CYCLOSTREMA. 289 



2. C. nitens *, Philippi. 



Delphinula nitens, Phil. Moll. Sic. ii. p. 146, tab. xxv. f. 4. Trochus 

 pusillus, F. & H. ii. p. 534, pi. lxxiii. f. 3, 4. 



Body closely resembling that of C. Cutler ianum. The ten- 

 tacles and lateral appendages of the foot, however, are not 

 quite so long ; the foot is shorter, broader, and more rounded 

 at each end, with the front corners detached to a greater ex- 

 tent ; and there are four tentacular appendages on each side. 



Shell not so globular, thin, or transparent as C. Cutleri- 

 anum, but somewhat depressed above and below, more glossy 

 and almost iridescent : sculpture consisting of only a few in- 

 distinct grooves on the upper part of the umbilicus ; the sur- 

 face is otherwise quite smooth and polished, even under the 

 microscope : colour whitish, with a faint tinge of yellow : 

 spire not much raised, and blunt : whorls 3, convex, ra- 

 pidly enlarging : suture rather deep : mouth as in the first- 

 described species ; peristome thickened and slightly reflected 

 on the columellar side : umbilicus narrow, placed obliquely, 

 not exposing any part of the middle whorl : operculum having 

 6-8 volutions, which are continued to the centre. L. 0-035. 

 B. 0-03. 



Var. Alderi. Shell thinner and more transparent. Skenea? 

 Icevis, F. & H. iii. p. 165, pi. lxxxviii. f. 5, 6. 



Habitat : Coralline zone on the coasts of Guernsey, 

 Devon, Cornwall, Ireland (north, east, west, and 

 south), west of Scotland and the Hebrides, Moray 

 Firth, and Shetland. Mr. Cocks has taken it " attached 

 to Algae in the pools on rocks, Gwyllyn vase," near 

 Falmouth. The variety was obtained by Mr. Barlee in 

 Skye. A single fossil specimen of the typical form 

 was found by Philippi in Calabria; and M f Andrew 

 dredged this species alive in the Mediterranean. 



It was described by me in the ' Annals of Natural 

 History ' for 1848 as Margarita pusilla. The name 

 given by Philippi has precedence by four years ; and it 



* Shining. 

 VOL. III. O 



