70 GUIDE TO KEPTILES AND AMPHIBIANS. 



in small mountain-streams, where it lies concealed under stones, etc., 

 and feeds on fishes, amphibians, worms, and insects. Like its 

 American relative, it will readily take a bait, and it is caught for 

 food by the natives. It does not appear ever to leave the water. 

 A specimen has lived in captivity for over 50 years. 



The typical representative of the family is the eel-like Three- 

 toed Salamander {Amphhmia means, 550; fig- 69) of North America. 



Passing on to the family Salamandrida', of which the distinctive 

 features are mentioned on page 69, we have the North American 

 Tiger-Salamander {Amblystoma tigrinum, 552) as the typical repre- 

 sentative of the sulvfamily Amblystomafinu', which includes seven 



Fig. 70. 



The Axolotl ; the egg-laying larval form of Amblystoma tigrinum, Mexico. 



(No. 552.) 



genera, characterised by the grouping of the palatal teeth and 

 the number (four or five) of hind-toes. Ordinarily A. tigrimmi 

 undergoes the usual development and transformations, commencing 

 life as an aquatic creature with external gills, and passing when adult 

 into a terrestrial air-breathing Salamander. In the lakes near the city 

 of Mexico the species remains, however, permanently in the aquatic 

 gill-bearing condition (fig. 70), reproducing its kind while in this 

 state. To the natives these permanent larva; are known by the name 

 of Axolotl. They are frequently brought to this country and repro- 

 duce in the gill-bearing phase, but occasionally, even in captivity, have 

 been seen to leave the water and change into gill-less Salamanders. 



