346 LITTORINID/E. 



tlie foot, which jerks forwards, first on one side and then 

 on the other. 



It is in all probability the Turbo pallidus of Donovan ; 

 and if his description (part of which is, ' ' whorls very 

 slightly bicarinated ,} ) were recognizable with sufficient 

 certainty, that name ought to have precedence of the 

 one proposed by Montagu. I willingly avail myself of 

 the doubt, in order not to alter the name by which this 

 shell is now generally known. Leach called it Medoria 

 Walkeri and M. Danmoniensis. 



2. L. divarica'ta*, Fabricius. 



Trochus divaricatus, Fabr. Fn. Groenl. p. 392. L. vincta, F. & H. iii. 

 p. 62, pi. lxxii. f. 10-12, lxxiv. f. 7, 8, lxxxvi. f. 6-8, and (animal) 

 pi. G G. f. 4. 



Body yellowish-brown faintly streaked with purple or tinged 

 with pink: head fleshcolour, large, broad, prominent, and 

 becoming wedge-shaped towards the extremity : tentacles ta- 

 pering, with blunt tips ; owing to their contractility they are 

 sometimes finely, but irregularly, scalloped at the edges : eyes 

 raised on short stalks : foot angulated at each of the front 

 corners, behind which it is contracted ; sole edged with a broad 

 white border : appendages short and ribbon-like. 



Shell obliquely conical, expanded and more or less bluntly 

 angulated at the base, usually thin, semitransparent, and 

 somewhat glossy : sculpture, numerous slight and sinuous 

 spiral impressed fines or striae, as in L. crassior, but always 

 perceptible and more regular: colour varying from white to 

 yellowish-brown, and often diversified by reddish-brown spiral 

 bands of different widths ; there are generally four of these 

 bands on the largest whorl (viz. two above the peripheral 

 keel and two below it), two on the penultimate, and one on 

 the antepenultimate whorl ; the bands are sometimes confluent, 

 and so disposed as to exhibit a white or yellowish -white zone 

 just below the suture of the last three whorls ; the apex is 

 often reddish-brown or horncolour : epidermis membranous 

 and thin : spire considerably raised and terminating in a blunt 

 point : whorls 6, compressed, the last occupying about two- 

 thirds of the spire : suture distinct, but not excavated : mouth 



* Spread out. 



