of distinguishing features, which refer to the conditions of the elements of the
vertebrate skeleton, their degree of developement, etc., it may be said that they
exhibit far fewer cases of questionable or intermediate existence than those of the
previous class. They are, first, the developement of the o. 0. frontoparietalia ;
second, of the prefrontalia; third, of the superficial cranial rugosities; fourth, of
vomerine teeth; fifth, of a postfrontal arch; sixth, of the ethmoid arch.

Whole number of species, ; . : ; é : : . ; wail
Frontoparietals fully developed, ; : A : : : a ug)

cc with rugosities penetrating derm,. : : : : ey ut
Prefrontals developed, —. : : : : : : : : : Bay edt

* H. affinis Baird, not Spix.

7 H. nebulosa Hallow., not of Spix.

GENERA OF THE ARCIFEROUS ANURA. 85

With vomerine teeth, : ; : ; : ; . ; : ; . 128
With postfrontal arch, . : - : : k : : sat ih
Ethmoid arch complete, 4 ; : : d : : ; . 130

Of the above characters, the lack of vomerine teeth is inconstant in Pithecopus,
being present in one, and wanting in another species.

There is a tendency to the Pseudis and Rana liberation of the outer metatarsus in
Hyla americana, hyposticta and dimolops, and Ranoidea aurea.

Parotoid glands occur in somespecies of Hylidze as an extensive stratum of crypts,
but never exhibit the definition seen in Bufoniform and some Cystignathid genera. It
even occurs in Scytopis venulosus irregularly, being sometimes present, and
sometimes wanting, in the female at least.

The xiphisternum exhibits the form which exists in the greater number of Cys-
tignathidx, excepting in eight species, where it only lacks the posterior emargination.

The natural genera are as follows:

I. No frontoparietal fontanelle.
a. Cephalic derm occupied by the external rugosities of the
cranial bones: prefrontals in contact.

A series of parasphenoid teeth or acute serrations ; vomerine teeth.

No dorsal sac; labial margin much prolonged, ; ; . TRIPRION.
Vomerine teeth; no parasphenoids or dorsal pouch, . : . TRACHYCEPHALUS.
Vomerine teeth ; a dorsal pouch; no parasphenoids, — . g . OPISTHODELPHYS.

aa. Skin free from the surface of the cranium.
A dorsal dermal pouch in 2 ; prefrontals partly united: vomerine
teeth ; dilatations small, 5 : . : : ; . NOTOTREMA.
No dorsal dermal pouch; prefrontals united; cranium with
caring; vomerine teeth, , : ‘ ' . , . OSTEOCEPHALUS.
No dorsal pouch; prefrontals united; no cranial carine ; vomer-
ine teeth, : : : : ; 4 : ! . SCYTOPIS.
No dorsal pouch ; prefrontals narrow, well separated; outer meta-
tarsi bound; a ?coccygeal diapophysis; vomerine teeth, . . DRYOMELICTES.
No dorsal pouch; vomerine teeth; outer metatarsi slightly free ;
no coecygeal diapophysis, : : 2 : . RANOIDEA.
II. Frontoparietal bones embracing an extensive fontanelle.
a. A dagger-shaped postorbital process of the frontoparietal
bone.
Vomerine teeth ; form stout, feet webbed, . F : . SMILISCA.*
aa. Frontoparietal simple.

* Species, 8. baudinii (Hyla baudind D. and B.); the name “ daulinva” must probably be considered an

erroneous orthography of the same.

na)
bo

86 ON THE STRUCTURES AND DISTRIBUTION OF THE

b. Posterior digits free, two opposed to three; xiphisternum
entire; pupil vertical.
A large prominent paratoid ; inferior palpebra transparent; tongue
extensively free laterally and behind, _. : : : . PHYLLOMEDUSA.
Parotoid very thin or wanting; tongue free; inferior palpebra
netted or transparent; second toe shorter than inner, : . PirHecopus.*
bb. Posterior digits rarely opposable, pupil rarely vertical ;

xiphisternum deeply emarginate.

c. Pupil vertical; inner posterior digits more or less opposable.

Tongue elongate, extensively free laterally and behind ; inferior

palpebra latticed; toes more or less webbed, second longer than
inner; sometimes thin parotoids, —. ‘ : : = . AGALYCHNIS.}+

cc. Pupil horizontal; posterior digits webbed, not opposable.
Tongue short, attached or little free; palpebra usually trans-
parent; vomerine teeth, : : . : : : . Hyna.
Tongue short; palpebra transparent; no vomerine teeth, . . HY ELLA.
Tongue extensively free; dilatations minute, palmation extensive
behind; vomerine teeth, : : : : ‘ ' . ACRIS.
ccc. Pupil horizontal; posterior digits flat, free.
Superior ethmoid plate osseous ; prefrontal bones separated, . CHOROPHILUS.
Superior ethmoid plate cartilaginous, the prefrontals developed, in
contact medially, . : : : : : : : . THOROPA.

The affinities of these genera are most readily exhibited by an arrangement like

the following :
4

Triprion
Opisthodelphys iDyanhoenbelte
Ph yllomedusa N aie ma —- Osteocephalus
| Pithecopus Scytopis

Agalychnis Ranoidea Dryomelictes
sal : 3 a

Hyla Acris

Smnilisca

Chorophilus Hylella
z 10

Thoropa

* Type P.azureus; second species P,-hypochondrialis (Hyla hypochondrials Daudin).

¥ Includes Phyllomedusa dacnicolor Cope.

GENERA OF THE ARCIFEROUS ANURA. 87

In the series 1—2 to Phyllomedusa a final diminution of palmation accompanies
continued size of the digital pallettes and increase in the length and breadth of the
ethmoid, and diminution of the frontoparietals, which features, however, are as
marked in Hyla palmata as in these succeeding types: they carry to its fullest
developement the cranial peculiarities of the family, and add other features before
mentioned ; they inhabit the continental subregion of the Neotropical. The other main
series (5 —4) leads, first, to a fuller developement of the frontoparietals, then to an ex-
tension of the prefrontals, and finally to covering of the cranium with “ dermodssifi-
cation,” on the one hand with the superaddition of a dorsal dermal sac, on the other
without it. This extreme finds its ‘greatest expansion in the West Indian subregion.
A singular incompleteness of the cranial box seems to mark Thoropa, which has the
strong nasal roofing of this second series.

Chorophilus exhibits an affinity to the Cystignathide, as does also Thoropa, which
represents in inferiority Eusophus in the same family.

The following is the geographical distribution of the genera and species :

R. R. R. R. R. R.
Australis, Neotropica, Nearctica, Palearctica, Aethiopica, Paleotropica,
Triprion, . : : , el
Opisthodelphys, ; : wil
Trachycephalus, ‘ ‘ md
Osteocephalus, i : ae
Nototrema, : ; : se Hl
Scytopis, ; : : sone
Ranoidea, : il
Dryomelictes, . : : ahi: -
Pithecopus, ; ; :; eae
Phyllomedusa, . 2
Agalychnis, ; : : . 4
Smilisca, . ; : : sak
Hyla, é : Pal bi On 12 1 0 (2 from without)
Hylella, . : ‘ : hz
Acris, 2 : 3 ; : : Pali
Chorophilus, —. : : ; : ws
Thoropa, ‘ ; ; aga
18 93 18 il ) (2)

Total, 131.

ON THE STRUCTURES AND DISTRIBUTION OF THE

io ¢
oO

This family was first defined by the author in the Natural History Review, 1865.
The most nearly correct limitation previously existing was that of Gtnther, who,

however, placed the species with parotoids in other families.

HEMIPHRACTID A.

Diapophyses of the sacral vertebra cylindrical; mandible supporting a series of
teeth. Cranium fully osseous. Terminal phalanges ?

Of this family almost nothing is known, as it is as yet represented by but two rare
species of the forests of the Neotropical region. It is probably intermediate between
the Hylide and Cystignathidx ; in superficial appearance it approaches nearest the
genus Triprion m., where the cephalic ossification and developement of additional
teeth are carried far, and the digital dilatations are in like manner not largely

developed.

HEMIPHRACTUS.

Wagler, Isis v. Oken, 1828, 735, 743, t. x. Peters, Monatsb. Preuss. Acad. 1862, 145.

In both species the vomerine teeth are in longitudinal series between the nares,
curved outwards, and there appears to be teeth on the palatine arch. They have an
acute prominence on the end of the muzzle, and the terminal tooth of the mandibular
series is several times as large as the others, and prominent.

CYSTIGNATHID i.

