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1033 



TERTIARY FAUNA OF FLORIDA 



faint radiations near the adductors, but no thickened ray appears. Lon. 12.5, 

 alt. 8, diatn. 4 mm. 



There is some little difference in the proportional height in different indi- 

 viduals, in the amount of inflation, and in the arcuation of the posterior dorsal 

 margin ; the posterior fold, or ridge bounding the posterior dorsal area, is 

 not strongly marked. Compared with T. tenclla Verrill, this species is a 

 heavier and higher shell, with the posterior end more pointed and decurved. 

 The dorsal margin of the right valve is not grooved in T. tenella, and the 

 adjacent lateral is longer than in T. dupliniana of the same size. 



Tellina (Angulus) umbra n. sp. 

 PLATE 46, FIGURE 13. 



Upper Miocene of North Carolina, at Wilmington, and in Duplin County, 

 at the Natural Well, and Magnolia ; and of St. Mary's, Maryland ; Pliocene of 

 the Waccamaw district, South Carolina, at Mrs. Guion's marl-pit, and of the 

 Caloosahatchie River, Florida ; Pleistocene of North Creek, Osprey, Florida. 



Shell small, solid, markedly flexuous, moderately convex, inequilateral, 

 nearly equivalve ; anterior end longer, rounded ; posterior end shorter, attenu- 

 ated, bluntly pointed ; beaks inconspicuous ; whole surface covered with close- 

 set, regular, even, concentric threads ; hinge normal, right anterior lateral 

 short and stout, posterior lateral small but prominent; pallial sinus long, 

 slightly convex above, reaching to the anterior ray (which is obviously thick- 

 ened), nearly similar in both valves, and wholly confluent below. Lon. 12.5, 

 alt. 6.5, diam. 3.5 mm. 



This species is nearest to T. sybaritica Ball, but is a larger and less slender 

 shell, with a less. angular posterior end. It is doubtless the precursor of that 

 species. 



Tellina (Angulus) propetenella n. sp. 

 PLATE 46, FIGURE 6. 



Upper Miocene of York River, Virginia, and Wilmington, North Caro- 

 lina ; Pliocene of the Caloosahatchie River, Florida, and of the Waccamaw 

 beds at Tilly's Lake, South Carolina. 



Shell small, solid, hardly convex, subequivalve, inequilateral, with rather 

 high beaks at about the posterior third; dorsal slopes rectilinear; anterior 

 end rounded, posterior bluntly pointed, hardly flexed, with the umbo-basal 

 ridge hardly marked ; posterior angle nearly basal with the basal margin 

 slightly incurved in front of it; surface with irregular, feeble, concentric in- 



