TRANSACTIONS OF WAGNER 

 6so 



TERTIARY FAUNA OF FLORIDA 



Oligocene of Rio Amina, St. Domingo ; Bowden, Jamaica, and Cumana, 

 Venezuela. 



Shell small, thin, greatly inflated, rounded, with incurved prosocoelous 

 beaks ; the left valve larger, the sculpture of the two valves slightly discrep- 

 ant; left valve with about thirty-four subequal, rounded, minutely nodulous, 

 radial ribs, separated by narrower channelled interspaces, and crossed by fine 

 incremental lines ; right valve with the ribs narrower, flat, and straplike, only 

 a few of the anterior ones showing nodulation ; hinge-line short, straight, 

 hardly angular at the ends ; the beaks nearly attaining the anterior fourth of 

 the length of the shell ; cardinal area very narrow behind the beaks and with 

 elevated margins ; in front of the beaks slightly wider, very short; its surface 

 with a few irregular longitudinal grooves ; hinge-teeth in two series, the an- 

 terior short and more or less broken up into granules, separated by a very 

 narrow gap from the posterior series, which is about twice as long, with small, 

 numerous vertical teeth, becoming longer and more oblique distally ; internal 

 margins of the valves with short, deep flutings. Lon. 28, alt. 26, diam. 27 mm. 



This little shell is doubtless an ancestor of Say's shell, from which it 

 differs by its smaller size, more rotund shape, finer and more nodulose sculp- 

 ture, and greater inflation. 



Scapharca (Argina) oampechensis Dillwyn. 

 " PL-chmcubis dense et profiindc siriaius, ovaK figura," Lister, Hist. Conch., tab. 237, fig. 



71, 1770; Bay of Campeachy. 

 Area No. 22; Schroter, Einleit. Conch., iii., p. 288, 1786. 

 Area campcehensis Gmel., Syst. Nat., vi., p. 3312, 1792. 

 Area ovalis Bruguiere, Encyc. Meth., p. no, 1792. 

 Area dccHvis Solander Ws&.,fide Dillwyn, 18 17. 

 Area eampcehensis Dillwyn, Descr. Cat. Rec. Sh., i, p. 288, 1817 (Syn. partim. exclus.), 



Jamaica and CaroHna ; not of Wood, Ind. Test., p. 46, pi. 9, fig. 28, 1825. 

 Area pexata Say, Journ. Acad. Nat. Sci. Phila., ii., p. 268, 1822. 

 Area scapha Ravenel, Cat., p. 5, 1834, yfrff Stimpson. 

 Area amerieana (Gray) Wood, Index Test. Suppl. , pi. 2, Area, fig. i, 1828; ibid., ed. 



Hanley, p. 205, 1856 ; Tryon, Am. Mar. Conch., p. 179, pi. 37, fig. 470, 1874. 

 Area amerieana Rve., Conch. Icon., Area, fig. 21, 1844 ; Hohnes, Post-PL Fos. S. Car., p. 



19, pi. 4, fig. 2, 1858. 

 Area pexata Q,xe:e.v,st, Mass. Cat., 1833 ; Gould, Rep. Inv. Mass., p. 95, fig. 60, 1841 ; 



Reeve, Conch. Icon., Area, fig. 22, 1844; De Kay, Nat. Hist. N. Y., Moll., p. 176, 



pi. 12, fig. 311, 1843 ; Stimpson, Shells of N. Engl., p. 8, 1851. 

 Area eampeehe7isis Ravenel, Cat. Coll., p. 5, 1834 ; Arango, Moll. Cubana, p. 262, 1880. 



