Page:Notes on the Slow Lemurs.pdf/10

536 sagittal crest; upper incisors, only two; outer and lower wall of orbit wide, about 7 mm.; bullæ not swollen, underparts grayish white.

Color.—Upper parts range from a light wood brown to a color between ochraceous and tawny ochraceous (type is of latter color, moderately frosted). Dorsal stripe and face marks range from a light, bright russet to a dark brown, similar to a dark burnt umber (latter color in the type). Dorsal stripe is widest in region of shoulder and gradually disappears on the rump or on lower back (as in the type). Underparts light grayish, irregularly spotted in two specimens (one the type), with a pinkish buff. Individuals may or may not be frosted, type moderately frosted.

Skull and teeth.—Temporal ridges never uniting to form a sagittal crest, forming instead two parallel ridges on top of skull. Never more than two upper incisors even in the very young; lower outer wall of orbit about 7 mm. wide, bullæ not swollen.

Measurements.—See table, page 537.

Specimens examined.—Seven skins with skulls and two alcoholics from western Borneo.

Remarks.—Nycticebus borneanus is very distinct and needs no comparison with any of the preceding species.

Type.—Adult female. Skin and skull, Cat. No. 124907, U. S. N. M., collected at Klabat Bay, Island of Banka, east of Sumatra, June 24, 1904, by Dr. W. L. Abbott. Original number 3432.

Distribution.—Island of Banka.

Diagnostic characters.—Like Nycticeus borneanus, but underparts darker, bullæ more inflated and lower outer rim of orbit narrow, about 3 mm. wide.

Color.—Type: Upper parts generally a color something between Ridgway’s ochraceous-buff and ochraceous with practically no frosting; dorsal stripe something between a dark russet and tawny. Dorsal stripe not of the well-defined type, disappearing in the lumbar region. Face markings concolor with dorsal stripe. Underparts a mixture of grayish and ochraceous-buff.

Skull and teeth.—Skull similar to that of Nycticebus borneanus, but the mastoid bullæ are slightly more inflated and the outer and lower walls of the orbit are narrow, about 3 to 4 mm. wide, against 6 to 8 in N. borneanus. Upper incisors only two.

Measurements.—See table, page 537.

Specimens examined.—One, the type.

Remarks.—Nycticebus bancanus is apparently a well-marked offshoot of N. borneanus. The skin of the type and only specimen is practically indistinguishable from Cat. No. 142233, U. S. N. M., one of the paratypes of N. borneanus, but the narrowness of the outer and lower orbital wall in N. bancanus at once distinguishes the two species.