1916] H. H. Godwin-Austen : Mollusca, VI. 557 



deep V"Shaped depression, in which the posterior part of the 

 animal rests. The mantle is quite abnormal, it is quite smooth 

 and skin-like, very thin ; on the right side, rather forward in posi- 

 tion, is the respiratory orifice ^ with small dorsal lobes on either 

 side, the left produced forwards forms the anterior dorsal part 

 of the mantle, and only this portion is minutely papillate and 

 speckled, distinct from the smooth cuticle covering the internal 

 shell and visceral sac. With the gradual reduction of the shell and 

 its anterior position, this appears to have been the course of develop- 

 ment ; the shell lobes have disappeared and their place has been 

 taken by the very thin skin of the visceral sac, through which the 

 dark intestine can be discerned. When this thin membrane is cut 

 an(i turned back, a lobe of the liver is exposed covering the ex- 

 treme posterior end of the visceral mass, other lobes in which the 

 intestine lies buried, succeed anteriority. Just behind the respira- 

 tory orifice (fig. 2e) the branchial sac comes in, long and narrow, 

 stretching diagonally across to the left side, the kidney and heart 

 lie alongside it on the anterior side ; covering these organs is the 

 minute, oval, thin calcareous shell (fig. 2b). 



Genitalia. — The male organ is a bulbous, short, solid mass, at 

 the apex of which is the retractor muscle; just below this there 

 is a very small pear-shaped accessory organ. The vas deferens is 

 at first large, convoluted, short, rapidly decreasing in size up to 

 the oviduct. This and the prostate are short. The spermatheca 

 is very short, pear-shaped. The amatorial organ is absent. 



The radula (fig. 2g) of this remarkable moUusk is very interest- 

 ing, and at once settles its subgeneric position in the Durgellinae. 

 It is of considerable breadth, the number of teeth in the row being 

 very great, 300.1.300, or over 600. The centre tooth is elongate, 

 with a blunt, rounded point, the teeth following are more pointed, 

 long and narrow. Throughout the teeth are of the same form and 

 about the same size, elongate, curved, rising from an oblong 

 plate, bicuspid, finely serrate on the outer edge, the teeth often 

 appear single pointed, due to a slight twist and to the position they 

 are viewed from, one point thus becomes hidden behind the other. 



The jaw is thin, narrow, straight in front. 



This is a very interesting animal, and an equally interesting 

 discovery. It goes far to clear up our knowledge of these Eastern 

 slug-like forms. 



In 1873, when surveying the Aughami Naga Hills, I found 

 near Kohima a small slug under stones on the hill slopes under the 

 village, of which I made drawings at the time. It was eventually 

 described in the Journal Asiatic Society of Bengal, vol. xliv, pt. 

 2, 1875, as Parmarion ? rubrum, plate ii, figs. 4 — ^e ; republished by 

 me in " Mollusca of India," 1887, vol. i, p. 228, pi. Ixi, figs. 4 — 

 4.d, and placed in Girasia with a query and with this remark : 

 " The exceedingly small rudimental shell, so completely enveloped 

 by the mantle, almost entitles this form to sub-generic rank ; but as 

 only one specimen has been obtained and was not fully examined 



