. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. CEPHALOPODA. 535 along that canal, being gradually lost in its inner membrane, the lamina next the gizzard is peculiarly enlarged, so as evidently to pre- sent an obstacle to the regurgitation of bile towards the gizzard. The inner surface of the rest of the intestinal canal presents a few lon- gitudinal rugae, with slightly marked transverse puckerings. In the Dibranchiate Cephalopods the gul- let, in consequence of the position of the stomach near the lower part of the visceral sac, is of great length (a, a, Jig. 221),
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. CEPHALOPODA. 535 along that canal, being gradually lost in its inner membrane, the lamina next the gizzard is peculiarly enlarged, so as evidently to pre- sent an obstacle to the regurgitation of bile towards the gizzard. The inner surface of the rest of the intestinal canal presents a few lon- gitudinal rugae, with slightly marked transverse puckerings. In the Dibranchiate Cephalopods the gul- let, in consequence of the position of the stomach near the lower part of the visceral sac, is of great length (a, a, Jig. 221), but varies in this respect according to the form of the animal. We have seen that in the Nautilus it is dilated into a pyriform crop; a similar dilatation occurs in the genus Octo- pus ; but its position is reversed, the larger end of the sac being uppermost, and probably as the result of the habitually reversed position of the animal with the head downwards, the crop is extended into a large cul-de-sac above the part where the oesophagus opens into it (b, Jig. 220). From this part the crop gradually contracts to its termination. In the Argonaut the crop commences by a similar lateral dilatation, but is continued of almost uniform breadth to the stomach. In the Sepia, Sepiola, Rossia, Onychoteuthis, Loligopsis, and Loligo, and probably in the other Decapods, there is no crop, the gullet being continued of uniform breadth to the stomach (a, a, Jig. 221).* The stomach (c, figs. 220, 221,) in all the Dibranchiate Cephalopods is a more or less elongated sac, having its two orifices, the car- dia (d) and pylorus (e), close together at the anterior or upper part of the sac, as in the gizzard of birds : the muscular fibres are simi- larly disposed, and radiate from two opposite tendons; they form a stratum of about the same thickness as in the stomachs of omnivo- rous birds. The epithelium, which is con- tinued from the O3sophagus and crop (a', b', fig. 220) acquires a greater thick
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