92 LITTORINIDiE. 



R. cosTATA, Aduins. 



Oblong-turreted, white ; whorls with strong longitudinal ribs : 

 base with a spiral carina : lip marginated ; throat smooth. 



Plate LXXVIII. fig. 6, 7. 



Turbo coshttus, Adams, Trans. Linn. Soc. vol. iii. pi. 13, f. 13, 14 (probably). — 

 Mont. Test. Brit. vol. ii. p. 31 1, pi. 10, f. 6. — Maton and 

 Rack. Trans. Linn. Soc. vol. viii. p. 174. — Rack. Dorset 

 Catalog, p. 51, pi. 19, f. 5.— Turt. Conch. Diction, p. 214.— 

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

 pi. 31,f. 107. 

 „ plicatus, MuHLF. Verh. Nat. Berlin, vol. i. pi. 9 (also called 3), f. 2. 



Cingula costata, Fleming, Brit. Animals, p. 305. — Brit. Marine Conch, p. 175. 



liisaoa exiyua, Michaud, Especes de Rissoa, p. 18, f. 29, 30 (not well). — Potiez 

 and Mich. Gal. Douai, Moll. vol. i. p. 269.— Desii. in Lam. 

 Anim. s. Vert. (ed. Desh.) 'vol. viii. p. 481. — Philippi, Moll. 

 Sicil. vol. ii. p. 125,— Menke, Zeitsch. Malak. 1845, p. 42. 



Cingula carinata, Philippi, Moll. Sicil. vol. i. p. 150, pi. 10, f. 10 (not well). 



Rissoa costata, Johnston, Berwick. Club. vol. i. p. 273. — Brown, Illust. Conch. 

 G. B. p. 11, pi. 9, f. 74. 



This beautiful little shell is moderately strong-, a little 

 translucent, often with a vitreous lustre, and of an oblong- 

 turreted contour. It is of an uniform white, and its sur- 

 face is traversed, as well by strong distant and obliquely 

 longitudinal ribs, as by crowded and spiral striae. The 

 latter, which under the microscope show themselves to be 

 slightly elevated, are chiefly perceptible in the interstices 

 of the costse ; the former commence at the suture, but do 

 not extend, upon the body, to the extreme base, but are 

 interrupted by a very prominent spiral carina, that revolves 

 from the top of the innor-lip to the anterior corner of the 

 outer lip, from the marginated rim of which last it is sepa- 

 rated by a narrow and somewhat concave strip of surface. 

 The body is scarcely, in general, so long as the spire, which 

 is composed of five somewhat ventricose turns, that are 

 profoundly, ratlior abruptly, and often subangulately divided 



