Dear Sir

It is only lately that I have had the opportunity of examining the specimen, regarding which you formerly asked me some questions about,—the Bornean Ape macacus inornatus Gray.¹

Previously I acquainted you with the external appearances and measurements of which you took notes at the time;² but in case these are mislaid I here add.

—In the living animal (a young female) there are two callosities, each 1$\frac{1}{2}$ inch long. The buttocks around around these callosities are flesh coloured or rosy in hue and covered with slight downy hairs.

Tail 1 inch in length, circumference at its root 1$\frac{1}{2}$ inches,—there is a slight tendency to curvature upwards.

Of the skeleton, the rough sketch of the pelvic parts may serve to convey a better notion of the relation of parts than a long description.

Caudal vert 9 to 10 in number   The three first have transverse processes. Together the 3 vertebrae have a length of 0.8 inch long. The remainder of the caudal vertebrae are devoid of transverse processes and the two last are mere ossicles partly coalesced.

These 6 or 7 terminal caudals are together 1 inch long.

The tail vertebrae therefore altogether measure 1.8 inch long—and the terminal point reaches backwards no further than the ischial prominences,—indeed if a vertical line is dropped from the point of the tail it falls upon or is slightly in advance of the superior (Posterior in human anatomy)³ angle of the ischeum while the inferior (or anterior of human anatomy lies behind that vertical line.⁴

I suppose the (free?) tail when living must have enclosed only those caudal vertebrae without transverse processes.⁵

I am | Dear Sir | Yours with much esteem | James Murie

C. Darwin Esq^r