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845 

 TERTIARY FAUNA OF FLORIDA 



have not seen it from the Claibornian. Gregorio's specimens were not 

 located, but probably are Jacksonian. 



Corbula (Aloidis) gibbosa Lea. 

 Corbtda gibbosa Lea, Contr. GeoL, p. 46, pi. I, fig. 14, 1833. 



Corbula {Necsrd) gibbosa de Greg., Mon. Claib,, p. 233, pi. 36, figs. 26-30, 1890; Coss- 

 mann, p. 6, 1S94. 



Claibornian Eocene of Claiborne, Alabama, and near Meridian, Mis- 

 sissippi ; at White Bluff and otlier localities in Arkansas. 



As shown by Cossmann, this is an excellent species which has frequently 

 been confounded with C. onisciis. 



Corbula (Aloidis) milium n. s. 

 Platk 36, Figure 19. 



Chickasawan Eocene, Wood's Bluff horizon at Thomasville, Clarke 

 Count)', Alabama; Burns. 



Shell minute, rounded, inflated, with prominent beaks a little in advance 

 of the middle line of the valves ; right valve larger, sculptured with fine, even, 

 concentric threads separated by narrower interspaces ; there is no radial stria- 

 tion, but near the posterior cardinal margin a well-marked sulcus extends 

 from the beak to the upper posterior margin, the surface above it and next 

 to the cardinal margin turgid; in front of the strongly prosoccelous beaks 

 the valve is impressed, though without any defined lunule ; left valve smaller, 

 less inflated, nearly smooth or with faint incremental lines ; a strong radial rib 

 close to the posterior hinge-margin ; interior and internal margins of the 

 valves polished ; a small ridge near the hinge reflects the posterior external 

 sulcus of the right valve; cardinal tooth small, conical, rather prominent, 

 the chondrophore hidden under the cardinal margin ; left valve with the chon- 

 drophore flat, squarish, projecting, and a socket for the point of the right 

 cardinal. Lon. 2.2, alt. 2.3, diam. 1.6 mm. 



This interesting little species recalls C. laqueaia Conrad on a smaller scale 

 and with proportionately finer sculpture. Though so small, there is no reason 

 to doubt that it is an adult form. 



Corbula (Aloidis) texana Gabb. 

 Corbula texana Gabb, Journ. Acad. Nat. Sci. Phila., 2d Ser., iv., p. 387, pi. 67, fig. 54, i860. 



Eocene of Lee County, Texas ; Singley in United States National Museum. 



This appears to be distinct from any of the others, being flatter, less 

 involved, and more distinctly triangular. It is a peculiarly solid shell. 



