rORAMINIFERA OV THE ATLANTIC OCEAN. 



71 



Disbihution. — This species seems to be fairly common in com- 

 paratively shallow water of tropical and subtropical seas but is 

 known as far north as the British Isles. It has not been met with 

 in the Alhafi'oss material except once, probably partly because the 

 material is not favorable for attached forms. It occurred at D2371 

 in the Gulf of Mexico in 26 fathoms (48 meters). 



PLACOPSIUNA CONFUSA, new species. 



Plate 14, lig. 6. 



PlacopsiUna ceaoniana H. B. Brady (part, not P. ceno))iana d' Orbigny), Hep. 

 Voy. Challenger, Zoology, vol. 9, 1884, pi. 36, fig. 3. 



Description.— Test small, early portion close coiled, later portion 

 formed of a considerable number of irregularly hemispherical cham- 

 bers in a more or less confused mass or in an irregularly winding 

 series, chambers distinct, wall arenaceous with much yellowish or 

 reddish brown cement; aperture small, at the end of the chamber; 

 color yellowish or reddish brown. 



Length, up to 0.60 mm. 



DistHhution. — Type specimens (U.S.N.M. No. 10549) from Alba- 

 tross station D2115 in 843 fathoms (1,542 meters) east of Cape 

 Hatteras. Other specimens occurred at stations in the same general 

 region. 



The species is attached to Rhahdammina and other arenaceous 

 species and is therefore easily overlooked being small and of the 

 same color as the material to which it is attached. The small size 

 and peculiar arrangement of the chambers also make it inconspicuous. 

 It is not unlike Brady's figure 3 of plate 36 of the Challenger Report 

 in its more regular form. The measurement of those specimens is 

 about 0.40-0.60 mm. while the typical P. cenomana of figure I is 

 nearly ten times this size and lacks the color of P. confxisa. 

 PlacopsiUna confusa — material examiiied. 