Vertebrae proccelian; no ribs; sacral diapophyses cylindrical, obtrihedral or
slightly depressed distally, inclined upwards. Coccyx separate, attached to two
condyles, without diapophyses. Terminal phalanges continuous, either uniformly
conic, or with divergent terminal processes or their rudiments. Manubrium wanting
or cartilaginous ;* xiphisternum distinct. Auditory apparatus developed.; No
teeth on the mandible.

This, after the Hylide the most extensive family of the Arcifera, embraces 101
species, which represent thirty-four generic types ; four additional species represent
four other supposed genera.

The most completely developed genus exhibits a cranium without fontanelle and
with complete ethmoid arch, and a styloid osseous xiphisternum, with terminal car-
tilaginous disc; the auditory organs perfectly developed: the lowest, undeveloped
ethmoid arch and frontoparietal roof, and disciform cartilaginous xiphisternum with-
out style, with Eustachian tubes and membranum tympani wanting. Consistently

* Except in Limnocharis. + Except in Alsodes, according to one author.

GENERA OF THE ARCIFEROUS ANURA. 89

with this succession, we have four modifications of this structure to adapt to as many
modes of life: the aquatic, the terrestrial, the arboreal, and the subterranean. As
the earth’s surface is the common medium between the above extremes, so the
species of terrestrial habits furnish us with none of the adaptive extremes of struc-
ture, but remain an intermediate group, from which the succession of structures,
interrupted, it is true, passes towards the divergent types. Developemental
structures accompany and confirm the adaptive, but by no means coincide; more-
over, the adaptive is the evanescent character, while the developmental is the
definitive.

The aquatic habit is attained when the digits behind are not only webbed, but
when the external metatarsi are separated by membrane also. The arboreal, when
the terminal phalanges are furnished with a terminal transverse limb, which sup-
ports an adhesive disc. The subterranean is shortened, and furnished with a great
development of the first cuneiform bone of the tarsus, which is covered by a
corneous sheath, and serves as a spade. The first may be combined with the third,
as in Mixophyes and Chiroleptes, or it may be furnished with a bony over-roofing of
the temporal muscles, and penetration of its integuments by the ossification of the
cranium.

The fossorial spur is weak in Helioporus, weaker in Platyplectrum, and just repre-
sented in Ceratophrys and Gomphobates. The palmate foot is diminished in Calypto-
cephalus, reduced in Mixophyes and Chiroleptes, and represented by a trace in
Hylorhina and Limnomedusa. The undeveloped ear is seen on one side only in a
species of Crinia, and in Alsodes.

With regard to the dermal attachments, the following important varieties occur;
in the family generally, but especially among Hylodes and Cystignathi, the dorso-
lateral septum is placed especially high up :—

PsEuDES.—Septa in Pseudis as in Rana; in Lysapus the lateroventral line is a
little widened. In Mixophyes fasciolatus the lateroventrals are very wide,
and leave the ventral free space very narrow behind the middle.

CrrAToPHRYDES.—In (Gomphobates and) Tomopterna the lateral septa are narrow,
and there are two posterior abdominal transverse septa, similar to those attached to
the sternum. In Ceratophrys ornatus these are wanting, but the dorsolateral line
is very broad.

Crini#.—Among these animals I have examined species of Helioporus, Platyplec-
23

90 ON THE STRUCTURES AND DISTRIBUTION OF THE

trum,* Crinia, Borboroceetes, Eusophus and Hyperolia, and in none can I find more
than lateral traces of the epicoracoid and coracoid septa, except in the Hyperolia
marmorata, where they are complete. The posterior abdominal is well developed

in Kusophus nebulosus.

PLEURODEMZ.—Ventrolateral low down, and posterior abdominal well developed in

Pleurodema bibronii.

Hy toprs.—Dorsolateral and ventrolateral far apart: the transverse posterior ab-
dominal septum in the species of Lithodytes, in Ephirexis lon gipes, in Enhydro-
bius vomerinus (Zlosia Girard) and Phyllobates ridens. Ihave not found it
in Lithodytes (Craugastor) conspicillatus Gthr., Enhydrobius parvus+
(Hylodes Gird.) and Limnocharis fus cus Bell (Elosia nasus Girard).

CystigNAtai.—In all the species the structure is similar to that of Rana, except in
the approximation of the dorsolateral lines, and the presence of the postabdominal
septum, which is continuous with the lateroventrals, and is indicated externally in
several of the species by a fold in its line of attachment.

The accompanying table exhibits the affinities of the genera, and the groups into

which they naturally fall :

*P. occidentale, sp. nov.

Skin smooth; crural gland small; above medially dark, laterally pale ash, below dirty white ; pupil erect ;
orbit less than length of muzzle.

Habit stout; distal end of tarsus not quite extending to end of muzzle; breadth of head behind scarcely less
than one-half length of head and body, and one-eighth more than from posterior border of tympanum to oppo-
site end of muzzle. Muzzle depressed in profile, retreating from prominent labial border, nostril nearer orbit
than margin, the former distance equal narrowest interorbital breadth. Eyes not prominent; eyelids narrow.
Vomerine series extending to exterior of choanz, which, with the ostia tube Eustachii, are of usual size.
Tongue extensively free. Tympanum concealed by skin. First, second and fourth fingers equal, the two inner
with very large penultimate subarticular tubercles. Brachium attached under angle of mouth; middle of ante-
brachium extended measures end of muzzle. Tarsus broad, short, scarcely equal antebrachium ; metatarsus
moderate, with none but the cuneiform tubercle, which is incurved and pale edged. Toes short, except the
fourth, with a trace of web, and margined.

Total length 1 in. 9'41.; muzzle to angle of jaws 8°51. ; tibia 91.; foot 1 in. 21 1.

Hatitat.—West Australia, Danzel.

+ Perhaps owing to small size of specimen.

9

RA.

-

GENERA OF THE ARCIFEROUS ANU

Cystignathi,
21 sp.

Pseudes,

/ Sp.

Ceratophrydes,
9 sp.

Pletrodeme,
9 sp.

Crinix,
28 sp.

Frontoparietal bones developed.
An osseous xiphisternal style.
Gnathophysa
systignathus
Tarsopterus
| | Gomphobates

Xiphisternum a cartilaginous disc.

( (a ; Hylodes

| Aan. | \ Pseudis Lithodytes
ees Lysopsus Exhydrobius

| Ps | Mixophyes Epirhexis Phyllobates
| { Pithecopsis Strabomantis Litnnocharis
( Zacheenus

| Stombus

| Ceratophrys

a Tomopterna

| Chiroleptes

l Limnomedusa

\

Frontoparietal bones undeveloped, embracing a fontanelle.

Xiphisternum with an osseous style.
Pleurodema Hylorhina
Liuperus \

\
\

Xiphisternum a cartilaginous plate. \

Neobatrachus
Helioporus
Platyplectrum

.Borboroceetes

“
4

Crinia
Hyperolia

Cyclorhamphus
Alsodes

; Frontoparietals and ethmoid arch undeveloped.

as follows:

r

The geographical distribution of these forms is

92 ON THE STRUCTURES AND DISTRIBUTION OF THE

Regio Australis. Regio Neotropica.

‘Chili and S. of La Plata. Central. Mexican. West Indian.

Cystignathi, 0 2 18 1 3
Hylodes, 0 0 16 3 8
Ceratophrydes, 1 iL 7 0 0
Pseudes, 1 0 6 0 0
Pleurodeme, 0 3) 6 0 0
Crinix, 23 7 OF 0 0

There are then known twenty-five Australian species, of which all but two possess
an incomplete cranium, and none a bony xiphisternal style. In the Patagonian sub-
region thirteen species, of which ten exhibit an incomplete cranium, and five a com-
plete bony xiphisternal style. In the Brazilian subregion fifty-three species, of
which only six have an incomplete brain case, and twenty-four the osseous xiphister-
nal style. Mexico, three species with complete cranium, and one of these with
style; the West Indies with eleven, none having the fontanelle, and three the style.

R. Australis, S.R. Patachonica, S. R. Brasil., S.R. Mexic., 8. R. Ind. Oce.

Tova ier, er 20: 13. 53. 4. 1.
Prefrontals fully developed, 0 3 22 (appr.) 3 10
Ear imperfect, : ; el 4 0 0 0
No vomerine teeth, 9 1 13 0 1
Toes webbed, 3 2 6 0 0
Fossorial shovel, . : il il 1 0 0

In regard to the cranial development, the West Indian region is preéminent in
this family as in the Hylide, the Brazilian inferior, and the Australian vastly below
all; the degradation appearing in a certain degree regular. In the lack of vomerine
teeth, (a feature of immaturity,) the Australian forms predominate. In possession of
the Raniform xiphisternum the West Indian and Mexican subregions show fewer
representatives than the Brazilian.

