ON TIIE BATRACHIA AND REPTILIA OF COSTA RICA. 



99 



are no cranial ridges except a protuberant supra-tympanic ; the superciliary ridges 

 are slightly prominent and continued behind in straight lines by two angles of the 

 parietal bone. No trace of membranum tympani. The canthus rostrales are 

 straight and angular, and the lores elevated ; the nares are nearer to each other 

 than each is to the orbit. The tongue is large and elongate. The skin of the 

 back and sides is studded with numerous spaced tubercles, and the lower surfaces 

 are nearly smooth. There is no tarsal fold, and the palmar and plantar tubercles 

 are obsolete. The digits are all distinct, those of the hind foot half-webbed. The 

 wrist of the fore limb, and the end of the second toe of the hind limb extended, 

 reach the end of the muzzle. 



M. 



. .025 



. .008 



. .003 



. .010 



. .021 



. .014 



. .005 



. .023 



. .013 



Upper surfaces blackish, the tubercles brown ; below black, thickly marked 

 with light blue spots. 



From 3000 to 5000 feet elevation on Pico Blanco. 



7. Bufo auritus, Cope, sp. nov. 



Vertex flat, bounded by a vertical superciliary crest on each side, which is 

 slightly bent where it gives off the postorbital crest, and then continues to the 

 posterior border of the cranium. Post-orbital ridge prominent, presenting an open 

 angle where it gives off the supratympanic, particularly prominent as the anterior 

 border of the tympanic membrane. Supratympanic horizontal, prominent. Supra- 

 orbital crests abruptly incurved at the loreal region, and separated by a narrow 

 groove at the summit of the muzzle. No preorbital crest. End of muzzle narrow, 

 produced beyond the line of the upper lip ; external nares nearer each other than 

 the orbit. Parotoid gland quite small, surmounted by several dermal spines. 

 Tubercles of the skin small, spinulose, most numerous on the sides, wanting below. 

 Tarsus without fold, spinulose ; palmar and solar tubercles insignificant. Digits 

 elongate, the fingers remarkably so; the toes half-webbed. The wrist reaches 

 beyond the end of the nose, as does also the heel of the extended hind limb. The 



