_Suprà nigricans, lumbis maculis 3 vel 4 nigris, albo-marginatis._
DESCRIPTION.—The head is short, the opening of the mouth small, the
tongue rather thick, very slightly emarginate behind, and with the
posterior margin free. The eyes small; the tympanum not very
conspicuous; there is a trace of a parotid gland on each side of
the neck. The body is rather thick, and the limbs proportionally
short. The hinder toes are only connected at the base by a
rudimentary membrane, the first four gradually increasing in
length, and placed along the side of the matatarsus, one beyond
the other; the fifth on the same line as the fourth, but not more
than half its length. The metatarsal tubercle is rather prominent,
and there are small subarticular tubercles on the toes of all the
feet.
COLOUR.—The colour of the upper parts is brownish black. On each side
near the thigh are three or four perfectly round black spots, each
surrounded with a white line. The under parts whitish.
Of this second species of a rare and remarkable genus, one specimen only
exists in Mr. Darwin’s collection. It is only the third known instance,
in the family of the RANIDÆ, of the absence of palatine teeth; 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 BUFONIDÆ 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.
Inches. Lines.
Length of the head and body 0 9
of the anterior extremities 0 5
of the posterior extremities 1 1
It was found by Mr. Darwin at Port Desire, and its habitat is very
remarkable. “It is bred in and inhabits water far too salt to drink.”
GENUS—PYXICEPHALUS. _Bibr._
PYXICEPHALUS AMERICANUS. _Bibr._