FAUNA OF ORTHAULAX PUGNAX ZONE. 139 



PHACOIDES (LUCINISCA) CALHOUNENSIS Dall. 

 Plate 24, fig. 5. 



Phacoides (Lucinisca) calhounensis Dall, Trans. "Wagner Inst., vol. 3, 

 pt. 6, p. 1371, pi. 52, fig. 16, 1903. 



Oligocene of the Tampa silex beds at Ballast Point, Tampa Bay, 

 and of the Chipola marl at the coimty bridge, Chipola River, Cal- 

 houn County, Florida. U. S. Nat. Mus. No. 165201. 



The Ballast Point specimens were badly worn before fossilization, 

 and present a different aspect from the perfectly preserved speci- 

 mens from the Chipola marl. 



Subgenus MILTHA H. and A. Adams. 



Miltha H. and A. Adajis, Gen. Rec. Moll., vol. 2, p. 468, 1S57. Sole example, 

 Lucina cJdldrenae Gray.— Dall, Trans. Wagner Inst, vol. 3, pt. 6, p. 

 1374, 1903. 



PHACOIDES (MILTHA) HILLSBOROENSIS Heilprin. 



Plate 19, fig. 5. 



Lucina Jiillsboroensis Heilprin, Trans. Wagner Inst., vol. 1, pp. 117, 120. 



pi. 16, fig. 62, 1887. 

 Phacoides (Miltha) hillsboroensis Dall, Trans. Wagner Inst.,. vol. 3, pt. 6, 

 p. 1376, 1903. 

 Oligocene of the Tampa silex beds. Ballast Point, Tampa Bay; 

 of the lower bed at Alum Bluff, Chattahoochee River; and of the 

 Chipola marl, Chipola River, Calhoun County, Florida. Heilprin, 

 Burns, and Dall. U. S. Nat. Mus. No. 114706. 



PHACOIDES (MILTHA) HERACLEUS Dall. 



Phacoides heracleus Dall, Trans. Wagner Inst., vol. 3, pt. 6, p. 1376, pi. 51, 

 fig. 10, 1903. 



Oligocene of the Tampa silex beds at Ballast Point, Tampa Bay, 

 and of the lower bed at Alum Bluff, Chattahoochee River, Calhoun 

 County, Florida. Dall and Burns. U. S. Nat. Mus. No. 111425. 



This is a large species, recalling the Pseudomiltha gigantea of the 

 Parisian Eocene, but the teeth are developed. Only one right valve 

 and a fragment have been so far collected. 



Family DIPLODONTIDAE. 



Genus DIPLODONTA Bronn. 



Diplodonta Beonn, Ital. Tert. gebirg., p. Ix, 1831. Type, Venus lupimis 



Brocchi, not Diplodon Spix, 1827. 

 Mysia Brown, Zool. Textb., p. 454, pi. 90, fig. 6, 1833 ; also of Sowerby, 1842, 



and Conrad, 1838, but not of Leach, in Lamarck, 1818. 

 Olocomene Leach, Moll. Gt. Britain, p. 313, 1852. 

 Cycladicama Valenciennes, Yoy, au Pole Sud, vol. 5, p. 116, 1854. 



