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840 



TERTIARY FAUNA OF FLORIDA 



As the ribs are not overrun by the radial sculpture, the effect is not 

 reticulate. C. Laralleana Orbigny, of the recent Antillean fauna, is said to 

 be radially striated, but I have not been able to obtain specimens of it for 



comparison. 



Corbula (Cuneocorbula) Whitfieldi n. s. 



PLATE ,;6, FIGURE 18. 



Uppermost Oligocene of the Alum Bluff beds at Oak Grove, Santa Rosa 

 County, Florida ; Burns. 



Shell small, solid, inflated, nearly equilateral, rounded in front, very 

 obliquely truncate, and pointed behind, with a well-marked rostral carina and 

 a slight emargination of the border of the valve below the rostrum ; beaks 

 low and inconspicuous; sculpture of rather coarse incremental lines and some- 

 what irregular concentric undulations, stronger in the middle of the shell, 

 feeble on the beaks, and with wider interspaces ; base of the right valve folded 

 upon the basal margin of the left valve. Lou. 7, alt. 4.5, diam. 3.4 mm. A 

 small tubercle behind the socket and resilifer, on the cardinal margin of the 

 left valve. 



This species is close to C. Barrattiana C. B. Adams, from which it differs 

 by greater inflation and usually by the smaller number of concentric undu- 

 lations, and especially by the absence of any radial threads on the dorsal area 

 of the rostrum. It recalls C. subcontracted Whitfield, which is a proportion- 

 ately shorter shell and not as large. 



Corbula (Aloidis) vieta C.uppy. 

 Corliula ".'ii'tii Guppy, Quart. Journ. deal. Soc. Loud., x\ii., p. 580, pi. 26, fig. 8, 1866. 



(Right valve.) 



l-'.ryiina 1,-nsn (Hippy, i>/>. <://., p. 582, pi. 26, fig. 6. (Left valve.) 

 Ci>r/>if/n ilisfiarilis Dall, Proc. U. S. Nat. Mus., xix., No. mo, pp. 327, 329, 1896. (Not 



of Orbigny.) 



Oligocene of Manzanilla and other localities in Trinidad ; Pliocene of 

 Matura, Trinidad, Guppy; and of Port Limon, Costa Rica, Hill. 



In my review of Mr. Guppy's fossils above cited this form was referred 

 to C. disparilis Orbigny, to which it is nearly related. A more thorough 

 study of a large amount of material of this puzzling group has shown, how- 

 ever, that there are constant, if not very conspicuous, differences between 

 them, and I have, accordingly, restored the form to specific rank. The recent 

 shell is larger, less compact, less regularly sculptured, and decidedly more 

 rostrate. 



