126 



SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1921. 



The sutures are not always covered with a 

 coarsely arenaceous layer hut are t^-pically so; 

 this layer is often darker than the test and very 

 distinct. Both megalospheric and micro- 

 spheric forms occur. None of the specimens 

 seem to have any definite regular spinose edge, 

 and this is also true of the Bvram specimens. 

 The specimens in the Mint Spring marl seem to 

 run slightly larger tlian those in the B^Tam 

 marl; otherwise they are very similar. 



Textularia subhauerii Cushman. 



Textvlr.riu sjihhuucrii ('nshraan, U. S. Oeol. .Siirve>' Prof. 

 Paper IL'9, f- «9. pi. 14, figs. 2a. 2b, 1922. 



Test large, stout, elongate, early portion 

 rapidly increasing in width with each newly 

 added chamber, later adult portion with the 

 sides nearly parallel, slightly lobulate; periph- 

 ery rounded but the median portion nearly 

 flat; chambers eighteen to twenty, increasing 

 in height as added, those of the later portion 

 nearly as high as broad, sutures usually rat.her 

 indistinct; wall coarsely arenaceous but 

 smoothly finished on the exterior; aperture at 

 the base of the inner margin of the chamber. 

 Length 2 millimeters or less. 



The only station at which this species was 

 obtained in the Mint Spring marl is station 

 6(347 (Chickasawhay River 1} miles southwest 

 of Boice, Miss.) , at which there were numerous 

 specimens. This is the only station oi the six 

 at which Textularia tnm'uhiJnm did not occur. 

 The specimens agree well with those from the 

 Byi'am marl describecl in the paper cited. 



Genus BOLIVINA D'Orbigny. 1839. 

 Bolivina cf. B. punctata D'Orbigny. 



Test small, elongate, slightly tapering, com- 

 posed of about twenty chambers; periphery 

 shghtly rounded; sutures (hstinct; wall finely 

 punctate. Length about 0.2-5 millimeter. 



A single specimen was obtained at station 

 6451, Mint Spring Bayou, Vicksburg, Miss. It 

 is very small and in its general characters is like 

 the recent material of the Gulf of Me.xico which 

 I have referred to Bolivina punctata D'Orbigny. 



Bolivina cookei Cushman. n. sp. 



Plate XXIX, ligure 1. 



Test elongate, tapering, the early portion 

 with the periphery slightly rounded, thick, the 

 later portion with the periphery subacute and 



the whole test broader and thinner: chambers 

 numerous; sutures indistinct; surface of tlie 

 earlier thickened portion ornamented by nu- 

 merous fine longitudinal costae; later portion 

 smooth but finely punctate. Length 0.25 to 

 0.35 millimeter. 



Type specimen from station 6647, Chickasaw- 

 hay River Ij miles southwest of Boice, Miss. 

 Single specimens also occur at stations 6447 

 (Glass Bayou, Vicksburg, Miss.) and 7671 

 ("Browna's Gave," Leaf River, Miss.). 



This is a small species but distinct in its gen- 

 eral character. The last-formed portion difi'ers 

 from the early part in its broader form and 

 smooth surface, the early part being much 

 tliicker and ornamented by fine longitudinal 

 costae. Young specimens do not show the later 

 characters. 



The species is named for G. Wythe Gooke, of 

 the United States Geological Survey, who has 

 ct)llected most of the material used in the 

 present paper. 



Bolivina vicksburgensis Cushman, n. sp. 



Plate XXIX, iigiire 2. 



Test elongate, tapering, apical end bluntly 

 pointed, gra(hially increasing in breadth for sev- 

 eral chambers, after wliich the sides are nearly 

 parallel during the remainder of the growth: 

 chambers distinct; sutures excavated; proxi- 

 mal angle of the periphery of each chamber 

 somewhat projecting bevond the general line 

 of the test, forming a serrate edge; chambers 

 distinctly triangular; sutures oblique; surface 

 with mrmerous punctations arranged generally 

 in k>ngitutlinal lines. Length 0.45 millimeter. 



Type specimen from station 6451, Mint 

 Spring Bayou, \'icksburg. Miss. This species 

 seems to be rare, not being found at any of the 

 other stations. It is distinct from any others 

 foujid in the Mint Spring marl or the Byram 

 marl. It can be distinguished by the peculiar 

 serrate periphery and the ornamentation. 



Bolivina frondea Cushman, n. sp. 



Plate XXIX. figure 3. 



Test much compressed, broad, composed of 

 several chambers, those of the early portion 

 elongate, forming a narrow test, those of the 

 adult extending- back, forming a broad test 

 similar to that seen in certain species of Fron- 

 dicularia; sutures distinct; wall smooth; periph- 



