MYA. 65 



from the Firth of Forth and Oban, and the abnormal 

 form from Exmouth. Fossil in all our newer tertiaries 

 up to the Red Crag; inclusive ; Nieuwerdiep, Friesland, 

 in excavating the Royal naval dock (J. G. J.) ; newer 

 beds of the " glacial formation " at Christiania, 50- 

 .200 feet above the level of the sea (Sars) ; Belgium 

 (Nyst) . In a living state M. arenaria is universally 

 spread over the shores of the western hemisphere as far 

 south as New York (de Kay), and the eastern hemi- 

 sphere as far south as Rochelle (D'Orbigny, pere), and 

 between the 30th and 40th degrees of latitude in China 

 (Debeaux) . Dr. Walker records it from South Green- 

 land at depths of from 10 to 120 f. ; and on the coast 

 of Norway it is enumerated by Danielssen as taken in 

 2-15 f., and bv M f Andrew and Barrett in 20-40 f. 

 It is, however, in the main a sublittoral species. 



M . arenaria received its name from Baster, and its 

 habits are well described in his ' Opuscula subseciva/ 

 He says that the foot, with which it penetrates the sand 

 or mud, is wonderfully flexible, and assumes various 

 shapes — now a trepan or pointed graving-tool, then a 

 sharp wedge, a bent hook, or else a spade or dibble — 

 each shape being adapted to some mode or other of 

 boring, displacing, or removing the material in which 

 this mollusk makes its abode. It is eaten and relished 

 by man and fish in Europe, Asia, and America. At 

 Southampton the fishermen used to call it " old maid" 

 according to Montagu ; and at Belfast it has the equally 

 strange name of f f Cockle-briilion." It forms one of the 

 numerous articles of Chinese diet, being brought to mar- 

 ket after having been boiled for a long time, and cooked 

 with a seasoning of which onion is the base ; the people 

 call it " Tse ga." The occurrence of this circumpolar 

 shell-fish so near the tropic of Cancer probably indicates 



