220 Records of the Indian Museum. [Vox,, VIII. 



is very granular. The cavities of the alveoli are mostly filled with 

 secreted material. Amongst the acini are seen their ducts which 

 consist of a layer of cubical epithelium with round or slightly 

 oval nuclei. 



The oviduct after emerging from the main mass of the female 

 portion passes downwards to end in the vagina. 



The vagina is a short tube which passes outwards to end in 

 the genital aperture. 



The receptaculum seminis is a pyriform body opening into 

 the vagina by a very short neck just before the vagina ends in 

 the genital aperture. 



The male genital organs consist of the following parts : — 



A fine thread-like tube which opens into the penial sheath 

 at its dorsal end near the attachment of the retractor penis muscle. 

 It is coiled several times round the distal end of the penial 

 sheath. It passes forwards along the outer side of the penial 

 sheath to its base, and then turns backwards along the inner 

 border to the base of the right Simrothian gland to nearly half 

 the length of the coecal tube from its attached end. 



The penial sheath consists of a tubular structure which opens 

 in connection with the right Simrothian gland at the base of the 

 right lower tentacle on its outer side. 



The penis is a short cylindrical body, connected to the penial 

 sheath at its distal end. 



The rectractor penis muscle is a long narrow strand, extending 

 from the posterior end of the penial sheath to the body-wall on 

 the right side a little behind the female genital aperture. The 

 muscle" passes over the female genital organs to its destination. 



The right vSimrothian gland is a long tubular body which 

 can be divided into two portions — (i) a long and fine tubular 

 portion which is closely coiled to form a more or less irregular 

 mass and (2) a thick tubular portion produced at its distal end 

 into a tubular coecum on the inner side. A few muscular strands 

 are seen to arise from the surface of the coecum and pass to be 

 inserted into the dorsum of the muscular foot. There is no left 

 vSimrothian gland. 



Minute structure. — The distal portion of the Simrothian gland 

 is so closely coiled that the adjacent portions of the loop become 

 more or less fused with one another by their outer coats, and it is 

 impossible to uncoil them without tearing through the outer coats. 

 The wall of the tube consists of the following layers from without 

 inwards : — 



(i) A layer of elongated cells, the protoplasm of which is 

 highly granular. The granules are stained with haema- 

 toxylin. The nature of these cells is obscure. The 

 layer is ensheathed by a membrane consisting of a 

 layer of flattened connective tissue cells attached end 

 to end 



(2) A layer of muscle fibres arranged circularly. 



