33 



dilation or crop. This is also lined with chitin, and 

 folded, and serves as a food reservoir when the stomach 

 is full (fig. 18, cr.). At the base the oesophagus dilates, 

 and its wall and chitinous lining become smooth. (To 

 expose the anterior part of the oesophagus it will be 

 necessary to remove the ventral wall of the cranial 

 cartilage and the sub-oesophageal ganglia.) 



Salivary Glands. — Eledone has five salivary glands: 



1. Anterior salivary glands, 1 pair, closely applied 

 to the external surface of the buccal mass, posteriorly 

 (fig. 17, r.s.g.). 



2. Posterior salivary glands, 1 pair, situated at the 

 side of the crop (fig. 17, r.s 1 g v and fig. 38a, s t g x ). 



3. One sub-lingual and median salivary gland, 

 situated in the ventral wall of the buccal mass (fig. 24, 

 s.l.g.). 



These glands are granular in appearance, soft and 

 spongy in texture, and of a translucent whitish colour. 

 The anterior pair is much smaller than the posterior, and 

 is attached in the angle between the oesophagus and 

 buccal mass (PL IV, fig. 20, s.g.). They are flattened oval 

 glands, bilobed posteriorly, and are about 10x12 mm. in 

 large specimens. The duct leads from a slightly elevated 

 ridge on the internal surface, inwards to the pharynx, 

 and is very short. Along with the duct, the artery and 

 nerve of the gland enter by this ridge (PI. IV, fig. 22). 



The posterior glands are large and flattened, and the 

 crop must be turned aside to expose them fully. They 

 are attached to the visceral sac by a suspensory ligament. 

 The duct leaves the anterior internal region where there 

 is a slight depression. Here also enters the artery of the 

 gland (PI. IV, fig. 21, s t g x dj). They measure about 

 32 mm. x 25 mm., and the duct after a short course joins 

 its fellow to form an unpaired median " posterior salivary 



