40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



thickness is respectively 6 and 5 mm. Figure 2 of plate 17 represents 

 two megalospheric specimens, X 5. The upper specimen has a nearly 

 flat rim surrounding the inflated central part ; while the lower specimen 

 is distinctly saddle-shaped. Plate 17, figure 3, represents a megalo- 

 spheric specimen, X 10, to show the detail of the surface ornamenta- 

 tion. Every intermediate between the extremes of the variations is 

 represented in the same lot of specimens. 



Plate 18, figure i, illustrates the type specimen of L. chattahooche en- 

 sis Cushman, X 10. The type specimen is a vertical section caused by 

 breaking. Figures 2, 3, 4 are illustrations of polished sections, each 

 X 10, of three specimens from the lowest bed exposed at Espinal. 

 Comparison of figures i and 2 shows that they represent the same 

 species. The other figures show variation. 



Plate 19, figure i, represents a vertical section, X 20, of a topotype 

 of L. favosa, while figures 2, 3, 4 illustrate topotypes of L. chat- 

 tahoocheensis, X 20. L. favosa varies in the thickness of its pillars 

 and in the length of its lateral chambers. Specimens from Antigua 

 completely overlap those from Espinal, Vera Cruz. 



Plate 20, figures i and 2, are respectively a vertical and an equa- 

 torial section, X 20, of megalospheric specimens from Espinal. Figure 

 3 represents the type specimen of Cushman's L. crassata from Cuba. 

 Figures i and 2 obviously represent the same species. 



Plate 21, figure i, is a vertical section, x 20, of a less inflated speci- 

 men collected by D. R. Semmes and myself at El Contento, Rio 

 Pantepec, State of Puebla. A horizontal section, not illustrated, shows 

 eulepidine embryonic chambers. Figures 3 and 4 represent vertical 

 sections, X 20, of specimens respectively from U.S.G.S. locality nos. 

 7518 and 7512, near Guantanamo, Cuba. These specimens have been 

 identified as L. sp. cf. L. margmata. I am convinced that they do not 

 belong to L. marginata. It is my opinion that figure 3 represents L. 

 favosa and that figure 4 probably does. Figure 2 of the same plate 

 illustrates an oblique equatorial section of a specimen collected by 

 D. R. Semmes and myself near Buena Vista Hacienda House, Rio 

 Pantepec, State of Puebla, not far from El Contento on the same 

 river. This specimen is a Nephrolepidina, but I suspect that it may be 

 a variant of L. favosa. Unfortunately, not enough specimens were 

 obtained to study its variations. 



Localities and geologic occurrence. — A number of specific localities 

 have been given in quoting the original descriptions and in the discus- 

 sion of the variation of the species. L. favosa is a common species in 

 the middle Oligocene Glendon formation in Georgia, Florida, and Ala- 

 bama; in the middle Oligocene Meson formation and the Oligocene 



