THE CEPHALOPODA 301 
pair of salivary glands is relatively slightly developed, and is 
conspicuous only in the Oigopsida (Spirula, Ommatostrephidae, Fig. 
282, II, Onychoteuthis, Veranya, Gonatus, ete.). In the Myopsida, 
however, there is an unpaired intra-bulbar glandular mass, lying 
behind the radula at the entrance of the oesophagus, and this 
corresponds to the embryonic condition of the anterior salivary 
glands of the Oigopsida and Octopoda. The last-named have also 
two pairs of well-developed salivary glands. The anterior pair 
consists of two flattened acinous glands attached to the posterior 
surface of the buccal bulb, their short ducts opening on either side 
into the postero-lateral part of the pharynx. The topographically 
posterior or abdominal glands are absent in Cirrhoteuthis, but in 
other Octopoda they are present, and are relatively larger than the 
similar pair in the Decapoda, but have the same structure and 
relations, save for the fact that they are situated farther back near 
the oesophageal proventriculus. The secretion of the posterior 
salivary glands of the Octopoda contains a proteolytic ferment and 
is poisonous ; the secretion of the corresponding glands of Sepia 
contains, in addition, a diastatic ferment. 
In addition to the salivary glands proper, all the Dibranchia possess 
a sub-lingual gland in front of the sub-radular organ. It is of small 
size and is formed by the infolding of the epithelium of this region. 
The oesophagus is long in all the Cephalopoda, and it may be 
enlarged to form a crop or proventriculus: this enlargement is 
gradual in Nautilus (Fig. 270, oe, cr), abrupt in the Octopoda, with 
the exception of Cirrhoteuthis, but in the Decapoda the oesophagus 
is of the same diameter throughout (Fig. 268, oc). The true 
stomach is a more or less globular or elongated pouch, with fairly 
thick muscular walls, and is situated at the summit of the visceral 
mass (Fig. 271, gizz): its two orifices, the cardiac and the pyloric, 
are anterior. 
At the initial part of the intestine, close to the stomach, is a 
thin-walled caecal diverticulum of various shape. It is spherical in 
Nautilus, Rossia, and Leachia, elongated and much larger than the 
stomach in Loligo, but it is more frequently coiled in a spiral, 
like the spiral caecum of sundry rhipidoglossate and other Gastro- 
poda; such is the case, for example, in Spirula (Fig. 268, p.s), 
Ommatostrephes (Fig. 269, e), Sepia, and the Octopoda. The hepatic 
ducts open into the stomachal caecum. 
The liver is formed by two symmetrical glands, which are 
separate from one another during development (Sepia), but are 
generally partially fused together in the adult. This organ 
exhibits its minimum state of concentration in Nautilus, consisting 
of four lobes, each with its proper duct. In the Dibranchia the 
liver is more compact and consists of two lateral lobes, which are 
only united to a small extent near the middle of their length in 
