434 REPORT OF NATIONAL MUSEUM, 1S93. 



Description * — Head tiiaiiguliii-. Two auterior frontals (iuternasals), 

 connected with superciliaries (supraoculars) ou each side by two large 

 plates; inside of these a second row; included space tilled by small 

 scales. Scales margining su])erciliaries (supraoculars) small; S(;at- 

 tered larger ones toward the center of the intermediate sfjace. Three 

 rows of scales between the suborbitals and labials. Suborbitals extend- 

 ing to the middle of the orbit. Labials 15 or IG above; lirst, fifth, and 

 seventh largest, and vertical; below, 18; lirst, fourth, and fifth largest. 

 Dorsal rows, 27; outer rows obsoletely carinated. Three or 4 dark 

 rings on tail. Three series of well defined perfect rhombs, 1 dorsal, 2 

 lateral, separated by narrow lines. Light stripe from sui^erciliary to 

 the angle of the mouth. 



Scales on the cheek smooth. Three rather large plates on the edge 

 of the upper part of the head, between the superciliajies (supraoculars) 

 and rostral, inside of which is a second row of o, also larger than the 

 rest. 



The two lower rows of lateral scales smooth. Third and fourth very 

 hiintly carinated. Scales ou the back and sides not conspicuously dif- 

 ferent in size except the lower two or three rows. Posteriorly, near the 

 tail, all the scales are carinated except the lowest. 



General color, yellowish gray, with rhomboidal black blotches, lighter 

 in the center, and with all the angles perfect. Or rather there is a 

 series of dull yellowish lines crossing obliquely from one side of the 

 abdomen to the other over the back, following the oblique series of 

 scales, and occupying generally the jiosterior half of each scale, the 

 basal portion being black. These lines, of which there are about 36 

 crossing from each side, from head to tail (9 on tail), decussate first on 

 the fifth or sixth lateral row, and then on the back, where they are 

 more or less confluent three or four rows. The rhomboids thus inclosed 

 and crossing the back are generally black for li or 2 scales within the 

 yellowish brown, mottled with darker. The intervals ou the sides 

 between the lines are mostly dark yellowish brow n, minutely mottled 

 with dark brown. These intervals constitute a lateral series of trans- 

 verse rhomboids, sometimes with the lower angle truncated. Opposite 

 to the dorsal rhomboids is a series of small triangles in the angles of 

 the first decussation. The distance between two i)arallel transverse 

 stripes generally consists of five rows of scales, occasionally of six. 



On the sides and posteriorly these markings are more or less indis- 

 tinct, though generally recognizable. The tail usually exhibits a good 

 deal of black. The under parts are dull yellowish white, or greeuish 

 white, clouded toward the sides with brown; no regular spots visible. 

 The black on the tail does not constitute complete rings, but is inter- 

 rupted in the middle of the lower surface, and in fact the black patches 

 alternate with each other, and are not opposite. 



' By S. F. Baird, iu Baird aud Girard's, N. Am. Seri)., p. 3, from a South Carolina 

 fcpecimeii, U. S. Nat. Mus., No. 250. 



