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1361 



TERTIARY FAUNA OF FLORIDA 



Subgenus Here Gabb. Type Lucina Richthofeni Gabb ( + Lucina Schum., 

 1817, non Lam., lygg; -\- Linga Greg., 1885 -\- Cardiolucina Sacco, 

 1901). 

 Shell globose, solid, with strong, concentric sculpture and developed dorsal 



areas, the lunule often deeply impressed and the right anterior cardinal effaced, 



the other teeth usually well developed. 



Section Gradilucina Cossmann, 1902. Type Lucina tabulata Deshayes. 

 Eocene of Paris. 



Shell small, inflated, with numerous stout concentric waves ; lunule large 

 but feebly defined ; escutcheon obsolete ; hinge-teeth well developed ; inner 

 margins entire. 



Deshayes' specimen of the right valve has the hinge apparently diseased or 

 abnormal, since there is no socket in the hinge of the left valve, as figured, 

 capable of holding the egregious anterior lateral of the former. 



Section Pleiirolucina Dall, 1901. 



Shell with a small number of large radial ribs in addition to the concentric 

 sculpture. Type Lucina leucocyina Dall, 1886, Proc. U. S. Nat. Mus., xii., p. 

 263, pi. xiv., figs. 6, 7, 1889. 



Section Cavilucina Fischer, 1887. Type Lucina sulcata Lamarck. 

 Shell small, compressed, concentrically striated, the areas and teeth more or 

 less obsolete ; the lunule small and often deep. 



Subgenus Lucinisca Dall, 1901. Type Lucina nassula Conrad. 



Shell lentiform, white, with well-marked dorsal areas, the sculpture reticu- 

 late and muricate, the right anterior cardinal obsolete. 



Subgenus Miltha H. and A. Adams, 1857. Type Lticina Childreni Gray. Gulf 

 of California. 



Shell solid, usually compressed, concentrically striate, with a conspicuous 

 periostracum, narrow impressed lunule, inconspicuous anterior and posterior 

 dorsal areas, deeply inset ligament and resilium ; hinge with two cardinals in 

 each valve, the inner pair bifid ; margins entire ; anterior adductor scar pro- 

 longed ; the valves sometimes diversely convex. 



Only two recent species of this type are known, but there are numerous 

 fossil species. 



Subgenus Pseudomiltha Fischer, 1887. Type Lucina gigantea Deshayes. 

 Parisian Eocene. 



