36 REPTILES. 
* 
j=>) 
ie 4) 
a. Scales square or six-sided, placed side by side. 
* Head elongate, depressed. 
. PELAMIS. 
** FTead moderate, rather compressed ; gape moderate. 
. Laremis. Head moderate, short, rounded in front; dorsal - 
scales square; ventral shield broad, six-sided. 
. ATurIA. Head moderate, short, rounded in front ; dorsal scales 
six-sided ; ventral shield six-sided. 
MicrocerHALopuis. Head small; scales six-sided; ventral 
scales keeled. 
b. Scales ovate, six-sided, imbricate, keeled, or with the keel 
reduced to a tubercle on the centre of the scales: head 
and gape moderate. 
Labial shields occupying the greater part of the lips ; the eyes over 
the fourth, or rarely over the third, or the fourth or fifth shield : 
ventral shield united. 
Ennyprina. Rostral plates narrow, erect; lower linear, sunken ; 
nasal narrowed in front: ventral shield flat: head moderate, 
short ; eyes moderate. 
. Hypropuis. Rostral broad, transverse ; lower triangular ; nasal 
truncated or notched in front: ventral shield flat: head short ; 
eyes small. 
. Curruyia. Rostral broad, transverse ; lower triangular; nasal 
truncated or notched in front; ventral shields flat: head elon- 
gate, depressed ; eyes large. 
. Keriuia. Rostral broad, transverse; lower triangular; nasal 
truncated in front: ventral shield broad, convex, forming a 
slight keeled ridge; the hinder ones with a keel on each side: 
head short, shelving: scales very large, broad, six-sided: eyes 
rather large, over third and fourth labial shields. 
