414 MACTRID^I. 



fathoms (Barlee). In the latter case only were the spe- 

 cimens perfect, although young, and without the animal. 

 Laskey gives " Dunbar," which (to say the least) is a 

 questionable locality. The notices of its extra-British 

 occurrence are as follows : Cherbourg (Re*cluz) ; coasts 

 of Spain and Portugal, Madeira and the Canaries, at 

 depths varying from 12 to 30 fathoms (M f Andrew) ; 

 St. Michael, Azores (H.Drouet); Bed Sea (Forbes and 

 Hanley) . 



The animal is unknown. M f Andrew seems to be the 

 only one who has taken this curious species in a living 

 state, and he probably had no opportunity of examin- 

 ing it. 



The A. nit ens of Montagu is West Indian and not 

 British. 



A. corneum (Mactra cornea, Poli, but not A. cornea 

 of Lamarck), being the Donax plebeia of Pulteney, A. 

 donacilla of Lamarck, and Donacilla Lamarckii of Phi- 

 lippi, is a common Mediterranean shell, but has never 

 been dredged or taken on our coasts under circumstances 

 that would preclude its being considered exotic. 



A. deauratwn (Turton), or Mesodesma Jauresii of De 

 Joannis, which according to Turton was dredged off 

 Exmouth, is a Newfoundland species. I was informed 

 that the original specimen came from Lieutenant Grif- 

 fiths, who had made more than one voyage to North 

 America, and whose mother's collection of shells was 

 much enriched by his endeavours to please her. Mrs. 

 Griffiths was an old correspondent of Dr. Turton, as is 

 evident from the frequent mention of her name in his 

 ' Dithyra.' 



