424 MACTRIM. 



in all our upper tertiary strata from the Scotch glacial 

 beds (Smith) to the Coralline Crag (S. Wood). Its 

 extra-British habitat seems to be southern rather than 

 northern. I observed specimens in the Royal Museum 

 at Copenhagen from the Danish shores of the Baltic ; it 

 has been enumerated in every list of French. Lusita- 

 nian, Italian., and Algerian shells ; Ehrenberg obtained 

 it in the Red Sea, and Forbes in the ^Egean ; and 

 M' Andrew dredged a single valve off the Canaries in 

 35 fathoms. The range of depth ascertained by the 

 last-named observer on the coast of Portugal was from 

 15 to 30 fathoms. Brocchi and Philippi have recorded 

 it as fossil in the newer tertiaries of Italy, the one from 

 the north, and the other from the south. 



Lister discovered and figured this shell. According 

 to Bouchard- Chantereaux its inhabitant serves for bait 

 to catch whiting in the bays of Normandy. English 

 fishes are not less fond of such savoury morsels, as may 

 be inferred from the following note of Mr. Dennis : 

 { ' When the steam dredging-machines were at work at 

 the mouth of Newhaven harbour last year [1861], they 

 turned up so many of the Mactra stultorum that the 

 beach at high-water mark (where a shell rarely occurs) 

 was covered with them ; and the trawl-fish, such as soles, 

 &c., found their way to the spot where the barges were 

 emptied, in such numbers that the Brighton trawlers or 

 'Hogboats' were most successful in capturing them 

 within one hundred yards of the shore." He adds that 

 " some of the people eat this Mactra" Shells of a 

 smaller size, but thinner and more beautifully rayed than 

 usual, were procured by Mr. Rich from the Silver-pit 

 fishing-grounds, in about 30 fathoms. This is similar to 

 the case of M. solida, var. elliptica, mentioned at p. 418. 

 The largest specimens are found in Burra fiord in Unst. 



