6l2 



Records of the Indian Mitsetim. 



[Vol. VIII, 



Size: major diameter r6-o, alt. axis yo mm. 



The largest major diameter 16-25. 



This species, looking at it from above, recalls and is very 

 closely allied to H. catostotna, W. Blf., of the same valley the 

 Diyung in the Naga Hills. It is larger than that species, is higher 

 in the spire, is not nearly so openly umbilicated and the aper- 

 ture distinguishes it at once, it is also very close to tapeina from 

 Teria Ghat. 



Animal. The foot is not divided below, there is no peripodial 

 groove or border to the margin and the extremity of the foot is 







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V\G. 7. — Mikiria diyioigensis, n. sp. 

 A. — Portion of the generative organs, X 2. 

 C. — ,, showing the spermatheca, X 2. 

 B. — ,, to show enlargement of the vas deferens, ><: 2. 

 D. — ,, oviduct and vas deferens, X 2. 



E.— Jaw, X 15. 



F. — Teeth of the radula at different parts of the row, very largely 

 magnified. 

 ep. epiphallus,_g-e72. ap. generative aperture, ov. o\'iduct, p. penis, mii. retractor 

 muscle, rmp. retractor muscle of penis, sp. spermatheca, -vd. vas deferens. 



rounded in the spirit specimen. The visceral sac is sparsely 

 mottled with black on the branchial cavity, closer and in larger 

 streaks near the mantle margin and line of the rectum. A tri- 

 angular small right dorsal lobe, the left reflected over the peristome, 

 single elongate and narrow posteriorly. 



From the form of the shell so openly and closely wound, the 

 principal retractor muscles extend far back nearly to the apex and 

 the visceral sac is very long, every organ of the animal is thus 

 drawn out and closely packed within it. The kidney takes this 

 form from above the heart in an anterior direction and is situated 

 between it and the line of the rectum. 



