NO. 1 CUSHMAN, MCCULLOCH: ARENACEOUS FORAMINIFERA 105 



1043, 546, 2045, 1046, 2038, 2027, 2046, 2002, 2033, 2057, 2059, 

 2003, 2065, 2029, 2058, 2037, 2053, 2067, 2054, 2008, 2033. 



The species is usually flatter than T. pacifica and the chambers are 

 higher in the whorl, with the sutures more durved. The base is also 

 flatter. 



Distribution. — The records in this investigation indicate a range 

 from San Francisco, California, to the Galapagos Islands, and Gorgona 

 Island, Colombia. 



Trochammina nitlda H. B. Brady 

 Plate 11, Figs. 7-9 



Trochammina nitida H. B, Brady, Quart. Journ. Micr. Sci., vol. 

 21, 1881, p. 52; Denkschr. Akad. Wiss. Wien, vol. 43, 1881, p. 100; 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 339, pi. 41, figs. 5, 6.— 

 Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, no. 9, 1894, p. 30, 

 pi. 6, figs. 225-230.— Millett, Journ. Roy. Micr. Soc, 1899, p. 363.— 

 Awerinzew, Mem. Acad. Imp. Sci. St. Petersburg, ser. 8, vol. 29, 

 no. 3, 1911, p. 21. — Pearcey, Trans. Roy. Soc. Edinburgh, vol. 49, 

 1914, p. 1011. — Heron-Allen and Earland, Trans. Zool. Soc. London, 

 vol. 20, 1915, p. 620; Trans. Linn. Soc. London, vol. 11, pt. 13, 1916, 

 p. 228, pi. 40, figs. 19-21.— Cushman, Bull. 104, U. S. Nat. Mus., pt. 

 2, 1920, p. 75, pi. 15, fig. 2.— Heron-Allen and Earland, British Ant- 

 arctic Exped., Zoology, vol. 6, 1922, p. 112. — Earland, Discovery 

 Rep'ts, vol. VII, 1933, p. 86; 1. c, vol. X, 1934, p. 101.— Hada, Zool. 

 Mag., vol. 48, Oct., 1936, p. 855, text fig. 11. 



Test small, trochoid, depressed, composed of about three volutions, 

 flattened above, convex below, somewhat umbilicate, periphery evenly 

 rounded ; chambers numerous, about 9 in the last-formed whorl, all 

 visible from above, only those of the last whorl from below, sutures 

 straight or slightly cui-ved, nearly at right angles to the periphery, 

 slightly depressed ; wall arenaceous, smoothly finished ; aperture a curved 

 slit near the base of the chamber; color gray brown, the last- formed 

 chamber often light gray. 



Diameter up to 0.50 mm. 



This species resembles T. inflata (Montagu) in its wall characters. 

 It is usually yellowish brown in color due to the excessive amount of 

 cement but some specimens have a considerable amount of arenaceous 

 material. The coil is very open on the dorsal side and the chambers 

 unusually distinct for species of this genus. It has occurred in consider- 