One species,—Lithodytes ricordii,—wanders from the R. Neotropica into the
southern projection—Florida—of North America; no others are known to occur
beyond the borders already stated. No species is common to the R. R. Australis and
Neotropica, and but one genus,—Borborocetes. Two Brazilian species occur in the
Southern West Indies, and two in Southern Mexico; probably three of the same
country must be included in the Buenos Ayrean list.

The whole number of species must be reckoned at 108, which fall into 35 genera.

As yet we are acquainted with the fossil remains of but one species of Cystigna-
thidse,—a Ceratophrys, from a Brazilian cave. It has been regarded as identical
with the C.dorsata by Giinther, Ann. Mag. Nat. Hist. 1859, pl. xv.

GENERA OF THE ARCIFEROUS ANURA. 93

This family was first characterized by the author in Proc. Acad. Nat. Sci. 1863, 46 ;
excluding, however, the genera Ceratophrys and Tomopterna; and subsequently
more exactly in the Nat. Hist. Review 1865. Several changes, approximations to
nature, are now proposed, and the genera for the first time defined. These were
distributed in the last systematic arrangement (1858) in six different families.

Group I. PsrupEs.—Frontoparietal bones fully developed. Toes webbed, external
metatarsi free; terminal phalanges acute. Xiphisternum a cartilaginous plate.
Ear perfectly developed. Tongue broad, entire, adherent.
Cephalic derm distinct: vomerine teeth: no cuneiform shovel or
lumbar gland. Prefrontals closely united; pupil horizontal, . PSrup1s.
Cephalic derm distinct: vomerine teeth ; no cuneiform shovel or
lumbar gland: prefrontals widely separated from each other
and frontoparietals, : : : ; F : : . LYSAPSUS.
Cephalic derm distinct ; vomerine teeth ; a cuneiform shovel ; no
lumbar gland; prefrontals not closely united; pupil vertical, . Mrxopnyes.
Cephalic derm distinct; vomerine teeth; no cuneiform shovel; a
lumbar gland; eyes anterior; prefrontals well united, trans-
verse, ays : ; : : ; ; f : . PITHECOPSIS.
Cephalic derm involved in a rugose cranial ossification, temporal
fossa overarched, completing postorbital arch ; vomerine teeth ;
no cuneiform shovel or lumbar gland; eyes anterior; prefront-
als extensively united and prolonged posteriorly, . : . CALYPTOCEPHALUS.

Group II. CrrAtopurypes.—Frontoparietal bones fully developed. Toes free or
slightly webbed; the external metatarsi bound; terminal phalanges simple.
Xiphisternum a cartilaginous plate (so far known, emarginate). Ear perfectly
developed. ‘Tongue entire, little free.

a. A cuneiform shovel; cephalic derm distinct; no postorbital
arch.
Eyelids not prolonged; prefrontals well separated ; vomerine teeth ;
toes slightly webbed; inner finger opposable ; form more elongate, CHIROLEPTES.

Prefrontals more or less united; eyelids not prolonged ;- vomerine R
teeth ; toes slightly webbed; cranium elevated ; form toad-like ;
inner finger not opposable ; abdominal derm areolate, A . TOMOPTERNA.

aa. A cuneiform shovel; cephalic derm involved in cranial ossi-
fication. A postorbital bony arch.
Prefrontals wholly or in part separated ; eyelids with a dermal pro-
longation ; vomerine teeth; toes more or less palmate; cranium
elevated ; form toad-like; inner finger not opposable ; pupil trans-

verse, : p 5 ee ‘ : : P ; : . CERATOPHRYS.
24

94 ON THE STRUCTURES AND DISTRIBUTION OF THE

aaa. No cuneiform shovel or postorbital arch; cephalic derm
not involved in ossification. ‘
Prefrontals widely separated; eyelids with dermal prolongation ;
vomerine teeth; toes nearly free; cranium elevated, form toad-
like; inner finger not opposable, 5 : ; : : . StomBus.*
Prefrontals in close contact ; eyelids not prolonged ; vomerine teeth

on palatine arch; toes free; cranium broad; eyes subanterior,

pupil horizontal; form squat, abdomen smooth, , : . ZACHANUS.t
Prefrontals not united, removed from the frontals; vomerine teeth ;
toes nearly free; pupil vertical, : : : . Limnomepusa.t
? 2 ?

Prefrontals? eyelids simple; no vomerine teeth; toes free; eyes
lateral, pupil horizontal; form frog-hke, — . : : ; . NATTERERIA.

Group III. Crinr2.—Frontoparietal bones embracing a large fontanelle; cephalic
derm free. Auditory apparatus developed, minute, or wanting. External
metatarsi bound, digits free, or rarely, webbed; terminal phalanges simple.
Prefrontals never closely united, rarely in contact. Xiphisternum not dis-
tinguishable into style and disc, broad, emarginate, cartilaginous. Tongue
largely free.

a, Ethmoid bone with superior arch complete; a metatarsal
shovel; toes margined or webbed. Vomerine teeth in
straight transverse series; form stout.
Parotoid glands continued to groin and on dorsum; feet nearly
free; pupil round, : : ; . HELIOPoRUS.
No parotoid glands; feet fully webbed, : ; : : . NEOBATRACHUS.
No parotoid glands; feet webless, : : ; . , . PLATYPLECTRUM.
aa. Ethmoid arch complete; no metatarsal shovel; toes
webbed ; form depressed.
Auditory apparatus minute; vomerine teeth ; xiphisternum with
a proximal semiossified portion, . : : : : . CYCLORHAMPHUS.
aaa. Kthmoid arch complete, or nearly so; digits free; no
cuneiform shovel.

Large parotoid glands; no vomerine teeth, ; : ; . HYPEROLIA.
No parotoid glands; vomerine teeth in transverse series; xiphis-
ternum broad, (with some basal bony deposit,) . : : . BorBoRoczTES.§

* Type Ceratophrys b oiei Wied.

7 Type Cystignathus parvulus Girard.

} Type Cystignathus macroglossus Dum, and Bibr,
@ Includes Limnodynastes Fitz. Giinther.

GENERA OF THE ARCIFEROUS ANURA. 95

No parotoid glands ; vomerine teeth wanting or in minute fasciculi;
xiphisternum slender, without bony deposit. Abdominal integumen
usually areolate, . : ; ; é : : ; . Crinia.*
aaaa. Ethmoid arch completed by cartilage above; digits free;
no shovel.
No parotoids; vomerine teeth; pupil round; auditory organs rudi-
mental, . : : ; : ‘ ; : ‘ : : . Kusopuus.
aaaaa. Ethmoid arch? No metatarsal shovel. “ Auditory organs
wanting.” Toes slightly webbed.

Vomerine teeth; no parotoids, . ; : : : ; ; . ALSODES.

Group IV. Prrvropema:.—Frontoparietal bones embracing a fontanelle; auditory
apparatus developed; digits free, or slightly webbed; external metatarsals
bound, terminal phalanges simple ; xiphisternum an osseous style, with one or
more distinct terminal cartilage discs. Tongue entire. Cephalic derm free.

a. Inguinal glands; pupil horizontal; xiphisternal cartilage
emarginate or bifurcate.

Vomerine teeth ; prefrontals well separated; terminal phalanges short, PLEURODEMA.
aa. No inguinal glands; pupil horizontal.

No vomerine teeth; prefrontals entirely separated; terminal phalanges

short, . ; f ‘ ; : : : : ’ ; . LIUPERUS.
aaa. No inguinal glands; xiphisternal cartilage entire; pupil
erect.
Vomerine teeth; prefrontals widely separated by the osseous ethmoid ;
terminal phalanges elongate; limbs elongate, : : : . HYLoRHINA.

Group V. Hytoprs.—Frontoparietal bones and auditory apparatus fully developed ;
digits free, or nearly so; external metatarsi bound; terminal phalanges with a
transverse limb, which supports dermal discs. Cranium elongate, plane.
Xiphisternum without style, scutiform, emarginate or bilobed, osseous or carti-

laginous.

* Crinia ignita m. sp. nov.

Prefrontals well separated; sides, throat, thorax and abdomen areolate; back without folds, but with
numerous oval and elongate warts; two metatarsal tubercles ; black, with scattered red spots; groins and
femora behind red, pink varied ; limbs brown above, black banded ; below white. A strong short tarsal fold ;
toes narrowly margined ; base of fourth toe extends to nostril; heel to orbit; sacral region nearly flat ; tym-
panum indistinct, one-third orbit ; tubercles of palm numerous, strong, two exterior largest. A flat glandular
aggregation at rictus oris ; nostril as near lip as orbit. End of forearm to end of muzzle. Length of head
and body about an inch.

This species has a considerably shorter head than the following.

Habitat.—West Australia, Daniel. Mus. Acad, Nat. Sci.

