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TERTIARY FAUNA OF FLORIDA 



terior lateral, short and smooth; a very short arcuate socket for an anterior 

 adjacent lateral above a pustular tooth equivalent to the right lamina in the 

 right valve. The interior is obscured by silicious rock. Length 65, height 70, 

 diameter (double) 50 mm. Horizon as above described. 



Genus BATISSA Gray. 

 Capsa (Anonymous) Mus. Calonnianum, p. 59, 1797, Venus erosa Solander, = Cyrena 



Keraudreni Lesson (= Batissa sp.?) ; not Capsa Bruguiere, 1797. 

 Batissa Gray, Ann. Mag. N. Hist., 2d Sen, xi., p. 38, 1853 ; B. tenebrosa and B. obesa 



Hinds; Deshayes, Cat. Conch. Brit. Mus., ii., p. 219, 1854; Tryon, Struct. Syst. 



Conch., iii., p. 185, 1854; White, Bull. U. S. Geol. Surv. No. 51, p. 60, 1889. 



Australia and the Indo-Chinese islands. 



This genus is characterized by large size and heavy ovate shells, with a 

 very prominent ligament and a violet or salmon tint of coloration. The pallial 

 line is not sinuated ; the lateral teeth are distant from the cardinals and feebly 

 striated. They are in the left valve and are received by sockets or paired laminae 

 in the opposite valve. There are three cardinals in each valve, the middle 

 ones bifid, the others entire ; the posterior right cardinal is usually oblique 

 and unusually elongated. The dental formula is L - QIO.""OIO.OIQ. 



R. iot.oioioi.ioi 



The characters are such as might diverge from Corbicula at any time, and 

 I doubt if the species of the Pacific coast Eocene and those now living in the 

 South Seas are connected by a common origin except in some such way- 

 Two species, Batissa Nezvberryi and B. dubia have been described by Dr. 

 C. A. White from the Puget Group of Washington on the Pacific northwest 

 coast, and further information in regard to them can be found in Bulletin 

 No. 51 of the United States Geological Survey, above cited. 



Genus EGERIA Roissy. 



Galatea Bruguiere, Enc. Meth., i., pi. ccl., figs. ia-c. (G. radiata Lamarck), 1797. 

 Galathea Lamarck, Ann. du Mus., v., p. 431, 1803 (not Galathea Fabricius, 1793) ; Rang, 



Man. des Moll., p. 313, 1829; Cuvier, Regne, Anim., iii., p. 147, 1830; Deshayes, 



Enc. Meth., ii., p. 165, 1830. 

 Egeria Roissy, Sonnini's Buffon, vi., p. 324, pi. Ixiv., fig. 5, 1805 (G. radiata Lam.) ; 



not Dumeril, 1806, nor JEgeria Fabricius, 1808; not Egeria Leach, 1815. 

 Trigona (sp.) Schumacher, Essai, p. 153, 1817; not Trigona Jurine, 1807. 

 <Cyanocyclas (sp.) Ferussac, Diet. Sci. Nat., xii., p. 280, 1818 (includes Egeria and 



Corbicula sp.). 



Potamophila Sowerby, Gen. Shells, fasc. iii., 1821; not Potamophilus Germ., 1811. 

 Megadesma Bowdich, Elem. Conch., ii., p. 8, figs. 2ia-b, 1822; not Megadesmus Sowerby, 



1839. 



