270 THE REPTILES OF EGYPT. 
I am indebted to Mr. Boulenger's Catalogue for the grouping of the following details 
by which it is possible to recognize the species of Zamenis met with in Egypt: — 
Synopsis of the Species. 
I. Intemasals and prefrontals distinct, not broken up. 
1. Scales in 19 rows (rarely 17, Z. gemonensis) . 
a. Frontal not or but slightly wider than the supraocular, more than once 
and a half as long as broad. 
Prseocular invariably excluded from frontal. Ventrals with indistinct 
lateral keel. Scales with two apical pits Z. gemonensis. 
Prseocular usually in contact with frontal. Ventrals with distinct 
lateral keel. Scales with a single apical pit Z. dahlii. 
b. Frontals anteriorly considerably broader than the supraocular. 
Height of the rostral nearly equal to its breadth. Ventrals 213-262 ; 
A. 1/1; S.C. 113-154 Z. rhodorhachis. 
Height of the rostral about half its breadth. Ventrals 195-215 ; A. 1/1 ; 
S.C. 95-105 Z. rogersi. 
2. Scales smooth, in 21 rows, rarely 23. One praeocular (rarely divided), with 
a subocular below it. Two labials entering orbit Z . jiorulentus . 
3. Scales obtusely or faintly keeled, in 21 to 25 rows. One or two prae- 
oculars; one, rarely two suboculars. Two or only one labial entering 
orbit " Z. ravergieri. 
II. Prefrontals broken up into a varying number of pieces. 25 to 33 rows of 
keeled scales. No labials entering orbit, or very rarely so. Eye surrounded 
by scales. 3 to 5 loreals Z. diadema. 