96 ON THE STRUCTURES AND DISTRIBUTION OF THE

a. Prefrontals well separated, rarely the convexities of the inner
borders in contact.
6. Manubrium cartilaginous.
Muzzle and canthus rostralis angulated, projecting; vomerine teeth ;

digital dilatations small, “ : : : : : : . ENHYDROBIUS.*
Muzzle and canthus rostralis contracted, little marked; vomerine
teeth ; digital dilatations large,- . ; ; : : ‘ . Eprruexis.t

Muzzle and canthus rostralis prominent, angulated ; no vomerine teeth, PHYLLOBATES.{
bb. Manubrium osseous, styloid.
Muzzle and canthus rostralis angulated; no vomerine teeth, —. . LimnocHaris.
aa. Prefrontals united throughout by close suture, and usually
in contact with frontoparietals.
Abdomen smooth; xiphisternum broad, s : 4 : . Lirnopy tes.
Abdomen areolate; xiphisternum slender, entirely cartilaginous, — . HyLopes.

Group VI. Cysrignatti.—Frontoparietals and auditory apparatus fully developed.
Cephalic derm free. External metatarsi bound, digits free, terminal phalanges
simple. Xiphisternum a distinctly defined slender osseous style, with distal
undivided cartilaginous disc.

a. Xiphisternal style emarginate, and with two distal cartilagi-
nous discs.

Form toad-like; no parotoids or vomerine teeth ; isolated inguinal

glands; two acute metatarsal spurs; pupil horizontal, : . GOMPHOBATES.
of Form more elongate ; no parotoids or vomerine teeth ; no inguinal
“A glands; metatarsal tubercles small, : 4 ‘ . TARSOPTERUS.
aa. Xiphisternal style and distal dise undivided.
No inguinal glands, : : : : : . CYSTIGNATHUS.
Glandular aggregations on the loins, : : : : ; . GNATHOPHYSA.

Genera incerte sedis.
1. Probably in Group Ceratophrydes.
Superior cranial plane much contracted, with elevated ridges behind.
Eyelids not prolonged; no cuneiform shovel or parotoid glands ;
small dilatations on toes of posterior extremity ; no palmations ;
belly areolate, . é : ; ‘ . STRABOMANTIS.
2. Among Cystignathi, or a new group.
Superior cranial plane contracted, probably no fontanelle ; auditory
apparatus undeveloped ; digits webbed, outer metatarsi bound, no
dilatations; no vomerine teeth ; pupil round, ; . TELMATOBIUS.
* Includes Hlos’a Tschudi.

t Type Batrachyla longipes Baird.
t Includes Crossodactylus Dum.,, Bibr

ceo}
=I

GENERA OF THE ARCIFEROUS ANURA.

3. Hylodes, probably.
Cranium broad, rounded ; digital dilatations supported by a strong
cross-limb; no parotoids; xiphisternum with a distal, entire carti-
lage ; vomerine teeth; muzzle and canthus, not marked, . . BATRACHYLA.
4. Hylodes or Cystignathi?
Head normal ; vomerine teeth ; parotoid gland; digits not webbed ;
thumb of male spurred ; minute posterior digital dilatations, . PLECTROMANTIS.
5. To ? Cystignathi or Ceratophrydes.
A cavum tympani. Xiphisternum? Sacrum? Cuneiform bone
little developed; form elongate; toes free; parotoid glands; no
vomerine teeth ; tongue extensively free; cranium probably com-
plete above pupil? —.. ‘ : ‘ : ‘ ; ‘ . NATTERERIA.

Supplement on the osseous structures of the Types of the Urodela.

It is as yet not always possible to distinguish differing plans of structure from
differing degrees of development of a single plan. The assumption of the faculty of
reproduction and cessation of developement at any of the various stages through
which most vertebrates pass, would give rise to a variety of genera and _ species.
That the comparative characters of existing genera, etc., do in very many cases illus-
trate in part such a hypothesis, is well known; and the fact, which has been laid down*
as a rule of zoology, that “every character distinguishing suborders, families, and
genera, will be found among the individuals of some species, living or extinct, to mark
“mere varieties or stages of growth,” is also in its favor; but it is opposed by the fre-
quent existence of superadded structures, which are of the nature of adaptations to
external circumstances. Both the more comprehensive “plans” or “ groups” and
the subordinate “genera,” differ from each other in ways which have the above
two kinds of significance separate or together.

With reference to these propositions, and the ultimate problem ef the origin of
species, no group presents greater facilities for investigation than the Urodele Batra-
chia. A few points are collated in the following pages, with this in view.

The Batrachia Urodela have been regarded as naturally distinguished into those

with persistent, and those with temporary branchiae,—perennibranchiata and caduci-

branchiata,—by almost all naturalists. The feature has been regarded either as of
2 fo)

primary importance, as by Wagler and Buonaparte, or as secondary, as by Cuvier,

Duméril, and Miller. The types known as Perennibranchiates are Siren, Proteus,

Necturus and Siredon. The skeletal features presented by these are so diverse

* Proc, Acad. Philada. 1862, 75: on p. 66 (middle) “ generic ” should be read genetzc.
25

98 ON THE STRUCTURES AND DISTRIBUTION OF THE

as to indieate at once their pertinence to widely different groups; and in the case of
Siredon, an identity with a known series of the Caducibranchiates, the Amblysto-
mata. This identity is rendered plain in the appended diagnosis.

In certain species of the genera Spelerpes and Amblystoma,* the branchiz remain
to near the adult age, and are the last larval features to disappear. I have frequently
seen the apparently adult Amblystoma mavortium with considerable stumps of
the branchie remaining, and even a few fimbrie. The abundance and size of the
larvae of Spelerpes salmoneus, and rarity of the adults, have been pointed out by
Prof. Baird,+ who also has recorded his belief in the great probability of the Siredon
pisciformis being the larva of some unknown Amblystoma. The latter creatures
are known to lay eggs, and hence the probability of their being adults, and not
larvee. In another species with completely developed gills and dorsal and caudal fin,
brought by Dr. Coues from Arizona, I find largely developed ovaries filled with eggs,
some in an advanced stage. Moreover, the carpal and tarsal bones are ossified, al-
though cartilaginous in many Urodela, which lose the branchi.

The question appears, however, to be finally settled by the remarkable facts ob-
served recently at the Jardin des Plantes by Prof. A. Duméril. Siredons laid eggs,
which hatched ; the larvae developed into Siredons, and, continuing to change, be-
came Amblystomas! a confirmation of the suspicion of Prof. Baird. The character
is in this case not even specific.

The position and tissue of the external branchize render them liable to injury;
the following illustrates how little such injury affects the vitality of the individual :
Dr. Coues states that his Siredons were taken in a well, by a baited hook. They
were laid in the scorching sun, and remained there nearly an hour before being carried
away and placed in water. They recovered perfectly; the skin exuded moisture
during their exposure to the heat. The gills were black in this species, in life.

Some years ago I had occasion to observe a Siren confined in an aquarium, which
had been taken near Alton, Ill. (Lat. 39°). I first saw it in midwinter; it was then
without gills, but frequently came to the surface and took mouthfuls of air, parts of
which would escape through the slits on the neck. There were frequently convulsive
movements of the latter region, by which the anterior and sometimes the posterior
slits were opened. Water was at the same time drawn in through the external nares,
and probably reached the pharyngeal cavity. The animal was said to have suffered an
absorption of the gills, which lasted two weeks, during which time it would take no

*In Amblystoma punctatum and opacum the branchie disappear while the animal is but half its
future size : the period at which they disappear in Desmognathus fusca appears to vary, but averages as the
preceding ; in Hemidactylium scutatum and Geotriton carbonarius their absorption takes place while
the animal is very small. In Plethodon erythronotus they also remain a very short time and are of no
functional value, as the larva does not enter the water after leaving the egg.

+ Jour. Acad. Nat. Sci. Philada., i. p. 281.

GENERA OF THE ARCIFEROUS ANURA. gy

food; but I suspected they had been nibbled off by some Pomotes (Sunfish) confined
in the same aquarium, who, attracted by their rosy color, thought them lawful prey,
There were very small stumps remaining, of which the two anterior, seventeen days
after my first observation, developed a minute brown fringe on the under side.
Twenty-four days later, the stumps were longer, and the two anterior now bore a
double series of processes, which were of a rosy slate color. The animal still came
to the surface for air, and disliked excessively to be removed from the water. It
measured 9 in. 9 lin. in length, and was at first pale brown, with numerous black
dots above, and pale slate below,—but became darker and the spots larger. There
was a golden band on the side of the lip and “ cheek,” and the toes were tipped with
acorneous cap. Further observations went no further than to show that this Siren
could live for more than two months deprived of its branchise, and that the latter
can be reproduced.

