National Resource Center for Cephalopods

Tompsett, D.H. 1939. Sepia. Liverpool Marine Biological Committee Memoirs. 32: 184 pp. London. Williams and Norgate.

Plate 9, Figures 25-29.

 

Fig. 25. Ventral dissection of the muscular system The mantle (M.M.) has been opened by a median longitudinal incision. The funnel has been cut through longitudinally along the middle line, the right half being freed from the head and neck, to which it is attached by the adductor muscles, and it has been displaced to the side. The adductor muscles of the funnel have been completely removed. The left retractor muscle of the head has been dissected away from the cephalic and brachial cartilages, and the left half of the funnel together with the left retractor muscles of the head and funnel have been almost completely cut away, so that only the more dorsally situated parts of these muscles remain. The anterior cephalic vein (Fig. 23, A.C.V.) has been removed. The diaphragm cartilage has been removed and a cut edge (A.D.C.) shows where the retractor muscle of the head was attached to it. The viscera the visceral dome have been removed en masse, leaving only the posterior salivary glands (P.S.G.) and the anterior part of the oesophagus (OES.) and cephalic artery (CE.A.) in situ. The shell epithelium on the ventral side of the shell has been cut away, so that the shell (SH.) can be seen bordered by the muscles. The pallial nerves (P.N.) and the anterior part of the visceral nerves (V.N.) have been left intact, but both the anterior and the posterior funnel nerves have been removed. The position of their emergence from the skull is indicated by the foramina (F.A.F. and F.P.F.). On the right side of the head a window has been cut to show the position of the pocket (T.PO.) in which the tentacle is kept, while on the left the ventral wall of this pocket has been completely removed so that the origin of the tentacle (TEN.) and its attachment to the brachial cartilage (BR.C.) can be seen. On the left side, part of the eye has also been exposed. Part of the left branchia has also been dissected away to show the course of the retractor muscle of the branchia (A.R.B. and M.R.B.).
Fig. 26. Cephalic cartilage: posterior view. The ventral side is uppermost. The membrane (M.P.B.) enclosing the posterior part of the brain has been left intact, and the paired buccal arteries (B.A.), the oesophagus (OES.) and the duct (D.S.G.) of the posterior salivary glands, all of which lie freely in the peri-oesophageal blood sinus (P.O.S.) are shown in transverse section.
Fig. 27. Cephalic and brachial cartilages: ventral view. The brachial cartilage (BR.C.) is drawn in the position it occupies relative to the cephalic cartilage.
Fig. 28. View of the right orbit of the cephalic cartilage, to show the foramina and nerves. The ventral side is uppermost.
Fig. 29. Anterior view of the cephalic and brachial cartilages. The ventral side is uppermost. The brachial cartilage (BR.C.) has been displaced away from the cephalic cartilage, which it would partly obscure if it were left in its natural position relative to the former.

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