axinus. 249 



It is widely distributed through the North Atlantic 

 from Spitzbergen (Torell) to the Canary Isles (M 'An- 

 drew), and likewise through the Mediterranean and 

 iEgean. The greatest bathymetrical limit recorded is 

 that by Danielssen, viz. 180 fathoms, at Vadso in Fin- 

 mark. "Postglacial" beds in the Christiania diocese 

 (Sars). Gould has described it as a Massachusetts 

 shell ; but in a review of his work by Philippi, in the 

 ' Zeitschrift ' for 1846, the North- American species is 

 stated to differ in several respects from ours, and the 

 name Lucina Gouldii was therefore given to it. Morch 

 refers the Greenland shell to this last species, and says 

 it is the Tyatira hyalina of Beck. I confess that I have 

 not been able to make out anything more than a varietal 

 difference between the Greenland specimens and those 

 of A. flexuosus from our own seas. 



Young shells are globular, and the principal fold on 

 the posterior side is visible in every stage of growth. 

 The liver is of a beautiful purple colour. The attach- 

 ment of the ligament to the hinge is slight, which 

 accounts for single valves being so frequently thrown 

 up on the shore, or taken by the dredge in sandy bays. 



Lamarck described this species in his ' Histoire na- 

 turelle des Animaux sans Vertebres/ both as Amphi- 

 desma Jiexuosa and Lucina sinuata. It is the Cryptodon 

 bisinuatum of S. Wood's Catalogue, and the Pty china 

 biplicata (afterwards changed to Axinus sinuatus) of 

 Philippi. The Venus sinuosa of Pennant and Donovan 

 (thus characterized, "Thin, convex, a deep obtuse sinus 

 or bending in the front") appears to be Thracia distorta, 

 which is often contracted in this way ; and Donovan's 

 figure confirms that idea. S. Wood, however, considered 

 it identical with the present species. The A. Sarsii of 

 Philippi, described by Loven in his admirable ' Index 



m 5 



