HABITS OF "AMBLYSTOMA TIGRINUM" AT 

 TOLLAND, COLORADO^ 



By Dean T. Prosser^ 



Ambly stoma Hgrinum, the salamander with which this paper 

 has to deal, is found in North America between the limits of northern 

 Minnesota and New Mexico. In Colorado specimens have been 

 taken all the way from the plains up to 10,000 feet. It is about 

 twenty-four centimeters long; one-half of this length being tail. 

 The general color is dark brown while the yellow ventral surface is 

 cut into thin cross bands by brown patches. The head is compara- 

 tively long. There are twelve costal grooves. The fore limbs when 

 pressed back reach the hind limbs. The male, besides being some- 

 what larger than the female, has the cloacal lips very much swollen 

 and nodular in appearance in distinction from the smooth Hps of the 



female. 



Changes from Larval to Adult Form 



This animal, like all other Amblystomatidae, develops from 

 a larval form which has gills. The larvae may reach a length of from 

 fifteen to twenty centimeters. They are thicker dorso-ventrally 

 than are the adult forms and narrower laterally. In passing from 

 larval to adult stage, the change is a gradual one in which the fol- 

 lowing are some of the most prominent features. 



(i) Absorption of filmy portion of tail. 



(2) Absorption of gills. 



(3) Appearance of head, body and tail curves. (See Fig. i.) 



(4) Growth of the posterior end of the operculum to the body. 



(5) Greater development of the limbs. 



Field Studies 

 Tolland, Colorado, where these investigations were undertaken, 

 is located about eighteen miles from Boulder, Colorado, the home 



» Publication of the Colorado Biological Survey, No. 2. 



' The author is indebted to Professor Francis Ramaley for criticisms and suggestions. 



257 



