308 littorinidj:. 



Littorina litorea. 



Turho Uttoreus, Lin. Syst. Nat. 12th ed. p. 1232, &c. 



Turbo mtnlatus, Lamauck, An. sans Vert. (cd. Dlsh.), ix. 214. 



Litturina vulgaris, Sovverby, Genera Shells, Lift. fig. 1. 



Littorina littorea, Johnston, Berwick Club, i. 207. 



Littorina litorea, Menke, Zeitsch. Malakozool. 1845, 49. — Stijipson, Check Lists, 5. 



Solid, not smooth, yet rarely ridged ; whorls not ronnded, l)nt 

 more or less flattened ; base and pillar not so produced, and aper- 

 ture not so filled up anteriorly as in rudis ; outer lip 

 joining the body at an acute angle, and more arched 

 below than above ; pillar lip not peculiarly broad, 

 usually white, its inner edge for the most part well 

 arcuated. 



Like most littoral shells, the species of this genus 

 are liable to great changes of shape and color ; the 

 former arises chiefly from the amount of elevation 

 displayed by the spire. Hence, the form ranges from sub-globose 

 to ovate-acute, which last we regard as the most ordinary and char- 

 acteristic appearance. The shell is solid, a little glossy, and its 

 coloring is either of a uniform tint, or disposed in rings. Impure 

 scarlet, black, fulvous, or brown, are the nsual tints ; the two latter 

 are often zoned with numerous narrow fillets of red, or smoke color. 

 There are six or seven volutions divided by a fine and simple sut- 

 ure, and terminating in a more or less acute apex. They are spi- 

 rally girt with densely disposed raised strite, which, however, are, 

 for the most part, much more manifest in the young than m tlie 

 aged specimens, where the surface, from abrasion, exhibits merely 

 the intervening stria?. The shelve of the whorls is considerable, 

 that is to say, they are much broader below than above ; they are 

 flattish, or })laiio-convex, and never much rounded. The propor- 

 tion of body to spire is very variable ; occasionally they are almost 

 equal ; in the produced form the dorsal length is in general as two 

 to one ; in the gloludar form the spire hardly occupies more than a 

 fourth of the entire length. There is very often, especially in the 

 more elongated specimens, a slight disposition to retusion beneath 

 the suture of the body whorl. Tlie aperture is large, ovate, dis- 

 posed to obliquity, and more or less contracted posteriorly. The 

 outer lip runs at a very acute angle to the l)ody, and typically (in 

 the adult) is more arcuated anteriorly than posteriorly, the base of 

 the shell being broad in the more characteristic examples. The 



