FREE INSTITUTE OF SCIENCE 



579 



TERTIARY FAUNA OF FLORIDA 



of the Antilles we have L. indigcjia Dall {L. hisulcata Guppy, 1867, not of 

 Meek, 1861), L. clara Guppy, Z. illccta Guppy, L. Packeri Forbes (+ incognita 

 Guppy), L. peltella Dall (pi. 32, fig. 5 ; = acitta Gabb, 1873, not Conr., 1832), 

 L. Guppyi Dall (Cercomya lediEforims Guppy), L. perlepida Guppy, and an un- 

 described species of Tindaria. There are several Darien species, probably 

 new, but as yet represented by material insufficient for full description. 



In addition to the species which persist from the Oligocene and the new 

 forms about to be described, the following are known from the North Ameri- 

 can Miocene : Z. acutidcns and cariuata H. C. Lea, Z. conc£ntrica Say (+ ebotea 

 Conr., 1846), Z. liciata Conr., Z. vitrca Orb. (+ Millcri Gabb), and the Cali- 

 fornian Z. penita Conr. 



In the Pliocene there appear newly only L. nicenensis Gabb of Costa 

 Rica, and on the Pacific side L. peruviana Dall {aciiininata Nelson, 1870, not 

 von Buch, 1845) and Z. tapJiria Dall (Z. cmlata Hinds, 1844, not Conr., 1832); 

 while from the Pleistocene of Maine we have Z. Jacksoni Gould (1841, + 

 bi/ccata{Sip) MoUer, 1842). 



The Ledas have been divided into a number of groups variously regarded 

 as sections, subgenera, or even genera. A synopsis of the principal ones may 

 be of use to students, and is here given before proceeding to describe the 

 species. I refer only to those represented in the Tertiary. 



Subfamily LEDIN.ffi. 

 Genus LEDA Scliumacher, senso lata. 



A. Leda Schum., sciiso stricto, 18 17. Type Z. rosiraia Mtg. 



Shell elongate, rostrate, with conspicuous concentric sculpture, slightly 

 gaping at the rostral end. 



B. LcnUntbis (Risso em.) Fischer, 1886. Type Z. pclla (L.) = Z. Rossianiis 



Risso. 



Shell shorter, with radial ribs on the rostrum, and oblique sculpture not 

 wholly coinciding with the incremental lines. Ex. Z. ccelata Conr. (not 

 Hinds), Eocene. 



0. Jupitcria Bellardi, 1875. Type Z. concava Bronn. 



Shell short, arcuate, inflated, sharply pointed behind the valves, not 

 gaping, sculpture concentric or faint, without radial ribbing, usually 

 small sized. 



