NO. lO AMERICAN SPECIES OF LEPIDOCYCLINA VAUGHAN 39 



also numerous in material from 7512, Ocujal; 7519, orbitoidal limestone, from 

 drift near top of landslide next north of Los Melones; 7521, limestone, top of 

 Mogote Peak, Cuba. All the specimens were collected by O. E Meinzer. 



Cushman's original description of L. chattahoocheensis is as 

 follows : 



Test of medium size, flattened or somewhat undulate; largest specimens 

 measuring 25 mm in diameter, most specimens less, 16 to 22 mm ; central region 

 much thickened, prominently umbonate, making up about one-third of the test, 

 nearly 5 mm through in the center of the thickened region in large specimens ; 

 the thin flattened peripheral border usually smooth or very finely papillate: the 

 umbonate central region pitted with numerous small depressions. 



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 di- 

 ameter; lateral chambers compressed, broad and low, somewhat convex in the 

 central region, where there are as many as 40 chambers in the central columns, 

 diminishing in number toward the periphery, where in the flattened flangelike 

 portion there are from 3 to S chambers superimposed, not together equaling 

 the height of the equatorial chambers at the periphery. Pillars in the umbonal 

 region strongly developed, wedge-shaped in 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. 



In some of its characters this species resembles L. favosa Cushman, from 

 Antigua, but it is less undulate, 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. chattahoocheensis. The number of lateral chambers in the central columns in 

 the species here described is unusually large. 



In my 1926 paper cited above I briefly discussed some of the 

 variations of L. favosa in considering L. undosa and its variants. 



For this paper I have prepared, arranged, and had photographed 

 a series of specimens to illustrate the features that I wish to emphasize. 

 All of the specimens represented on plate 17 were collected by W. S. 

 Adkins in the village of Espinal, State of Vera Cruz, Mexico, and all 

 are from one lot from the base of what Adkins called the upper 

 horizon. The six microspheric specimens illustrated by figure i, X 2, 

 range from almost globose to compressed-undulate. The diameters can 

 be measured on the figure. The thicknesses, measured from left to 

 right, are as follows: First row, 6 mm, 8.5 mm, 6 mm; second row, 

 7.5 mm, 5.5 inm, 5 mm. 



The specimen 8.5 mm thick has a diameter smaller than that of 

 either of the specimens at the right-hand end of the rows, and their 

 4 



