FREE INSTITUTE OF SCIENCE 



1447 



TERTIARY FAUNA OF FLORIDA 



fCyrena cubensis Prime, Mon. Am. Corbie., p. 29, 1865. 



Cyrcna protexta Conrad, Am. Journ. Conch., v., p. 107, pi. xii., fig. 3, 1869. 



Cyrena donaciformis Sowerby, Conch. Icon. Mon. Cyrena, pi. xix., fig. 108, 1878. 



Not Cyrena floridana Sowerby, op. cit., pi. xviii., fig. 102, 1878 (= C. caroliniana Bosc?). 



Pleistocene of North Creek, near Osprey, West Florida, Willcox; living 

 in salt water buried at the roots of sea grass from Tampa Bay south to the 

 Florida Keys, Bahamas, and Cuba, and westward to Yucatan. 



This species is variable in outline from subtrigonal to elongate and rostrate 

 or even subovate. It is usually thin and with a delicate hinge, but occasionally 

 under favorable circumstances becomes quite solid. It may be pure white, 

 white streaked with violet, brownish, or wholly dark violet. I have not seen 

 Cuban specimens and supposed that the heavier hinge illustrated on Or- 

 bigny's plate was a specific character, but I have since seen specimens quite 

 as heavy which are undoubtedly varieties of C. floridana. I therefore conclude 

 the two forms should be united. Conrad in one of his lapses of memory re- 

 described his own species under the name of protexta, while Sowerby figures 

 what is probably C. caroliniana Bosc under the name of floridana, and rede- 

 scribes the true floridana as C. donaciformis. 



Cyrena (Polymesoda) caroliniana Bosc. 



Cyclas caroliniana Bosc, Hist. Nat. des Coq., iii., p. 37, pi. xviii., fig. 4, 1802; Say, Am. 



Conch., vii., pi. Ixii., 1833. 



Cyrena caroliniensis Lamarck, An. s. Vert., v., p. 553. 

 Cyrena carolinensis Hanley, Rec. Shells, p. 93, pi. xiv., fig. 54, 1842. 

 Cyrena caroliniensis Holmes, Post-Pi. Fos. S. Car., p. 31, pi. vi., fig. 7, 1860. 

 Cyrena floridana Sowerby, Conch. Icon., 1878; not of Conrad, 1846. 



Pleistocene of Simmons Bluff, South Carolina, and of North Creek, near 

 Osprey, on the west coast of Florida; recent from South Carolina to Florida 

 and westward to the coast of Texas, in streams and brackish water near the sea. 



Subgenus LEPTESTHES Meek. 



This group is chiefly lower Eocene and is numerous in the Wahsatch, 

 Laramie, Judith River, and allied horizons in the west and in the Puget Group 

 of the Pacific coast. The following species have been named: C. (L.) fracta, 

 subelliptica, and planumbona by Meek ; C. (L.) brevidens and car dime for mis 

 by White. C. crassatelliformis Meek and macropistha White, from their form, 

 probably belong here. 



