190 Illinois State Lahoratonj of Natural HiMory. 



distinct species. The northern form is probably the B. lentig- 

 inosuSy var. americanus. and the southern form the var. len- 

 tiginosus of authors. 



Diemi/cti/liis viriclescens, Raf. 



Rather common in southern Illinois, but never observed 

 on the prairies of the central counties. The relation of D. 

 viridescens and D. itiiiiiafKs as foiiiis of one species appears to 

 have been conclusively established by several observers. 



Amhlystoma microstomum, Cope. 



Not rare in the prairie ponds in spring, becomiufj com- 

 moner eastward. A good Amblystoma. 



Amhlystoma tigrinum^ Green. 



This is the commonest salamander of the temporary ponds 

 on the prairies of Illinois. Thousands collect in these to breed, 

 as soon as the snow disappears in spring. The shallow water 

 sometimes freezes after they have resorted to it, and many are 

 then destroyed. The eggs are laid in large masses attached to 

 dead vegetation. The very young are provided with "balan- 

 cers" like those of the related A. punctatum. Fully grown exam- 

 ples still retaining rudiments of branchicC and the imperfect 

 tongue of the larva are sometimes taken, a condition probably 

 to be accounted for by the fact that the eggs are occasionally 

 deposited in waters from which the young cannot readily escape. 

 It is just possible that the larval characters might be retained 

 by this species indefinitely in case of an enforced residence in 

 the water. 



