Mr. Jeffreys on a Species of Limopsis. 343. 



XXXVI r. — On a Species of Limopsis, now living in the British 

 Seas ; with Remarks on the Genus. By J. Gwyn Jeffreys, 

 F.R.S., F.G.S. &c.* 



The only result of any interest which accrued from my dredgings 

 this year in the northern seas of these islands was the discovery 

 of the Limopsis aurita of Sassi in a living state. Last year I 

 procured a few small single valves in the same spot ; but, as I 

 had experienced so much difficulty in distinguishing fossil from 

 recent shells, I was not quite certain whether these valves might 

 not have come from a submarine pleistocene bed, notwithstand- 

 ing the freshness of their appearance, and the epidermis being 

 retained on some of them. However, all doubt was removed on 

 the present occasion. A specimen containing the animal was 

 dredged about twenty-two miles off the Island of Unst in Shet- 

 land, at a depth of 85 fathoms, in sandy gravel, together with a 

 tolerably large single valve in an equally recent state. My 

 friend Professor Allman was with me at the time, and has very 

 kindly made a drawing of the soft parts, which I have now the 

 pleasure of exhibiting. 



As nothing could be seen of the animal, although it was con- 

 stantly and carefully supplied with sea-water for some time, I 

 had no alternative but to kill it by immersion in boiling water, 

 in order to examine it and the interior of the shell ; and the 

 sketch made by Professor Allman and my notes were therefore 

 post mortem^ and are not so complete or satisfactory as I could 

 wish. 



The appearance of the Limopsis while living and in its native 

 element was extremely beautiful. The surface of the shell was 

 clothed with long and fine hairs, which projected far beyond the 

 edge of the valves, like a fringe of silken eyelashes. These hairs 

 form part of the epidermis, and are not contractile ; and they 

 doubtless serve to protect or warn the feeble moUusk against 

 the insidious attacks of other animals. When the shell becomes 

 dry, the epidermidal hairs shrivel up, and to some extent lose 

 their former beauty. 



The body is of a milk-white colour. The mantle is open in 

 every part except behind ; it has no tubes or folds, and its edges 

 are thickened and furnished with papilliform glands. The gills 

 or branchiae are disposed as in other members of the same family. 

 The foot is large in proportion to the rest of the body, and is 

 shaped like a tobacconist's knife ; it can in all probability forai 

 a suboval disk at the central portion, as in Pectunculus. The 

 few and imperfect particulars here given serve, however, to show 



* Communicated by the Author, having been read at the meeting of the 

 British Association held at Cambridge in 1862. 



