ON THE ANATOMY OF THE NORTHERN BELUGA. 399 
is thrown into well-marked longitudinal ruge. It presented no trace of the 
glandular apertures described by Dr Murie* in Globiocephalus melas, but it is 
possible that the somewhat unsatisfactory state of the part prevented the 
recognition of these in Beluga. 
Stomach—Exaternal appearance.—When this viscus is distended with air and 
its exterior examined, the cesophagus appears to terminate at the junction of 
its first and second compartments, leading to the belief that it communicates 
with both. As we shall presently see, this appearance is deceptive, the ceso- 
phagus terminating in the first compartment, and in it alone. The latter, as in 
several other cetacea, resembles much the paunch ofthe ruminant. It measures 
11 inches in length and 9 inches in greatest breadth. When viewed from below 
it appears to be of an oval form, an appearance which is due to the fact that 
when the parts are in their natural position the first is to some extent over- 
lapped by the second compartment. When the latter is drawn aside the 
paunch is seen to be cordiform rather than oval, its rounded apex projecting 
horizontally backward. The second compartment measures 12 inches in length 
and 44 inches in greatest breadth. It is oval in form, and tapers slightly to its 
posterior extremity which is closely applied to the wall of the cavity on its 
right. The third stomach is not visible externally, and consequently any 
description of the organ based upon the mere examination of its exterior is 
altogether misleading, so far as an accurate determination of the number of 
its cavities is concerned. The fourth stomach is reniform, and when distended 
measures 5 inches in length and 24 in breadth. It is separated externally by 
a well-marked sulcus from the second compartment, which lies to its left. 
The ji/th compartment, 13 inches in length, recalls to mind the form of the 
ruminant abomasum. Its left extremity is the larger, the diameter of its 
cavity diminishing slightly from its commencement to its termination. It 
extends for 9 inches to the right, and then curves upon itself to become con- 
tinuous with the duodenum at the pylorus. 
Interior of Stomach.—When the stomach is opened the cesophagus is seen to 
terminate in the first compartment: the cesophageal opening is of the same dia- 
meter as the rest of the tube. Immediately below, and slightly to the right of 
this aperture, is the orifice by means of which the first communicates with the 
second stomach. Its diameter is rather less than that of the cesophagus. A 
well-marked fold of mucous membrane extends from the inferior margin of the 
oesophageal opening, obliquely backward and to the right, and subsides on the 
superior wall of the second compartment after forming the superior lip of the 
aperture of communication between the first and second stomachs. This fold 
appears to correspond to the posterior lip of the cesophageal groove which in 
*Ll.sp. 256. 
