1880.] PAL.«ARCT1C AND jETHlOPIAN TOADS 559 



old specimens ; the first and third fingers are about equally long j 

 the first being laid against the second, exceeds it by about one 

 third or one fourth of its own length ; the subarticular tubercles are 

 double, although often imperfectly. The principal palmar tubercle 

 is relatively larger than that of B. viridis. 



The hind limb is longer than in the preceding species ; being cat 

 ried forwards along the body, the metatarsal tubercles reach the tip 

 of the snout in males, the anterior corner of the eye, or slightly 

 beyond, in females ; the calf is much longer than the head, and with- 

 out parotoid-like gland. The cutaneous tarsal fold is like that of B. 

 viridis. The metatarsal tubercle at the base of the first toe is strong, 

 oval, very prominent ; that at the base of the fourth toe rather 

 smaller, subcircular, flat. The toes are somewhat longer than those 

 of B. viridis, slightly depressed, very obtuse ; the fourth is one third 

 longer than the third, which is a little longer than the fifth ; they 

 are united at the base by a short web, which extends as a fold 

 along their borders ; most of the subarticular tubercles are two- 

 rowed. 



The warts of the back and sides are like those of the preceding 

 species, and sometimes spinose. The upper surface of the forearms 

 and calves, instead of being nearly smooth, are strongly warty. The 

 granules of the inferior surfaces are larger and more distant from one 

 another upon the lower belly and vmder the thighs. 



The upper parts are greenish yellow or brownish, with large, in- 

 suliform, rarely confluent, olive, or reddish-brown black-margined 

 spots. M. Heron Royer has shown me a living specimen which is 

 above light grey, with some traces of spots on the head only. The 

 lower surfaces are dirty white or yellowish, without spots. The tips 

 of the fingers and toes are, at least during the breeding-season, 

 reddish-brown or blackish. 



The iris is light yellow ; on each side of the pupil, the black ver- 

 miculations, which are nearly absent above and beneath, cover the 

 yellow tint, and produce the aspect of a dark vitta through the eye. 



The males are provided with a subgular vocal vesicle, which is 

 nearly as much developed as in B. calamita ; the few males I have 

 had the opportunity to examine have either two vocal slits or only 

 one on the right side. During the breeding-season the throat is 

 bluish, and the first three fingers are provided with black rugosities 

 like those of B. calmnita. 



Skeleton. — The skull of B. mauritanicus is very remarkable, and 

 differs greatly from that of the preceding species, approaching in 

 some respects that of some Indian and American species, B. mela- 

 nostictus and B. agua for instance. The fronto-parietal bones, which 

 do not show any trace of a fontauelle, and which are even sometimes 

 nearly soldered together, expand laterally into a sort of crest, which, 

 united with smother one formed by the supraorbitals, to which they 

 are quite soldered, borders the orbit above and behind ; these bones 

 are ;very concave, and nearly twice as broad backwards as for- 

 wards. The prefrontals are large, a little broader than long. Some- 

 times the prefrontals and fronto-parietals meet together along their 



