TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



etc., some of which are convenient, but all intergrade as far as can be judged 

 from the shells, though the extreme forms are very distinct. The number 

 of species is probably larger than that of any other American Tertiary genus. 

 They often require very critical treatment, and, unfortunately, very few have 

 been adequately described, figured, or compared. Descriptions based on 

 internal casts are of value only as indicating the presence in the horizon 

 concerned of the genus or its near relatives. It would be impossible to 

 identify a species from such data with any certainty. Yet quite a number 

 of names in American lists rest on no better basis. A thorough review 

 would probably increase the number of species while rejecting a certain pro- 

 portion as unidentifiable. Much carelessness has also been shown in using 

 preoccupied specific names for new American forms. Both Gabb and Conrad 

 have given entirely distinct species at different times the same specific name, 

 and names already applied by European writers to species of Lcda have been 

 I'epeatedly used for new species here. A few of these errors will be corrected 

 here, but the subject needs a monographic revision. 



Among the older Eocene species Lcda inilaiiieiisis Harris, L. quercollis 

 Harris, L. Aldricldana Harr. {elongatoidea Aldr. var. ? Harr., Midway, Bull. 4, 

 not of Aldrich), L. saffordana Harr. (= protexta Gabb, pars), L. robiisia, L. 

 corptdentoidea, and L. elougatoidea Aldr. have been described ; to which will 

 be added here two apparently undescribed forms from Wood's Bluff 



The Claiborne and Jackson, or Middle Eocene group, has a larger number, 

 some of them very peculiar species, of which we may enumerate Leda albi- 

 rupiana and L. [Adrana) aldrichiaiia Harris, L. cequalis Conr. (non Reuss ? 

 + ? media Lea, non Wissm.), L. hastropeiisis Harr., L. bcUa, L. ccrdata (not of 

 Hinds), and L. calcarensis Conr. ; L. cidtellifoniiis Rogers, L. houstonia Harr., 

 L. improcera Conr., L. (Adrana .?) lisbonensis Aldr., L. magna and media Lea 

 (? + carolinensis Conr.), L. Vamixend Dall [L. mncronata Conr., 1847, not of 

 Sowerby, 1825), L. opidenta Conr., L. parva Rogers, L. plana, plicata, pnlclier- 

 rima, and semen Lea, L. semenoidca Aldr., L. subtrigona Conr., L. smirna Dall 

 (L. eborea Conr., i860, not of Conr., 1846), L. linifera Conr., L. mater Meyer, 

 L. midtilineata Conr., and a new form now described from Wahtubbee. 



The Oligocene, except in the Antilles, is less populous with Leda, but 

 offers L. parilis and sei'ica (not sericcd) Conr. from the Vicksburgian, which also 

 includes L. midtilineata Conr., and from the Upper Oligocene L. acuta Conr. 

 (1832, not of Sby., 1837, or Gabb., 1873), L. floridana Conr. (probably never 

 described), L. flexiiosa Heilprin, and L. tellimda Conr. From the Oligocene 



