TRANSACTIONS OF WAGNER 

 1446 



TERTIARY FAUNA OF FLORIDA 



Oligocene sile'x beds at Ballast Point, Tampa Bay, Florida : Dall and Will- 

 cox. 



Shell thin, obliquely trigonal, feebly, irregularly, concentrically striated ; 

 beaks high, full, somewhat prosogyrate, situated near the anterior fourth of 

 the shell ; anterior end short, rounded ; posterior slope rapidly descending, 

 long, the end of the shell subrostrate ; one or two faint, shallow sulci extend 

 from the beaks to the posterior extreme ; a very small subcordate impressed 

 area in front of the beaks may represent a lunule ; hinge normal, the anterior 

 right and posterior left cardinals slender, entire, the others larger and bifid ; 

 the anterior laterals short, low, adjacent, smooth ; the posterior laterals longer 

 and distant from the cardinals ; nymphs rather long, their opposing surfaces 

 smooth; muscular impressions small and rather high in the shell; pallial line 

 obscure, but probably only slightly subtruncate behind and without a sinus ; 

 margins of the shell thin and smooth. Length 40, height 36, diameter 27 mm. 



This species is rather peculiar in the thinness of its shell and the closely 

 adjacent anterior lateral, but these characters do not appear to be more than 

 specific, ,and are paralleled in some of the oriental forms and, especially the 

 hinge character, in some of the European fossils. 



Cyrena (Pseudocyrena) duplinfana n. sp. 



Plate 56, Figure 22. 



Upper Miocene of the Natural Well, Duplin County, North CaroHna, and 

 in the Pliocene of the Caloosahatchie beds, Caloosahatchie River and Shell 

 Creek, Florida ; Dall and Burns. 



Shell small, thin, compressed, trigonal, subrostrate and acute behind, 

 rounded in front ; beaks subcentral, small, pointed ; posterior slope direct, 

 with a broad, low, rounded rib extending from the beak to the posterior ex- 

 treme and limiting a slightly depressed posterior dorsal area ; lunule not de- 

 fined or impressed ; basal margin arcuate ; hinge-teeth small but clear-cut, 

 laterals slender, the anterior rather long; nymphs short, smooth; paUial line 

 with a small angular sinus. Length 8.5, height 7.5, diaineter 5.0 mm. 



This species may grow larger, though all the specimens found were small. 

 They retain traces of purple coloration. 



Oyrena (Pseudocyrena) floridana Conrad. . 

 Cyrena floridana Conrad, Proc. Acad. Nat. Sci. Phila., iii., p. 23, pi. i., fig. i. 1846; Prime, 



Mon. Am. Corbie, p. 28, fig. 21, 1865. 

 fCyrena maritima Orbigny, Moll. Cubana, ii., p. 280, pi. xxi., figs. 47-5°, 1853; not C. 



maritima C. B. Adams, Ann. N. Y. Lyceum N. Hist., v., p. 499, 1852. 



