VAEIATIONS OF GARTER-SNAKES. 



93 



in these localities than to the northward the southern margin may 

 be placed tentatively at the Ohio River." 



If we admit for the time being that hutleri and hracliystoma are 

 identical, we find that for twelve years after its description the type 

 of the latter (which was taken in Franklin, Venango County) repre- 

 sented the only Pennsylvania locality from which the form was known 

 to occur. In 1905, however, Mr. H. F. Fowler, of the Academy of 

 Natural Sciences of Pliiladelphia, secured a second specimen (Stone, 

 1906, 165) near Port Allegheny, McKean County. This specimen is of 

 interest, as not only extending the range considerably to the east- 

 ward, but as also probably representing approximately the eastern 



Fig. 30. DisTEiBUTioN of Tuamnopiiis butleri, as indicated by the locality kecords. 



limit of its occurrence. These specimens will be further discussed in 

 the consideration of the variation of the group. 



At tliis point mention should again be made of the tlu-ee specimens 

 in the U. S. National Museum from Milwaukee,Wisconsin. I have given 

 my reasons for referring these specimens to radix, but it must be 

 admitted that they resemble hutleri so closely as to be indistinguish- 

 able, and it may be that further material will show them to belong 

 to this form and extend the range around the southern end of Lake 

 Micliigan, but the solution of the problem given on page 85 seems 

 the most plausible one at present. 



It is impossible with our imperfect knowledge of the limits of its 

 range to point out any close relations betw^een tlie distribution of 



«As this paper is passing through the press I have received a specimen of butleri 

 from Dayton, Ohio. 



