FREE INSTITUTE OF SCIENCE 



I2SQ 



TERTIARY FAUNA OF FLORIDA Jy 



Shell trigonal, plump, subequilateral, thin, smooth, with a vernicose peri- 

 ostracum and a peculiar olivaceous tone of coloration; lunule and escutcheon 

 not distinctly defined ; cardinals three in each valve, with well-marked anterior 

 laterals ; the middle left and two anterior right cardinals entire, smooth, the 

 others grooved or bifid ; right nymph and posterior left cardinal corrugated ; 

 dorsal margins, beyond the hinge-plate, grooved to receive the edge of the 

 opposite valve ; internal margins smooth, the pallial line with a shallow arcuate 

 flexuosity but no angular sinus. 



Distribution chiefly in the seas of Japan, China, and the Asiatic islands in 

 the western Pacific. 



Genus CALLOCABDIA A. Adams. 

 Callocardia A. Adams, Ann. Mag. Nat. Hist., 3d Ser., xiii., p. 307, 1864 (C. guttata Ads.) ; 



E. A. Smith, Chall. Rep., Biv., p. 155, 1885 ; Ball, Bull. Mus. Comp. Zool., xii., p. 274, 



1866 (ex parte) ; do., xviii., p. 439, 1889; Proc. U. S. Nat. Mus., xii., p. 268, 1890; 



xviii., p. 17, 1896; E. A. Smith, Proc. Mai. Soc. Lond., iv., p. 81, 1900. 

 Caryatis Sowerby, P. Z. S., 1888, p. 212; E. A. Smith, Proc. Mai. Soc. Lond., iv., p. 81, 



1900; not Caryatis, Hiibner, Lepidoptera, 1816. 

 <^Caryatis Romer, Mai. Blatt, ix., p. 58, 1862 (=Pitar Romer, 1857, olim) ; Mon. Venus, 



i., p. 79, 1867; Stoliczka, Cret. Pel. India, p. 151, 1871; Tryon, Syst. Conch., iii., p. 



178, 1884; not of Hiibner, 1816. 

 Veneriglossa Dall, Bull. Mus. Comp. Zool., xii., p. 275, Sept., 1886 (Cytherea vesica 



Dall); Bull. U. S. Nat. Mus., No. 37, p. 56, 1889; Proc. U. S. Nat. Mus., xii., p. 



270, 1889. 

 Atopodonta Cossmann, Cat. Illustre, bas. Paris, i., p. 98, Oct., 1886 (A. coniformis Desh. 



Cossm.) ; Mem. Soc. Roy. Mai. de Belgique, xxi., p. no, 1887; Fischer, Man. de 



Conchyl., p. 1088, 1887. 



Shell ovate, plump, thin, concentrically striated, with more or less involute 

 umbones; pallial sinus nearly obsolete; lunule feebly circumscribed, not im- 

 pressed ; escutcheon not defined ; left anterior and right posterior dorsal mar- 

 gins beyond the hinge-plate grooved to receive the edge of the opposite valve ; 

 inner margins of the valves entire. Type Callocardia guttata A. Adams. 



The group begins in the Eocene and is widely distributed in the warmer 

 seas. 



Subgenus AGRIOPOMA Dall. 

 Agriopoma Dall, Proc. U. S. Nat. Mus., xxiv., p. 509, 1902. 



This group differs from Callocardia by its large, heavy, and chalky shell 

 without polish or coloration, and by its deep and angular pallial sinus and less 

 involute umbones. Type Cytherea texasiana Dall, 1892. 



