788 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxiii. 



ferruginosa. The name of this species appears in the Moll. Marins du 

 Roussillon, 1898, page 805, ?i'ti Aximts ''^ ferrvgineiis^'' Forbes. 



THYASIRA (AXINULUS) CYCLADIA S. Wood (as Kellia), 1853. 



Baffins Bay, in 1,750 fathoms. Valorous expedition; North Atlantic 

 and Mediterranean, 3,038 fathoms. 



Poroniya xuhtrlgona Jeffreys, 1858, is identical. 



THYASIRA (AXINULUS) EUMYARIA M. Sars (as Axinus), 1870. 



Baffins Ba}^, 1,100 fathoms. Valorous expedition; Norway and Medi- 

 terranean, m 200 to 1,156 fathoms. 



THYASIRA (AXINULUS) SUCCISA Jeffreys (as Axinus), 1876. 



Off Fernandina, Florida, in 21>1 fathoms; North Atlantic, \H to 1,366 

 fathoms; Mediterranean, 10 to 120 fathoms. 



This is perfectly distinct from Axinus incrassatus Jetfre3's, 1876 

 {=Z(i/}taxini'f< sp.) of which Jeffreys regarded it as a variety. 



THYASIRA (AXINULUS) ELLIPTICA Verrill and Bush, 1898. 



Off Marthas Vineyard, Massachusetts, in 1,151 fathoms. 



This is Axinodoii elliptlcHH Verrill and Bush, a species near T. 

 cycladia S. Wood, but more rounded behind. The resilium is thicker 

 and expanded behind on its ventral aspect, but is not internal in the 

 strict sense of being occluded by the shell dorsally. A microscopic 

 nodulation under the beaks does not seem to differ, except in being 

 much smaller, from the occasional nodulations frequently found in 

 typical Thyaslra in the same region. Only one specimen is known, 

 and the evidence seems quite insufficient to separate it from A.i'inalus 

 as yet. 



? THYASIRA (AXINULUS) SIMPLEX Verrill and Bush, 1898. 



Casco Bay, Maine, to Marthas Vineyard, Massachusetts, in 319 

 fathoms. 



This has the aspect of a iie})ionic slull and may even not Ixloiig to 

 this family. 



? THYASIRA (AXINULUS) PYGM^ A Verrill and Bush, 1898. 



Halifax, Nova Scotia, to Marthas Vineyard, Massachusetts, in 2ti() 

 to 199 fathoms. 



Possi))ly the young oi frrruglnoKd. At all events, it has the appear- 

 ance of a nepionic shell and re<(uires contirmation to rank as a species. 



? THYASIRA (AXINULUS?) species indeterminate. 



Off Bernuulii. in 150 fathoms. Challenger expedition. 

 An undetcrinin<Hl species, reported by E. A. Smith in his report on 

 the Challenger Belecypoda, page 195, 1885. 



