CADUCIBRANCHIATA. 29 



AMBLYSTOMA 



Synonym, Plagiodon, Dumeril and Bibron, includes 

 Xiphonura, Tschudi and Heterotriton, Gray. 



Palatine teeth in a transverse, often interrupted row, 

 sometimes in the form of an arch or crotchet ; toes, four 

 in front, five behind, never palmate; tongue fleshy? 

 round or long, centrally attached, with lateral and ante- 

 rior margins free; quadrato-jugal bone wanting; skin 

 smooth, slimy, perforated with mucous pores, especially 

 above the orbits and in the parotid region; costal fur- 

 rows strongly marked; tail short, round to oval at the 

 base, but compressed towards the extremity; vertebra? 

 amphiccelous ; parasphenoid not dentigerous; orbito- 

 sphenoid and pro-otic separated by membranes; pos- 

 terior margins of palatines bearing the teeth; carpus^ 

 tarsus, and basi-hyal ossified in adults. 



As Prof. Cope (24, m) has given a very line analytical 

 table of this genus as well as descriptions of the species I 

 have transferred his table to this work and have abridg- 

 ed many of the descriptions from those given bv him 

 and would refer persons desiring a more complete study 

 to his very able presentations of the subject. His an- 

 alysis is as follows: 



I. Series of teeth along the external fissure of the inter- 

 nal nares, Plicae of tongue radiating from its posterior 



