54. ZAMENIS. 38 J. 



** Scales in 17 rows. 



t Snout moderately projecting, obtuse. 

 Third and fonrtli (rarely fourth and fifth) 

 labials entering the eye ; ventrals 160- 



190 ; subcaudals 74-104 5. constrictor, p. 387. 



Fourth and fifth labials entering the eye ; 



ventrals 184-197 ; subcaudals 110-128. 6. lineatus, p. 388. 

 A single labial entering the eye ; ventrals 



185-202 ; subcaudals 111-113 7. mentovarius,-p. 389. 



tt Snout very prominent, rather pointed ; ventrals 

 180-203; subcaudals 85-99. 



13. spinalis, p. 394. 



fl. Frontal not or but slightly wider than the supraocular ; 

 ventrals 182-211. 

 A subocular below the prseocular ; two 



labials entering the eye ; subcaudals [p. 389. 



80-1 12 8. flagdliformis, 



A subocular below the prseocular ; two 



labials entering the eye ; subcaudals 



115-157 9. tceniatus, p. 390. 



No subocular ; three labials entering the [p. 392. 



eye ; subcaudals 133-152 10. puleherrimus, 



h. Portion of rostral visible from above as long as or a 

 little shorter than its distance from the frontal ; ven- 

 trals 175-206. 

 Three labials entering the eye ; subcaudals 



127-135 11. mexicanus, p. 392. 



One or two labials entering the eye ; sub- 

 caudals 75-108 12. grahami, p. 393. 



2. Scales in 19 rows (rarely VI va. Z. gemonensis). 



a. Frontal not or but slightly wider than the supraocular, 

 more than once and a half as long as broad. 

 Ventrals rather indistinctly angulate late- 

 rally ; scales with two apical pits 14. gemonensis, p. 395. 



Ventrals very distinctly angulate laterally ; 



scales with a single apical pit 15. dahlii, p. 397. 



6. Frontal anteriorly considerably wider than the supraocular. 



(I. Nine upper labials, two of which enter the eye. 

 Ventrals 214-262 ; subcaudals 113-145. . 16. rhodorhachis, 



[p. 398. 

 Ventrals 199-211 ; subcaudals 82-119 . . 17. ventrimaculatus, 



[p. 399. 

 ft. Nine upper labials ; a subocular separates the eye from 

 the sixth labial 18. Icarelinii, p. 401. 



