498 Mr. Garner on the Nervous System of Molluscous Animals. 
circle then is double inferiorly, as we saw so low in the scale as in Conchifera, 
and the anterior division supplies, as in them, the organs of locomotion, and 
the posterior, the branchiz, &c. In conjunction with the siphonic nerves 
avises on each side a nerve (y.), which pierces the cranium and enters the 
orbit, supplying two small muscles of the eye, of which one unites with its 
fellow of the opposite organ, and the conjoined tendon slides backwards and 
forwards in a pulley on the anterior and superior part of the cartilage. The 
branchio-visceral nerves descend on each side of the vena cava, giving many 
nerves, and amongst others, many filaments (¢.) to the oesophagus, joining 
those from the pharyngeal ganglia. It divides behind the rectum, a branch 
going outwards to the base of the gill (w.), forming there an oblong gan- 
glion (F.), and supplying that organ, &c.; minute filaments go to the peri- 
cardium and heart; the remaining branches get upon the cesophagus (o), 
and with those previously described, form a large ganglion (G.), in the Sepia 
a quarter of an inch in its long diameter, upon the stomach, between the 
cardiac and pyloric orifices. From this sympathetic ganglion filaments of a 
large size go to the czcum (v.), intestine, ink-duct, penis and oviduct (w.), 
meeting filaments from the branchio-visceral. The nerve of the mantle gives 
a few nerves to the muscles, pierces the pillars supporting the head, divides 
into two branches, of which one forms the great ganglion (H.) of the mantle, 
from which nerves radiate in every direction to that part. The other continues 
to descend, receiving a large nerve from the ganglion, and then gets behind 
the large longitudinal cartilage, supporting tbe fin, where it subdivides, supply- 
ing that organ with large nerves (z.). Before it has pierced the muscle this 
nerve gives off fine filaments, which, running along the hepatic artery, get upon 
the cesophagus, and mix with its other filaments derived from other sources. 
All the Cephalopoda*, perhaps, have acoustic vestibules, containing a bag of 
fluid on which the nerve ramifies; also a small calcareous body, which in the 
Sepia has an accidental resemblance to the human incus. 
In the eye there is a nervous coat or retina behind the pigmentum nigrum ; 
and it has been a problem how it could be affected by light. "The author is 
* Not, however, according to Mr. Owen, in the Nautilus. The author has not seen them in the 
Sepiola, where the cranium is membranous ; but probably it has been concealed, from its small size 
in the latter. 
