264 MR. E. A. SMITH ON THE MOLLUSCA [May 6, 



reflexed and appressed over the umbilical region, and joined to the 

 extremity of the outer lip by a thin callosity- 

 Greatest diameter 23 millim., smallest 19, height 15. 

 Hab. Wild Island. 



The bands on this interesting species are usually three in number, 

 one just below the periphery and two above it. In some specimens 

 there is an additional one above, in others there are but two alto- 

 gether, sometimes both above the middle, or again one of them being 

 beneath ; in other examples there may be only a single line either 

 above or below the centre ; and, finally, others are altogether unhanded. 

 It recalls to mind H. eddystonensis, Reeve, which differs in being 

 umbilicated, more acute at the periphery, more conical in the spire, 

 with a sharper apex. 



3. Helix (Geotrochus) labillardierei. (Plate XXII. 

 figs. 3, 3 a.) 



Shell small, imperforate, somewhat trochoid, totally white, or with 

 a broad suffused brownish band below the middle of the body-whorl, 

 or entirely light pinkish brown, always tipped with dark brown at 

 the apex. Whorls 5, rather rapidly enlarging, moderately convex, 

 sculptured with fine lines of growth and microscopical spiral striae ; 

 last rather sharply keeled at the middle, scarcely descending in 

 front, and a little convex beneath. Aperture small, oblique, coloured 

 like the exterior. Peristome white, broadly expanded, very slightly 

 reflexed, thickened within the basal edge by a pale pinkish ridge. 



Greatest diameter 15 millim., smallest \2\, height 10^. 



Hab. Wild Island. 



Two characters are quite constant in this species — the dark 

 coloured apex, and the peculiar thickening within the basal margin 

 of the aperture. H. helicinoides, Hombron and Jacquinot, is related 

 to this species, but differs in wanting the above peculiarities. 



4. Helix (Hemiplecta) infrastriata. (Plate XXII. figs. 4, 

 4 a.) 



Shell thin, semitransparent, corneous, narrowly perforate, de- 

 pressedly concavely conical. Whorls 6, slightly convex, slowly 

 enlarging, margined above the suture with a thread-like keel, very 

 slightly glossy, sculptured with fine lines of growth, and more or 

 less with microscopic spiral striae ; spire somewhat elevated, with 

 concave outlines ; last whorl acutely carinate at the middle, not 

 descending in front, a little convex beneath, glossy, marked with 

 lines of increment and fine concentric wavy striae. Aperture oblique, 

 angularly lunate. Peristome thin, not expanded or reflexed. 

 Columellar margin almost perpendicular, expanded and reflexed over 

 the narrow perforation. 



Greatest diameter 15 millim., smallest 13, height 10^. 



Hab. Dentrecasteaux Island, Admiralty Group. 



This species bears some resemblance to H. eucharis, Deshayes 

 (non Reeve), but has a more concave spire, is more sharply keeled, 

 and somewhat differently sculptured. The single shell described 



