SNAKES. 29 



4. EcHis. 



Siibcaudal plates one-rowed : nostiils minute, in suture of two 

 small scales : the anterior frontal shields minute, smooth : pupil 

 round : eyes surrounded by small scales : superciliary shield small, 

 scale-like or single, elongate and distinct : scales elongate, keeled 

 to the tip. 



Echis, Merrem, Tent. 149, 1820. Grai/, Zool. Misc. 96. Wag- 

 ler^ Syst. 177. Scytale, Latr. Rept. iii. 158. Daud. v. 339. Cuvier, 

 R. A, ii. 79, not Alerrem. Boa sp., Shaiv, Zool. 



* Superciliary shields small, like a scale. Toxicoa. 



1. The ToxicoA. Echis arenicola,5oze, 7m, 1827, 558. Gale- 

 rie, Zool. t. 48. Wagler, Amph. 177. Gray, Zool. Misc. 96. Vipera 

 pyramidarum, Geoff. Rept. Egypt, t. 7, /. I. Savigny, R. E. t. 4, 

 /. 1 — 4. Vipera JEgyptiaca, Ruppell, Mus. Francf. Echis pavo 

 and Echis varia, Rev.ss. Mus. Senk. ii. 137, 160, t. 7, /. 2. ? Col. 

 Libetinus, Linn. 3Tus. Ad. Fr. ii. 43. S. N. i. 165. Foiskal, Faun. 

 Arab. 13. Vipera Libetina, Latr. Rept. iii. 324? Daud. Rept. v. 

 137? Vipera Echis, var. 2, Schlegel, Phys. Serp. 583. 



Superciliary scales small, like the other ocular ones : gray- 

 bro\\Ti, with angular white streaks, and a series of whitish vertebral 

 spots : crown dark, varied with arrow-shaped white streaks. 



a — c. In spirits. Adult. N. Africa, Egypt. Presented by Sir J. 

 Gardiner Wilkinson. 



** Superciliary shields elongate, distinct. Echis, Merrem. 



2. The HoRATTA Pam. Echis carinata, Merrem Tent. 149. 

 IVagler, Amph. 177. Gray, Zool. Misc. 96. Horatta Pam, Russell, 

 Ind. Serp. ii. t. 2. Boa Horatta, Shaw, Zool. iii. 359. Pseu- 

 doboa carinata, Schneid. Hist. Amph. ii. 285. Scytale bizonata, 

 Daud. Rept. v. 339, t. 70. Vipera Echis, var., Schlegel, Ph. Rept. 

 583, t. 21, /. 10, 11. ? Boa Krait, Williams, Asiat. Research. 

 ii. 328. Pseudoboa Krait, Schneid. Amph. ii. 288. Scytale Krait, 

 Daud. Rept. v. 326. Echis Krait, Merrem, Tent. 149, E. ziczac. 

 Gray, Ann. Phil. 1825, 205. 



Superciliary' scales elongate, larger than the others : gray- 

 brown, with angular white streaks : crown of head dark, with large 

 dark-edged oblong spots. 



D 3 



