1862. ] OF PITHECIA MONACHUS. 331 
divides posteriorly into two branches, of which the lower is the 
longer. The collateral sulcus (7), instead of passing downwards and 
forwards along the inner side of the temporal lobe, turns abruptly 
outwards, and appears on the outer face, in the rather sharp angle on 
the inferior border of the hemisphere at the junction of the occipital 
and temporal lobes. 
The dental formula is, I. ==, C. =, P. ==, M. —=36. 
The incisors of both upper and lower jaw project forward, so that 
their anterior edges form together an angle of 100°. The upper 
central incisors are of moderate size, and rounded at the edges. The 
upper lateral incisors are extremely small; there is a considerable 
diastema between them and the canines, which are strong and conical, 
and project downwards and somewhat outwards. The two rows of the 
upper molar series are perfectly straight and parallel. The premolars 
increase in size from the first to the third, the first being notably 
smaller than the others and unicuspidate. The first molar is rather 
larger than the second; their crowns are square, nearly flat, but 
grooved longitudinally in the middle, the raised edge on the outer and 
inner sides being slightly divided into two tubercles. The crown of 
the third molar is just beneath the gum. The four lower incisors are 
long and narrow, of nearly equal size, the outer ones slightly rounded 
at the corners ; their outting edges form a continuous gently curved 
line. A very small interval exists between them and the sharply 
pointed conical canine, which is of very nearly the same size as the 
upper one. The first premolar is very small; the two succeeding 
ones increase in size. The first and second molars are nearly equal, 
and the third not very markedly inferior. As with the upper series, 
these teeth are very slightly tuberculated ; they have the appearance 
of being considerably worn, but, as the animal was so young, this is 
scarcely probable. There is a carious spot on the posterior part of 
the third premolar on both sides. 
The length of the tongue, from the base of the epiglottis to the tip, 
is 1°4 inch; its breadth °5 inch ; its sides are parallel, the end square, 
with the corners slightly rounded. The sublingual organ is fleshy, 
except towards the end, which is sharp-pointed and cleft at the ex- 
treme tip; it is free to the extent of *25 inch, and its apex is °3 
from the tip of the tongue. 
The left lung has two lobes, quite separate from one another, each 
having a special division of the bronchus ; the right lung is composed 
of four distinct lobes. The main arterial trunks are given off from 
the aorta as in man, the innominata dividing into right subclavian and 
right carotid, and the left carotid and left subclavian coming off se- 
parately. 
The stomach is simple, its general form nearly globular, but the 
pyloric portion is lengthened and tubular. The cardiac and pyloric 
orifices are much approximated. The small intestine, from the py- 
lorus to the ileo-czecal valve, measures 50 inches; its diameter is 
nearly uniform throughout, about -4 inch. Peyer’s agminated glands, 
the largest 14 inch long, are scattered at tolerably regular distances 
