. 1895.] NEW MOLLUSCS FBOM BOBNEO. 243 



1. Anatomy. 



Visceral Mass, Sfc. — On removing the shell, the visceral mass 

 presents a single coil (fig. 5), the apical portion being distinct and 

 terminating bluntly. 



The jaw (fig. 7) is straight and narrow, very slightly concave 

 on the cutting-edge, with a straight central portion less than 

 one-third of the whole breadth. The Ungual ribbon (fig. 8) 

 is broad and square, having a great number of equal-sized 

 and similarly-shaped teeth in the row. The lingual ribbon was 

 incomplete in the specimen examined, but the following were 

 counted: — 175 — 1 — 175. The central tooth is elongate with 

 three points close upon the same level, Jieur-de-lis in form, 

 contracting below this and widening again at the base. The 

 succeeding lateral teeth are all uniform, curved, very elongate, 

 with two closely-set points, the outermost being rounded and the 

 innermost sharp and pointed. 



Generative, Organs (tigs. 9-12). — From the somewhat large thick- 

 walled vagina the penis passes off ; its first third is a thick mus- 

 cular-walled tube which dilates into a more sac-like portion, above 

 which it becomes suddenly constricted, and then dilates into a 

 bulbous head (figs. 10 & 11). Attached to the upper portion of 

 the penis, above the vas deferens, is a short but strong retractor 

 muscle (figs. 10 & 11, r.m.). From the side of the bulbous head 

 of the penis the vas deferens passes off as a thick tube narrowing 

 gradually as it approaches the prostatic portion of the common 

 duct. The free oviduct commences immediately above the opening 

 of the receptaculum seminis, this latter organ opening into the 

 vagina; it is a small ovoid sessile body (fig. 9, r.s.). The first 

 portion of the free oviduct (fig. 9, ov .) is thrown into a series of 

 constrictions. The oviduct is a wide tube and densely folded, the 

 prostatic and oviducal portions terminate in a bulbous head lying 

 immediately in front of the globular albumen-gland. The herma- 

 phrodite gland is almost circular and appeared flattened, showing 

 a slight fold or indentation in^*he centre. The amatorial organ 

 is a large, wide, thick, muscular-walled tube, making a single coil 

 above the middle half, which would increase its elasticity and act 

 like a spiral spring ; just below this is the calcareous dart. Its 

 basal portion is funnel-shaped, the dart itself being long and 

 pointed (fig. 12). 



2. Affinities. 



Damayantia smithi is in every way a most interesting species, 

 differing in many important particulars from Girasia and its 

 allies of the Indian Region, of which the following may be 

 mentioned : — 



1. The spiral form of the visceral mass is very noticeable, and 

 we probably have here .indicated a relationship with forms 

 having a more perfect spiral shell. In Girasia, when the 

 shell is removed, this is not apparent. 



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