2i6 Records of the Indian Miisenm. [Vol. VIII, 



The pharj'nx (buccal bulb or buccal mass) is a stout thick- 

 walled tube lying in the anterior portion of the proboscis. The 

 mouth opens into the anterior portion of the phar^nix. There is no 

 mandible. The radular portion of the pharynx (radular sac) is a 

 thick conical body placed on a lower level than the pharynx proper. 

 The tip of the radular portion is curved forwards, and gives attach- 

 ment to retractor muscles which can be traced to a broad muscle 

 band behind. The radula lies in the radular portion, forming a 

 membranous expansion which spreads on the anterior end of a 

 prominence in the cavity of the radular portion. The membranous 

 expansion consists of radiating fibres held together by transverse 

 fibres placed sparingly in an arch-like fashion. The teeth are ar- 

 ranged in V-shaped rows, the angle of the SJ being turned backwards. 

 The teeth are lateral, there being no central or marginal; they are 

 unicuspid and uniform in shape, but they increase in size from 

 within outwards. The three outermost teeth are very small in size, 

 while the fourth one is larger in proportion than the outer three. 

 From the fifth onwards the teeth gradually increase in length, 

 the longest one being 0*45 mm 



The salivary glands form a much-lobulated mass lying in 

 contact with the anterior end of the digestive gland on the ventral 

 aspect and to the left. The posterior surface of the left gland pre- 

 sents a shallow concavity which fits into the convex surface of the 

 liver. The two glands are apposed to one another to form a single 

 mass, the left one being larger than the right. The small right 

 salivary gland lies beneath the left one over the tip of the pedal 

 gland, being connected to the latter by strands of connective tis- 

 sue. 



The two salivary ducts are much coiled and very fine. They 

 run with the oesophagus through the aperture in the ganglionic 

 mass to the right side beneath the radular sac till they reach the 

 circular groove in front of the radular sac. Then they turn up- 

 wards along the right side of the groove nearly to the dorsal aspect, 

 where they open into the base of the pharynx by the side of the 

 oesophagus. 



In connection with the anatomy of Atopos {Podangia) sangiii- 

 nolenta, I described the salivary glands as an accessory digestive 

 gland, as I could not trace the salivary ducts in those specimens. 

 Now taking the minute structure into consideration, 1 find these two 

 organs are identical, and the accessory digestive gland is nothing 

 but the salivary glands forming a single mass. 



Minute structure. — The gland consists of numerous lobules 

 held together by very thin layers of connective tissue. Each 

 lobule consists of a group of irregularly polyhedral cells closely 

 applied to one another. The cells fall into two groups — (i) 

 mucous and (2) serous, the latter preponderating over the former 

 in number. The mucous cells contain coarse granules which are 

 stained blue with haematoxylin ; their nuclei are indistinguishable. 

 The serous cells have clearer protoplasm with fine granules which 

 take a brownish vellow stain with Van Giesen's stain. The nuclei 



