H. B. Kirk. — On the Anatomy of Sepioteuthis bilineata. 157 



The hepatic ducts are two, and open close together into the commence- 

 ment of the pyloric coecum. They have developed upon them the light- 

 coloured spongy "pancreatic " glands, which show under the microscope a 

 loose fibrous tissue interspersed with yellow concretions (fig. 4). The 

 fibrillar tissue is more loose and the yellow concretions larger, but less 

 numerous, than in the liver. There is everywhere a network of ramifying 

 tubes. 



The whole of the organs are enclosed in a peritoneal membrane, which 

 sends three mesenteric reflexions to the mantle, one of the arterial branches 

 from the posterior aorta running along the anterior border of each 

 reflexion. 



Nervous System. 



The main masses of the nervous system are aggregated into a large 

 circular band (pi. vii., fig. Id) surrounding the gullet and lying in the 

 aperture of the cephalic cartilage. On the anterior side of the gullet 

 lie the cerebral and superior buccal ganglia, almost confluent and on the 

 posterior surface are the inferior buccal, pedal, and parieto-splanchnic gan- 

 glia. The cerebral ganglion sends off optic nerves which enlarge greatly, 

 forming the optic ganglia (pi. vii., fig. 1 e). I have not been able to dis- 

 cover the auditory nerves. From the parieto-splanchnic ganglia two nerves 

 run, one on each side, towards the anterior aspect of the animal, passing 

 under the columellar muscle and each forming on the back of the pallial 

 chamber and at the side of the gladius a large stellate ganglion (fig. 1 g), 

 which sends branches over the mantle. For about half their course the 

 nerves to these ganglia are imbedded in the liver. 



On the intestine, at the point where the pyloric coecum is given off is a 

 well-marked ganglion (fig. 1 1), which appears to be connected with the 

 main nervous centres by a nerve following the course of the intestine. This 

 ganglion gives off radiating fibres on all sides. 



Eyes. 



The eyes are lateral, are large and prominent and are covered by 

 a transparent layer of integument. The eyeball is invested by a silvery 

 tapetum composed of loose cells in two layers, one or both of which contain 

 numerous refracting corpuscles. In front this passes into the loose iris, 

 but I have not been able to observe any cartilage of the iris. The tapetum 

 is lightly attached and can be easily removed. Then comes a thin, trans- 

 parent, apparently muscular membrane, covering a thin cartilaginous coat 

 which becomes thickened slightly in front. The membrane is not continued 

 beyond the thickened front edge of the cartilaginous coat. Within the 

 opening is suspended a cartilaginous ring, to which is attached a fringed 

 radiating membrane having the lens in its centre. This is the corpus 



