FOKAMINIFERA OF THE ATLANTIC OCEAN. 



Ill 



CRISTELLARIA IOTA, new species. 



Plate 29, fig. 2; pi. 30, fig. 1. 



Cristellaria cultraia H. B. Brady (not Montfort), Rep. Voy. Challenger, 

 Zoology, vol. 9, 1SS4, p. 550, pi. 70, figs. 4-6. 



Description. — Test close-coiled, compressed, umbonate, the peri- 

 phery with a thin broad keel, nearly transparent, 13-15 chamb:.rs 

 in the last- formed coil, narrow; sutures slightly curved, very 

 slightly limbate, but not raised above the general surface, lunbonal 

 region occupied by a large thickened transparent knob ; wall smooth, 

 thin; aperture radiate, at the peripheral angle of the test, those of 

 the early chambers distinct throughout the last-formed coil. 



Diameter up to 2.50 mm. without the keel. 



DisfTibution.— Type-specimen (U.S.N.M. Cat. No. 18939) from 

 Albatross station D2399, in 196 fathoms (359 meters), in the north- 

 ern part of the Gulf of Mexico. I have a single specimen also from 

 an Albatross station in the Caribbean. It would be interesting to 

 know the station from which Brady's specimens figured in the 

 Challenger report came. However, as the species is recorded from 

 both stations 23 and 24, off Sombrero and Culebra Islands, and 

 as these specimens are so similar to those in the Gulf of Mexico and 

 Caribbean, they may have come from one of these stations. This 

 was referred to Cristellaria cultrata Montfort by Brady. There are 

 numerous records for G. cultrata Montfort, many of them from the 

 Atlantic, especially off the British Isles, but figures are not given, 

 and I doubt very much if this species which seems to be rather 

 widely distributed in the warmer western Atlantic is found on the 

 shores of the British Isles. 



Cristellaria iota — material examined. 



CRISTELLARIA LUCIDA, new species. 



Plate 30, fig. 2. 



Cristellaria articulata H. B. Brady (not Reuss), Rep. Voy. Challenger, 



Zoology, vol. 9, 1884, p. 547, pi. 69, figs. 10-12.— Flint (part). Rep. 



U. S. Nat. Mus., 1897 (1899), p. 317, pi. 64, fig. 2. 



Description. — Test close-coiled, somewhat compressed, umbilical 



region not umbonate, periphery slightly keeled, G or 7 chambers in 



the last- formed coil, somewhat inflated, periphery slightly lobulated ; 



sutures distinct, vei-y slightly if at all depressed, nearly straight and 



