172 DR. J. MURIE ON THE FORM AND STRUCTURE OF THE MANATEE. 
narrower, expansion. The first is very glandular, and with convolute ruge; the second, 
thinner walled, assumes interiorly the character of the rest of the great intestines. 
These in the female, including cecal appendage, are 17 feet 9 inches long, and in the 
male 18 feet—the greater muscular contraction of the former probably accounting for 
the difference. The ruge are very numerous, close-set, and chiefly longitudinal, and 
obliquely interdigitate, forming shallow elliptical depressions, among which are glan- 
dular patches. Halfway on the gut the rugz and glands diminish in size and number. 
To supply a desideratum as regards the abdominal viscera in their natural position, I 
have given in fig. 20 a reduced copy of a diagrammatic sketch taken from the young 
male animal. It represents the parts as seen when a median longitudinal section has 
been made from near the anus forwards to the middle of the sternum, the fleshy walls 
being dragged outwards. Anteriorly the heart appears to occupy the full breadth of 
the chest, the severed pericardium stretching across at its bifid apex. Behind is the 
liver, segmented into four divisions,—a very large triangular portion of the right and 
another equal-sized portion of the left lobe filling respectively the right and left sides 
of the cavity; whilst between them, in the triangle bounded by the pericardium and 
their anterior borders, are two much smaller lobes, the right one of which contains the 
rather large gall-bladder. No lungs or diaphragm are exposed, the apparent and not 
real absence of the latter doubtless having deceived Dr. G. A. Perkins! in his examina- 
tion of Wyman’s” Manatus nasutus. Mesially situated and betwixt the hinder fork of 
the great liver-masses, a small piece of the stomach and curved appendix are exposed. 
The remaining posterior half of the abdominal cavity shows only intestinal coils, and 
partially the urimary bladder when this viscus is distended. 
When, however, the thoracico-abdominal cavities with the entrails in situ are 
examined sidewards, a representation of which has been given in the body-section 
(fig. 37, Pl. XX VI.) with the ribs in place and the intervening tissues removed, a 
widely different view is obtained. ‘The relations of the parts mentioned (heart, liver, 
intestines, and bladder), to some extent, remain good. But above them is brought out 
in relief the enormous lung, which reaches from the first to the last rib, and extends 
more than midway downwards, just permitting a fringe of the elongated diaphragm to 
peep through below and be the barrier line betwixt the dorsal pulmonary and ventral 
cardo-alimentary compartments. 
3. Glands concerned in Digestion. 
Of the secretory apparatus connected with the mouth, the most conspicuous bodies 
are the parotid glands. As briefly noted by Stannius, these are very large and lie at 
the sides of the lower jaw. They have a coarse granular texture, are broad and flat, 
and reach from the insertions of the cephalo-humeral and levator claviculi muscles 
forwards to beyond the angles of the mandible. In the vertical and horizontal direc- 
* Proce. Boston Soc. Nat Hist. (1845-48) vol. ii. p. 198. * Ibid. vol. iii. p. 192. 
