702 DR. GWYN JEFFREYS ON THE MOLLXJSCA OF THE [June 7, 



riety), 16 (var. rotunda), 17 (same variety), 17a (same variety), 22 

 (var. i'otunda), 24 (var. polygo7ia), off C. Sagres (same variety), 

 26-28a, 29 and 30 (yar. pobjffona) ; Mediterranean, Cartagena B. 

 (var. pohjffom), 50, off Jijeli, G. Bona, Rasel Amoush (var. poly- 

 ffona), G. Tunis, Adventure Bank. 



Bistribution. Spitzbergen, Siberian coasts, Iceland and Greenland 

 to the Archipelago and Adriatic, Mogador, Canaries, Azores, La- 

 brador to St, Thomas and Gulf of Mexico, Queen-Charlotte Islands, 

 west coast of North America, and Korea; 2-1012 fms. 



Fossil. Miocene, PHocenc, and Post-tertiary: Smith's Sound, 

 Norway, Great Britain and Ireland, Belgium, France, Italy, Madeira, 

 and United States ; 0-80 ft. 



Extremely variable in shape, size, and consistency ; one of the 

 numerous synonyms is Gryptodo7i obesus of Verrill. The variety 

 rotunda resembles Axinopsis orbiculata of G. O. Sars, but is desti- 

 tute of a cardinal tooth ; that shell appears to be restricted to the 

 arctic zone, and I dredged it at Holsteinborg, on the coast of Green- 

 land, in 10 fathoms. Lucina sinuosa of Donovan, as described and 

 figured by Homes, who referred it to the Tellina jiexuosa of Mon- 

 tagu, is not the present species. Donovan's shell is Thracia distorta. 



t^ 2. AxiNus ORBicuLATUs, Scgueuza. (Plate LXI. fig. 5.) 



Verticordia orbiculata, Seg. Sulle Verticordie fossili del plioceno 

 Italiauo (R. Accad. d. Sc. fis. e matem., 1876), p. 9. 



' Porcupine ' Exp. 1869 : St. 23. 1870 : Atlantic, 3, 6, 25-30. 



Bistribution. Bay of Biscay (' Travailleur' Exp.), Naples and 

 Sicily, Canaries; 49-645 fms. 



Fossil. Pliocene : Calabria and Sicily. 



A. granulosus, Jeffr. (MS.). Not A. (Kellia) orbicularis of 

 Searles Wood, nor Axinopsis orbiculata of G. O. Sars. 



This species is smaller than A. ftexuosus, and is more triangular, 

 with prominent beaks ; and it has two ridges in the middle, and a 

 remarkable granular epidermis. 



3. AxiNus TORTUOsusS Jeffreys. (Plate LXI. fig. 6.) 



Shell oval, obliquely twisted to one side, convex, thin, glossy, 

 and semitransparent ; sculpture, irregular concentric lines of growth : 

 coloiir pale yellowish-white : epidermis filmy : mai'gins rounded in 

 front and at the sides ; below the beak, on the posterior side, that 

 part of the margin is excavated ; there is no fold or furrow on the 

 anterior side : beaks prominent, pointed, and incurved : lunule nar- 

 row, with a thickened edge : ligameut elongated, enclosed in a 

 narrow groove ; hinge-line obtusely angular, occupying about one 

 third of the circumference : hinge-plate thick, containing the liga- 

 ment : teeth none : inside glossy, exhibiting faint but numerous lon- 

 gitudinal strise : pallial scar narrow and distinct : muscular scars 

 inconspicuous. L. 0"175, B. 0-2. 



' Porcupine ' Exp. 1870 : St. off C. Espichel ; a single valve, 

 Bistribution, Bay of Biscay Q Travailleur' Exp.); 645-1012 fms, 



' Twisted. 



