490 PROCEEMN1GS OF THE NATHONIAL MUSEUM vol. 93 



ocular single, large, in contact with second and third supralabials; 

 one postocular; 1-2 temporals (the anterior abnormally fused with 

 penultimate labial on one side) ; 7-7 supralabials, penultimate largest; 

 6-6 infralabials, the last elongate and not quite reaching even with 

 posterior margin of last supralabial; two rather large anterior chin 

 shields, in contact with three anterior infralabials; posterior chin 

 shields separated from each other medially, scarcely larger than small 

 gular scales; lour small scales from posterior chin shields to the first 

 full-width ventral. 



Dorsal scale rows 17-17, with single apical pits, all smooth; ventrals 

 119; anal divided; subcaudals 38; two subcaudals entire. 



Dorsal surface slate-gray; a middorsal series of small, black spots 

 extending from nape onto tail; these spots involving the edges of 

 the paravertebral scale rows, separated from one another by spaces 

 of less than one scale length. Most dorsal scales with dark bases, 

 and scattered, irregular dark streaks over the rest of the surface. 

 Belly whitish, with a very few, small, dark spots on the posterior 

 edges of the ventrals, near their ends; tail whitish, slightly stippled. 



Variations. — Most specimens are colored like the type, but a few 

 are reddish instead of gray in ground color. The pattern closely 

 resembles that of I. lineata. 



The variation of the entire series of 69 specimens examined is as 

 follows : One has 16 scale rows near the anus, all others 17 throughout 

 the body. In 30 females the ventrals vary from 120 to 130, average 

 126.2 ( 120, 1 ; 123, 1 ; 124, 4 ; 125, 5 ; 126, 5 ; 127, 7 ; 128, 2 ; 129, 3 ; 130, 2) ; 

 in 39 males they vary from 117 to 126, average 120.9 (117, 3 ; 118, 4; 119, 

 5 ; 120, 9 ; 121, 5 ; 122* 3 ; 123, 2 ; 124, 3 ; 125, 3 ; 126, 2) . The caudals vary" 

 in 30 females from 25 to 33, average 29.2 (25, 2 ; 27, 4 ; 28, 4 ; 29, 8 ; 30, 4 ; 

 31, 3; 32, 4; 33, 1) ; in 38 males they vary from 34 to 43, average 38.5 

 (34, 1; 36, 5; 37, 4; 38, 8; 39, 10; 40, 6; 41, 2; 42, 1; 43, 1). Eighteen 

 specimens have 1 to 21 entire subcaudals; of the 30 females only four 

 specimens have entire subcaudals (1, 1, 3, 6), while of the 39 males, 

 14 have entire subcaudals (1, three ; 2, three ; 3, four ; 4, one ; 5, one ; 16, 

 one; 21, one) ; the latter two are of moderate size, of 219 mm. and 

 162 mm. total length, respectively; the others are of varying length, 

 from 287 to 106 mm. ; with the character there is no obvious linkage 

 with lethal characters. The posterior chin shields are separated in 45 

 (23 $ , 22 5 ) in contact medially in 24 (16 S , 8 5 ). The number of 

 small gular scales from the posterior chin shields to the first full-sized 

 ventral varies from 3 to 6. The total ventral counts, including three 

 -mall scales, from chin shields to anal plate, vary from 126 to 136 in 

 females, 122 to 131 in males; the range of variation with this count is 

 not increased over that obtained by excluding the smaller anterior 



