26 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



"Diameter l/25th inch (1 mm.)." 



Distribution. — Brady described this species from various stations, 

 among which were two from the North Pacific off the Philippine 

 Islands, 95 fathoms and the Hawaiian Islands, 40 fathoms. I have 

 had frequent specimens from one Nero station, 2071 in 271 fathoms 

 off the Hawaiian Islands. 



Genus TRETOMPH ALUS Moebius, 18SO. 



Rosalina (part) d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, 



"Foraminiferes," p. 104. 

 Cymbalo pora (part) Carpenter, Introd. Foram., 1862, p. 216. — H. B. Brady, 



Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 638. 

 Tretomphalus Moebius (type, T. bulloides (d'Orbigny)), Forarn. Mauritius, 1880, 



p. 98. 



Description. — Test free, early stages Discorbina-like, in a low con- 

 ical spire; last formed chamber globular, larger than the entire early 

 growth; wall perforate, the last formed chambers with very large 

 ones; aperture in adult chamber rounded with an entosolenian neck. 



The genus Tretomphalus seems worthy of distinction from Cym- 

 balopora as the development of the final chamber is very different. 

 In its adult form it is found in a pelagic condition, especially in the 

 vicinity of coral reefs. The development of the spherical form and 

 the large pores fitting it for a pelagic life are very analogous to those 

 seen in Orbulina, Pulvinulina lateralis, and other forms. 



TRETOMPHALUS BULLOIDES (d'Orbigny). 

 Plate 14, figs. 3, 4. 



Rosalina bulloides d'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. Cuba, 1839, 

 "Foraminiferes," p. 104, pi. 3, figs. 2-5. 



Cymbalopora bulloides Carpenter, Parker, and Jones, Introd. Foram., 1862, p. 

 216— H. B. Brady, Quart. Journ. Micr. Soc, vol. 19, 1879, p. 80; Rep. Voy. 

 Challenger, Zoology, vol. 9, 1884, p. 638, pi. 102, figs. 7-12, text-figs. 20 o-c— 

 Egger, Abh. kon. bay. Akad. Wise. Munchen, CI. n, vol. 18, 1893, p. 381, pi. 

 18, fig. 53.— Earland, Journ. QuekettMicr. Club, ser. 2, vol. 8, 1902, p. 309, 

 pi. 16, figs 6-9.— Millett, Journ. Roy. Micr. Soc, 1904, p. 697, pi. 7, fig.4.— 

 Rhumbler, Zool. Jahrb., Abt. Syst., vol. 24, 1906, p. 72. 



Tretomphalus bulloides Moebius, Beitr. Meeresfauna Insel Mauritius, 1880, p. 

 98, pi. 10, figs. 6-9. 



Discorbina bulloides Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 19, 1882, p. 

 106, pi. 8, figs. 262, 263. 



Description.— Test free, subglobular; early chambers rotaliform, 

 numerous, finely perforate, final chamber very large, inflated, making 

 up the large portion of the test; aperture in the adult composed of 

 numerous circular openings, usually with a single entosolenian neck 

 from the largest. 



Diameter 0.60-1.00 mm. 



