THE SALAMANDER TRIBE 



2667 



is ligamentous posteriorly in Pachytriton, which has also the tail cylindrical at 

 the base, instead of compressed throughout. The former genus, in which the skin is 

 extremely warty, is represented by one species from Siam and the Eastern Him- 

 alayas, and a second from the Liukiu islands, while the latter is known only by a 

 single Chinese form. 



Although properly speaking .the term axolotl applies only to the per- 

 manent larval form of the Mexican representative of the genus Am- 

 blystoma, it will be found convenient in practice to make it include all the members 

 of that group, whether mature or immature. Together with certain other genera, 



I.ARVAI. STACK OF MEXICAN AXOI.OTI.. 



(Two-thirds natural size.) 



AmUystoma constitutes a second subfamily (Amblystomatina) distinguished from 

 the Salamandrina by the teeth on the palate forming a transverse or posteriorly con- 

 verging series, and being inserted on the hinder portion of those bones known as the 

 vomers, as well as by the bodies of the vertebrae being cupped at each end. The 

 type genus is specially characterized by the palatal teeth forming a nearly straight 

 or angulated series, not separated by a space in the middle line; and likewise by the 

 radiating folds of skin on the tongue, which are oval or nearly circular in form, 

 with the sides completely and the front partially free. There are five hind-toes, 

 and the tail is more or less compressed. Represented by a number of North- 



