OCR Text |
Show 614 PROF. R. COLLETT ON A [Dec. 6, to which S.femoralis and S. obscurus belong, and appears to be closely related to S. hosei from North-west Borneo l, described in 1889 by Mr. Thomas. The distribution of the colouring is in several respects identical with that of the latter, but there is a characteristic difference in the colouring of the cheeks, which do not, as in S. hosei, form a connected white area with the white forehead, but the area is broken by a black band from the edge of the mouth to the ear (in the young male and the female); in the old male the upper parts of the cheeks are nearly entirely black. The crest likewise does not slope evenly backwards as in S. hosei, but is reversed on the back of the head and runs upwards towards the centre of the crown. From S.femoralis, to which especially the old male seems to be nearly related, it is distinguished by the white forehead and the wholly white under surface, both of head, body, and tail. Size.-The fully developed male is about 620 miilim. in length (head and body) ; the length of the tail is about 810 millim. The fully developed female is somewhat smaller. The length of the body (head included) is about 600 millim. The length of the tail varies, but is about 650 millim. ; in one specimen it was only 590 millim., whilst in another specimen of equal size it was 710 millim. The hair-coveriny of the head.-The greatest height of the longitudinal crest on the crown is about 75 millim. in the old male, while in the female it is shorter, or from 42 to 58 millim. It juts out from the centre of the forehead at a short distance from the eyebrows. On the front of the head the crest slopes backwards ; but on the back of the head it is directed forwards, there being a hair spiral behind each ear. The hairs on the crown thus converge and form a high point on the occiput. On the neck the hairs of the crest again slope backwards. On the sides of the forehead the hairs have likewise (especially in the females) a disposition to form a low crest which runs parallel to the central crest; the hairs here run together to a projecting point, where they meet the spiral behind the ear. There is scarcely any trace of a chin-tuft, as seen in S. hosei and other species. Colouring.-Tbe upper part of the body is of exactly the same shade as in £. hosei, being a uniform grey colour owing to each hair being black and white in turn (without, however, having the rings sharply defined). On the sides of the body and tbe hinder parts of the thighs the grey colouring shows a tendency to form a darker line in the transition to the white, especially in the older specimens. The crest on the crown is black; the occiput is partly whitish. The forehead is white, and divided in the middle by a black stripe, which joins the crest. The side crest, which extends from behind the side of the eye to the ear, is black and encloses in front (behind the eye) a whitish space. The lower part of the cheeks and the underside of the head are also white, but a black stripe which stretches backwards to a pointed whisker always runs from the upper jaw 1 Proc. Zool. Soc. 1889, p. 159, pi. xvi. |