112 J ournal of the Asiatic Society of Bengal. [April, 1914. 



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portions, — an acinar portion (or glandular portion) and an 

 albuminiparous portion. This type occurs in all the other 

 species. 



The hermaphrodite gland consists of a large number of 

 acini held together by connective tissue. Each acinus consists 

 of a wall of thin fibrous layer lined by a single layer of flat- 

 tened fusiform epithelial cells. These cells give rise to both 

 ova and spermatozoa so that both the elements are developed 

 side by side in the same acini. 



Collinge described the gland as ovary in his species, A. 



maximus and A. sarasini. But in all the species I studied I 



have found both the ova and spermatozoa after careful histo- 

 logical work. 



2. The albumen gland, in accordance with the types of 

 the hermaphrodite gland, is also represented in two forms: 



In the first type, it forms an elongated irregular mass sur- 



rounding the hermaphrodite duct, which may be coiled in 



various ways. The gland surrounds the duct, and is intimately 

 connected with it. 



In the second type, the albuminiparous portion consists of 

 irregular masses of simple racemose glands which open sepa- 

 rately, sometimes at fairly long intervals, into the herma- 

 phrodite duct. 



3. The hermaphrodite duct is a fairly stout tube which 

 passes forwards for a shorter or longer length to end in the ex- 

 ternal aperture on the right side in the groove between the foot 

 and the margin of the mantle at a little distance from the 

 opening of the combined tube of the penis and the right 

 Simrothian gland. 



4. The receptaculum seminis is a pyriform sac opening 

 into the hermaphrodite duct by means of a narrow stalk. 



The hermaphrodite gland has no connection with the penis. 

 Simroth described a vas deferens from the hermaphrodite gland 

 to the penis, but in all other species, described both by Collinge 

 and myself, no such structure was found. 



5. The penis is a stout tubular body lying in a sheath 

 with which it is connected at the free end. The penial sheath 

 is fusiform and dilated at the proximal end, but is narrowed 

 down to a tubular structure opening into the exterior behind 

 the right lower tentacle in conjunction with the right Simrothian 

 gland . 



6. A fine tubular structure is always found opening into the 

 distal end of the penis. It passes forwards along the penial 

 sheath, and then curves backwards for some distance along 

 the base of the right Simrothian gland. This has been termed 

 vas deferens by Collinge (2), but it corresponds to the flagel- 

 lum described in Helix. 



7. The retractor penis muscle is a fine strand which arises 

 from the posterior end of the penial sheath and passes back- 



