22 REPTILES. 
Fam. Il. Virerip2. 
Face without any suborbita] pit on the side: upper jaw tooth- 
less, with fangs in front: rostral shields broad, band-like. Scales 
keeled (except in Acanthophis). Tail short, tapering. 
Viperine, Oppell, Serp.1811. Viperide, Bote, Isis, xx. 510, 
1827. Gray, Zool. Mise. 1842. Viperide and Crotalide part, Gray, 
Ann. Phil. 1825, 209. Les Serpents Vénémeux proprement dit, 
part, Schlegel, Phys. Serp. 820. Aspidophis part and Chersophis, 
Fitz. Consp. Syst. Ophid. 1846. Holochalina part, Muller. ; 
Synopsis of the Genera. 
T. Head depressed, rounded on the sides, covered with acutely keeled 
scales. 
a. Nostrils large, subsuperior, anterior, in the centre of a ring- 
like shield, edged with a large scale above. Clothonina. 
1. Dapota. Eyes convex, pupil round: head elongate; scales regu- 
larly keeled ; nasal shield smooth in front. India. 
SS) 
. CLotHo. Eyes convex; pupil oblong, erect: head short, broad, 
scales keeled, ending in a spine; nasal shield interrupted by a 
small shield in front. Africa. 
b. Nostrils small, subanterior, sublateral. Cerastina. 
3. CerastEs. Subcaudal plates two-rowed ; nostrils lunate on the 
hinder part of a small nasal plate; eyelid of males horned. 
4. Ecuis. Subcaudal plates one-rowed; nostrils minute in suture 
of two small scales; the anterior frontal shields minute, smooth ; 
pupil round. 
Il. Head more or less shielded ; nostrils anterior, lateral. 
a. Head flat-topped, high on the sides, shielded in front ; nos- 
trils in the middle of a shield ; tail end simple ; subcaudal 
plates two-rowed. Viperina. 
. Virera. Superciliary shield distinct ; rest of the head covered 
with small smooth plates; nose more or less recurved. 
Gr 
6. Pazias. Vertebral, occipital and superciliary plates distinct ; 
front of head with small shields; nose blunt. 
