TURBINACEA. MOLLUSCA. littorina. 257 



It is the smallest of the species of this genus that we find. It is most 

 obviously distinguished from small specimens of the last species by its 

 dead surface, which may be well compared to chased silver ; and, on a 

 more intimate examination, it is found to have more uniform and de- 

 cided revolving lines, and its spire is more elevated. 



I wa$ at first disposed to regard it as the M. cdrnea^ Lowe ; (Zool. 

 Journ., ii. 107, pi. v. f. 12, 13, 132). But, in the following essential 

 characters belonging to that, it differs from our shell, viz. an acutely 

 pointed spire, an angular aperture, and a uniform yellowish flesh- 

 color. The revolving lines, too, are said to be elevated and sub-distant, 

 terms which allow of much latitude of meaning, but \vhich we should 

 not be likely to apply to the crowded, miscroscopic lines on our shell. 

 They appear quite conspicuous on the figure quoted. The young of 

 M. undulula would answer better to that description. If it is not M. 

 cdrnea^ it has not been described ; Mr. Sowerby hesitates to call it so. 



Genus LITTORINA, Fe'russac. 



Shell ^hirJc, top-shajyed, spire of a feiv rounded ivhorls ; aper- 

 ture entire, rounded-ooate, large; outer lip sharp, inner lip some- 

 what flattened ; lips not cdniinuous posttriorly ; operculum horny, 

 spiral. 



Littori'na rudis. 



Shell strong and coarse, volutions convex and ivell defined, 

 with revolving ridges ; pillar flattened, prolonged so as to form an 

 angle in front ; color yelloivish. 



Figure 165. 



Statfe ColL, No. 39. Soc. Cub., No. 881. 



Turbo rudis, Donovan; Brit. Shells, i. t. 33, f. 3. Montagu ; Test. Brit., 304. 

 Turton's Lin. ; iv. 480. Cunch. Diet., 197. Chemn. ; Conch., v. t. 185, f. 1853. 

 Maton and Rackett; Lin. Trans., viii. 159, t. 4, f. 12, 13. Wood ; Index, p], 

 30, f. 7. Lam.; £n. saris Vert., (Isted.,) vii. 49. Fleming; £fit. Mim., 2D8, 



Turbo obligcitus, Say; Journ. Jlcad. JS'at. Sc, ii. 241. 



Shell broaci-ovate, strong and coarse, generally yellowish or 



ash-colored, sometimes orange or olive, for the most part of one 



uniform color, but occasionally banded with white, or blotched 



with som€ lighter color ; surface marked with very perceptible 



33 