I have seen a specimen of the Siren striata in which the branchial
fimbrize were thickened, and the three main rami adherent throughout their length
to the pharyngeal walls between the fissures; being thus entirely abortive and in
part atrophied. In skeletal and other features, this species does not differ from the
Siren lacertina.

Another feature characteristic of the immature stages of both tailed and tailless
Batrachia, is permanent in the “ perennibranchiate ” types just mentioned, and in the
Amphiuma and Protonopsis,—7. ¢., the cartilaginous condition of the intervertebral
tissue, and consequent retention of the biconeave or fish-like vertebra. It does not
appear to have been previously pointed out that this feature persists in all the species
of the American types Amblystomidx and Plethodontide, contrary to the condition
in the forms of the Old World.

Prof. Baird, in the first synopsis of our genera published, pointed out the difference
between Amblystoma and our other genera, in the ossification of the tarsus and
carpus of the former, and cartilaginous state of the latter. This is again a strictly
developmental difference, identical with the Perennibranchiates and extinct
Xenorhachia.

With respect to the cranial and tarsal ossifications, the Siredon is first identical
with the larva of Amblystoma,—e. g., punctatum,—when half the dimensions of
the adult; bearing distinct nasal and prefrontal bones with maxillaries, and the
longitudinal palatines with a slight ligamentous connection with the reduced ptery-
goids, forming an arch separate from the parasphenoid. In some Siredons the carpal
and tarsal bones are fully ossified,—a condition which I have not yet observed in any
Amblystoma larva,

The structural features of Necturus are very different, as has been in part pointed
out by authors, and are identical with those of the larva of Spelerpes rubra and salmo-

nea. Both types lack the maxillaries, nasals and prefrontals, and exhibit a broad

100 ON THE STRUCTURES AND DISTRIBUTION OF THE

continuous palato-pterygoid arch, in close contact with the parasphenoid. The two
ceratohyals are confluent, the posterior is present, and there are but three superior
hyoid arches. These structures coéxist in the larva of Spelerpes salmonea, at
a period when it has attained double the size of that of Amblystoma punectatum,
and equal to that of its adult. The hyoid elements only I have not yet seen as fully
ossified in Spelerpes larva, as in the Necturus. The relation then between Necturus
and Spelerpes is probably the same as that between Siredon and Amblystoma, and
the same (as I have pointed out, Proc. Acad. Phil. 1862, p. 66) as that between Pro-
tonopsis and Megalobatrachus, in respect to the pharyngeal fissures and hyoid
pleurapophyses.

Dr. Gray, after Prof. Baird, has very judiciously excluded the Siredons from the
Perennibranchiates proper, though Miiller retained them as the type of his family
Acholotida. They undoubtedly belong to the group Caducibranchiata, and family
Amblystomidx. A priori, therefore, Necturus might be placed among the Plethodon-
tide of the same great series, but its structure, so far as observations have been made,
is permanent. It also represents a far less advanced larval bony structure than
Siredon, but so do the adult Plethodontidz in most respects than the Amblystomas.
The incomplete coincidence of advance in different organs may be thus illustrated :

AMBLYSTOMIDA. PLETHODONTIDE.
Superior. Inferior.
Carpus and tarsus osseous. Carpus and tarsus cartilaginous.
Premaxillary fontanelle closed. Premaxillary fontanelle open.
Inferior. Superior.
O. pterygoideum persistent. O. pterygoideum obliterated.

The inferiority of some Plethodontidx is seen in the non-distinction of the digits
(Geotriton), the thinness of the ossification of the parietal membrane bones (Batra-
choseps), and in Spelerpes lineolus m, from Vera Cruz, the persistence of the
membranous cranium by the limitation of the parietal bones to two small oval iateral
scales, and the wide divarication of the posterior extremities of the frontals.

We may then conclude that developmental features are thoroughly constant in most
types, but in some one or more cases in many, some are known and the others will
probably be found, to illustrate the law of variation above laid down. We are then
brought face to face with phenomena of modification of species, which do not come to
view in the irregular aspect of a theory of “descent with modification” by a fortuitous
“natural selection,” which could affect only a certain class of structures. We want a
theory which will explain the times and causes of the stability of types consisting
of co-existent structures, and the instability of such co-existences; just as the com-
pounds of the elements have their conditions of stability and instability; the elements,
of stable or unstable union. We want to ascertain that law of harmony by which the
coincidences of structures have been varied by their reproduction being shifted from
stage to stage of individual development, till the present fame are the result.

GENERA OF THE ARCIFEROUS ANURA. 101

This view has not been overlooked by Darwin, who, however, treats of it very
briefly, and appears to attach it to the theory of adaptations, or modification for a
physiological purpose. He says, Origin of Species, 388, (American Edition, 1860) :
“We may extend this view to whole families or even classes. The fore limbs,
which served as legs in the parent species, may become, by a long course of modifica-

tion, adapted in one descendant to act as hands, in another as paddles, in another as

wings; and on the above two principles,—namely, of each successive modification
supervening at a rather later age, and being inherited at a correspondingly late age,
—the fore limbs in the embryos of the several descendants of the parent species will
still resemble each other closely, for they will not have been modified. But in each
individual new species, the embryonic fore limbs will differ greatly from the fore
limbs in the mature animal; the limbs in the latter having undergone much modifi-
cation at a rather late period of life, and having thus been converted into hands,
paddles or wings.” He then inclines to assign this change to the necessity of exter-
nal circumstance. But such modification must be the same in kind as others, which
the same hypothesis must explain ; and of which the same author remarks (p. 382) :
“ We cannot, for instance, suppose that in the embryos of the Vertebrata the peculiar
loop-like course of the arteries near the branchial slits are related to similar con-
ditions in the young mammal, which is nourished in the womb of its mother, in the
egg of the bird which is hatched in a nest, and in the spawn of a frog under water.
We have no more reason to believe in such a relation than we have to believe that
the same bones in fhe hand of a man, wing of a bat, and fin of a porpoise, are related
to similar conditions of life. No one will suppose that the stripes on the whelp of the
lion or the spots on the young blackbird are of any use to these animals, or related to
the conditions to which they are exposed.”

Among the higher groups of animals can be detected series “ homologous” on the
same principle as the alcohols (?compound radicals) and their derivatives; and the
component types of each can be, and have been in many instances, shown to be
“heterologous,” as are the ethers,—mercaptans, aldehydes, acids, ete. Among
the Mammalia two (homologous series) have been pointed out: Implacentialia and
Placentialia ;* possibly such are the types Altrices and Praecoces among Aves. Of a
lesser grade in this class are the parallel series of Pullastre and Galline, of Clama-
tores and Oscines. Among Tortoises I have alluded to the Pleurodirat as compared
with the remainder of the order, already parallelized by Wagler; and of lesser grade,
the series among Lacertilia of Acrodonta and Ignania, parallelized by Duméril and
Bibron, and of Teidee and Lacertidse, compared by Wiegmann: I have discovered a

* Perhaps more exist, as Flower and Huxley cast doubts upon some of the supposed distinctions of these
two. Professor Dana’s Megasthenes and Microsthenes may also be such, but they lack as yet the necessary

anatomical demonstration.
t Proc. Acad. Philada., 1864.

102 ON THE STRUCTURES AND DISTRIBUTION OF THE

full parallelism between the Raniform and Arciferous Anura.* It is carried out be-
tween the Characini and a group of remaining Physostomous fishes perhaps not yet
well defined :} it is exhibited between the orders Diptera and Hymenoptera among
insects. None of these comparisons can be allowed, of course, without the most
searching anatomical, histological, and embryological analysis. ’

This heterology is what Swainson and others called “analogy,” as distinguished
from affinity. It generally relates genera of different zoological regions. Mimetic
analogy, on the contrary, relates genera of the same region; it is a superficial
imitation which has occurred to critical biologists, and is of much interest, though as
yet but little investigated. It has as yet been observed in external characters only,
but occurs in internal also; it has been accounted for in the first case by the supposed
immunity from enemies, arising from resemblance to well defended types. No such
explanation will, however, answer in the latter case. I believe such coincidences
express merely the developmental type common to many heterologous series of a
given Zoological “ Region.” This will be alluded to a few pages later.

To return from this digression.

Three principal types of Urodela may be discovered in their skeletal arrange-
ments ; viz. :

TRACHYSTOMATA (Mueller).

O. maxillaria wanting: nasalia embraced by spine of premaxillaria: prefrontalia
wanting; palatina wanting; pterygoidea wanting; orbitosphenoids large, anterior,
forming part of palate; mandible with condyle, without teeth on the dentale. Cera-
tohyals, first two distinct. , |

With branchiz, biconcave vertebra, and cartilaginous carpus, as characters of less
intrinsic value.—

Fam. Sirenidae. Genus Siren.

