174 DR. J. MURIE ON THE FORM AND STRUCTURE OF THE MANATEE. 
margin of each; and the left possesses a small subtriangular lobule at its posterior 
spinal corner. The third smaller anterior and semidivided lobe, transversely bitrian- 
gular or o-shaped, Steller’s anvil-formed and Owen's quadrate-figured portion, may 
either be regarded as the homologue of the so-called cystic lobe of some mammals, 
or as representing additional upper or anterior lobules of the right and left lobes, 
bridged together by a diminutive /obus guadratus. This last, as in the human subject, 
is that portion bounded dorsally by the transverse fissure, laterally by the gall-bladder 
on the one side, and the round ligament and short longitudinal fissure on the other. 
There is a compressed boot-shaped diminutive lobule immediately to the right of the 
inferior vena cava, and a second rather elongate, but terminally flattened, lobule 
attached to the left wall of the same vein. Both of these small lobules spring from 
the root of the main right lobe, and respectively appear to be homologous with the 
caudate and Spigelian lobes. 
Owen remarks that the small Spigelian lobulus in the Dugong is continued from the 
root of the left lobe. This origin, however, according to my observations in those 
mammals where the liver is deeply cleft, would not precisely correspond with the 
Spigelian lobule, which arises from the right moiety, and is separated from the left lobe 
by the ductus venosus. Notwithstanding, it does not militate against the Professor's 
clear definition that “the homologue of the ‘ Spigelian lobule’ is shown by its relation 
to the lesser curvature of the stomach ”}. 
All the hepatic fissures are shallow. The most marked ones, the longitudinal and 
that of the ductus venosus, being filled up by strong fibrous tissue, covering the vessels 
therein. As to the ligaments, the suspensoriwm hepatis is moderately broad, and firmly 
fixes the organ to the pericardium and the diaphragm. The round ligament, as usual, 
forms the anterior or ventral one positionally. In the young male it was a narrow 
cord, nearly impervious, 1 inch from the liver. The two lateral ligaments diverge 
from the vena cava, and traverse lengthwise the right and left lobe about an inch 
outside their vertebral margins. 
The pyriform but forwardly projecting gall-bladder lies superficially on the ventral 
aspect of the small anterior right lobule. When distended it is 2} inches long and 
1 inch in diameter at the fundus. The cystic duct, of considerable calibre, winds in an 
S-shaped manner, and at about three quarters of an inch distance from the neck of the 
gall-bladder receives singly the united hepatic duct on its left wall, as Daubenton and 
Vrolik have recorded. In the Dugong the cervix of the gall-bladder is said to be 
obliquely pierced by two hepato-cystic ducts, entering, as the ureters do, into the 
urinary bladder. The ductus communis choledochus in the male Manatee was as thick 
as the barrel of a goose-quill, and penetrates the intestine about three inches from the 
pylorus. 
1 «The Anatomy of Vertebrates’ (1868), vol. iii. p. 483. See also Owen “ On the Anatomy of the Cheetah,” 
Trans. Zool. Soc. vol. i. p. 131. 
