FREE INSTITUTE OF SCIENCE 



oi c; 



TERTIARY FAUNA OF FLORIDA 



Ervilia triangularis n. s. 



1'l.ATK 3J, FlCURK 19. 



Oligocene of the Chipola beds, at McClcllan's marl bed. 



Shell small, solid, plump, subtriangular, inequilateral, with steep, nearly 

 straight, dorsal slopes and an evenly arched base ; surface smooth or marked 

 only by rather irregular incremental lines; pallial sinus rounded, falling a little 

 short of the vertical from the beaks; umbones low, calyculate; hinge strong, 

 with the cardinal teeth prominent, and the marginal grooves in the right valve 

 to receive the dorsal edges of the opposite valve long and well marked. 

 Lon. 5.5, alt. 4, cliam. 2.5 mm. 



This form may prove to be an extreme variety of E. cliipolana, but the 

 specimens so far collected are distinguished by their smoother surface, much 

 more triangular form, and more inequilateral shell. It seems to be compara- 

 tively rare in the marl, and further study is required to settle its systematic 

 value. 



Ervilia lata n. s. 

 PI.YIK 33, KICURK 20. 



Newer Miocene of the Natural Well and at Magnolia, Duplin County, 

 North Carolina, Burns ; and of Walton County, Florida, L. C. Johnson. 



Small, very similar to E. conccntrica, from which it differs by being 

 broader between the beak and the basal margin, with the beaks slightly 

 more equilateral and the dorsal margin behind the umbo usually more im- 

 pressed ; the surface is usually covered with concentric ridges, which are 

 flattened and coarser and less regular than those of E. conccntrica; the 

 hinge-teeth also are less strong than the latter species. Lon. 4.5 ; alt. 3.5 ; 

 diam. 2.2 mm. 



This form on casual inspection would be referred to E. conccntrica as a 

 mere variety, but when a large number of specimens are examined and the 

 characters above mentioned seem to be fairly constant, I believe it is best to 

 recognize the average differences by a name, than to overlook them by con- 

 solidation with what I regard as probably a distinct species. The Floridian 

 specimens are particularly triangular and small. 



Ervilia planata n. s. 



Oligocene sand (Alum Bluff beds) of Oak Grove, Yellow River, Santa 

 Rosa County, Florida ; F. Burns. 



Shell small, subtriangular, flattened, smooth or obscurely concentrically 



23 



