268 CERITHIID^. 



It is sluggisli, but not shy ; the tentacles are some- 

 times folded back against the front of the shell, as in 

 Natica. Professor Sars dredged an abnormal specimen 

 in Mangerfiord, which had only two ridges on each 

 whorl_, in that respect analogous to the monstrosity 

 Cla7'kii of Cerithiopsis tubercularis ; he named his shell 

 Cerithium bicinctum, with a doubt as to its being speci- 

 fically distinct. 



Described and figured by M^Andrew and Forbes as 

 C. nitidum. 



2. C. reticula'tum^, Da Costa. 



Strombifor^nis retmdatus, Da Costa, Br. Concb. p. 117, pi. viii. f. 13. C. 

 reticulattim, F. & H. iii. p. 192, pi. xci. f. 1, 2, aud (animal) pi. II. f. 2. 



Body yellowish- white or whitish, mottled and streaked with 

 purplish-brown or faintly tinged with pink [ashcolom^ speckled 

 with brown (PhiHppi)] ; the tentacles and foot are of a paler 

 colour, the former spotted -wdth purplish-brown, and the latter 

 with flake-white : mantle not furnished with any filament or 

 process : pallial fold wide, open, and scalloped at its edges, 

 fining the notch at the base of the shell : liead nearly cylin- 

 drical, long, strongly and closely wrinkled across (unless when 

 fuUy extended), or marked with dark bars : mouth vertically 

 cloven and bilobed when the animal is crawling, but expansile 

 and forming a circular disk when it is feechng or at rest ; 

 underneath is a pink stripe on each side : tentacles slender, 

 although not pointed, somewhat compressed above and below, 

 shghtly serrated or jagged at their edges ; a double line of pink 

 frequently runs down each tentacle in a siphonal form : eyes 

 rather large in proportion, placed on short pale-coloured off"- 

 sets or bulbs : foot long, squarish or gently curved and double- 

 edged in front, with shght angular corners, attenuated towards 

 the tail, which is sometimes rounded and rather broad, at other 

 times bluntly pointed ; sole finely grooved down the middle : 

 opercular lobe expanded on each side, and extending beyond 

 the operculum at the hinder end of the foot ; I could not de- 

 tect any such cirral process as is presented by Rlssoa, notwith- 

 standing the statement of Loven, " An. Rissooi lobo operculi- 

 gero utrinque subalato, cirro postico rotundato-lanceolato." 



* Reticulated. 



