500 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
and the outermost has a broad basal attaching portion (PI. 
IV, fig. 25, Ce., 1, 2and 3). The radula, when removed 
from its sac, is about 50 mm. long. In front of the 
tongue is another outgrowth, the Sub-Radular organ, on 
the tip of which opens the duct from the posterior salivary 
glands. Thus the secretion from these glands is poured 
on to the food before it is acted on by the radula (fig. 24, 
s.7.0., 8,9,d,). This duct enters the buccal mass below the 
radular sac, after running above the sub-lingual gland 
which is on the ventral surface of the bulb (fig. 24, s./.g.). 
The paired ducts from the anterior salivary glands open 
into the pharynx laterally and posteriorly (fig. 24, s.g.d.). 
Thus it will be seen that the massive muscular wall of 
the buccal bulb is formed chiefly by the muscles working 
the jaws and the radula. Anteriorly it is attached to the 
bases of the arms by a circular muscle band (PI. ILI, 
fig. 14, and PI. IV, fig. 20, circ. m.), and posteriorly by two 
ligaments (Pl. VII, fig. 53). Posteriorly the pharynx is” 
continued into the oesophagus. 
The Oesophagus is a narrow tube running down 
posteriorly to the stomach (fig. 17, oes.), dorsal to the 
hepatic gland (Pl. V, fig. 38a). Its posterior end ‘marks 
the limit of the stomodaeum, the stomach, spiral caecum 
and intestine being hypoblastic in origin in all Cephalo- — 
pods, while that part of the rectum posterior to the — 
aperture of the ink duct represents the very small 
proctodaeum (Korschelt and Heider). 
The internal surface of the oesophageal wall is thrown 
into numerous longitudinal ridges (Pl. IV, fig. 18, and 
Pl. V, fig. 33). Internally it is coated by a thin 
chitinous layer, ridged correspondingly, which is 
continued posteriorly as the chitinous lining of the 
stomach (fig. 33, Cut. L.). About half-way down, the 
oesophagus bears a large pouch-hke non-glandular 
