14 ZOOLOGY. 
the vertical or interocular, and the occipitals, by a concentric series of small plates. There is 
but one and a rather small nasal, in the midst of which the nostril opens, leaving but a nar- 
row rim. The loral region is occupied by several small plates. The anterior suborbitals are 
more developed than the posterior, all of which being provided with a keel along their inner 
margin. The surciliary ridge is composed of about six elongated, narrow, and obliquely 
superposed plates. The lids are covered with very small plates, the marginal series being 
somewhat more developed than the rest, except on the periphery of these organs, and yet may 
still be distinguished from the latter by their regular shape and disposition. The rostral is 
transversally elongated and very low. ‘The upper labials are very elongated and very narrow, 
six or seven in number, increasing in length from the first to the fourth inclusive, then dimin- 
ish considerably backwards. The supralabials have the same general appearance as the labials 
themselves, save in being a little smaller. Occasionally two or more minute plates may be 
observed upon the loral region between the loral plates proper and the supralabials. The tem- 
poral plates are of moderate development, and of nearly equal size with the post-occipitals. 
They are irregularly rounded, slightly imbricated, and provided either with a rudimentary 
tubercle or an obsolete carina. The symphyseal is larger than the rostral, and especially 
broader upon its middle region. The inferior labials (five or six in number) are broader than 
the upper, more conspicuous therefore, and diminishing gradually backwards. There are four 
or five pairs of mental shields: the anterior pair being the largest and contiguous upon their 
inner margin, whilst the other pairs diverge, and gradually diminish in size backwards. Be- 
tween the mental shields and lower labial plates there exists a complete series, and part of a 
second, of small infralabials. The inferior surface of the head, the throat, the belly, the pre- 
anal region, thighs, and legs, are covered with smooth, posteriorly obtuse, and generally entire 
scales or scutelle of moderate development, a little smaller under the head and larger under — 
the hind limbs ; some few on the sides of the belly exhibiting a small notch posteriorly. The 
sides of the neck, the insertion of the limbs, the interior surface of the forearm, and the poste- 
rior surface of the thighs, are granular. On the sides of the abdomen the scales are irregu- 
larly rounded, subtuberculous, or subcarinated, and smaller than those on the dorsal region, 
which are distinctly, though moderately, carinated, and posteriorly obtuse. The upper surface 
of the limbs and the inferior surface of the arm are covered with scales similar in shape and 
structure to those on the back; on the palm of the hands and the sole of the feet they are 
much .smaller, acute posteriorly, and distinctly carinated ; around the fingers and toes they 
constitute irregular verticiles—the superior ones being more irregular in size than the inferior, ~ 
and less distinctly carinated. The inner or first finger is the smallest ; the outermost is the 
next in length; then the second; then the third, which is nearly as long as the fourth, which 
is the longest. The nails are rather short, compressed, acerated upon their extremity, and 
gently curved. The first toe is the smallest ; the second is*the next in length; then the fifth; 
then the third; the fourth is the longest. Their nails do not differ materially from those of 
the fingers. The scales which cover the tail are the most conspicuous of all; they constitute 
oblique series upon the base of that organ, and annular rows further backwards. The oblique 
series have the same shape as those of the back. Those constituting the annular rows are su- 
periorly subquadrangular and elongated, with their carina oblique; whilst beneath, they be- 
come much narrower, posteriorly acute, with a straight carina along their middle region. 
The ground-color is blackish brown in the male, and greenish brown in the female ; in either 
sex there are two parallel series of transverse black bands, convex anteriorly, margined with 
a whitish, or else a lighter tint along their concavity. These bands, however, are more con- 
spicuous in the female than in the male. They may be traced from the head, on each side of 
the dorsal region, to the posterior extremity of the body, where the series, from either side, 
combine more or less into one, which extends along the upper surface of the tail. The limbs, 
as well as the tail, are transversally barred with black. In the female, the dorsal region and 
the flanks are either dotted with black or spotted with whitish ; whilst in the male, these spots 
