MOLLrSCA OF INDIA. 315 



being larger in proportion to the anterior part, this last in deshaysei 

 being also much broader and spread out. 



Generative organs (fig. 6). The retractor penis is given off from 

 the end of a shortish sheath, from the side of which there is a 

 thick very elongate tube on the rounded termination of which the 

 vas deferens unites, and this is very long. The spermatheca is a 

 globose sac at the end of a short stalk. Near the base of the 

 generative aperture there is a long accessory organ or gland. The 

 ovotestis is large. 



The radula (fig. 8) has the formula of 21 . 24 . 1 . 24 . 21, or 

 according as the transition teeth are counted : 



16 . 29 . 1 . 29 . 16 

 or 45 . 1 . 45. 



The central tooth is tricuspid, the admedians broad and even in 

 size also tricuspid, the marginals short and stout, with no side 

 cusps. The jaw (fig. 7) 'n smooth, oxyguathous, dark coloured, with 

 a slight central projection. 



I have purposely kept back any further description of this 

 interesting species, until I had seen the animal of true Parmacella 

 from North Africa, with which I could compare it. 



An exhaustive excellent description of the anatomy of Parmacella 

 olii'ieri, Cuv., from the Caspian, is given by Dr. Heinrich Simroth 

 in Jahrbucher d. Deutschen Malakozool. Gesells. 1883, with 

 beautiful figures of the difi"erent parts of the animal. This has 

 proved most valuable, for I was able to obtain last summer 

 (1912) through M. P. Pallary of Eckmuhl, Oran, specimens of 

 Parmacella des7ia)/esi which reached me alive, but with all the care 

 1 bestowed upon them they did not survive long. A comparison 

 of their anatomy with Simroth's figures and those of the Afghanistan 

 species is very interestiijg. In the first place, the principal difference 

 between P. oUvieri and deshayesi consists in the greater distance 

 the spermatheca of the latter is situated from the genital aperture. 

 Secondly, in the presence of what ISimroth terms the clitoris 

 (PI. CXLII. fig. 9«, cl.l and cl.2), corresponding to the dart-sac 

 of the Helices. There is difference in the details, they have not 

 the same outward form, but their position is similar close to the 

 generative aperture. I opened out both of these to see the interior 

 as shown in fig. 7 of Simroth's Plate. In the first {cl. 1), near the 

 apex, there is a sharp fold of the wall forming a long narrow pale 

 coloured ridge fining out gradually forwards. This is soft and 

 muscular apparently, if hard it would be a perfect dart: may it not 

 be its analogue ? In the other {cl. 2) the inner walls are smooth 

 and creased, and there is one, elongate rod-shaped, fairly thick at 

 the base, tapering to a fine point at the free end, and attached for 

 its whole length to the wall of the sac. By the side of this is 

 another branched and isolated similar ridge or folding. Having seen 

 these accessory organs in the North African species, still more 

 interesting became the anatomy of the one from Afghanistan, and 



