VARIATIONS OF GARTER-SNAKES. 185 



(5) ohscura. — Tliis so-called variety of various authors has had an 

 interesting history. Defined by Cope as differing from sirtalis in the 

 fusion of the lateral spots, it has been made by various writers to 

 embrace slightly anomalous specimens of sirtalis, parietalis, and 

 hutleri. The original specimens from Westport, New York, are 

 sirtalis, and they are peculiar only in that the ground color above is 

 so dark as to obscure the spots on the scales (by no means an uncom- 

 mon occurrence). The '' ohscura^ ^ specimens of Morse which are not 

 referable to hutleri are also of this description. Cope (1900, 1074) 

 further describes specimens from Lac Qui Parle, Minnesota, as follows: 

 ''The fusion is complete as to the superior row of spots, but the infe- 

 rior may be seen faintly outlined on stretching the skin, as in some 

 dark forms of E. s. imrietalis." This would seem to denote that the 

 spots on the other specimens referred to ohscura by Cope (those from 

 Westport, New York) were entirely fused on the skin; but this is not 

 true, for on stretching the skin of the latter the spots are seen to be 

 perfectly distinct. As a matter of fact the Minnesota specimens 

 referred to ohscura by Cope are "parietalis (in which the upper row of 

 spots is normally fused), the New York specimens of this writer and 

 the Ohio specimens (in part) of Morse being rather dark specimens of 

 sirtalis. 



I have already alluded to the fact (see p. 88) that both Morse and 

 Cope have referred specimens of hutleri to ohscura. This was made 

 possible by the insufficiency of the original description of the latter, 

 which gives the impression that the spots are fused on the skin in 

 typical specimens, w^hich is the case to a considerable extent in hutleri. 



(6) In many specimens from Indiana, Ohio, southern Michigan, 

 and western Pennsylvania the skin between the first and third or 

 fourth scale rows is more or less red. On the basis of such specimens 

 it has been asserted that parietalis occurs in the above named States. 

 These specimens are typical sirtalis in every other character, W'hile 

 the red when present is always in such a small amount that the speci- 

 mens need never be confused with parietalis. 



Wliile in my judgment it is impossible to recognize any of the above 

 forms as distinct,^ I believe that the first three (ordinatus, grami- 

 nea, and pallidula) are significant in that they represent the same 

 tendency in the form, i. e., toward an increased darkness in color. I 

 believe that the increasing darkness of the stripes (which leads to 

 their obscurity) is an evidence of such a tendency. Tliis explains 

 the fact that the extremes in this direction ( those in which the stripes 

 are obscured and which have been described as distinct) have no 

 distinct geographic range, but are liable to crop up in any consider- 

 able collection of specimens from almost any locality in the range of 

 the form. Nevertheless it seems to be evident also that the tendency 

 is much more pronounced in the north and northeastern than in south 

 and southeastern parts of the range, although a considerably larger 



