COUES AND YARROW ON HERPETOLOGY. 291 



Specimens, 



Jnue 24, 1873. 

 June 28, 1873. 

 July 28, 1873. 

 Aug. 11, 1873. 

 Au!^. 1, 1873. 

 1137. Two Forks of Milk River. July 15, 1874. 



Common in suitable situations all along the* line. In all the speci- 

 mens observed, the metamorphosis from the Siredon stage was completed 

 at a length of four or five inches. In other regions, I have procured the 

 same species, still in the Siredon stage, but nearly twice as large. Indi- 

 viduals were found in damp places about the buildings at Fort Pembina 

 and vicinity, and still more numerously around the pools at the western 

 base of Turtle Mountain. They wandered freely away from the water, 

 and in some instances entered our tents. 



In life, the coloration of the specimens examined was clear olive above, 

 more glaucous or greenish-white below, everywhere variegated in bold 

 pattern with black. 



In addition to the foregoing, the only species of the genus observed 

 by the commission, a second is described as inhabiting the region about 

 the eastern portions of the line. This is the Ambystoma laterale of Hal- 

 lo well (Journ. Acad. Nat. Sci. Phila. iii. 1858, 352), now regarded as a 

 variety of Amblyst07na jeffersonianum Bd. {op. cit. i. 1849, 283) [Xi/plionura 

 jeffersoniana Tschudi, Class. Batrach. 1838). 



Amhlystoma aterrimum Cope (Proc. Acad. Nat. Sci. Phila. 1867, 201) 

 is a species described from the Northern Kocky Mountains, in the region 

 explored by Lieutenant Mullan. 



