Page:The Zoologist, 3rd series, vol 2 (1878).djvu/148

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126
THE ZOOLOGIST

search for it is necessary. In appearance the shell is not very unlike Pupa, but more transparent, with fewer whorls and with the spire less blunted. Mr. Unwin notes it as rare in the neighbourhood of Lewes. He has found it at the roots of moss (Hypnum lutescens and cuspidatum), on a moist bank sloping towards the " Cut," near Landport.

Mr. Borrer would include amongst the Land and Freshwater Mollusca of Sussex, Conovulus denticulatus and C. bidentatus, which he notes as occurring in brackish marshes under stones and amongst roots, and abundant around Newhaven and near Shoreham Bridge. Mr. Gwyn Jeffreys, on the other hand, considers that they should be "excluded from the category of land shells, and placed with those having a marine habitat." The late Dr. Gray, in his edition of Turton's 'Manual of the Land and Freshwater Shells of the British Islands,' places these two species in the same family (Auriculidæ) with Carychium minimum, and remarks: —

"These Mollusca appear by habit and character to be exactly intermediate between the land and freshwater univalve Mollusca. They have the sessile eyes of the Pond-snails, placed behind instead of in front of the tentacles of the land-snails; but the tentacles are not retractile under the skin of the neck. In the same way the Carychia and Acmea are terrestrial, living in damp moss; the Conovuli live in the mud at the mouths of rivers, or in the sea—they seldom leave salt, or at least brackish water."

Fam. Cyclostomatidæ.

Cyclostoma elegans. The Elegant Circle Shell.—In hedges and umler stones on the chalk. Abundant in the copses under the South Downs. The mouth of this shell is closed with a very solid operculum, covered on both sides with a thick epidermis, a double fringe of which completely encircles it, and causes it to appear laminated. The animal itself is of very shy and retiring habits, and in dry weather buries itself in the earth, where it often falls a prey to carnivorous beetles, notwithstanding its closely-fitting operculum.

Acme lineata. The Striated Pointed Shell.—Amongst decayed leaves in open drains, and under stones in woods. Included in the lists from Brighton and Lewes (where Mr. Unwin marks it as rare), under the name Segmentina lineata.

(To be continued.)