5*6 



COLLEGE ZOOLOGY 



Triton torosus, the newt of western North America, is a large 

 species reaching a length of six inches. It feeds on earthworms. 



The common 

 fire salamander of 

 Europe is Sola- 

 mandra maculosa, 

 a species about six 

 inches long. It is 

 black, with bright 

 yellow spots, and 

 the glands of the 

 skin secrete a 

 poisonous sub- 

 stance. The 

 inemies cf salamanders are supposed to be " warned " by the 

 conspicuous colors and will not attack this poisonous species. 



Pronounced sexual dimorphism, i.e. differences between the 

 male and female of the same species, is exhibited by Triton 

 cristatus (Fig. 431), the European crested newt. The male is 

 conspicuously colored and 



Fig. 431. — Triton cristata. i, female; 2, male as he 

 appears during the breeding season. (From Shipley 

 and MacBride, after Gadow.) 



high serrated 



the breeding 



develops a 

 crest durin 

 season. 



Family Ambystomid^e. — 

 A common member of this 

 family is Ambystoma tigri- 

 num (Fig. 432). This species 

 occurs from New York . to 

 California and south to cen- 

 tral Mexico, and reaches a 



length of from six to nine inches. It is dark colored and marked 

 with yellow spots. The larval form, called axolotl, was for a 

 long time considered a separate species because the external 

 gills persisted in the adult. Later it was discovered (1865) that 

 if forced to breathe air the axolotls would shed their gills and 



Fig. 432. — The axolotl stage of the 

 tiger salamander, Ambystoma iigrinum. 

 (From the Cambridge Natural History.) 



