RISSOA. 147 



Turbo coniferiis, Mor^T , Test. Brit. vol. ii. p. 314, pi. 15, f. 2. — Maton and 

 Rack. Trans. Linn. Soc. vol. viii. p. 173. — Rack. Dorset 

 Catalog, p. 50, pi. 19, f. 6.— Turt. Conch. Diction, p. 213.— 

 DiLLW. Recent Shells, vol. ii. p. 858. — Wood, Index 

 Testae, pi. 31, f. 103. 



Ci/iffula cord/era, Fleming, Brit. Aoimals, p. 306. 



Turritella „ British Marine Conch, p. 17G. 



Rissoa „ Brown, lUust. Conch. G. B. p. 10, pi. 9, f. 68. 



The descriptions of this shell are all derived from the same 

 source, the " Testacea Britannica," unless, perhaps, that in the 

 " Dorset Catalogue ;" the figures, too, are all copied from the same 

 work, except that of Brown, which seems original, and more like 

 Brugieri, but does not represent the basal canal of its aperture. 

 Montagu's figure, if intended for the Mediterranean species, is a 

 very bad representation of it ; his description fairly enough 

 agrees, except that " cavities " would be an exaggerated expres- 

 sion for the slight sutural indentations that result from the pos- 

 terior projection of the longitudinal costse. 



" A strong, taper, white shell, with six volutions terminating 

 in rather an obtuse point, and furnished with about twelve un- 

 dulated ribs, interrupted only by a fine separating line ; the 

 interstices between them, at the top of each volution, are formed 

 into small cavities, giving that part a scalloped or denticulated 

 appearance ; these singular indentations continue throughout the 

 spiral divisional line ; the ribs are crossed by extremely fine, 

 close-set strite, not discernible without the assistance of a lens : 

 aperture oval, oblique, strongly marginated : pillar-lip not re- 

 flected. Length a quarter of an inch ; breadth one-third its 

 length. This very elegant shell we were favoured with by Mr. 

 Bryer, who found it at Weymouth." 



R. DEcussATA, Montagu. 



Helix decussata, Mont. Test. Brit. vol. ii. p. 399 ; Suppl. pi. 15, f. 7. — Rack_ 



Dorset Catalog, p. 55, pi. 19, f. 17. 

 Turbo arenarius, Maton and Rack. Trans. Linn. Soc. vol. viii. p. 209. — Turt. 

 Conch. Diction, p. 210. 

 „ decussaius, Dillw. Recent Shells, vol. ii. p. 882. 

 PliasiuncUa decussata, Fleming, Brit. Animals, p. 302. 

 Rissoa alaia, Menke, Synopsis Mollusc, (ed. 2) p. 138 (from description). 



,. deformis, Sowerbv, Genera Shells, Ris. f. 2 ; from which Reeve Conch. 

 Systemat. vol. ii. pi. 208, f. 2 ? 



