430 MACTRIDiE. 



coasts of Northumberland and Galway. L. elliptica is 

 fossil in all our upper tertiaries from the Scotch glacial 

 beds to the Coralline Crag ; Subapennine strata (Broc- 

 chi); neighbourhood of Bordeaux (Lamarck); Sicily 

 (Philippi). It is also recent in Finmark (Lilljeborg); 

 Bergen (Sars); north of France (De Gerville and Bou- 

 chard-Chantereaux) ; shores of Spain and Portugal 

 (M f Andrew); Algeria (Weinkauff); Sicily (Maravigna 

 and Philippi). 



Our earliest conchologist, Lister, discovered this spe- 

 cies. It is edible in spite of its muddy habitation ; for 

 we are told by Mr. M f Andrew that it is sold in Vigo 

 market; and Mr. Dennis says, "the Herm people eat 

 every kind of shell-fish which is big enough ; even Lu- 

 traria elliptica and L. oblong a — c Clumps'' as they call 

 them." The following observations by Montagu may be 

 useful to those who are so devoted to conchology as not 

 to object to turning mudlarks : — " It is rarely obtained 

 alive, except by digging, and that only when the tide is 

 unusually low : their place of concealment is generally 

 known by a dimple on the surface, through which they 

 eject water to a considerable height, though the shell is 

 frequently buried two feet beneath." The shell is occa- 

 sionally distorted, and varies in the proportion of length 

 to breadth. 



It is the Mactra lutraria of Linne, Chama magna of 

 Da Costa, and L. vulgaris of Fleming. 



2. L. oblon'ga*, Chemnitz. 



My a oblonga. Chernn. Conch.-Cab. vi. p. 27, t. 2. f. 12. L. oblonga, F. &H. 

 i. p. 374. pi. xiii. f. 1. 



Body pale yellow : mantle closed to the same extent as in 

 the last species : tubes of unequal size ; the alimentary (or 



* Oblong. 



