390 TELLINID.E. 



= Macroma tenera, Leach = T. proximo, Brown = T. 

 sordida, Couthouy, may be classed with Hypothyris 

 psittacea, Pecten Islandicus, Astarte crebricostata, and 

 A. borealis as having long ago existed in that part of 

 the Atlantic which then covered the greater part of the 

 British Isles; but all of them are now extinct in our 

 seas. I have dredged valves of T. calcarea, but always 

 in a semifossilized state (although retaining part of the 

 epidermis), among the Hebrides and Shetlands ; M f An- 

 drew has taken similar specimens in Loch Fyne ; and 

 Professor Macgillivray mentions that one was brought 

 up by a fishing-line off Aberdeen. This species survives, 

 however, on the Danish coasts of the Baltic, and north- 

 wards to Spitzbergen, as well as on the shores of Asia 

 and America from Behring's Straits to Massachusetts. 

 It is one of the shells most characteristic of " glacial " 

 deposits, and occurs in every tertiary bed up to the Red 

 Crag. Its name ought always to be associated with 

 that of the veteran geologist James Smith of Jordan 

 Hill, who was the first to detect the remains of an 

 Arctic fauna in this country. This was a quarter of 

 a century ago; and we can even now understand the 

 delight with which the discovery was hailed by scientific 

 men, including of course Edward Forbes, whose pithy 

 saying on the occasion " Conchology is ris' " will not 

 easily be forgotten. 



T. remies of Linne (T.fausta, Pulteney), T. reticulata 

 of Linn! (T. proficua, Pulteney), T. lineata of Turton 

 (T. Braziliana, Lamarck), T. bimaculata of Linne, and 

 T. similis of J. Sowerby are tropical species, and have, 

 from accidental mistakes as well as from ignorance of 

 the laws which regulate the geographical distribution 

 of the Mollusca, been considered indigenous to this 

 country. There is a greater probability that the T. 



