BUCEPHALUS CAPENSIS.
mode of arrangement of the scales. On the tail, however, different characters
exist, the scales covering it, instead of being carinated, are quite smooth like
those on the temples and nape, and are more or less six-sided, one side being
always formed by the base, and another by the apex, the last is generally
very short, and scarcely to be appreciated in many of the scales, more
particularly in those towards the tip of the tail. The point of the tail, in
many specimens is formed of a scaly pointed tubercle, in others it is covered
with a number of small imbricate scales. The abdominal plates are slightly
arched, the convexity backward, their extremities arched or slightly semicircular
; the subcaudal scales are disposed in two rows, and each scale is
distinctly six-sided till near the point of the tail, where they become more or
less distinctly four-sided: in the six-sided scales the sides forming the
extremities are much shorter than the two middle ones. The skin of the
neck, and of rather more than the first half of the body, is more than sufficient
to enclose the parts contained within it, and is very loosely attached to the
parts it encloses; in consequence there is a superabundant portion, which
portion is usually disposed in two longitudinal folds, one at each side of the
abdominal plates ; these folds are always in existence, except when the gullet
and stomach are fully distended with food. On the sides and back of the
head, and also on the hinder portion of the body and tail, more especially on
the latter, the skin is not more than sufficiently extensive to cover the parts
it encloses, and in these situations it is firmly and closely united to the
subjacent parts. The usual length of an adult specimen of this variety is from
4i to 5 feel, of which the tail generally forms between a fourth and a fifth
part: individuals are occasionally found, however, exceeding 6 feet. The
following are the measurements of the specimen figured, and of two others
now before us ; also the number of abdominal plates and subcaudal scales
existing upon each :—
SEX OF LENGTH FROM NOSE LENGTH OF SUBCAUDAL SUBCAUDAL
SPECIMEN. TO BASE OF TA IL. TA IL. PLATES. SCALES.
Ft. In. Ft. In. No. :-No.
Male 3.11 I 0 188 . 65-65
Male 3- d& 1 2 189 106-106*
Female 3 9 1 1 184 94-94
The Female is never so freely variegated with yellow on the sides as the
male, and many specimens are met with in which merely the centre of each of
the scales adjoining the abdominal plates is faintly tinted with greenish
yellow. The yellow of the abdominal plates is also of a duller tint in the
female, and often with a strong tinge of green.