PROTEIDA (Mueller).

O. maxillare and prefrontalia wanting; palatinum and pterygoideum present, con-
tinuous ; nasalia wanting; orbitosphenoid elongate, not forming part of palate; man-
dible with teeth on the dentale. Ceratohyals, first two connate.

Subordinate features: branchie, biconcave vertebra, and cartilaginous carpus and
tarsus.—

Fam. Proteidae; Proteus and Necturus.

CADUCIBRANCHIATA.}

O. maxillare present; prefrontale present, (with one exception); premaxillaria
embraced by nasalia; palatina present, not approximated to usually present ptery-
goidea ; orbitosphenoid large, not reaching palatal surface ; mandible with teeth on
the dentale.

* Proc. Acad. Nat. Sci., 1864, 181.

} Gill's Eventognathi and Nematognathi being of course omitted.

i This name, though not strictly applicable to Siredons included in the suborder, may be retained.

GENERA OF THE ARCIFEROUS ANURA. 105

Branchiz or fissures present or absent; vertebrae amphi- or opisthoccelian ; tarsus
and carpus cartilaginous or osseous.—

Families Amphiumidae, Protonopsidae, Desmognathidae, Ple-
thodontidae, Amblystomidae, Hynobiidae, Salamandridae,
Pleurodelidae.

PROTEIDA.

This suborder was established by J. Miiller, and is the same as the Proteidz of
Gray.

But one species of Proteus is generally recognized, though Fryer* in 1846 pointed
out the probable existence of a second, and Fitzinger in 1850+ described and named
seven. The latter author had over four hundred specimens at his disposal, and gives
good diagnoses from external characters, including color. The latter feature is
liable to change of shade according to Michahelles,{ who states that of twenty speci-
mens kept by him, only six retained their original flesh color after a lapse of some
months, the remainder becoming bluish black. Dr. Fitzinger promised to make
public the results of an anatomical study of his species, but has not yet, to my
knowledge, accomplished it. In the meantime I drew up the following characters of
five undoubted species from seven skeletons, types of the above, preserved in the

private museum of Prof. Hyrtl, in Vienna.

A. Two condyles on the o. 0. supraoccipitale.

Longitudinal and transverse occipital crests none. Vertebree 25. Premaxillary
teeth, seven each side ; mandibulars seventeen, no teeth on the ov. operculare. From
coronoid -process to angle of ramus, nearly as long as from coronoid to symphysis.
Muzzle narrowed, canthus rostralis weak, F : ; : : 5 VAKOIL Shy

AA. No condyles on the supraoccipitale.
I. Twenty-three dorsal vertebrae; an occipital crest.

Premaxillary teeth eight, mandibulars twenty-one, a few operculars. Coronoid
process scarcely developed. Muzzle, and hence the o. o. frontalia exceedingly slen-
der; latter, with the parietals convex, (? from drying ?) ; : . carrarae.

II. Twenty-five to six dorsal vertebra ; a longitudinal occipital crest.
a. No teeth on o. operculare ; premaxillaries 8—9.

21—2 mandibulars ; from coronoid process to angle much shorter than from former
to symphysis; no groove below coronoid process. Muzzle longer than following ;
o. o. frontalia concave medially, parietalia plane; canthus rostralis strong,

xanthostictus.

* Archiv. fiir Naturgeschichte, 189.
+ Sitzungsberichte Wiener Academie, 291.
{ Isis von Oken, 1831, 505.

104 ON THE STRUCTURES AND DISTRIBUTION OF THE

aa. Teeth on operculare; premaxillaries 8.

Mandibulars 21; from coronoid to angle much shorter than from former to sym-
physis; groove below coronoid extending anteriorly ; muzzle shorter ; frontals plane,
parietals and occipitals concave ; canthus strong, . ; : . schreibersii.

aaa. Teeth on operculare, premaxillary teeth ten (9).

Twenty-nine (four) mandibulars ; coronoid without groove below, much nearer

angle mandible than symphysis; muzzle long, frontals narrow plane; canthus not

strong, : ‘ ; . : é : 4 , : : .anguinus.

I have retained the name of the original species for the last of these species, which
Fitzinger has called P. lawrentii. Zoisii is the stoutest in proportion to the
length. P. carrarae is from Dalmatia, while the others are from Carinthia. <A
specimen like P. xanthostictus, but with nine premaxillary teeth, has been
named /reyeri, and one very near anguinus, with twenty-four mandibulars, has

been named heidingerii.

CADUCIBRANCHIATA.

It is customary to regard this group as presenting two types, one with, and the
other without pharyngeal fissures. But this feature is of no greater value than any
other, as the very nearly allied genera Protonopsis and Megalobatrachus differ in this
respect.

A. An axial cranial bone (? vomer) in front of orbitosphenoids, and one form-
ing palatal surface in front of parasphenoid. ‘Teeth on the outer anterior
margin of palatines. Urohyal and basibyals distinct; two anterior cerato-
hyals connate.

I. Prefrontals and pterygoids present.

Parietals prolonged laterally, not reaching prefrontals. Orbitosphenoid separated
by membrane from prodtic. Vestibule wall osseous internally. Premaxillaries
consolidated.

Carpus and tarsus cartilaginous.

Vertebrz biconcave.

Neck with a pharyngeal slit.

Occipital condyles on cylindrical pedestal.

Mandible elevated in part by tendon passing over parietal bone, and arising from
atlas.

AmpuiumMIp&—T wo genera, Amphiuma, Mureenopsis.

The occipital condyles and temporo-cervical tendon are quite as in Desmognathus;
they have not been previously described. In Amphiuma means there is a minute,
not articulated bone on the suture between the o. o. frontalia and preefrontalia, in the

situation of a lachrymal.

GENERA OF THE ARCIFEROUS ANURA. 105

There are some approximations to Coecilia in Amphiumide. It does not appear to
have been noticed that the latter possess minute scales; the free margin of the
frontal seems to foreshadow the overroofing of the orbit and temporal fossa seen in
Ceecilia. There is also a very large foramen or canal passing through the o. maxil-
lare from near its middle to the orbit, foreshadowing the canalis tentaculiferus of
Coecilia : a narrow one occurs in the same situation in Protonopsis. Further, the
prominent horizontal anterior inferior processes of the vertebral centra are the same
in Amphiuma and Ceecilia.

B. No anterior axial cranial bone ; teeth on anterior margin of o. 0. palatina,
Il. Prefrontals and pterygoids present.

Parietals and prefrontals prolonged, meeting and embracing frontals.

Orbitosphenoid separated from prodtic by membranous wall.

Wall of vestibule membranous internally.

Premaxillaries separated.

Carpus and tarsus cartilaginous.

Vertebre biconcave.

Occipital condyles sessile.

Proronopsip#.—Genera Protonopsis, Megalobatrachus ; Nearctic and Palearctic.

C. No anterior axial bone ; palatines not prolonged over parasphenoid bearing

teeth on the posterior portion. No postorbital arch.

Ill. Prefrontals and pterygoids present.
Parietals and prefrontals prolonged, meeting, embracing frontals.
Orbitosphenoid separated from pro tic by membranous wall.
Wall of vestibule osseous.
Premaxillaries distinct, usually not embracing a fontanelle.
No dentigerous plates on the parasphenoid.
Carpus and tarsus osseous.
Vertebree amphiccelian (biconcave.)
Occipital condyles sessile.
AmBLystomip&.—Genera, Amblystoma, Ensatina, and Onychodactylus. North
America; one species in Japan.

IV. Prefrontals present, pterygoids wanting. .
Prefrontals not prolonged or embracing frontals; parietals slightly embracing.
Orbitosphenoids separated by membrane from proétic.
Vestibule, inner wall osseous.
Premaxillaries always embracing a fontanelle.

Dentigerous plates on the parasphenoid.
27

106 ON THE STRUCTURES AND DISTRIBUTION OF THE

Carpus and tarsus cartilaginous.

Vertebree amphiccelian.

Occipital condyles sessile.

PLeTHoponTID#.—Genera Plethodon, Hemidactylium, Spelerpes, Geotriton, and
Batrachoseps. North America; seven north neotropical species, one in Siam, one in
South Europe.

This family, with that preceding and that following, have been regarded by Dr.
Gray as subtypes of one family,—his Plethodontidx. Dr. Hallowell elevated the
Amblystomide to its present rank in 1859, and I have followed him, and can now
add several confirmatory characters. Nevertheless, the frontals are not embraced by
the parietals and prefrontals in Onychodactylus, but are as in Plethodon; I do not
know the structure of its tarsi and carpi. In Ensatina also, the premaxillary embra-
ces a fontanelle, as in the present family. LEschscholtz correctly represents Batra-
choseps attenuatus as without prefrontals. An elongate process of the frontal
occupies only part of its place, forming no suture with the maxillary; this is quite
different from Desmognathus, where the orbit is completed by the union of frontal
and maxillary. In Batrachoseps quadridigitatus the prefrontal occupies this
depression as an elongate vertical scale.

