40 LACERTILIA. 
shield much larger and so much produced backward as to touch the vertical; and the 
same peculiarity occurs in a specimen from some part of the Pacific coast of Central 
America, whilst in two other specimens from the same locality the shield is of the 
usual size. 
Figures of these three last specimens are given on Tab. XXYV, figs. A-C, to show the 
variation of the shields :— 
In one (figg. A, A’) shield c is of moderate size, a small unpaired shield is intercalated 
between a and a’, 6 and 0! are in contact with each other. 
In the second (fig. C) ¢ is so much enlarged as to come in contact with the front 
central, and to separate 6 and J’. 
In the third (fig. B) c is produced backwards, separating d and d’, and 6 and a” are 
confluent into one shield. 
The last-named anomaly, viz. the confluence of 6 with a”, is of very common occurrence 
in Californian specimens. 
In specimens called L. grandis, from Oregon, the central shield is much enlarged at 
the expense of J—4A', which are small and widely apart from each other. 
A specimen from Cartago (Costa Rica) with normal scutellation is figured on 
Tab. XXV. fig. D. 
All the figures are of the natural size. 
13. Gerrhonotus obscurus. (Tab. XXV. figg. E, F’.) 
Hab. Mexico (Brit. Mus.). 
Dorsal scales keeled, in fourteen longitudinal and fifty (between occiput and root 
of tail) transverse series; nuchal scales in eight, ventral in twelve longitudinal ; the 
latter in forty-two (between front of humerus and vent) transverse series. Nasal shield 
not in contact with the rostral; supranasals present. Seven shields on the upper 
a—a! 
surface of the snout, between vertical and rostral, disposed thus arn ; ¢ is pro- 
d d! 
duced backwards, meeting the vertical and separating shields d from each other; 
6 and d, and 6’ and d' are in contact. Brown above, with a black median line; sides 
and abdomen black, with greenish-white specks and vermiculations. ach of the large 
gulars with a greenish-white spot. 
Length tothe tympanum . . . . . 14 millim. 
- humerus. . . . . . 22 ,, 
- vent . . 65 
29 
(Tail partly reproduced.) 
The specimen is figured of the natural size, but the views of the head are magnified. 
