Clark The Short-Mouthed SnaJce. 85 



striking difference between the two species, as indicated by Cope, 

 but his description of the color of brachystoma is very mislead 

 ing, owing to the changes produced by the alcohol. In life, brachy 

 stoma is very dark brown above, many of the scales being al 

 most black, as are portions of the skin; in some specimens, when 

 the skin is stretched, these black areas appear as a more or less 

 complete double series of squarish spots on each side of the dor 

 sal region; the mid-dorsal row of scales and the inner half of the 

 scales in the row on each side of it are bright yellow anteriorly, 

 gradually becoming duller posteriorly and losing their distinct 

 ness on the tail; a similar stripe occurs on each side of the body 

 and includes all the scales of the third row, the lower half of 

 most of those in the fourth row and the upper half of many in 

 the second row; these lateral stripes fade away on the tail but 

 are very bright anteriorly, where they expand so that the entire 

 sides of the neck are very yellow; on this yellow area are several 

 prominent black spots; the first row of scales and the outer ends 

 of the gastrosteges are deep brown, the latter with a dusky 

 yellowish tinge; the ventral surface is dull light olivaceous, 

 darkest near vent, sparsely speckled with black (the exact shade 

 varies considerably, No. 6 having the whole lower surface dark, 

 becoming almost black in front of vent); there is a narrow black 

 spot on the anterior margin of the outer end of the gastrosteges; 

 the head is brown, with a greenish tinge anteriorly; labials yel 

 low, chin white and throat yellowish; parietal spots yellow, very 

 evident. Gastrosteges 132141 (average 136+); urosteges 61-72 

 in <? , 52-58 in 9; upper labials 6; lower labials 8; postocu- 

 lars 3; scale rows 19. 



The question which naturally arises is: What is the relation 

 of brachystoma to sirtalis f Had Cope's type remained unique, 

 it might well have been regarded as a sport, merely an unusual 

 ly aberrant sirtalis, and the discovery of a single specimen in 

 Olivet or elsewhere would not necessarily have disproved the 

 correctness of this view. But in the light of the evidence fur 

 nished by six specimens of both sexes, taken at various times in 

 several places, such a view is certainly incorrect and there can 

 be no doubt of the distinctness of the two species. The differ 

 ence in color is constant, in spite of the extraordinary variety 

 shown by sirtalis; in the latter the lateral stripes are mainly on 

 the second, partly on the third, row of scales instead of on the 



