420 [October, 



jaw; for notwithstanding all that has been said of their harmless nature, they will 

 strike as any other venomous snake will, as T experienced last spring with 

 one of the largest I have ever seen. Moreover, in some foreiojn specimens of this 

 genus, if the fangs were always perpendicular in the jaw, the mouth would not 

 be closed without their piercing entirely through the lower lip. 



The Committee on Mr. Girard's descriptions of new ReptileS; reported 

 in favor of publication. 



Descriptions of nevj species of Reptiles, collected hy the IT. S. Exploring Expedi- 

 tion, under the command of Capt. Charles Wilkes, U, S. iV. 

 Second Part. Licluding the species of Batrachians, exotic to North America, 



By Charles Girard. 



Taking for our guidance the structure of the vomerine or palatine teeth, that 

 of the tympanum and tongue, we have been led to subdivide the genus Cystigna- 

 tluts as understood byDumeril and Bibron, in the "Erpetologie generale." The 

 structure of the fingers and toes have afforded accessory characters which are 

 not to be neglected, although comparatively less important. 



Leptodactylus, Fitz. Vomerine teeth disposed in two transverse series, each 

 constituting either an angular arch or a regular curve, and situated behind the 

 inner nostrils. Tongue slightly notched posteriorly. Tympanum very distinct. 

 Toes either provided with a rudimentary membrane or entirely free. 



Obs. Leptodactylus ocellatus, Fitz. (C ocellatus^ Dum. and B.), L. la- 

 BYRiNTHicus {Rana lahyrinthica, Spix ; C.lahyrinthicivs, Dum. and B.), and L. 

 TYPHONius, Fitz. (C. typhonius, Dum. and B.), belong to this genus. 



Cystignathus, Wagl. Vomerine teeth disposed upon a transverse or oblique 

 row, more or less interrupted in the middle, and situated either between the 

 inner nostrils or behind them. Tongue circular, subcircular or subcordiform, 

 posteriorly entire, and either attached by its whole surface, or very slightly free 

 behind. Tympanum distinct. Toes either bordered by a membranous fold or 

 slightly vv^ebbed at their base. 



Obs. Cystignathus macroglossus, C. gracilis and C. roseus of Dumeril and 

 Bibron will remain in this genus. 



Pleurodema, Tsch. Vomerine teeth disposed in two oblong groups situated 

 between the inner nostrils. Tongue subcircular, either slightly emarginated or 

 entire posteriorly. Tympanum indistinct. Toes either entirely free, or else 

 provided with a rudimentary membrane at their base or along their margin. Skin 

 pustulous or granular ; sometimes a large lumbar gland on each side. 



Obs. Pleurodema arunco {Biifo arunco, Schn.) ; P. bibroni, Tsch. (C 

 hibroni, Dum. and B.) ; P. bufoimum, Bell ; P. darwinii. Bell ; P. elegans, Bell, 

 and P. nodosa (C. nodosus, Dum and B.), constitute another generic group. 



Crinia, Tsch. Vomerine teeth either absent or else existing in a rudimentary 

 state. Tongue elongated, subelliptical, posteriorly entire, or very slightly 

 emarginate. Tympanum indistinct or hidden under the skin. Eustachian tubes 

 very small. Fingers and toes subcylindrical, tapering to a point and perfectly 

 free. 



Obs. This genus as characterized above, may not meet with the approba- 

 tion of Erpetologists, as combining species deprived of vomerine teeth and 

 others possessing but very few of them. Indeed, if we had more than one 

 species differing from the others in similar characters, we should not hesitate 

 to make two genera in the following manner : 



Crinia, Tsch. Vomerine teeth few, constituting two groups at the posterior 

 margin of the inner nostrils. Tongue entire, oblong. Tympanum not very dis- 

 tinct. Eustachian tubes quite small. Fingers and toes without membrane. 

 Crinia georgiana, Tsch."* 



