340 A. E. Verrill — Noi'th American Cephalopods. 



the ventral border of the laminae. Parallel with these arise small, 

 capillary, efferent vessels, wliich join larger transverse vessels, between 

 and parallel with the afferent ones ; these in turn join the larger effer- 

 ent vessel that runs along the ventral edges of the laminae, and these 

 marginal vessels pour their contents into the large brauchio-cardiac 

 vessel {bo) which runs along the middle of the gill, on the ventral 

 side, and carries the purified blood to the heart. 



The buccal membranes, the pharynx, with its horny jaws, the 

 odontophore, armed with seven rows of recurved teeth on the radula, 

 and the thin, chitinous, lining membrane, which has numerous 

 sharp, scattered, recurved teeth, both on the palate and in the throat, 

 have already been described (pp. 311, 312). The oesophagus is a 

 long, narrow, but dilatable tube, having two oblong salivary glands 

 attached to it, within the bilobed anterior end of the liver {I); it then 

 runs backward in a groove along the dorsal side of the liver, to a 

 point beyond its middle, where it passes obliquely through the liver, 

 accompanied by the aorta («o), and dorsally enters the stomach {S). 

 The stomach consists of three parts, which are often sufficiently dis- 

 tinct externally, when the stomach is empty, or nearly so, but when it 

 is greatly distended with food (as often happens), the apparent divis- 

 ions almost disappear and the whole becomes one great, long-pyriform 

 sac. The first division {S) or 'true stomach,' is plicated internally 

 and has thickened glandular walls. It is supplied with blood by a 

 conspicuously ramified vessel, the gastric artery (so). This lobe of 

 the stomach is sometimes contracted into a firm glandular mass, 

 strongly constricted where it joins the more saccular second stomach ; 

 but I have seen specimens greatly distended with food in which it 

 was scarcely or not at all distinguishable as a lobe, and seemed as thin 

 and saccular as the other parts. The remainder of the stomach {S') 

 usually has the form of a long, more or less swollen, ovate sac, 

 tapering backward to a somewhat acute posterior end, which reaches 

 back nearly to the end of the body ; anteriorly its most swollen 

 portion is about opposite the junction with the first stomach, and 

 just behind the heart; from this swollen portion it narrows rapidly, 

 but extends forward along the posterior part of the liver, above and 

 in advance of the heart, where it gives off the intestine. The 

 more swollen anterior portion {k), of this sac, the second stomach, 

 has a glandular lining and is distinctly radially plicated, and is, there- 

 fore, clearly anatomically distinguishable from the thin and non-pli- 

 cated posterior portion, or c«cal lobe, {IS') which seems to serve 

 mainly for the temporary storage of large quantities of food. 



