220 NATICID.E. 



In Shetland also it occasionally takes or sucks the 

 fish-baits. Its horny jaws are large; and when ex- 

 panded they form a triangular plate. The size of my 

 largest specimen is If^ x f^ inch. This species differs 

 from N. Grcenlandica in size,, solidity, colour, and the 

 umbilicus. 



It is perhaps the Nerita Icevida of Laskey (Mem. 

 Wern. Soc. i. p. 409), who says, ^^ It bears some resem- 

 blance to N. glaucina [iV. cateyia] , but has a more pro- 

 (kiced apex, and is divested of the markings of that 

 shell. ^^ It appears to be the N. glaucina'^ of Scacchi. 

 Swainson^s N. sordida is A^. jjlumbea of Lamarck, an 

 exotic species, to which Philippi erroneously referred 

 the Eui'opean shell. 



4. N. cate'na^. Da Costa. 



Cochlea catena, Da Costa, Br. Conch, p. 83, t. v. f. 7. -A". moniJifera. 

 F. & H. iii. p. 326, pi. c. f. 1, and (animal) pi. PP. f. 6 (by mistake 

 as N. canrcna). 



Body yellowish or drab, with a purplish tinge on the upper 

 part, and faintly lineated with purplish-brown : snout fleshy : 

 mouth or orifice of the proboscis globular, small, lying under- 

 neath the snout : tentacles rather long, slender, and pointed, 

 placed in the middle above the snout, and nearly concealed by 

 the front lobe of the mantle : [e^jes '' so excessively minute as 

 scarcely to be \asible" (Clark):] foot very voluminous, and when 

 at rest enveloping the greater part of the shell, divided across 

 so as to form two unequal portions, the posterior of which is 

 the larger, bluntly pointed behind ; front lobe notched or in- 

 dented in the middle : mcde organ situate under the right ten- 

 tacle : ov((ry pale yellow : liver dull olive. 



Shell globose, and somewhat resembling an AmpuUaria in 

 shape, moderately thick and solid, opaque, glossy : sculj)ture, 

 microscopical and very close-set flexuous spiral stride : colour 

 pale yellowish -Avhite or buff, ornamented with a row of red- 

 dish-brown or light chocolate short, oblique, or zigzag, longi- 

 tudinal streaks at the top of each whorl, and sometimes (fre- 



* From Its chain-like rows of spots. 



