AMPHIBIANS. 



31 



eighteen days and transformation occurs some time during July or 



August. 



This species resembles Plctliodo)i glutinosus, which has been re- 

 ported from Kent (Gibbs, Notestein and Clark, 1905), Wayne 

 (Cope, 1889) and Marquette (Ruthven, 1906) Counties. However, 



Fig. 6. Distribution of Ambystoma jeffersonianum. 

 Horizontal ruling, specimens examined; vertical ruling, reports only. 



the specimens listed from Wayne and Marquette Counties are in 

 the University Museum and have been re-identified as Amhijstoma 

 jeffersaniamun. The two species may be distinguished by the fact 

 that the parasphenoid teeth are present in Plethodoti glutmosus 

 and absent in Amhy stoma jeffersonianum. We have not seen speci- 

 mens of the former from the state. 



