258 CERITHIID.E. 



It is sluggish, 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 

 Clarkii of Cerithiopsis tubercularis ; he named his shell 

 Cerithium bicinctumj with a doubt as to its being speci- 

 fically distinct. 



Described and figured by M f Andrew and Forbes as 

 C. nitidum. _ . ... 



* I *U 



!>! fro 2. C. RETICULA'TUM*, Da Costa. 



Strombiformis reticulatus, Da Costa, Br. Conch, p. 117, pi. viii. f. 13. C. 

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



BODY yellowish-white or whitish, mottled and streaked with 

 purplish-brown or faintly tinged with pink [ashcolour, speckled 

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

 colour, the former spotted with 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, 

 lining the notch at the base of the shell : head nearly cylin- 

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

 fully 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 feeding or at rest ; 

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

 although not pointed, somewhat compressed above and below, 

 slightly 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 slight 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 Rissoa, notwith- 

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

 gero utrinque subalato, cirro postico rotundato-lanceolato." 



* Eeticulated. 



