RISSOA. 141 



science, to risk again his fragile treasure, after it had 

 ah-eady been injured by a previous transmission. Upon 

 close comparison of it with an adequate suite of the present 

 very variable species, we believe it to be only an aberrant 

 colourless variety of mntrosa, since we are unable to detect 

 any further characters, beyond the snowy whiteness of its 

 hue, by which we may distinguish the two shells. 



R. vhVM, Pennant ? 



Smooth, tawny, not variegated, more or less opaque and strong, 

 not much polished. Whorls flattened. Outer lip simple, not 

 patulous ; pillar -lip reflected and rather broad. 



■Plate LXXXI. fig. 4, 5, 8, 9 ; Plate LXXXVII. f. 2, 8 ; and (Animal) 

 Plate J. J. fig. 8. 



Turbo ulv(B, Pennant, Brit, Zool. ed. 4, vol. iv. p. 132 (probably), pi. 86, 

 f. 120 ?— Da Costa, Brit. Conch, p. 105. — Mont. Test. Brit, 

 vol. ii. p. 318. — Maton and Rack. Trans. Linn. Soc. vol. viii. 

 p. 164. — Rack. Dorset Catalog, p. 49, pi. 18, f. 12. — Turt. 

 Conch. Diction, p. 204. — Dillw. Recent Shells, vol. ii. p. 840. — 

 Wood, Index Testaceolog. pi. 31, f. 58. 

 Helix „ Pulteney, Hutchins, Hist. Dorset, p. 49. 



„ Jcverana, Megerle Muhlf. Verh. Gesel. Nat. Berlin, vol. i. pt. 4, p. 215, 

 pi. 8, f. 5 (probably). 

 Cingula ulvce, Fleming, Brit. Animals, p. 308. — Brit. Marine Conch, p. 180. 

 Rissoa subumhiliaita, Berkeley, Zoolog. Journ. vol. v. p. 430, pi. 19, f. 5 (pro- 

 bably).— Macgil. Moll. Aberd. p. 342, (probably). 

 Paludina uJvcb, Forbes, Malac. Monensis, p. 18. 

 Littorina „ Johnston, Berwick. Club, vol. i. p. 269 (with animal). — Brit. 



Marine Conch, p. xxxix. f. 88. 

 Rissoa Burled, Jeffr. Ann. Nat. Hist. vol. xix. p. 310. 



This species, in its ordinary condition, ranges in shape 

 from oblong-conic to turreted-conic ; it is, however, liable 

 to a kind of distortion, by which the body-whorl is occa- 

 sionally relaxed from its symmetrical embrace of the pre- 

 ceding turn, the suture bends down, the mouth projects, 

 and the spire is narrow and produced. It is strong, and 



