4 University of Michigan 



These specimens indicate a well-marked race, always recog- 

 nizable at a glance by the peculiar pattern. The latter seems 

 to have resulted from a fusion by twos of the dorsal blotches 

 or saddles of fasciata. Furthermore the postocular light band 

 is very prominent, and its lower dark border may be reduced 

 to practical absence. Specimens from southeastern Louisiana 

 show the closest relationship with fasciata. Indeed a few 

 specimens examined by the writer and labelled "New Orleans" 

 must be identified as X. fasciata fasciata, and ]Mr. Percy Vios- 

 ca informs me that in this region both phases occur in the 

 same localities in "almost infinite variation, sometimes appar- 

 ently in the same brood." New Orleans is therefore within 

 the region of subspecific intergradation. 



Other characteristics of this form are tabulated 1)elow. 



Discrimination of the subspecies of the fasciata group : — 

 Perhaps the most constant feature by which the subspecies, 

 A'', fasciata fasciata, N. fasciata confiucns, and N . fasciata pic- 

 tiventris may be distinguished from other species of Natrix 

 with similar scutellation is the light yellowish or brownish 

 band extending backwards from the eye to the angle of the 

 mouth. A specimen is rarely so melanistic that wetting the 

 head will not reveal traces of this feature, and specimens of 

 confiucns may have it obscured only by its broadening and the 

 practical disappearance of its lower dark border. But within 

 the fasciata group it is not always so easy to distinguish .V. 

 fasciata fasciata from A'', fasciata pictiventris. Indeed there 

 is a real temptation to synonomize the latter with the former. 

 Numerous average differences appear, however, which lead the 

 writer to believe that more thorough study on large series of 

 specimens will amply justify the sei)aration here maintained. 



