MARSHALL : NEW BRITISH MARIXE SHELLS. 39 



This species is characterised by a ver_v short spire and long 

 body-whorl. Its nearest British ally is 0. inscttlpta var. 

 laevissima, but in that shell the spire is longer and turreted, with 

 a channelled suture,, the aperture is oblong instead of pear- 

 shaped, and there is a sinus at the upper corner of the outer lip. 

 Its proper place is between 0. insculpta and O. diaphana. 



In comparison with O. diaphana, this is a stouter shell, with 

 a distinct though slight tooth instead of an obscure fold, and the 

 spire is not attenuated and spindle-like as in that species. 

 From O. obliqna this species differs in being smaller, the 

 suture is not so oblique, and the sculpture is absent. It is 

 distinct from O. tenuis, Jeff., in being thinner, the spire 

 shorter, the edge of the aperture does not describe a peristome, 

 and the inside of the aperture is not grooved. From O. nitens, 

 Jeff., it is marked off by being more oval, it has two whorls less, 

 the apex is intorted, and it has a small tooth instead of an 

 almost invisible fold ; and finally, O. oblongula is thicker, broader, 

 and is not so glossy as O. crystallina, ]\Ionts. MS. 



I had at first taken these shells for two species, and the 

 IMarquis de Monterosato did the same ; in fact, he allocated the 

 first to the Liostomia group, represented by O. clavula, and the 

 variety to the Auricidina group, represented by 0. obliqua. But 

 on full consideration I prefer to unite them, as intermediate 

 specimens may yet be found to connect the two. At first sight 

 they are very unlike, but I can detect no specific difference 

 between them, except in the shape and in the presence of an 

 umbilicus in the variety. 



^lacgillivray described an O. ohlonga, '-'■ but that is our well- 

 known 0. interstinda, a very diSerent shell. 



SevcHoaks, Torquay, 



May, 1S95. 



* as did A. Adams from the Japan Seas, Ed 



