212 KELLIID.E. 



and somewhat thickened margin, sometimes marked with faint 

 lines which radiate from the beak : scars remarkably distinct, 

 the muscular impression on the anterior side being larger and 

 much longer than the other. L. 0-2. B. 0-3. 



Var. oblonga. Shell narrower, and having the front and 

 dorsal margins nearly straight. M. oblonga, Turt. Conch. 

 Dith. p. 61, tab. 11. f. 11, 12. 



Habitat : Muddy ground, from 7 to 85 fathoms, on 

 all our coasts. It is, however, a local species, and is 

 seldom found in a perfect state. The variety is not un- 

 common, and occurs with the typical form, as well as 

 with intermediate gradations. Grainger has recorded 

 this shell from the Belfast deposit, and Searles Wood 

 from the Coralline Crag. Loven and Malm have de- 

 scribed it as Swedish, the latter giving a depth of 18-50 

 fathoms ; Recluz found a single valve in the stomach of 

 a turbot on the French side of the English Channel ; 

 Lamarck mentions Cherbourg as the locality for his 

 Amphidesma pur par as c ens, which is probably our spe- 

 cies ; and I noticed it in M. Martin's collection of 

 shells from the Gulf of Lyons. 



Professor Loven published, in the ' Proceedings * of 

 the Royal Swedish Academy of Sciences for 1848, some 

 important information as to the production and deve- 

 lopment of the fry of this species (as well as of M. biden- 

 tata) ; and in the c Annals of Natural History ' for March 

 1850 (2nd ser. v. p. 210) is contained an excellent paper 

 by Mr. Alder on the same subject, and also with respect 

 to the habits of the adult. My description of the ani~ 

 mal is taken from Mr. Alder's notes. He mentions that 

 the specimen which he observed was taken from " the 

 stomach of a haddock — a very unpromising locality cer- 

 tainly for meeting with anything in a living state ; but 

 the little creature on being placed in sea-water appeared 

 quite lively, and not visibly the worse for the uncom- 



