44 



SHORTER CONTRIBUTTONS TO GENERAL GEOLOGY, 1919. 



convexity becomes less, and over the flattened 

 margin there are but six to eight layers of lat- 

 eral chambers. At the border this number is 

 somewhat increased, but it falls off again at the 

 extreme outer margin. There are traces of 

 pillars in the central umbonate region, but they 

 are not prominent. 



Diameter of type specimen 12 to 14 milli- 

 meters. 



Type specimen and others from U. S. G. S. 

 station 6924, from the St. Bartholomew lime- 

 stone at point on northwest side of St. Jean 

 Bay, St. Bartholomew, Leeward Islands; col- 

 lected by T. W. Vaughan. The St. Bartholo- 

 mew limestone is of upper Eocene age, accord- 

 ing to Vaughan. 



There are sections which resemble this closely 

 in the material from U. S. G. S. station 6512, 

 in the big wliite limestone from the river bed 

 above the ice plant near David, Panama; col- 

 lected by D, F. MacDonald. 



Orthophragmina flintensis Cushman. 



Plate IX, figures 3-6. 



Orthophragmina flintensis Cushman, U. S. Geol. Survey 

 Prof. Paper 108, p. 115, pi. 40, figs. 1, 2, 1917. 



Test small, circular, much compressed; 

 slightly thickened in the central portion, thence 

 gradually sloping to the periphery; surface 

 slightly pustulate but not papillate, almost 

 smooth in some specimens; the raised pustules 

 generally in concentric lines. 



The horizontal section shows very narrow 

 rectangular chambers in the equatorial band 

 and the embryonic chambers with one small 

 and spherical, almost entirely sm-rounded, ex- 

 cept at one side, by the much larger second 

 chamber. 

 . Diameter, about 5 millimeters. 



The type locality is U. S. G. S. station 7117, 

 in the lower portion of the Ocala limestone, in 

 bluff on west bank of Flint River If miles 

 above the Georgia Southwestern & Gulf Rail- 

 way bridge near Oakfield, Lee County, Ga. ; 

 upper bed. No. 2 of section; C. W. Cooke, col- 

 lector. Other stations mentioned with the 

 original description are mostly along Flint 

 River in Georgia, in fine-grained light-colored 

 limestone. It also occurs at station 3626, in a 

 similar fine-grained limestone at Philema, Lee 

 County, Ga. ; T. W. Vaughan, collector. 



A. specimen which seems identical Avith tliis 

 species was obtained at station 6408, in the 

 Brito formation, on the Pacific coast of Nicara- 

 gua, 2 miles northwest of Brito Harbor; C. W. 

 Hayes, collector. This specimen shows the size 

 and exterior well, while others show the equa- 

 torial chambers. With this is a species of 

 Opereulina, which also occurs with it in Geor- 

 gia, and a specimen of 0. georgiana, as noted 

 under that species (p. 45). 



Orthophragmina floridana Cushman. 



Plate IX, figure 7. 



Orthophragmina floridana Cushman, U. S. Geol. Survey 

 Prof. Paper 108, p. 116, pi. 40, fig. 3, 1917. 



Test circular, much flattened, of medium 

 size; central region very slightly i-aised and 

 umbonate, thence gradually sloping toward 

 the periphery; whole test very thin; surface 

 ornamented throughout with fine but dis- 

 tinctly raised, almost spinose papillae, ar- 

 ranged in concentric lines parallel to the periph- 

 eral margin. 



Equatorial chambers in horizontal section 

 very narrowly rectangular. 



The vertical section shows S to 10 lateral 

 chambers in a vertical column in the central 

 portion, the walls convex on the side nearer 

 the surface, the whole series convex at each 

 papilla instead of parallel to the equatorial 

 series, the papiUae being formed by the local 

 convexit}' of the lateral chambei's rather than 

 by pillars as in some other species. 



Diameter of adult specimens, 10 to 14 

 niillimeters. 



The type locality is U. S. G. S. station 6768, 

 m soft white Ocala limestone on Chipola River 

 at wagon bridge half a mile east of Marianna, 

 Fla., No. 1 of section; C. W. Cooke, collector. 

 The species is abundant at this locality. Addi- 

 tional records are the following: 



7192. Same locality as the type station, No. 3 of sec- 

 tion; C. W. Cooke, collector, a single horizontal section in 

 hard limestone. 



8259. About 6 miles southeast of Campbellton and 12 

 miles northwest of Marianna, on road to Cottonwood, Ala., 

 half a mile from its intersection with the Marianna-Camp- 

 bellton road, in Jackson County, Fla.; C. W. Cooke, col- 

 lector. Abundant in soft Ocala limestone. 



7125. West bank of Flint River in Baker Coimty about 

 3 miles below Dewberry Ferry (Baconton Landing) and 

 about 13 miles above Newton, Ga.; a single specimen of 

 small size; J. E. Brantly and C. W. Cooke, collectors. 



