298 A. G. RUTHVEX. 



a view which is also held by Professor Cope ('92, p. 660) and Dr. 

 Stejneger ('93, p. 214). This view is perhaps supported by the 

 great variability of leptoccplmla, but leptocephala occurs in a dis- 

 tinct region while butleri occurs in the same region, in the same 

 habitat and in almost equal abundance with typical forms of E. s. 

 sirtalis ; and at the same time its distinctive characters are so 

 constant, that no variations have been found that can be regarded 

 as transitional forms between the two species. The average num- 

 ber of gastrosteges in butleri is about 1 39 while in sirtalis sirtalis it 

 is about 151. The temporals are also more constant than appears 

 in the table ; it is true that there is not always a single large tem- 

 poral in the second row, but when there are two as in sirtalis sir- 

 talis, the upper one, as far as we know is always much smaller than 

 the lower one, which lies posterior and inferior to it. The form 

 and coloration are, however, the most characteristic features. 

 The body is more robust, the tail shorter, and the head smaller 

 and more conical than in sirtalis sirtalis. As stated under varia- 

 tion, the color is remarkably constant for a member of this genus 

 and while there is much color variation in the E. sirtalis group, 

 I have never seen a variation that could be confused with butleri. 

 Its striking coloration, robust form, small indistinct head and 

 peculiar movements, make this snake very conspicuous and ren- 

 ders it almost impossible to confuse it with any other form. I 

 have not seen enough specimens to determine its relationships 

 with other groups, but the coloration, position of the lateral 

 stripe, and reduced number of infralabials point strongly toward 

 E. radix which meets it on the west. 



Desirable as it is, therefore, to cut down the species in this 

 genus, it must, I think, be concluded, from the specimens which 

 have been collected that Entcenia butleri is a good species. 



