MOLLUSCA or INDIA. 89 



The spermatheca is very long, swelling out slightly towards its 

 free extremity, and lies buried in the coils of the oviduct. Just 

 below the point where the vas deferens leaves the side of the ovi- 

 duct the uterus is bent into a sharp fold. 



The amatorial organ is long and cylindrical, tapering to a point 

 and giving off a retractor muscle. On cutting open the anterior 

 thickened end or atrium (fig. 4) the blunt papilla of the dart i.« 

 exposed : in this species it has a papillose surface. The interior 

 of this atrium is wrinkled concentrically, indicating its contractile 

 nature. The amatorial organ itself (fig. 4 a) consists of a flexible 

 pointed rod of concentric structure, 0*75 mm. in diameter, having 

 a central nucleus, and surrounded outside by a glandular mass 

 radiating from it (fig. 4 b). 



It may be noticed that the base of the spermatheca in my draw- 

 ing (fig. 2) is very rounded and even in outline. This was due to 

 the sac being literally full of spermatophores, no less than seven. 

 It was one of the most beautiful objects I have ever dissected out, 

 for the state of their preservation was perfect, and I show, by 

 dotted lines, how they were packed away inside the spermatheca. 

 The spermatophore (fig. 5) is of delicate and graceftil outline, and 

 unlike any I have seen before in the great length of the canal or 

 " flume," which measures 38 mm. in total length, of which the 

 capsule is 10 mm. The spines on the marginal sides (fig. 5 6) of ' 

 the " flume " are set at regular intervals and branch into two points, 

 which sometimes are again bifid. They are larger close to the base 

 of the capsule, where there are three strong simple spikes (fig. 5 a). 

 This capsule is beautifully transparent and terminates in a hard 

 solid point. Some of the capsules were quite empty, others were 

 full of a granular mass, representing, I presume, the remains of the 

 spermatozoa that once filled it. 



The hermaphrodite -duct (fig. 2 a) is very large, joining the 

 albumen-gland by a very closely convoluted tube. The ova testis 

 was not extracted from the lobe of the liver, in which it was closely 

 imbedded. 



In all important characters except one (the male organ) this species 

 is a MacrochJamys, but it is a section of the genus, more correctly, 

 perhaps, a link with it. The shell-lobes show this, the most noticeable 

 diff"erence being the very moderate development of the right shell- 

 lobe. In the generative organs the manner in which the retractor 

 muscle is given off recalls its position in Girasia and Austenia ; but 

 closer examination shows a considerable difference in the presence 

 of a sharp bended caecum (fig. 3 a) at this point, and this is an 

 interesting approach to the diverticular coil so well developed in true 

 Macrochlamys, in Oxytes, and in Bensonia. The flagellum of M.pedina 

 is far longer than in Girasia, and thus, again, it more resembles 

 M. 7iardwicJcei, &c. (See Plate XX VIII. figs. 1, 1 «, Vol. I.) 



From Ariophanta and Nihjina it differs completely in having a 

 long spermatheca, but a somewhat similar type of male organ : the 

 spermatophore also may be compared with that of Nilgiria tnm- 

 fjuebarica ; the difference is very great (vide Plate LXXXI. figs. 3 c, 



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