28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



Cushmaii's original description and figures were based on the 

 megalospheric form of the species. His description is as follows : 



Test of medium size, 10 to 12 mm in diameter, very thin, flattened or very 

 slightly sellaeform ; central portion very slightly thickened but usually forming 

 no definite umbo distinguishable from the remainder of the test ; surface very 

 smooth except where eroded and at the periphery, where the walls of the 

 equatorial chambers form a slight reticulation of the surface ; whole test thin 

 and fragile ; thickness usually about i mm or less. 



The horizontal section shows the equatorial chambers to be hexagonal and 

 with fairly thick walls. Embryonic chambers not seen. 



The vertical section shows the equatorial band of chambers unusually low 

 throughout, increasing very little from center to periphery ; the chambers toward 

 the center thin-walled and broader than high; those toward the periphery are 

 thick-walled, slightly higher than wide, and the vertical walls slightly convex 

 and thickened; lateral chambers very low and broad, in central region with 

 not more than six chambers in a vertical column, generally lessening in number 

 toward the periphery, where there may be but one or even none. No pillars 

 apparent. 



Type specimens from U.S.G.S. station 7194, Ocala limestone, at mouth of 

 cavern about 200 yards southwest of wagon bridge over Chipola River, east of 

 Marianna, Fla. ; bed 4 of section ; C. W. Cooke and W. C. Mansfield, collectors. 



In 1924 I published an illustration showing that the embryonic 

 chambers were of nephrolepidine type. In the present paper plate 14. 

 figure I represents a vertical section of a megalospheric specimen ; 

 figures 2 and 3, two parts of one half of a vertical section of a micro- 

 spheric specimen ; and figure 4, the equatorial chambers near the 

 margin of a microspheric specimen. All of the figures are enlarged 

 20 diameters. 



L. fragilis is a large species ; 30 mm is a common diameter of 

 microspheric specimens and some specimens are almost 40 mm in 

 diameter. 



Both the equatorial and lateral chambers are well illustrated in the 

 figures. In general, the lateral chambers are rather low and are long. 

 Pillars are neither so well nor so regularly developed as in L. georgiana. 

 and the chamber cavities are not so open. The surface of L. georgiana 

 is definitely and rather coarsely papillate, whereas the surface of L. 

 fragilis is smooth, flaky, reticulate, nonpapillate. Cushman's enlarged 

 views of the surface features of the two species are good. 



Because of similarity in form and size, the microspheric forms of 

 L. georgiana and L. fragilis look alike, but actually they belong to 

 different subgenera. L. georgiana is Lepidocycylina s.s., and L. 

 fragilis is, as has already been stated, Nephrolepidina. 



