I 
CYSTAGNATIIUS SENEGALENSIS. 
the fingers, four in number, rounded, rather short, blunt at the point, and 
with a small tubercle under each joint ; they are slightly webbed at the base, 
the second toe from the outside rather the longest, the outermost next in 
length, the third, and innermost, equal and rather shorter. • The hinder 
extremities are moderately robust, particularly the thigh, and when they are 
extended along the sides, the base of the longest toe reaches to the tip of the 
nose ; the second toe, reckoning from the outside, is considerably the 
longest ; the outer one and the third nearly equal, and not so long by two 
joints as the second ; the fourth is considerably shorter, and the fifth not 
quite so long as the fourth ; at the base of the latter is a pointed and rather 
lengthened tubercle, somewhat resembling a rudimentary toe ; under each 
joint a prominent tubercle, as on. the fore feet. Under the throat, in the 
male, is a raised oval disc with loose edges, excepting close to the chin ; and 
on each side of this, towards the posterior extremity, is an irregular depres- 
sion, bounded by plaited or puckered skin (fig. a). The depressions result from 
a portion of the skin of each side being inverted, by means of the apparatus 
destined to diminish the size of the cavity for air ( guttural sac), which exists 
on each side, under and behind the disc already mentioned. The skin 
which covers the sac is everywhere puckered or plaited, in order to accom- 
modate itself to the condition of the parts interior to it. The openings by 
which the air enters the guttural cavity are two short, narrow fissures, one on 
each side of the lower jaw, a little in front of the angle of the mouth. Lower 
parts of the sides, and outer portion of the belly, with a number of 
narrow longitudinal subgranular plaits; middle of the belly with the same 
description of plaits, only much more delicate ; the hinder aspect of the 
thighs rugose from a like structure. The upper surface of the body, and all 
the other parts not above noticed, have the skin perfectly smooth. Full- 
grown specimens generally measure about two inches. 
This frog is not found in the Cape Colony, though specimens are occasionally obtained 
not far beyond it. It lives in burrows, under ground, and is exceedingly noisy during dull 
weather, or immediately before rain. The noise is no doubt produced by the forcible ejection 
of the air from the guttural sac, by means of appliances with which the male is furnished ; 
it consists of a very loud and sharp whistle, repeated once or oftener in a minute. Many, 
perhaps twenty persons, were occupied for hours searching for the individuals which first 
attracted our notice, but no traces of them could be discovered till a Hottentot, noticing a 
small hole in the ground, suspected what we were in search of was in it. It was the 
entrance to a burrow, in which was at least one of the individuals which had caused us such 
anxiety. The secret having been discovered, we procured many specimens. 
