42 SHALLOW-WATER FORAMINIFERA OF TORTUGAS REGION. 



nudum, as the species was described and figured by d'Orbigny in 

 1839, and also appears earlier, both on the plate and in the text, than 

 does poeyi. Therefore there is no alternative, if the two are consid- 

 ered the same species, but to use the name squammosa for this species. 

 There is some variation in the height of the test, but not enough 

 to warrant separation into two varieties. The West Indian species 

 dififers in some ways from those of the Pacific, but it may be a question 

 whether or not they both belong to a single species. This is related 

 to Tretomphalus bulloides d'Orbigny, but, as will be noted under 

 that species, the two are distinct, as C. squammosa does not form a 

 "float-chamber." 



Genus TRETOMPHALUS Moebius, 1880. 

 Tretomphalus bulloides (d'Orbigny). 



Rosalina bulloides d'Orbigny, in De la Sagra, Hist. Fifl. Pol. Nat. Cuba, 1839, "Forami- 

 nifferes," p. 104, pi. 3, figs. 2 to 5. 



Cymhalopora bulloides Carpenter, Parker, and Jones, Introd. Foram., 1862, p. 216. — H. B. 

 Brady, Quart. Journ. Micr. Soc, vol. 19, 1879, p. 80; Rep. Voy. Challenoer, Zool- 

 ogy, vol. 9, 1884, p. 638, pi. 102, figs. 7 to 12; text-figures, 20 a to c— Egger, Abh. 

 kon. bay. Akad. Wiss. Miinchen, CI. II, vol. 18, 1893, p. 381, pi. 18, fig. 53.— 

 Murray, Nat. Sci., vol. 11, 1897, p. 20, fig. 3. — Chapman, Journ. Linn. Soc. London, 

 Zoology, vol. 28, 1902, p. 189; Earland, Journ. Quekett Micr. Club, ser. 2, vol. 8, 

 1902, p. 309, pi. 16, figs. 6 to 9.— Millett, Journ. Roy. Micr. Soc, 1904, p. 697, 

 pi. 7, fig. 4.— Rhumbler, Zool. Jahrb., Abt. Syst., vol. 24, 1906, p. 72.— Heron- 

 Allen and Earland, Trans. Zool. Soc. London, vol. 20, 1915, p. 688. — Heron-Allen, 

 Phil. Trans., ser. B, vol. 206, 1915, p. 252, et seq., pis. 16, 17 (in part). 



Tretomphalus bulloides Moebius, Beitr. Meeresfauna Insel Mauritius, 1880, p. 98, pi. 10, 

 figs. 6 to 9.— Cushman, Bull. 71, U. S. Nat. Mus., pt. 5, 1915, p. 26, pi. 14, figs. 

 3, 4; fig. 29 (in text); Proc. U. S. Nat. Mus., vol. 59, 1921, p. 58, pi. 13, fig. 13. 



Diseorbina bulloides Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 19, 1882, p. 106, pi. 8, 

 figs. 262, 263. 



Test free, subglobular; early chambers rotaliform, numerous, rather 

 coarsely perforate, forming a cap to which is attached a large final "balloon- 

 chamber," subspherical, with coarse perforations on the ventral side, and 

 within a "float-chamber" with a single opening at the base, from which 

 a tubular neck projects inward; color of the early chambers dark brown, the 

 large chamber eolorless. 



Diameter of the Tortugas specimens up to 0.40 mm. 



D'Orbigny originally described this species as Rosalina bulloides 

 in the Cuban monograph, his specimens being from Cuba and 

 Haiti. By most authors it has been assigned to Cymhalopora, but 

 Moebius in 1880 erected the genus Tretomphalus for this species, 

 and in view of the structures revealed by later studies it seems best 

 to use this name. The Cymhalopora rnillettii of Heron- Allen and 

 Earland should also be known as Tretomphalus millettii. These two 

 species have had considerable attention from various authors, 

 especially Moebius, Murray, Brady, Earland, and Heron-Allen. 



Tretomphalus bulloides occurs both as a pelagic species and as 

 a bottom form. This fact has led to various theories concerning 

 its life history. From what is known of the pelagic form it un- 

 doubtedly becomes empty and sinks to the bottom. Whether all 



