140 



SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1921. 



slightly sigmoid, the inner portion excavated 

 and broadened; umbilical region at each side 

 of the test occupied by a large projecting knob 

 of clear shell material; aperture at the base of 

 the last-formed chamber. Diameter 0.75 milli- 

 meter or less. 



Type specimen from station 6647, Chicka- 

 sawhay River 1\ miles southwest of Boice, 

 Miss. It also occurred at station 6447, Glass 

 Bayou, Mcksburg, Miss. 



This is an unusual form and may perhaps 

 not belong to the genus Nonionina. It seems 

 more like some species of P<>h/f:tomella, but 

 there appear to be no icti-al processes. 



FamUy MILIOLIDAE. 



Genus CORNTJSPIKA Schultze, 1854. 



Cornuspira involvens (Reuss) Reuss. 



OpcrcuUna involvens Reuss, Akad. Wiss. Wien Denkschr., 



vol. 1, p. 370, pi. 45, fig. 30, 1849. 

 Cornuspira involvens (Reuss) Reuss, Akad. Wiss. Wien 

 Sitzungsber., vol. 48, p. 39, pi. 1, fig. 2, 1863 (1864). 

 H. B. Brady, Challenger Rept., Zoology, vol, 9, p. 200, 



pi. 11, figs. 1-3, 1884. 

 Cushman, U. S. Nat. Mus. Bull. 71, pt. 6, p. 25, pi. 1, 

 fig. 2; pi. 2, fig. 2, 1917; U. S. Geol. Survey Prof. 

 Paper 129, p. 101, pi. 25, fig. 1, 1922. 



Specimens similar to the tropical form of this 

 species occur at tliree stations, as follows: 



0447. Glass Bayou, Vicksliurg, Miss. 



6451, 6452. Mint Spring Bayou, Vicksburg, Miss. 



The adults among these specimens are un- 

 like the typical form of the species in having 

 the last coil somewhat broadened and flattened, 

 giving somewhat the appearance of 6'. carinata 

 (Costa). The species was recorded from the 

 Byram marl, but the specimens there were very 

 small, measuring only 0.4 millimeter. Some of 

 those from the Mint Spring marl measure 2 

 millimeters in diameter. This larger form of 

 the species is common in the shoal waters of the 

 Tropics, especially in the Indo-Pacific. 



Genus SPmOLOCULINA DOrbigny. 1826. 



Spiroloculina imprimata Cushman. 



Spiroloculina imprimata Cushman, U. S. Geol. Survey 

 Prof. Paper 129, p. 101, pi. 25, figs. 3a, 3b, 1922. 



Test broad and flat, complanate, nearly cir- 

 cular in outline, composed of numerous cham- 

 • bers, those of the last-formed coil failing to ex- 

 tend to the base of the preceding chamber, leav- 



ing a gap; periphery square, lateral faces nearly 

 flat; the surface ornamented by a series of pits 

 in a more or less linear arrangement. Length 

 about 1 millimeter. 



A single specimen, much like that from the 

 Byram marl, already described, occurred at 

 station 6451 (Mint Spring Bayou, Vicksburg, 

 Miss.), but this species was not found elsewhere 

 in the material from the Mint Spring marl. 



Spiroloculina antillarum D'Orbigny. 



Plate XXXIII, figure 1. 



Spiroloculina m^tillarnm D'Orbigny, in De la Sagra, 



Histoire physique, politique et naturelle de I'ile de 



Cuba, Foraminiferes, p. 166, pi. 9 figs. 3, 4, IS39. 



H. B. Brady, Challenger Rept., Zoology, vol. 9, p. 



155, pi. 10, fig. 21, 1884. 

 Cushman, U. S. Geol. Sur\'ey Bull. 076, p. 21, pi. 8, 

 fig. 2, 1918. 



Spiroloculina grata Terquem, See. geol. France M^m., 

 3d ser., vol. 1, p. 55, pi. 5. figs. 14a-15b, 1878 (and 

 subsequent authors). 



Test elongate, twice as long as broad; 

 chambers subtriangular; peripheral margin 

 broadly rounded, ornamented by numerous 

 longitudinal costae; apertural end extended. 

 The costae are distinct and continue from one 

 end to the other of the chambers without any 

 trace of branching or anastomosing. Length 

 1 millimeter or less. 



As noted in a paper on the recent Foramini- 

 fera from the shallow water of Jamaica" this 

 species, described by D'Orbigny from specimens 

 obtained in Cuba and other West Indian 

 localities as 5. antillarum, is very similar to 

 Terquem's ,S'. grata, if not identical, and has 

 priority <tf date. Specimens from the Mint 

 Spring marl are very close to this form now 

 living in the West Indies; they were found at 

 stations 6451 and 6452, Mint Spring Bayou, 

 Vicksburg, Miss. 



Genus VERTEBRALINA DOrbigny, 1826. 



Vertebralina sp. 



A single specimen from station 6451 (Mint 

 Spring Bayou, Vicksburg, Miss.) is evidently 

 the young of a species of Vertebralina, but the 

 specimen is worn and can not be specifically 

 identified. 



' Cushman, J. A., U. S, Nat. Mus. Proc., vol. 59, p. 63, pi. 14, figs. 14, 

 15, 1921. 



