DENDROPHIS (PHILOTHAMNUS) ALBO-Y ARI AT A.
plate narrow; frenal plate oblong and quadrangular ; pre-ocular plate narrow
inferiorly, broadest superiorly; post-ocular plates two quadrangular ; temporal
plates five or six, rather large and irregularly shaped. Scales of upper
lip, exclusive of nostral, nine ; of lower, exclusive of mental, ten, the sixth from
the mental much the largest. Submental plates six, the centre pair elongated,
the anterior and posterior sides oblique, the hinder pair narrowest towards their
posterior extremities (vide Plate LXIV., fig. 3, 3 a, and 3 &). Eyes moderately
large, pupil circular, nostrals sub-circular. The scales on the nape of the neck
small and sub-circular, on the back near the head subovate, more remote rhom-
boidal, best seen when a scale is detached, each being at other times so overlapped
that it exhibits rather a quadrangular than a rhomboidal form, the
anterior and posterior sides appearing oblique. The hinder edge of each row of
scales overlaps slightly the base of the row immediately behind it. On the
tail the scales are large, short, broad, and six-sided. Abdomen and under surface
of tail slightly keeled on each side ; the abdominal plates, towards each
extremity, slightly emarginate behind, where the keel terminates. Apex of tail
armed with a short horny aculeus. Abdominal plates 164. Subcaudal scales
12*2 pairs. Length of specimen described, from head to anus 21 inches ; from
anus to point of tail 11^ inches.
This species is generally found, at least in Southern Africa, in country covered with
brushwood. It climbs with facility, and is usually observed oh branches of underwood.
Besides being found in South Africa towards the Tropic of Capricorn, it is also frequently
obtained in Northern Africa, especially on the Gold Coast, and about Sierra Leone and the
Gambia. The white linear variegations afford a ready means whereby to distinguish this
from the two species above described. Besides colour, other diagnostic characters exist,
such as the form of the frontal plate, the obliquity of the side of the fronto-nasal plate,
which is in contact with the frontal, &c^ The size of the eye, in proportion, is much inferior
to what it is in Dendrophis Natalensis.
In this and Dendrophis Natalensis the scales of the body are less closely set than in Dendrophis
semivariegata. In the latter they cannot be so far separated as to admit of the intermediate
skin being distinctly seen; on the other hand, in the two first referred to that is
always exposed whenever the body is much distended. They are probably the more typical
species, and possibly live chiefly on small birds and objects of a size which, if swallowed,
would occasion great inconvenience provided the skin did not admit of considerable extension.