786 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxiii. 



Axinv,s ai'Mculat^us Jeffrej'^s, 1881 (not Axhiopsis orhieidatus Sars, 

 1878) is 8ynon3^mous. Its identitA' with the Sicilian fossil Vcrtirordm 

 orhiculata,^ although claimed by Jeffreys, is very doubtful, and Jeffrej^s' 

 figures of the sculpture are probably taken from the fossil and not from 

 the recent shell, agreeing- much better with the former and not at all 

 with the surface of his types in the U. S. National Museum. 



THYASIRA PLICATA Verrill (as Cryptodon) , 1885. 



Off Marthas Vineyard, Massachusetts, in 1,073 to 1,122 fathoms. 



THYASIRA GOULDII Philippi (as Axinus), 1845. 



Greenland to Stonington, Connecticut, in 5 to 400 fathoms; also on 

 the west coast of America in Bering Sea, south of Bering Strait, and 

 southward to the Queen Charlotte Islands. 



Liicina Jlexioosa Gould, 1841, but not of Montagu, 1803; and Thyasira 

 hyaline^ Morch,^ 1857, are synonymous. 



THYASIRA SARSII Philippi (as Axinus), 1845. 



Greenland according to Posselt;* Norway, Spitsbergen, Iceland; 

 Sars and others. 



THYASIRA TRISINUATA d'Orbigny (as Lucina), 1846. 



Labrador to Martinique, in 15 to 192 fathoms, North Atlantic, Vigo 

 Bay, and Mediterranean, Jeffreys; also Sitka Harbor, Alaska, in 10 

 fathoms, and on the coast of Korea, by Captain St. John, R. N. 



Axinus flexuosus var. i^olygona ^^^v^yss^ 1863, and Cryptodon ohesus 

 Verrill, 1872, are synonymous, and perhaps Lucina jiexuosa of Beau's 

 catalogue of the shells of Guadeloupe. 



THYASIRA FUEGIENSIS Dall (as Cryptodon), 1889. 



Magellan Strait, in 77 fathoms; also on the west coast of Patagonia, 

 in 449 fathoms. 



A large and feebly plicated species, recalling T. mmi Philippi." 



THYASIRA PLANA Verrill and Bush (as Cryptodon), 1898. 



Halifax, Nova Scotia, to Cape Cod, Massachusetts, in 8 to 100 fathoms. 



Approaching the young of T. sarsli^ but none of the size of adult 



sarsll have been obtained from the American cojist south of Greenland. 



THYASIRA INiEQUALIS Verrill and Bush (as Axinulus), 1898. 



Halifax, Nova Scotia, to Cape Cod, Massachusetts, in 14 to 49 fathoms. 

 Distinctly plicate behind, and therefore not an Axinidus. 



'Seguenza, Vert. Plio. Ital., 1876, p. 9. 



■■'Beck manusc-ript, 1847. 



Til Kink's (Treenland. 



^Coisp. Fauna GriuiL, 1898, p. 80. 



^Brit. Concli., II, p. 248. 



''It is figured in Proc. U. S. Nat. Museum, XII, pi. xiv, fig. 2. 



