AMERICAN SPECIES OF ORTHOPHRAGMINA AKD LEPIDOCYCLINA. 



65 



onic chambers are rather large, of the usual 

 American type, of two nearly equal chambers, 

 lateral chambers m vertical columns with a 

 very few rather well developed pillars. 



Type specimen from station 6021, from the 

 Emperador limestone in cuttings of the Panama 

 Railroad near Caimito Junction, Panama, 

 U. S. N. M. catalogue No. 324739, collected 

 by T. W. Vaughan and D. F. MacDonald. 

 Specimens were abundant in this light-gray 

 to cream-colored sandy limestone. Specimens 

 were also abundant in the collection from 

 station 6673, at the same locality, obtained 

 later by MacDonald. Specimens that are 

 apparently the same species are abundant 

 in a fossiliferous limy sandstone collected by 

 MacDonald at station 6255, half a mUe south 

 of Miraflores station on the wagon road to 

 Panama. 



One of the most characteristic features of 

 this species is the much thickened peripheral 

 border, the increase toward the extreme edge 

 being very rapid, leaving the periphery itself 

 sharply truncate. This gives the appearance 

 in hand specimens of a sharply defined outlme 

 and in sections of the limestone is still more 

 striking when vertical sections are seen. 



Specimens from Georgia (U. S. G. S. station 

 7095, east bank of Flint River at old factory 

 2 miles above Bainbridge, occurring in chert 

 and embedded in clays referred to the Chatta- 

 hoochee formation; W. C. Mansfield, collector) 

 have very much the characters of L. vaugliani, 

 especially in the chambers of the horizontal 

 section. None of the specimens show the 

 periphery well, so that its characteristic form is 

 not available for comparison. 



Lepidocyclina chattahoocheensis Cushman, n. sp. 



Plate XXIII, figures 1-4; Plate XXIV, figures 1,2. 



Test of medium size, flattened or somewhat 

 undulate; largest specimens measuring 25 

 millimeters in diameter, most specimens less, 

 16 to 22 millimeters; central region much thick- 

 ened, prominently umbonate, making up about 

 one-third of the test, nearly 5 millimeters 

 through in the center of the thickened region 

 in large specimens; the thin flattened periph- 

 eral border usually smooth or very finely pap- 

 illate ; the umbonate central region pitted with 

 numerous small depressions. 

 131049°— 20 6 



The horizontal section shows the chambers 

 of the equatorial band either hexagonal or 

 with the peripheral angle an even convex 

 curve; walls rather thin; annuli somewhat 

 irregular in thickness. 



In vertical section (PI. XXIII, fig. 4) the 

 equatorial chambers increase in height toward 

 the periphery, where they are at least three 

 times as high as their diameter ; lateral chambers 

 compressed, broad and low, somewhat convex 

 in the central region, where there are as many 

 as 40 chambers in the central columns, dimin- 

 ishing in number toward the periphery, where 

 in the flattened fiangelike portion there are 

 from 3 to 5 chambers superunposed, not 

 together equalmg the height of the equatorial 

 chambers at the periphery. Pillars in the 

 mnbonal region strongly developed, wedge- 

 shaped m section, the distal ends broadest 

 and projecting beyond the lateral columns of' 

 chambers, giving the characteristic pitting of 

 the surface. 



Type specimen a vertical section from U. S. 

 G. S. collection 3392, from the Chattahoochee 

 formation at Glenns Well, 5 miles southeast of 

 Bainbridge, Ga., collected by T. W. Vaughan. 

 Specimens apparently identical with this species 

 were obtained in material from the following 

 localities : 



3388. Upper fossiliferous horizon, Red Bluff on Flint 

 River, 7 miles above Bainbridge, Ga.; T. W. Vaughan, 

 collector. 



3397. Old factory about 1| miles above Bainbridge, Ga. ; 

 T. W. Vaughan, collector. 



3647. Five miles south of Jackson, Ala. ; T. W. Vaughan, 

 collector. 



7074. Coralliferous flint, Hales Landing, west bank of 

 Flint River, 7 miles southwest of Bainbridge, Ga.; T. W. 

 Vaughan, C. W. Cooke, and W. C. Mansfield, collectors. 



? 7075. East bank of Flint River just above Lamberts 

 Island, about 10^ miles below Bainbridge, Ga. ; C. W. 

 Cooke and W. C. Mansfield, collectors. 



7133. Silicified fragments, lower end of Fort Scott bluff, 

 west bank of Flint River, about 12 miles above River 

 Junction, Decatur County, Ga. ; C. W. Cooke, collector. 



In some of its characters this species resem- 

 bles L. favosa Cushman, from Antigua, but it is 

 less imdulate and its umbonal region is not so 

 prominent nor so distinctly reticulate as in 

 L. favosa. L. favosa does not attain so large 

 a size as L. chattaliooclieensis. The number of 

 lateral chambers in the central columns in the 

 species here described is unusually large. 



