204 BULLETIN OF THE 



Family PLATIDIID^. 

 Genus PLATIDIA Costa. 



Platidia anomoides Scacchi. 



Platidia anomoides Dall, Bull. M. C. Z., IX. p. 104. 



Terebratula anomioides Scacchi, Philippi, Moll. Sicil., IL p. 69, pi. xviii. fig. 9, 1844. 



Habitat. Near Morro Light, Cuba, Station 16, 292 fms. ; Station 253, 92 

 fms. ; Barbados, Station 280, 221 fras. ; Grenada, Station 260, 291 fma.; St. 

 Vincent, Station 232, 88 fms. Also San Diego, California, Orcutt; and off 

 the coast of North Carolina in 16 fms. by the U. S. Fish Commission, 1885. 



Variety radiata Dall, Proc. U. S. Nat. Mus., 1885, p. 661. 



Shell radiately ribbed with small irregular ribs, apex of the dorsal valve 

 not notched but even with a trace of flattened area ; haemal valve deeply 

 notched ; mai^in with rather prominent setae lying in the grooves correspond- 

 ing to the ridges ; labia as usual with short brachial membrane and fringe 

 behind them ; a broad smooth area of membrane in front of them ; about 

 25-30 single brachial processes on each lobe turned down and curled under ; 

 the point of the septum projects in front of the broad membranous area ; the 

 anterior labium and perhaps both of them, somewhat reinforced by chitine ; 

 size the same as the typical form. 



Habitat. Station 139, off Santa Cruz, in 218 fms., bottom temperature 

 51''.0; sessile on smooth Terebratula. The Califpmian specimens are also 

 of this variety. 



This specimen was sacrificed to get at the soft parts. This is the only form 

 in which "^he brachia are turned downward, and the only living form in which 

 the haemal v2^e is notched in the adult state, as far as known to me. 



Family THECIDIID^. 

 Gends THECIDIUM Sowebbt. 



Thecidium mediterraneum Sowekbt. 

 ? Thecidium mediterraneum Sowerby, Dall, Bull. M. C. Z., IX. p. 104. 



Habitat. Station 241, 163 fms. 



The specimens being loose dorsal valves, it is possible that they may belong 

 to the preceding species ; but Mr. Davidson thought not. No complete speci- 

 mens were found in the Blake collection. 



