192 JOURNAL OF COXCHOLOGY, VOL. ID, NO. 6, APRIL, I902. 



which is compressed, like Helix obvoluta^ the spire being quite flat 

 and the umbiUcus considerably expanded. Another from the same 

 ground ha.s a barnacle as large as itself attached to it. On some 

 dredging-grounds the surface of the shell is much eroded or pitted, 

 and the spire frequently so. 



Jeffreys' figure is the type, and Sowerby's the var. conica, but both 

 are too large ; four lines in length and breadth is the maximum size, 

 as given by Forbes and Hanley, and their figure is just the thing. 



N. affinis Gm. — This species has been dredged well within sight 

 of the British Isles, and is entitled to be considered indigenous (see 

 J. Conch., vol. 7, pp. 258-9, 1893). Var. elatior Moll, has been 

 dredged in the Shetland-FiBroe Channel ("Triton")! It is analogous 

 to N. montacuti var. conica. 



The N. nana of Moller resembles the last species in having the 

 umbilicus covered in the adult stage by a shelly pad, but the oper- 

 culum is horny. Two dead specimens were dredged in the Minch in 

 80 f. during the " Porcupine " cruise of 1869. It is similar in size and 

 shape to N. glaiuina var. suboj'a/is. 



I have a specimen of Nerita virginea L., from Guernsey, and Mr. 

 Heathcote another which was dredged at Port Erin, Isle of Man. 

 It is West Indian. 



Two living specimens of Solaniini sicniuin Cant, were dredged by 

 the "Porcupine" off Valentia, Ireland, in 1 13-180 f., and several 

 specimens of S. carocollatuin Lamk. on the Channel slopes in 257- 

 539 f- (Jeffi'cys), while a living specimen of S. pseudoperspectivum 

 Brocc. was dredged by the " Research " sixty miles off Cape Clear in 

 400 f. (Bourne). 



Adeorbis subcarinatus Mont. — Scilly Islands (Smart and 

 others) : Jersey (Duprey and J.T.M.); Aberdovey ; Mayo, Sligo, and 

 Bundoran ; Oban, lona, and N. Rona. 



Var. interrupta Marsh, n.var. — Shell more depressed and quoit- 

 shaped, with three carinations instead of six — one underneath, one at 

 the base, and One surrounding the suture of the penultimate whorl. 

 Sometimes there is a fourth ridge round the periphery. Found in the 

 Channel and Scilly Islands with the type, and probably in other places, 

 but rare. 



I first discovered this species alive in 1868, at Herm Island, and 

 sent a specimen to Gwyn Jeffreys, who made a note of it ('Brit. Conch.,' 

 vol. 5, p. 216) ; two years afterwards, in the same island, I was fortu- 

 nate in discovering its habitat, with plenty of specimens, adhering 

 under large stones which are firmly and sometimes deeply embedded 

 in muddy sand, at low water of ordinary tides. My written notes of 

 the animal, accompanied by a rough sketch, agree with the descrip- 

 ( To l>e continued). 



