VARIATIONS OF GAKTEE-SNAKES. 



Ill 



lifflit greenish olive, the darker ones often (Lark brown. The hiteral 

 stripe is always present, but, as stated above, the dorsal stripe is 

 usually obscure. Still, although sackeni is usually described as hav- 

 ing the dorsal stripe obscure or wanting, tliis is decidedly not always, 

 the case, for in some of the specimens in the U. S. National Museum 

 from Georgiana, Florida, it is not only well defined but also of a bright 

 color. This variation is not geographic, but may occur in individuals 

 apparently anj^wdiere in the range. 



Affinities. — Fortunately there is little difficulty in determining the 

 affinities of this form. The position of the lateral stripe on the third 

 and fourth rows and tlie length of tail at once proclaims it a member 



140 



13 2 



124 



116 



108 



Fig. 44. 



of the Sauritus group. It differs from proximus only in the greater 

 average length of tail and the consequent larger number of sul)caudal 

 scutes, a smaller number of ventral plates, and the frequent obscurity 

 of the dorsal stripe. A knowledge of the variations, however, shows 

 that these differences are slight, for (1) the dorsal stripe in proximus 

 is occasionally obscure, (2) the length of tail and number of sub- 

 caudal scutes in proximus apparently increases, while the number of 

 ventral plates decreases in southern Louisiana to approximate the 

 condition in sackeni. As a matter of fact there is no reason to believe 

 that the two forms do not intergrade perfectly in southern Mississippi. 

 It should be borne in mind, however, that although sackeni has a 

 longer tail and more subcaudal scutes than proxiiyius it apparently 



