80 DR. R. E. GRANT ON THE ANATOMY OF SEPIOLA VULGARIS, 
of considerable size, and extends to a great length from the sac; the lateral valvular 
prolongations of its base are broad, and pass deep into the cavity of the mantle. About 
the middle of the dorsal surface of the canal of the syphon, is seen the usual tongue-like 
valvular fleshy fold, extending forwards, with a cavity behind it like that of the semi- 
lunar valves of the heart of Mammalia, and serving for the same purpose. This valve 
of the syphon, and the lateral prolongations of the base of the funnel within the mantle, 
serve to direct the currents of water in respiration ; and the former protects the viscera 
of the sac from the impulse of the water when the animal is swimming forwards, as the 
valvular nostrils of diving Mammalia. 
The cavity of the mantle is comparatively small in this Cephalopod, and its whole 
extent is occupied by the abdominal and pelvic viscera. The genital organs, as in higher 
classes, occupy the bottom of the cavity, and the digestive organs, as usual, lie imme- 
diately above them. The circulating and respiratory organs occupy the middle of the 
sac, and the liver and ink gland its upper part. From the back part of the base of the 
syphon, two strong muscular bands pass forwards and downwards on each side of the 
anus, and are attached to the anterior portion of the sac on its inner surface. These two 
strong muscles, which first present themselves on opening the sac, are calculated to act 
as a frenum to limit the dilatation of the mantle. As the rectum passes up to the base 
of the funnel between them, they may act as a sphincter to the anus; and as they pass 
over the two lateral lobes of the ink gland, they also serve to compress powerfully that 
organ, and expel the ink when required. All the viscera contained in the sac are 
largely developed in this minute Cephalopod, particularly the digestive organs, the ink 
gland, and the two glands of the oviducts. The entrance of the alimentary canal is 
provided with powerful organs of prehension in the large muscular arms with their 
pedunculated suckers, and with strong organs of mastication in the density of the man- 
dibles, and the magnitude of their muscles. The tentacula, however, are not provided 
with suckers at their extremities ; they present here a villous surface, on the usual place 
of the suckers in Loligo and Sepia. The minute filaments of this villous part of the 
tentaculum, when examined through a lens, present the appearance of very small soft 
transparent suckers, incapable of performing their ordinary function. The mouth, sur- 
rounded by the usual double muscular fold, is provided with a short, broad, fleshy 
tongue, covered with strong white shining recurved teeth. Some of the larger teeth, 
arranged like a comb on the anterior part of the tongue, have their points of a brown 
colour, as we observe in the larger Cephalopods. On removing the oral apparatus from 
the cup-like cavity which it occupies immediately above the cesophageal ganglia, we 
perceive a large white nervous trunk passing from the anterior ganglion of the esophagus 
to the base of each of the arms around the mouth. These eight large nerves pass in a 
radiating manner along the floor of this cavity, and the nerves of the two tentacula come 
from the same part by more than one trunk on each side. The tentacula themselves 
