266 DE Johnston's descriptive catalogue of the 



ami is spirally strifitcd ; i>illar white, thickened ; outer lip thin, even, with 

 a brownish margin ; tliroat brown. Opercnhun horny, thin, ear-shaped, 

 turned spirally at the inferior and inner margin, whence fine striae diverge 

 to the circumference. 

 The animal bui-ies in sand at tlic very lowest recess of the tide, and is dis- 

 covered by th(> little hillocks which it raises above the shell. Dr Gould, 

 in his valual^le and elaborate " Eeport on the Invertebrate Animals of 

 Massachusetts," p. 232, asserts that the Naticne are all very voracious, 

 and play a conspicuous part in devouring the dead fish and other animals 

 which are thrown up by the tide. The small circular holes with which 

 bivalve shells are often drilled are also, according to Dr Gould, the work 

 of these snails, and made by them to gain aii entrance to the animal 

 apparently so well secured against such a foe. Their foot is very large, so 

 as completely to envelope the objects on which they prey. 



2. iV. Alderi, shell subglobulai', smooth, flesh-coloured with a white 

 zone at the sutures and base, the body with five rows of arrow- 

 shaped brown spots, one continued round the base of the lesser 

 whorls ; spire small, slightly produced ; umbilicus partly covered 

 hy callus and brown. Length iVths ; breadth about -iVths. 

 Forbes, Faun. Mon. 31. Nerita glaucina, var. B. Turt. Conch. 

 Diet. 125. Hoffff, in Lin. Trans, xiv. 320. tab. 9. fig. 3-8. 



Hah. Berwick Bay, OL'ca«ionally found in the refuse of fishing-boats. 



Operculum semilunate, horny, with a narrow membranous edge. The white 

 band on the shoulder of the body -whorl, under the suture, is occasionally 

 obscure or obsolete. A brown, narrow fascia always enters within the 

 umbilicus, and the callus, on the pillar above it, is more or less tinted 

 with the sanie colour. 



3. JV. helicoides, shell ovato-conical, smooth, white, immaculate, 

 coated with a yellowish epidermis ; whorls five, rounded, separated 

 by a channelled suture ; the spire produced, rather obtuse ; aper- 

 ture pure white with a small fissure on the pillar. Length -i^ths ; 

 breadth scarcely iVths. Lyell in Phil. Mag. for May 1840, p. 

 365, fig. 12. 



Hah. Berwick Bay, very rare. 



This new species was found in the refuse of one of our fishing-boats. When 

 the epidermis is removed, the whorls appear to be very finely striolate in 

 a spiral direction. 



This shell, which departs from the normal form of the genus, Mr Lyell finds, 

 in a fossil state, in the " Norwich crag," when it appears to have been 

 much more abundant than in our present sea. Mr Lyell has given an 

 excellent figure of it, which will correct the faults of our own. In habit 

 the species is closely allied to the Natica canalicidata of Gould. See his 

 Report, p. 235, fig. 161. 



I found, some time since, among the refuse of a fishing boat, a specimen of a 

 Natica which appears to be identical with the Natica glaucinoidks of my 

 friend Dr Thomas Thomson (Rec. Gen. Science, i, p. 133.) and which Mr 

 Alder tells me is certainly the Nat. clausa described by Mr Smith as a 

 fossil found in the pliocene deposits of the British islands. I cannot, 

 however, affirm that the species still lives in our Bay, for the shell was 

 dead, and presented the same appearance as the subfossil specimens. 



