428 Lt.-Col. H. II. Gotlwin-Austen on 



pitted sculpture of the shell, in Mr. Ponsonby's collection, 

 but has strong rough lines of growth in addition. 



The animal has no shell-lobes and therefore it cannot be 

 mistaken for a Macrochlamys. The left dorsal lobe is in two 

 parts, the smaller posterior well separated from the larger 

 anterior. The visceral sac is closely mottled with black, 

 with a tendency to form bands of that colour crossing it 

 transversely. Towards the apical whorls black predomi- 

 nates, speckled with white. The branchial chamber is 

 very ample and long. This description is taken from a 

 specimen collected in the forests by Dupont. 



The genitalia (fig. C) are of the same type as in the pre- 

 ceding species, with the same lengthened twisted flagellum. 

 The spermatheca differs in being more ample and bulbous at 

 the free end. There is also a peculiar dark pigmented 

 globose expansion in the free oviduct, just below the point 

 where the vas deferens is given off, which may be an ovitheca. 

 The generative organs agree well with Semper's figure of a 

 Bourbon specimen. 



The radula, like that of the ]neceding species, has a 

 great number both of admedian and minute marginal teeth ; 

 tliese and the larger marginals being bicuspid, inner cusp 

 the longest. The formula is: 58 . 2 . 19 . 1 . 19 . 2 . 58, 

 or 79 . 1 . 79. The jaw is solid, cutting-edge concave with 

 central projection. 



Subgenus DuroNTiA, nov. 



Type E. pe?hicida. 



Shell umbilicated, very depressedly conoid, thin, glassy to 

 the eye. Animal with a raucous gland overhung by a well- 

 developed lobe. Foot divided. 



The penis has a very long flagellum and an accessory 

 organ in the shape of a small sac attached to the penis- 

 sheath towards its distal end, Spermatheca long. Radula 

 with about 100 teeth in the row : the central and admedian 

 teeth sho7't and blunt with no side cusjis ; the laterals evenly 

 bicuspid. 



Tlie generative organs, radula, and shell differ from those 

 of Ercpta rufozonata &c. — the first, although of the same type, 

 by the presence of the peculiar accessory gland ; the second in 

 the form of the central and admedian teeth without cusps. 



A comparison with the African genus Martensia is 

 interesting, because the genitalia are of the same type, as 

 regards an accessory gland being also present {vide Proc. 

 Malacologieal Soc. vol. i. pt. 6, July 1895, p. 282, pi. xix. 

 fig. 1 d) ; the radula and shell, however, are quite different. 