In Spelerpes rubra the quadratum presents a small internal anterior ala, which
has a superficial resemblance to a pter goid. In this species there is apparently an
azygus bone behind the premaxillaries ; this is, however, only the exposed extremity
of their united spines, which are nearly or quite isolated by the approximation of the
anterior parts of the nasale. It does not occur in the 8S. salmonea.

All the characters of this family are those of low developement, and approximations
to the larval condition, except the loss of the pterygoid; one of the species exhibits a
subocular cirrhus, which occurs in some of the Gymnophidia (Coecilia) and Dactyle-
thra among Anura. It is probably the persistence of that long subocular tentacle
characteristic of the early larval stage of Salamandridxwe and Pleurodelidx (e. g.,
Salamandra Notophthalmus), and of a later larval stage of Dactylethra (vid. Wyman
and Gray), where they resemble the appendages of the Silurida. They have been
called crochets by Rusconi, and homologized with the cylindric cephalic processes of
the larval Rana, with what correctness remains to be proven by observations on
other types. In the young*larva of Bufo americanus they are not developed,
but the transverse black line, at whose extremities they appear in Rana, instead of
vanishing, becomes a fissure, separating two longitudinal lateral lips from an equally
prolonged transverse anterior lip, which has much the form of the labram of an
insect, as, e. g., Locusta.

When the remains of the intervertebral cartilages ave visible, they adhere to the
posterior of two vertebra, except in the single specimen of Hemida actylium scuta-
tum, which I have examined, where they adhere to the anterior.

GENERA OF THE ARCIFEROUS ANURA. 107

V. Prefrontals and pterygoids wanting.

Parietals not embracing frontals.

Orbitosphenoid separated by membrane from prootic.

Vestibule, internal wall osseous.

Premaxillaries embracing a fontanelle.

Dentigerous plates on the parasphenoid.

Carpus and tarsus cartilaginous.

Vertebrae opisthoccelian.

Occipital condyles on cylindrical pedestai,

Mandible elevated by tendon, which arises from atlas and moves over o, parietale.

DESMOGNATHIDE.—One genus, Desmognathus, North America.

This family is now first characterized.

The absence of o. prefrontale does not-appear to be the result of its confluence at
any late period, with the nasale ; its ordinary position is traversed by the frontal
suture. The frontal bone is decurved, and closes the preorbital aspect of the super-
palatal vacuity, usually open.

D. No anterior axial bone. Palatines in contact, prolonged over parasphe-
noid, bearing teeth on posterior external margin.
VI. Prefrontals and pterygoids present, well developed.

Frontal not embraced by parietals and prefrontals.
Orbitosphenoid separated by membranous wall from prodtic.
No dentigerous plates on the parasphenoid.
Carpus and tarsus?
Vertebree ?
Postfronto-squamosal arch or ligament none,
Occipital condyles sessile.
Hynosup&.—Genus Hynobius, Japan.

E. No anterior axial bone. Palatines with posterior separate processes ex-
tending over the parasphenoid, bearing teeth on their inner margins.
VII. Prefrontals and pterygoids present.
Parietal entirely separated from prefrontals by broad frontals.
Orbitosphenoid confluent with prodtic.
No dentigerous plates on the parasphenoid.
No postfronto-squamosal arch or ligament.
Carpus and tarsus osseous.
Vertebra opisthoccelian.
Occipital condyles sessile.

SALAMANDRIDA.—T wo genera: Salamandra, Triton, Regio Palsarctica.

108 ON THE STRUCTURES AND DISTRIBUTION OF THE

This family was characterized by Dr. J. E. Gray, in Proc. Zoological Soc. London,
1858, 142.

VIII. Prefrontals and pterygoids present.

Parietals not embracing the broad frontals.

Orbitosphenoid

No dentigerous plates on the parasphenoid bone.

A. postfronto-squamosal arch, sometimes ligamentous.

Carpus and tarsus osseous.

Vertebrae opisthoccelian.

Occipital condyles sessile.

PLEURODELIDA.—Genera Hemisalamandra, Neurergus, Lissotriton, Lophinus,
Kuproctus, Cynops, Notophthalmus, Pleurodeles, Glossolega, Siranota. Regio Palz-
arctica; three species in North America.

These genera form a series measured by the increasing strength and ossification of
the post-frontoparietal arch, which has been pointed out by Gray and figured by Ger-
vais, Duméril, and Dugés. It is first bony in Lophinus: in Glossolega it is very
stout, and leaves but a small crotaphite foramen, while in Siranota it fills up the
foramen, being entirely continuous with the parietal bone. On this ground Dr.
Gray has regarded this genus as representing a family,—“ Siranotide:,’#-but it does
not appear to be more different from Glossolega than the latter is from Neurergus
and Hemisalamandra.*

The study of the Mammalia, the Rapacious, Pullastrine, Gallinaceous and Passe-
rine Birds, of the Sauria, Tortoises, Tailless Batrachianst and Malacopterygian
Fishes, leads to the conclusion that these portions of the Fauna Neotropica represent
much lower stages in their respective series than do the same types in the Regio
Paleotropica. In a few types, as Zygodactyl Birds and Ophidia, there is, as far as
our present knowledge extends, a seeming equivalency ; but in no single group can a
superiority be proven for the Fauna Neotropica; the tests of the grade being ever
the retention of the characters of the incomplete stages of the extremes of the series,
the relations of generalized and specialized structure, or, where we have not yet demon-
strated thoroughly, by the affinities with forms whose relations in these respects ave
known. These relations coincide in kind with those contrasting the Faune of earlier
and later geological periods, but not in degree, since they refer to the subordinate or

* The genera adopted are those arranged by me, Proc. Acad. 1862, 343. The preparations on which the
preceding investigations have been made are the collections of Prof. Baird and myself; the former in the
Museum of the Smithsonian Institution, Washington,

+ This is in opposition to the following proposition of Giinther, (Proc. Zool. Soc. Lond., 1858,) the contrary
of which, I think, has been abundantly proven. He says: ‘‘ Such a difference between the animal life of the
New World and that of the Old as pertains to other parts of the animal kingdom, is not to be observed in the
Batrachians. Dissimilarity and similarity of the Batrachia Fauna depend upon the zones.”

GENERA OF THE ARCIFEROUS ANURA. 109

homologous divisions of the classes and subclasses, and not to the classes themselves.
Hence the relations between the two Faun will be those of differing minor epochs
in geological time, through several of which some special forms may range; and we
may safely conclude, from data above alluded to, that the Regio Paleotropica is one
or more geologic epochs in advance of the R. Neotropica.

Between these Faunz come the Nearctic and Palearctic, of which Agassiz has said
that the former was an epoch behind the latter. The undeveloped condition of our
predominant types of Salamanders, our Pleurodont Saurians, our more numerous
Clamatores and nine-quilled Oscines, and the comparative fewness of the ten-quilled
Oscines, especially the highest, Turdidx (including Sylviide), would indicate from
an anatomical stand-point that this view is correct, though the balance of difference
is small, and the northern regions are nearly identical.

As to the Regio Aithiopica, excepting of course Madagascar, in reptilian features it
is almost equivalent to the R. Indica; in several points the southern extremity must
be excepted from this comparison.

Of the R. Australis, Prof. Agassiz* bas said that none of its animal products present
that degree of peculiarity exhibited by the Mammalia. Its inferiority is plain, how-
ever, in the points below included ; and if we consider any distributions from the
centres to have taken place during brief epochs»of time, this region will have had
every opportunity of acquiring its few high types, as some Acrodont Lacertilia, and
numerous birds,f which can be most readily transported; including a few high
Oscines from its neighboring Paleotropical area.t

On the whole, it cannot be said that the evidence for the succession here claimed
is as yet much more than fragmentary; yet it appears to be sufficiently indicated,
which cannot be said of any other order or succession.

The succession of the great regions and grounds therefore, may then be imper-

fectly illustrated as follows :

R. Australis.—lInferior in Monotrematous and Marsupial Mammalia, Pullastri-
form and Struthious Birds, Serpentiform Pleurodont Lacertilia, Arciferous Ba-

* Contrib. I. 44. Prof. A. also gives a table of Scincide from Dumeril and Bibron, illustrating its distribu-
tion, from which it would appear that the greater number of limbless and digitless types are from other regions
than the R. Australis. But of the twenty genera, with toes less than 4—4, but ezght belong to the Scincide.
Adding to these two from Gray’s Catalogue, we have seven of them Australian, one South thiopian, one
Palearctic, and one Paleotropical. It possesses in addition the limbless families Pygopodide, Lialiside, and
Aprasiide. It must at the same time be remembered that the most elevated Scincidw belong to the same
region Cyclodus, Hinulia, ete.

