BABLEEIA. 393 



area, crosially and vertically cloven, containing the usual 

 masticatory processes of the Littorinida ; neck dark, but not 

 so much so as the rostrum, quite plain and without appen- 

 dages. Tentacula very short, strong, broad, not in the least 

 setaceous, with perfectly rounded, somewhat spatulate extre- 

 mities ; they are not vibrated on the march j colour very pale 

 yellowish-white, with a line of sulphur-coloured beads or 

 minute flakes running centrally from base to point ; eyes 

 very large, black, fixed on bright sulphur inflations at the ex- 

 ternal bases. Foot an elongated, rather narrow oval, anteally 

 arcuated, labiated, with scarcely perceptible auricular points, 

 posteally rounded, emarginate in the centre of its termination ; 

 colour, in the middle of the upper part, confused flake-white, 

 margined with a belt of pale smoke hue ; sole pale yellow, 

 with a decided depressed longitudinal line on the centre of 

 the posterior half, not constricted under the slight auricles as 

 in Rissoa, and not so slender. The operculigerous lobe is 

 small, very little alated anteriorly, but expands below into a 

 dark, flat, arcuated membrane ; no cirrhus is visible, and I 

 believe none exists; it carries a strong, red-brown, suboval, 

 testaceous operculum, sharp above, rounded below and at the 

 outer edge, and straighter on the columellar side. The struc- 

 ture of the fine striae on the upper surface is of subannular 

 figure, with a longitudinal furrow about the middle, which 

 forms a raised rib on the under part, the whole of that area 

 being thick, coarse and irregular, with, at the nucleus (which 

 is nearer the base than the centre), a testaceous apophysis, 

 more prominent than in Jeffrey sia y and stronger and longer ; 

 indeed, as much so as in some of the Chemnitzia. 



These animals inhabit the lower littoral levels at Perzance ; 

 their locomotion is deliberate, and they evince considerable 

 shyness. There are many fasciated varieties and a white one. 



This animal approaches the Littorinidan group, and con- 

 ducts from Rissoa to Jeffrey sia : as the latter and it have analo- 

 gous subtestaceous opercula and apophyses, they naturally lead 

 to the Pyramidellidae. But this species cannot be placed in 

 Rissoa on account of the singular operculum (as the like is 

 not seen in any species of that genus), and many other animal 



