TRANSACTIONS OF WAGNER 

 998 



TERTIARY FAUNA OF FLORIDA 



Abra sequalis Say. 

 Amphidesma cequalis Say, Journ. Acad. Nat. Sci., ii., p. 307, 1822; Am. Conch., iii., pi. 28, 



1831 ; Conrad, Fos. Med. Tert., p. 76, pi. 43, fig. 9, 1845 ; Tuomey and Holmes, Pleioc. 



Fos. S. Car., p. 93, pi. 23, fig. 3, 1856. 

 Abra squalls Holmes, Post- PI. Fos. S. Car., p. 50, pi. 8, fig. 7, 1859; Conrad, Proc. Acad. 



Nat. Sci. Phila. for 1862, p. 574, 1863. 



Abra nuculiformis Conrad, Am. Journ. Conch., iii., p. 14, 1867. 

 Not Abra cequalis Whitfield, Mio. Moll. N. J., p. 80, pi. 14, figs. 11-15, 1894; = Semele sp. 



Miocene of North Carolina, near Wilmington, Stanton ; of South Carolina 

 at Goose Creek and Smith's, Tuomey; Pliocene of the Waccamaw district, 

 South Carolina, and of the Caloosahatchie River, Florida. Living from Cape 

 Hatteras, North Carolina, to the Gulf of Mexico in moderate depths of water. 



This species varies a good deal in outline in the same locality, but southern 

 specimens of the recent shells, especially those from Florida, have the anterior 

 dorsal slope less rounded and the umbonal angle smaller than those from more 

 northern localities. The fossils are generally of this type rather than like 

 the more rounded northern recent specimens. From A. angulata Holmes, 

 of the Post Pliocene of the Carolinas, A. cequalis is separated by the same 

 characteristics, only more pronounced. This would indicate that the larger 

 rounded form is correlated with water of a lower temperature. From A. 

 lioica Dall, of the recent fauna, A. tequalis is distinguished by its less trans- 

 verse and quadrate form, and also by having on the anterior right dorsal 

 margin a long groove continuous with the hinge-plate, bordered by a ridge 

 below, while A. lioica has a short, developed lateral tooth separated by a wide 

 gap from the hinge-plate. 



Abra or Amphidesma subobliqua Conrad (Proc. Acad. Nat. Sci. Phila., 

 vii., p. 29) is apparently an undescribed form, or a lapsus pennce. Other 

 species in the literature which have been referred to Abra, especially those 

 of Conrad (1863 and 1865), will be found treated of under the genera to 

 which they really belong, such as Semele, Aligena, and Fabella or Sportella. 



Genus CTJMINQIA Sowerby. 



Cumingia Sowerby, P. Z. S., 1833, p. 34. Type C. mutica Sby. 

 Mactra (sp.) Conrad, 1831. 

 Anatina (sp.) H. C. Lea, 1845. 



Harpax Gistel, Naturg. Thierr., p. viii., 1848; not of Parkinson, 1811. 

 Lavignon (sp.) Orbigny, 1846, and Tuomey and Holmes, 1856. 

 Mikrola O. Meyer, Proc. Acad. Nat. Sci. Phila. for 1887, p. 53. 



This is a well characterized genus, though intimately related to Scrobicu- 



