TRANSACTIONS OF WAGNER 

 840 



TERTIARY FAUNA OF FLORIDA 



Subgenus CORBULAMELLA Meek and Hayden. 

 Proc. Acad. Nat. Sci. Phila. for 1857, p. 143. 



Shell subglobular, inflated, like Corbula s. s., except that the posterior 

 adductor is inserted in each valve on a raised lamella, recalling that of Cncnl- 

 Icea. Type C. grcgaria Meek and Hayden. Cretaceous of Nebraska. 



I have examined a very large number of adult Corbulas, and in none of 

 them have I found any traces of lateral teeth or any more than a single cardi- 

 nal tooth, well developed, in the right valve. When not erect the beaks are 

 invariably prosogyrate ; but Bernard has shown that in the nepionic young 

 there are traces of an anterior and posterior left cardinal and two left anterior 

 lamellae, and similarly in the opposite valve are traces of denticulation, which 

 become obsolete in the adult, but which tend to show the relations of the 

 group to the Myacea. 



In the Eocene of the Pacific coast are found Corbula {Anis0rhy?ich?is) 

 alcBformis Gabb, 1868, and C. (A.) ailtrifonnis Gabb, from the Tejon and the 

 Martinez group respectively. If the name of the former be regarded as insuf- 

 ficiently distinguished from C. aliformis Conrad, 1866, it might be changed to 

 C. Gabbii. C. {Cuneocorbula) Evansana Shumard, 1858, from the Port Orford 

 coal measures (Arago beds), C. (C) Hornii, C. (^C.) farilis, and C. {}) pi'imorsa 

 Gabb, 1868, from the Tejon of California, complete the list of Pacific coast 

 Eocene species so far recorded. 



From the brackish-water Tertiaries of the West, Meek (1877) has de- 

 scribed Corbula (AnisorlLynchus) pyriformis, for which C. concentrica Meek 

 (1861) was an earlier but preoccupied specific name. With it in Utah 

 was found C. (yCuneocorbuld) Eugelmanuii Meek (1877). From Nebraska 

 Corbulamclla gregaria and Corbula [Aloidis f) perundata, C. [Erodona) 

 mactrifonnis, and C [E.) subtrigoualis Meek and Hayden were described in 

 1857. 



The peculiar and polymorphous section Anisothyris from the Pebas clays 

 of the upper Amazon is represented by the following species : C (A.) ama- 

 zoneusis (Gabb as Tellimi), C. (A.) tenuis Gabb (H- Hauxivelli Woodward, -f- 

 ovata Conrad), C. (A.) crccta Conrad, C (A.) obliqua Gabb, C. (/i.) armifera 

 Dall (+ carinata Conrad non Phillips), C. (A.) spheniclla Dall (+ cuneata Con- 

 rad non Say), and C. (/^.) ledcefonnis Dall. 



Species of the Eastern Eocene. 

 Turning now to the eastern Tertiary of the United States, the earliest 



