110 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



CRISTELLARIA FORMOSA, new species. 



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



Cristellaria calcar H. B. Brady (part) (not Linnaeus), Rep. Voy. Challen- 

 ger, Zoology, vol. 9, 1884, p. 551, pi. 70, figs. 13, 14.— Flint (part), 

 Rep. U. S. Nat. Mus., 1897 (1899), p. 318, pi. 66, fig. 1 (central 

 figure). 



Description. — Test large, close-coiled, somewhat compressed, cen- 

 tral portion strongly umbonate, periphery with a thin keel and flat- 

 tened rowel-like, spines; chambers numerous, 11-13 in the last- 

 formed coil; sutures distinct, slightly limbate, of clear shell ma- 

 terial, not raised, much curved ; surface smooth, central portion occu- 

 pied by a large somewhat projecting boss of clear shell material 

 through which the chambers of the earlier coils are visible ; aperture 

 peripheral, radiate, slightly projecting. 



Diameter up to 3 mm. 



Distribution. — Type-specimen (U.S.N.M. Cat. No. 18807) from 

 Albatross station D2377, in 210 fathoms (384 meters), in the north- 

 ern part of the Gulf of Mexico. Flint gives this same station among 

 his records for Cristellaria calcar. I have also a single specimen 

 from Albatross station D2150, in the Caribbean. 



It is interesting in this connection to note that in his records for 

 the occurrence of Cristellaria calcar, Brady mentions three stations 

 in the northern Atlantic at which good specimens have been found — 

 off Sombrero Island, West Indies, 450 fathoms (823 meters), off 

 Culebra Island, 390 fathoms (713 meters), and off the Azores, 450 

 fathoms (823 meters). His figures (pi. 70, figs. 13, 14) are of the 

 typical form seen in the Gulf of Mexico, and from the identity of 

 most of the species at the two Challenger West Indian stations noted 

 and those of the Gulf of Mexico, it may be supposed that tlie two 

 figures given by Brady were from one or the other of these two 

 stations. It is a very different species from the others which have 

 been assigned to Cristellaria calcar. The number of chambers, the 

 compact form, the flattened rowel-like spines and the clear boss 

 of shell material are enough to distinguish it from most of the other 

 species assigned to Cristellaria calcar. 



Cristellaria formosa — material examined. 



