36 BULLETIN 161, UNITED STATES NATIONAL MUSEUM 



LOXOSTOMA UMBATUM (H. B. Brady) var. COSTULATUM (Cushman) 



Plate 10, Figures 2-4 



Bolivina limbata Chapman, Journ. Linn. Soc. Zool., vol. 28, p. 409, pi. 36, fig. 12, 

 1901. — Heron-Allen and Earland, Trans. Zool. Soc. London, vol. 20, 

 p. 646, pi. 50, figs. 1-4, 1915. 



Bolivina limbata (H. B. Brady) var. costulata Cushman, Carnegie Tnst. Washington 

 Publ. 311, p. 26, pi. 3, fig. 8, 1922; U. S. Nat. Mas. Bull. 104, pt. 3, 

 p. 37, 1922; Carnegie Inst. Washington Publ. 342, p. 19, pi. 5, figs. 2, 3, 6, 

 1924; Publ. 344, p. 76, 1926, B. P. Bishop Mus. BuU. 27, p. 125, 1925 (1926). 



Loxostoma limbata (H. B. Brady) var. costulata Palmer and Bermudez, Mem. Soc. 

 Cubana Hist. Nat., vol. 9, p. 248, 1935. — Cushman, Cushman Lab. Foram. 

 Res. Special Publ. No. 8, p. 187, pi. 21, figs. 30, 31, 1937. 



Variety dijffering from the typical form of the species mainly in the 

 addition of longitudinal costae usually few in number and mostly near 

 the base of the test. Length, up to 2.00 mm.; breadth, 0.40 mm.; 

 thickness, 0.20 mm. 



This variety is much commoner than the typical form wherever the 

 species occurs and often has a larger test and is usually strongly 

 twisted. In our Pacific material this variety has occurred most 

 abundantly at Guam Anchorage, Ladrone Islands, in 21 fathoms, but 

 specimens also occur at Nairai, Fiji, 24 fathoms; Vavau Anchorage, 

 Tonga Islands, 18 fathoms; Rotonga, 7 fathoms; Rangiroa; and also 

 at the Albatross stations in deeper water given in table 17. 



Table 17. — Loxostoma limbatum var. costulatum — material examined 



LOXOSTOMA LOBATUM (H. B. Brady) 



Plate 10, Figure 5 



Bolivina lobata H. B. Brady, Quart. Journ. Micr. Sci., vol. 21, p. 28, 1881; Rep. 



Voy. Challenger, Zoology, vol. 9, p. 425, pi. 53, figs. 22, 23, 1884.— Millett, 



Journ. Roy. Micr. Soc, 1900, p. 543, pi. 1, fig. 4.— Cushman, U. S. Nat. 



Mus. Bull. 71, pt. 2, p. 46, figs. 74, 75, 1911. 

 Loxostoma lobatum Cushman, Cushman Lab. Foram. Res. Special Publ. No. 9, 



p. 188, pi. 22, figs. 2-4, 1937. 



