DENDROPHIS (PHILOTHAMNUS) SEMIVARIEGATA. 
the body are subovate, and disposed in oblique rows across the body, the rows 
most distinct towards the head ; the scales of the rows laterally overlap each 
other more or less, that is, the dorsal edge of each scale lies more or less over 
the outer edge of the one inside of it. The points of the scales of each row, 
for they do not laterally overlap to a degree to render the hinder edge of the 
row quite continuous, extend slightly beyond the base of those of the fol- 
lowing row, or in other words, they are imbricate. Towards the tail the 
scales increase in width, and cease to exhibit the arrangement observed 
towards the head ; they are large, six-sided, slightly imbricate, and not 
disposed in rows, as towards the head. Each row towards the latter consists 
of fifteen scales, the middle or dorsal one rather differently formed to those 
on each side of it. Body sub-cylindrical above, flattened below ; tail rounded 
superiorly, strongly angular at each side, and very flat beneath, its apex a 
slender horny prickle. Abdominal plates, 207; subcaudal scales, 112; tail 
nearly one-fourth of the whole length ; adult specimens from 3 feet to 3| feet. 
The abdominal plates have a keel or angle towards each extremity, and 
their hinder edge at the angles is emarginate. 
Young. Plate LX. In most specimens the ground colours resemble those 
of the adult, but the number of black bars are more numerous, and extend 
over a greater portion of the body. The lower portions of the sides are 
variegated with small black spots, eyes coloured as in the adult. 
A full grown specimen of this species was obtained on the Bushman Flat, and several 
young ones, in heaps of stones, in the country beyond Kurrichaine. It climbs underwood 
with facility, and upon it, probably, seek its food. 
This and two other South African snakes (to be hereafter described) may prove only 
aberrant species of Dendrophis, yet, in the absence of sufficient materials to enable us to judge 
correctly, I have thought it best to regard them, for the present, as members of a subordinate 
group. They exhibit many of the characters of the true Dendrophis ; and taking D. picta and 
Boeii as typical species, we find in Philothamnus the same sort of teeth ; the nostrils similarly 
formed ; the same form of pupil, and the same keel or angle towards each extremity of 
the abdominal plates. The arrangement and form of the scales, particularly towards the 
bead, are, however, very different. In both groups they are arranged in rows; in Dendrophis, 
the rows extend nearly directly across the body ; in Philothamnus, they are more or less 
oblique ; in Dendrophis, the scales overlap each other laterally, to admit of the free distension 
of the skin ; in Philothamnus, if that occurs, it is only to a very trifling extent; in Dendrophis, 
the points of the scales are so close on each other that the hinder edge of each row of scales 
appears a continuous line ; in Philothamnus, the points are apart, so that the line behind appears 
serrated or broken. This peculiarity in the arrangement of the scales proclaims the species, 
of which we have formed a subordinate group, to be either typical species of an aberrant 
group, or aberrant species of a normal group. 
