AMPHIBIA AND REPTILIA OF COLORADO 49 



Genus AMBYSTOMA Tschudi 



Ambystoma Tschudi, Classification der Balrachier, p. 92, 1838. 



Ambystoma tigrinum (Green) 

 Tiger Salamander 



Salamandra tigrina Green, Journ. Acad. Nat. Sci. Phila., Vol. V, p. 116, 1825. 



Amblystoma mavorlium — Yarrow, Wheeler Survey, Vol. V, pp. 516-519, 1875 

 (Denver, San Luis Valley). 



Amblystoma trisruptum— -Yarrow, U.S.N.M. Bull. 24, p. 150, 1882 (South 

 Park, Colo.). 



Amblystoma tigrinum — Cope, U.S.N.M. Bull. 34, p. 85, 1889 (South Park, 

 Colo.) ; Elrod, The Museum,Vol. I, p. 263, 1895 (Pike's Peak, Colo.) ; Cockereix, 

 Univ. Colo. Studies, Vol. VII, p. 131, 1910 (Meeker, Colo.); Prosser, Univ. Colo. 

 Studies, Vol. VIII, pp. 257-263, 191 1 (Tolland, Colo.); Cary, N. Am. Fauna, 

 No. 33, pp. 22 and 40, 191 1 (Loveland and Estes Park, Colo.). 



Head longer than wide, its width equal to or slightly less than that 

 of the body; body stout and somewhat depressed, with 12 costal 

 grooves; tail compressed and long, its length usually about equal to 

 that of the body and head; digits, 4-5, not webbed; sole of the foot 

 with two tubercles ; size medium, length up to twelve inches. 



Ground color brown, blue-black or black, of a waxy luster, with 

 numerous irregular spots and bars of yellow which are often so united 

 as to cover a greater area than the ground color; ventral parts yellow, 

 or blackish overlaid with yellow; throat bright yellow. 



The larvae of this species are a rather uniform dark brown and 

 may be recognized by the large bright red tufts, the external gills, on 

 each side of the throat. 



A. tigrinum ranges from Maine to California and south well into 

 Mexico, a range greater than any other North American species of the 

 Caudata. In the southern part of its range the larvae often become 

 sexually mature and reproduce without transforming into adult sala- 

 manders, a condition which may be brought about artificially by con- 

 fining the larvae to the water and keeping it warm enough. These 

 sexually mature larvae are known as Axolotls and are quite abundant 

 in the lakes and ponds in Mexico. They are highly prized by the 

 natives for food. The eggs are laid in the early spring. They are 



