71 
eighths of an inch thick from front to back. This bony enlargement 
is perforated with various apertures on each surface, which in a na- 
tural state are covered by a delicate semi-transparent membrane.” 
Col. Hamilton Smith exhibited some drawings of Mammals from 
the Himalaya Mountains. 
Mr. Yarrell exhibited the second fasciculus, and the first and 
second parts of the letter-press, of Sir William Jardine’s ‘ Scottish 
Salmonide.’ 
Mr. Waterhouse called the attention of the Members to some im- 
perfect skins of various species of Monkeys from Fernando Po, pre- 
sented to the Society by George Knapp, Esq. The Curator observed, 
that he had selected these specimens from a large number of skins, 
sent from the locality mentioned, and that on a former occasion he 
had had an opportunity of examining a similar series, from which the 
specimens were selected which were described in the Proceedings for 
May 1838, p. 57, under the names Colobus Pennantii, Colobus Satanas, 
Cercopithecus Martini, and Cercopithecus erythrotis. In the present 
collection is a skin of the Cercopithecus erythrotis, in which the face 
is nearly perfect, and exhibits a transverse red mark, crossing the 
nose; this mark is not due to the colour of the skin, but to short, 
bright, rust-coloured hairs. The upper lip is covered with blackish 
hairs, and a band composed of long blackish hairs runs backwards, 
from the upper lip, across the cheeks, which in other parts are 
covered with whitish hairs. The length of the skin is two feet, and 
the tail measures two feet five inches. 
Of the Colobus Pennantii there were many specimens in the collec- 
tion, all of which presented the characters pointed out in the descrip- 
tion in the Proceedings. 
The skin of the Cercopithecus Martini, on the table, Mr. Water- 
house observed, also agreed essentially with specimens formerly ex- 
hibited, excepting in being of a larger size, the head and body 
measuring nearly twenty-six inches, and the tail thirty-one inches 
in length. The tail is of an uniform black colour, excepting near 
and at the base, where the hairs are obscurely annulated with gray : 
the hairs on the under parts of the body are of a grayish soot-colour, 
obscurely annulated with whitish, and the upper surface of the head, 
as well as the occipital portion, the shoulders, and fore-limbs, are 
black : on the fore-part of the head the hairs are distinctly annulated 
with yellowish white. 
