66 



BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



Distribution. — Most of the records for this species seem to be from 

 the Indo-Pacific, ranging from the Arabian Sea (Chapman) coral 

 reefs of Honolulu, 40 fathoms (73 meters) ; Hongkong Harbor, 7 

 fathoms (13 meters) ; in dredged sand from Torres Strait, off Raine 

 Island, 155 fathoms (283 meters) ; shore sands from the east coast of 

 Madagascar; shallow water on the coast of Ceylon (Brady); coast 

 of Mauritius, 411 and 374 meters (224 and 204 fathoms); off west 

 Australia, 359 meters (196 fathoms) (Egger); Malay Archipelago 

 (Millett), and Ceylon (Dakin). The only record hitherto for the 

 Atlantic is that given by Woodward ''Hamilton Harbor, Bermuda, 

 5 fathoms (9 meters)." 



I have had two specimens of this species from Albatross station 

 D2758 in 20 fathoms (37 meters) off the coast of Brazil. It seems to 

 be very rare in the Atlantic, and it has not been found in any of the 

 shallow-water material I have had from the coast of Florida or in 

 the West Indies. 



Brady mentions "a long, somewhat attenuated variety" which 

 occurs in shallow water off Madagascar and Ceylon. 



Chrysalidina dimorpha — material examined. 



Genus TRITAXIA Reuss, 1860. 



Teztularia (part) Reuss, Verst. Bohm. Rreid., pt. 1, 1845, p. 39. 



Tritaxia Reuss (type, T. tricarinata (Reuss) = Textularia tricarinata B.eus3), Sitz. 

 Akad. Wiss. Wien, vol. 40, 1860, p. 228.-11. B. Brady, Rep. Voy. Chal- 

 lenger, Zoology, vol. 9, 1884, p. 388. — Chapman, The Forarainifera, 1902, p. 

 167.— CusHMAN, Bull. 71, U. S. Nat. Mus., pt. 2, 1911, p. 61. 



Description. — Test triserial, at least in the earlier portion, usually 

 triangular in cross section; aperture central and terminal with or 

 without a distinct neck and lip, rounded; wall usually arenaceous. 



This genus as used by Reuss and later by Brady includes triserial 

 forms which are "in their early development with a Textularian aper- 

 ture, later becoming uniserial and the aperture circular and terminal." 

 In this form they correspond somewhat to a triangular Clavulina. 

 Tritaxia caperata H. B. Brady has been separated and forms the 

 type of Tritaxilina. 



The geological history of this genus apparently goes back to the 

 lower Cretaceous. In the present ocean it seems to be largely con- 

 fined to the Indo-Pacific resrion. 



