SNAKES. 71 



streaks ; belly white, with two broad black streaks, formed of two 

 large semicircular black spots on the front edge of each ventral 

 shield ; subcaudal shield black, with a narrow white edge ; loreal 

 shield small ; oculars small, two anterior and three posterior, lower 

 very small. 



a. In spirits. India ? Presented by the Zoological Society. 



24. Helicops. 



Head ovate, indistinct, shielded : frontal anterior trigonal, be- 

 tween the nasal plates ; superciliaries small ; occipital elongate ; 

 upper labials entire ; loreal distinct : two anterior and two posterior 

 oculars ; body fusiform ; scales (19 rows) truncated, polished, smooth, 

 of middle of hinder part of back and tail keeled : tail tapering. 

 American. 



Helicops sp., Wagler, Syst. Amph. 170, 1830. Fitz. S. R. 25, 

 1843. Helicops, Gra?/, ZooL Misc. 65, 1842. Pseudoenx sp., Fitz. 

 N. Class. Rept. 55, 1826. Natrix sp., Wagler, Serp. Braz. 27. 

 Anat., Schlegel, Phjs. Serp. 353. 



1. The Helicops. Helicops carinacaudus, Wagler, Amph. t. 7. 

 Fitz. S. R. 25. Col. aeneus, Hemprich, Mus. Berlin. Pseudoeryx 

 aeneus, Fitz. N. Class. Rept. 55, 1826. Homalopsis carinacauda, 

 Boie, Isis, xx. 551. Schlegel, Phi/s. Serp. 350, t. 13,/. 18, 19. 

 Coluber carinacaudus, Neuwied, Beitr. i. 302. Ahhild. xi. t. 3. 



Dark olive, paler beneath, darker on the edge of the plates : 

 scales of the front and sides of body smooth, of the hinder part of 

 back and tail strongly keeled. 



a. In spirits. N. America. From the Leyden Museum, 



fff Hinder labial large, like others ; scales smooth. 



25. HVPSIEHTNA. 



Head small, distinct ; crown shielded : frontals 3 ; anterior 

 transverse, small ; vertebral and superciliary rather small ; occipi- 

 tal moderate ; loreal square ; upper labial large, entire ; seventh 

 large : eye over the fourth or fourth and fifth labial : body fusiform ; 

 scales smooth ; tail conical. 



Hypsirhina, Wagler, Syst. Amph. 169, 1830. Gray, Zool. 

 Misc. hb, 1842 Fitz. S. R. 25. Hypsiscopus, Fitz. S. R. 25, 