+ Much must yet be allowed for the incompleteness of anatomical knowledge of the birds. The only system
which, in many features, appears to nearly accord with nature, is that published by Wilh. Lilljeborg, Upsala
Transactions, 1862.

t Vide articles by A. Wallace on distribution in the Malaysian and Australasian Archipelagos.

28

110 ON THE STRUCTURES AND DISTRIBUTION OF THE

trachia, Pleurodire Tortoises, its Elapid venomous snakes, and the whole Flora,
according to Unger.

R. Neotropica.—Marsupial” and Edentate Mammalia, Inferior Rodentia and
Quadrumana, Pleurodire Tortoises, Pleurodont Lacertilia, Arciferous Batrachia,
Clamatorial and Pullastriform Birds, Characin and Erythrinid Malacopterigi.

R. Nearctica—tLacking most of the inferior types of the preceding, it retains
more Arcifera and Bufoniformia, Pleurodont Lacertilia, and Clamatores, than
the following; possesses the inferior Urodela, the Aphredoderus and Percopsis,
and wants as types of the

R. Palaearetica—Higher Urodela, Acrodont Lacertilia, higher Galline* and
Oscines. This is inferior, however, to the last in Ophidia Solenoglypha.

R. Palaeotropica or Indica,—Superior in types of Teleostei, Batrachia Anura,
Lacertilia Acrodonta, Testudinata,} Gallinacéous and Oscine Aves, Mammalia,

including Homo.

If the above succession be marked out in present time, it has no doubt existed
throughout a longer or more probably shorter series of recent geologic periods or
epochs, and over areas of course only partially coinciding with those of the present
Regions. This points to the Regio Paleotropica, faunally and florally most advanced
in time, as the seat of first origin of the human species, as already indicated by revela-
tion and tradition. The fact of its being the source of such a majority of the vegeta-
ble and animal products most useful to the species, is in harmony with this view ;
and more so is the known, almost regular departure from the typical symmetry of
form and expression of mind by body, in the men of the different Regions. That these
areas were occupied by man in this succession, determined by their preparation for
maintaining a degree of developmental perfection, sufficient to enable him to take his
part in “the struggle for existence,” is a natural sequence of the relation in time.

Paleontology is as yet too incomplete to answer the question as to how ancient
such a relation may be. Its indications are quite contradictory, and perhaps may
not be relevant, prior to Ceenozoic time.

Thus the resemblance between existing Australian and American types and terti-
ary Kuropeant forms successively, harmonizes with the existent relations between
the faunze here proposed ; but the similarity between fresh water shells of the Upper

Missouri Lignite and recent Indian forms, between American Kocene and European

* KH. g., Phasianus, Tetrao, Lyrurus, Tetraogallus, ete.

} Possesses a greater number of distinct types of Emydide and T'estudinidw than the R. Nearctica, though
not much beyond it.

{ Among others, the extinct genera Polysemia Myr. and Heliarchon Myr. exhibit the unossified carpus and
tarsus of the recent American Plethodontide.

GENERA OF THE ARCIFEROUS ANURA. 1g Gl

Miocene plants, and between American Cretaceous and European Eocene plants, are
of exactly contrary significance. Of the same meaning is the appearance of true
Crocodiles* in American Cretaceous, equal European Eocene.

As progress is the rule in paleontology, the lapse of time will probably see a later
equivalency of some kind between the characters of the products of the inferior
Zoological Regions, ¢. y., Australis, Neotropita, and of those characterizing the
highest,—e. y., Palzotropica, at the creation of man,—and mosily still remaining.

The ready and rapid naturalization of Palxotropical and Palearctic plants in the
North and South American and Australian regions, is a remarkable feature often
noticed.; This will furnish the future paleontologist with the explanation of the
modification of flora of a region on the introduction of a new epoch, and that by no
course of descent within that region; and constituting a nearer equivalency, as
above proposed, with that higher flora established long since in the Regio Palso-
tropica.

The extent of time during which the regions owe their products to migrations and
modifications, may have been limited to periods or epochs only. In respect to
terrestrial cold-blooded vertebrata, the following facts in their geographical distribu-
tion are patent ; they have been observed also in other types :{

First, the identity of many of the boreal genera throughout the earth; second, the

* With regard to the amphiceelian Crocodile genus Hyposaurus Owen, of the New Jersey Green Sand, I
would state that it differs in one feature from all known extinct Crocodilians. The neural spines of the cervi-
cal vertebrae are acumin ate, of considerable—finally, of great—height, the anterior standing transversely on
the neural arch, the median subtetragonal, the posterior, as usual, longitudinal in section. In an anterior
cervical vertebra, length 2 in., the spine is 2 in. 10 1. above the ceiling of the arch, and is acute; it receives a
strong lateral wing from each posterior zygapophysis, which does not disappear till near the tip. These en-
close a deep groove on each side behind, with a strictly perpendicular posterior median rounded rib; in front
a narrow keel extends from the tip to the neural canal ; the lateral ale are curved backwards. On a more
posterior cervical, the lateral ale are very heavy, short and rounded, and enclose no groove with the slightly
projecting posterior vertical rib, while the anterior keel has become a strong compressed wing, dividing two
shallow anterior grooves ; breadth and length equal in section. Ina last cervical, length 2 in. 2 1, the longi-
tudinal section (equal about an inch) is longitudinal cuneiform, owing to the projection of the anterior ala. In
an anterior dorsal the section is longitudinal (1 in. 5 1.); the lateral ribs remain at the base only, and the
posterior carina is strong and sharp; it is acuminate, and was probably subacute, but is broken at tip; if re-
stored would measure 4 in. 6 ]. at least.

This creature possessed some kind of elevated dorsal carina, probably dermal, as in some Anolide and
Iguanide, though the spines are not acute and ribbed in the latter. Their appearance in Hyposaurus suggests
some kind of conic dermal horny sheath as defensive weapons; the vertebral line could not in any case have
been covered bygfat bony plates, as in ordinary Crocodilia, (See Leidy’s Cretaceous Reptiles of the United
States, 1865, p. 18.)

7 See Dr. J. D. Hooker's article (Linnean Society) on Naturalization of European Plants in New Zealand,
and Prof. A. Gray’s Botany of the Northern United States.

{ A. Murray on Coleoptera, Old Calabar. Trans. Linnean Soc. Lond., 1863.

112 STRUCTURES ETC. OF THE GENERA OF THE ARCIFEROUS ANURA.

occurrence of closely affined forms in the most nearly approximated regions of West
Africa and South America; third, the appearance of similar forms in the most
adjacent parts of South America and Australia.

Finally, as Guyot* points out that the races of man are inferior as we reach the
southern extremities of the continents which are prolonged into the great Water
Hemisphere, so it can be shown that these extremities produce the greater number of
“degraded” or “undeveloped” genera of Batrachia Anura, as indicated by the con-
dition of their cranial bones, sternum, ete.

* Karth and Man.

EXPLANATION OF PLATE 25.

. Thoropa missiesii Bzbr., Rio Janeiro. Anterior part of cranium above.

moe

Chorophilus oculatus Daud. (Cystignathus ornatus Gthr., not C. oculatws Holbr.) a, premaxillaries ;
b, maxillaries ; c, prefrontals ; d, ethmoid; e, frontoparietal ; f, quadratum ; g, prodtic ; h, exoccipital.
From Georgia.

3. Scytopis venulosus Daud., Brazil.
4, Smilisca baudinii D. § B.. Mexico: g, anterior and posterior terminal phalanges.
5. Hyla palmata, Brazil.
6. Agalychnis moreletii, Guatimala.
7—8. Triprion petasatus m,, Yucatan,
9. Scaphiopus solitarius, Georgia.
10—11. Discoglossus pictus, Greece: a, arched cartilage ; 6, acromial ; c, coracoid; d, xiphisternal; e, ribs;
f, coccygeal diapophyses.

12. Pelobates fuscus, Austria.

13. Megalophrys montanus, Java, ;

14. Chiroleptes australis, New 8.

15. Gnathophysa ocellata, Surinam,

16. Pithecopus fuliginosus, Brazil.

17. Borborocaetes peronii, Australia,

18. Hylorhina aenea, Chili.

19. Phyllobates bicolor, Cuba,

20. Enhydrobius vomerinus, Rio Janeiro.

21. Lithodytes oxyrhynchus, West Indies

22. Zaphrissa eurypelis m., sp. nov. Fossil. S

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