222 PTRAMIDELLIDiE. 



contour, is not dilated, but projects anteriorly without 

 forming any peaked extremity. Tlie peristome is con- 

 tinuous, or very nearly so. The outer lip is simple, acnte, 

 and much arcuated ; its edge advances towards the base. 

 The pillar-lip is thin, narrow, rather elongated, curved, and 

 erect ; it curls slightly back, but is neither appressed, nor 

 decidedly reflected. 



The animal has not been met with. 



We regard the species as very rare, a specimen or two 

 only having been obtained in each locality during each 

 research. Our best was dredged between Guernsey and 

 the adjacent islet of Herm ; the coral sand of Bantry Bay 

 supplied us also with a few individuals (S. H.); Devon, 

 Tenby, Swansea, and Dublin Bay (Jeffreys). 



A. uNicA, Montagu. 

 Aciculatc ; with longitudinal costelltc, and spiral strife. 



Plate XC. fig. 4, 5. 



Turbo unicus, ]\IoNT. Test. Brit. vol. ii. p. 299, pi. 12, f. 2. — Maton and Rack. 

 Trans. Linn. Soc. vol. viii. p. 174. — Turt. Conch. Diction, p. 209, 



— DiLLW. Recent Shells, vol. ii. p. 860 Wood, Index Testa- 



ceolog.pl. 31, f, 10». 



Turritella unica, Fleming, Brit. Animals, p. 303. — Brit. Marine Conch, p. 1 90, 

 f. 35. 



Pyramis unicus, Brow.v, lllust. Conch, G. B. p. 14, 



Ckemnitzia unica. Alder, Cat, Moll. Northumb. and Durh. p. 49. 



This extremely fragile shell is aciculate in shape, taper- 

 ing, very thin, and of an uniform more or less shining 

 semipellucid snow-white hue. There are nine peculiarly 

 rounded whorls, that enlarge with moderate quickness, 

 are rather high, the height being usually to the width as 

 two to three, are strongly defined, but only separated by 

 a delicate and very oblique suture ; the body viewed 



