KEVISION OF THE KING Sl^AKES. 57 



white areas vary from squarish, about 2 scales by 2 to oblong and 

 about 4 or 5 scales long and 3 or 4 wide. In position the dorsal 

 bands may be transverse or oblique, and extend across from 9 to 15 

 or more rows of scales. The lateral alternating spots are always 

 located on the first few rows of scales; they are usually longer than 

 wide and nearly always overlap onto the ends of the ventrals. De- 

 pending upon the upward extension of these spots and the downward 

 extension of the cross bands, the forks may be horizontal or set at as 

 much as a 45 degree angle. It is rather more common for the white 

 scales to be all white, but frequently these scales, particularly in 

 the cross bands, are tipped, up to as much as half their area, with 

 deep black. 



These variations seem to be all common and widespread, and 

 appear not to be of geographic significance. Of other variations the 

 opposite can be said. 



From Georgia to southern Virginia the number of white cross 

 bands averages close to 30, northward this is increased to more than 

 40 near the District of Columbia and in New Jersey, and southward 

 into northern Florida it likewise is increased to 40. Correlated with 

 the change in number of bands northward is an intensification of the 

 white and a blackening of the ground color, and southward a lessening 

 of the distinction between the light and dark. 



In southern Georgia and northern Florida it is by no means uncom- 

 mon for the scales of the dark areas to develop white centers. These 

 may extend to all the dark scales, but usually are best developed 

 midway between the white cross bands, fading gradually to disap- 

 pearance on either side. It seems likely that the potentiality for 

 the development of white centers is an inheritance from the form 

 JiolhrooM. Evolution mto floridana seems to have proceeded by an 

 enlargement basally, then distally, of these white centers, a softening 

 of their sharp outlines and a lightening of the dark parts, accom- 

 panied by an increase in number of cross bands and a decrease in 

 their distinctness, resulting in a light brown spotted appearance in 

 which the remains of the original pattern are to be distinguished 

 with difficulty. This reaches its logical outcome in extreme southern 

 Florida. In this phase, which has recently been described by 

 Barbour as hrooksi, the cross bands have completely disappeared, 

 and all the dorsal scales are yellow at the bases, shading to dark 

 brown at the tips. 



Along with the general reduction in scutellation to the north is a 

 slight decrease in size of body, perhaps best realized by comparison 

 with the distinctly larger individuals from central and southern 

 Florida. 



Mention must here be made of a most interesting individual from 

 Occoquan Creek, Virginia (Cat. No. 59354, U.S.N.M.). This is a 



