56 BULLETIN 17 5, UNITED STATES NATIONAL MUSEUM 



The coloration is distinctly black and white. The dorsum bears a 

 median series of large black spots, which are more or less quadrangular 

 in shape anteriorly and become elongated laterally on the posterior 

 part of the dorsum and on the tail, by fusion with the lateral series of 

 spots. The anterior spots frequently have a narrow light stripe in- 

 cluded on either side. The spots vary from 4 to 8 scales each in length 

 and from 10 to 12 in width, and are separated by interspaces from 3 

 to 5 scales long, the anteriormost of which often bear each a narrow 

 black spot or transverse bar. Lateral to the median dorsal series 

 three series of smaller black spots are present, which alternate with one 

 another and with the dorsal series. Anteriorly in some specimens the 

 small spots of the interspaces and of the three lateral series of each 

 side are so arranged as largely to obliterate the light ground color; 

 and frequently the spots of the median lateral series fuse to form a 

 broken longitudinal stripe for a short distance anteriorly on each side. 

 Posteriorly the ventralmost series of lateral spots (and, even more 

 posteriorly the dorsalmost series) fuse with the lateral series of spots 

 on the belly; while the spots of the median lateral series fuse posteri- 

 orly with the dorsal spots. The belly bears on each side a lateral 

 series of black spots, which are each 1 to 3 scutes in length and sep- 

 arated by 2 to 9 scutes (generally 4 or 5), and in addition a number of 

 spots, which are progressively more numerous posteriorly, scattered 

 irregularly between the lateral series. The under side of the tail is 

 irregularly spotted. The ground color of dorsum, belly, and throat is 

 yellowish white. The head is more or less spotted with black, and 

 black lines are present on manj'^ of the sutures between the head 

 scales, particularly the supralabials and infralabials. (Fig. 27.) 



Variation. — Far too few specimens of this form are available to 

 reveal with any certainty whether geographic variation exists. What 

 slight variational tendencies appear to be present occur, however, be- 

 tween the eastern specimens of the pine barrens of the Coastal Plain, 

 and the western ones from the Allegheny Mountains of Virginia, North 

 Carolina, and eastern Tennessee. As seen by the accompanying graphs 

 (figs. 28 to 32), evident variations are found in the ventrals, the 

 caudals, the labials, and the number of spots. It must be pointed out 

 that a study of a large series of specimens might greatly modify, or 

 even completely reverse, these results. 



One specimen, of which the locality is given (probably erroneously, 

 since no such coimty can be found in Virginia) as Atston, Birmingham 

 County, Va., is very erratic in the presence of 249 ventral scutes and 

 was disregarded in graphing the normal variation of that character. 

 The same specimen has the anal plate partially divided but is in all 

 other respects a typical melanoleucus. All the specimens having 9 

 supralabials on one or both sides, except one for which no locality is 

 given, are from New Jersey, as are also all those with 7, while the only 



