Skull and teeth.—Skull large, temporal ridges of the type forming a sagittal crest, although in the figure they have not yet met. Upper incisors two on a side.
Measurements.—See table, page 537.
Specimens examined.—None.
Remarks.—This species is usually regarded as the same as Nycticebus coucang, but the descriptions and figures of the two certainly make them appear distinct. Not much can be determined until good series from the type localities are examined.
NYCTICEBUS MALAIANUS (Anderson)
1881. Nycticebus tardigradus var. malaiana Anderson, Catalogue Mammals Indian Museum, I, p. 95.
Distribution.—Malay Peninsula and the coast regions of Sumatra.
Diagnostic characters.—Size small, face markings prominent, temporal ridges forming a crest in old age, audital and mastoid bullæ moderately inflated, upper incisors usually two on a side.
Color.—General color of the upper parts ranges in different specimens from wood brown to a dark ochraceous huff; more or less frosting is caused by the subterminal white band of the long hairs. The dorsal stripe usually widest over the shoulders may extend the whole length of the back or gradually disappear in the lumbar region. In color it varies from a rich, deep brown similar to seal brown to a dark tawny. Face markings are conspicuous and concolor generally with the dorsal stripe. Underparts dirty pinkish or cream buff, the slaty bases of the hairs showing through.
Skull and teeth.—Temporal ridges meet to form a sagittal crest in old age. Upper incisors four in the young and usually in the adult, though they may be reduced to three or two; audital and mastoid bullæ smooth, rounded, and moderately inflated.
Measurements.—See table, page 537.
Specimens examined.—Seven skins with skulls, five from the Malay Peninsula and two from the west coast of Sumatra, and one alcoholic from west coast of Sumatra.
Remarks.—One specimen. Cat. No. 84389, U. S. N. M., from Trong, Lower Siam, has a skull differing considerably from the others of the series. Its brain case is much depressed and the outer and upper walls of the orbit stand out and up from the rest of the skull much more than they do in the other specimens. The two Sumatran specimens, one from Tapanuli Bay and the other from Tarussan Bay, I am unable to associate with Nycticebus hilleri Stone and Rehn, which is a slightly larger animal and has less inflated and more furrowed bullæ.
