panum not very conspicuous; th e re is a trac e o f a p aro tid g lan d on each side o f th e neck. T h e
body is ra th e r th ick , an d the limbs proportionally short. T h e h in d e r toes are only connected
a t th e base by a ru d im en ta iy membrane, th e first four gradually incre asing in len g th , and
plac ed along th e side o f th e matatarsus, one beyond tlie o th e r ; th e fifth on th e same line as
th e fourth, b u t n o t more th a n h a lf its length. T h e metatarsal tuberc le is ra th e r prominent,
an d th ere arc small subarticula r tubercles on th e toes o f all th e feet.
C olour.— T h e colour o f th e u p p e r p a rts is brownish black. O n each side n e a r th e th ig h are th ree
or four perfectly ro u n d black spots, each su rrounded with a white line. T h e u n d e r p arts
whitish.
O f this second species of a rare and remarkable genus, one specimen only
exists in Mr. Darwin’s collection. I t is only the third known instance, in the
family of the R a n i d * , of the absence of palatine te e th ; the others being
Oxyglossus Lima of Tschudi, and Leiuperus marmoratus of Bibron. The present
genus must be considered as nearly approaching the family of the BopoNiDiE in
the absence of palatine and the extreme minuteness of the maxillary teeth, in
the extremely small gape of the mouth, the thick form of the body, the shortness
of the limbs, and the existence of rudimentary parotid glands. I have not had
an opportunity of comparing this specimen with those on which Bibron founded
the genus, but I cannot doubt the specific distinction between them.
DIMENSIONS.
In. Lin.
Length of the head and b o d y ....................................... 0 9
of the anterior extremities .............................. 0 5
of the posterior extremities 1 1
I t was found by Mr. Darwin at Port Desire, and its habitat is very remarkable.
“ I t is bred in and inhabits water far too salt to drink.”
G e n u s— PY X IC EPH A LU S . Bibr.
P y x i c e p h a l u s A m e r i c a n u s . Bibr.
P late X V IIL—F ig . 2.
Linguá cordiformi; dentibus palatinis in lined transxwrsá interruptd, inter nares
posteriores positis; tympano celato; dorso mammillato.
This curious species has, I believe, only once before been found. A single
specimen exists in the French Museum, which was brought from Buenos Ayres
by Mons. d ’Orbigny, and which formed the subject of Mons. Bibron’s description.
Mr. Darwin’s specimen was taken on the open plains at Monte Video.
Of the three species of this remarkable genus a t present known, two are
inhabitants of Africa, from whence they were brought by Delalande. As neither
of them has as yet been figured, it was thought desirable tha t the present opportunity
should be taken to exhibit some of the generic characters, and especially
the hard horny spur on the hinder foot.
This genus is one of those bufonine forms of the R a n i d .® which irresistibly
lead us to doubt the correctness of the present received arrangement of the anourous
Amphibia.
G e n u s -A L SO D E S . Bell.
Caput convexum. Lingua anticè acutè-producta, posticè rotundata, et libera. Dentes
palatini inter nares posteriores. Tympanum celatum. Aperturæ Eustachianæ
hand conspicuce. Digiti anteriores ad basin tantum—posteriores usque ad pha-
■em iertium membrana connexi.
A genus of the Raniform group, nearly allied, as Mons. Bibron observes, to
Scaphiopus, by the structure of the hands, which, although without any projecting
rudimentary thumb, has a small process under the skin, along the extreme margin
of the first finger. In common with the genus Bombinator, it has the opening
of the Eustachian tubes so small as scarcely to be detected.
A l s o d e s m o n t í c o l a . Mihi.
P late X V I I I .—F ig. 3.
D e s c r ip t io n .— H e a d semi-elliptical, somewhat convex, w ith th e muzzle n e a rly p e rp en d icu lar;
v e rte x smooth. E y e s o f moderate size. Nostrils very small, open in g upwards. Tongue
b ro a d a n d ro u n d e d b ehind, narrowing to a p o in t a t th e apex, d eta ch ed a t th e posterior p art.
P a la tin e te e th in two small approximate patches, betwe en th e posterior nostrils. Openings o f
th e E u sta c h ia n tu b es scarcely visible. E x trem itie s o f moderate len g th . T h e fore fe et, with
four ra th e r sh o rt toes, conne cted a t th e base by a sh o rt m em b ra n e ; th e in n e r toe b ro ad , an d
w ith a slig h t p ro jec tio n u n d e r th e skin, along its in n e r m a rg in ; h in d e r toes c o n n e c ted as far as
th e jo in t o f th e second an d th ird j
The colour of the only specimen in the collection has become totally changed
into a smoky brown by the spirit, but the following is Mr. Darwin’s description