TRANSACTIONS OF WAGNER 

 1254 



TERTIARY FAUNA OF FLORIDA 



Miocene of the lower clay bed at Plum Point, Maryland ; of the York River 

 and Petersburg, Virginia; of Edgecombe County, North Carolina, and the 

 Santee River, below the Congaree junction, in South Carolina. 



This species has suffered from the failure of Mr. Conrad's memory and 

 other faculties towards the end of his life. Say described the species from 

 South Carolina and figured a half-grown valve. Conrad in 1838 copied Say's 

 figure and description. In the sixties he became impressed with the idea that 

 the shells from Petersburg represented a different species from that of Say, 

 and in his endeavors to get this idea recorded in print he renamed his own 

 copy of Say's figure (idonea), and gave names to a pathological young shell 

 (densata) and to the full-grown adult from Virginia (virginiana). The 

 species appears to be subject to a pathological excessive deposit of shell sub- 

 stance inside the pallial line, as remarked by Say. The old shells are shorter 

 and broader in proportion than the young ; an occasional healthy specimen has 

 the shell not much thicker than M. nimbosa. I see no reason for more than 

 one specific name. 



Macrocallista nimbosa Solander. 



Venus nimbosa Solander, Portland Cat., p. 175, No. 3761, 1786; after Favanne, pi. xlix., 



fig. P. 

 Venus gigantea Chemnitz, Conch. Cab., x., p. 354, pi. clxxi., fig. 1661, 1788; Gmelin, Syst. 



Nat, vi., p. 3282, 1792; Dillwyn, Descr. Cat. Rec. Sh., i., p. 202, 1817; Encyc. Meth., 



pi. cclxxx., fig. 3, 1797; Bosc, Hist. Nat. Coq., iii., p. 59, 1801 ; Wood, Ind. Test, p. 40, 



pi. viii., fig. zoo, 1825. 



Pectunculus nimbosa Humphrey, Cat. Calonn., p. 49, 1797. 

 Paphia ala-avis Bolten, Mus. Bolt., p. 175, 1798; ed. ii., p. 122, 1819. 

 Cytherea gigantea Lamarck, An. s. Vert., v., p. 564, 1818; De Kay, Zool. N. Y., Moll., p. 



216, 1843 ; Hanley, Rec. Sh., p. 97, 1843 ; Conrad, Am. Journ. Sci., 2d Ser., ii., p. 44, 



1846; Sowerby, Thes. Conch., ii., p. 628, pi. cxxxi., fig. 86, 1851. 

 Dione gigantea Deshayes, Cat. Conch. Brit. Mus., i., p. 80, 1853 ; Reeve, Conch. Icon., 



xiv., Dione, pi. v., fig. 17, 1863. 



Cytherea multiradiata Menke, Verzeichn. Conch., No. 2668, 1830. 

 Cytherea gigantea Conrad, Tert. Sh. in Morton, Syn. Org. Rem. App., i., p. 2, 1834; not 



of Sowerby, in Philippi, Abb. und Beschr., Cytherea, pi. vii., fig. I, = Dosinia sp. 

 Callista gigantea Romer, Mon. Venus, i., p. 54, pi. xv., fig. I, 1866; Chemn., Man. Conch., 



ii., p. 87, fig. 382, 1862; H. and A. Adams, Gen. Rec. Moll., ii., p. 425, 1857; Holmes, 



P.-P1. Fos. S. Car., p. 36, pi. vii., fig. 3, 1860; Tryon, Am. Mar. Conch., p. 160, pi. 



xxix., fig. 396, 1874. 

 Callista (Macrocallista) gigantea Meek, Pal. Upper Missouri, p. 179, 1876. 



