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TERTIARY FAUNA OF FLORIDA 



is flat and smooth ; in the right valve the keel is less distinct and the escutcheon 

 less smooth, but these features are, nevertheless, distinct. The species has no 

 radial sculpture. Length of shell 24, height 21, diameter 13 mm. 



Chione (Chamelea) spada n. sp. 

 PLATE 55, FIGURE 13. 



Oligocene of the silex beds of Ballast Point, Tampa Bay, Burns, Dall, and 

 Crosby ; and of Bailey's Mill Creek Sink, Florida, L. C. Johnson. 



Shell resembling C. nuciformis but more produced and pointed behind, with 

 a distinct keel bordering the escutcheon, which is flat and smooth in the left 

 valve ; hinge normal, adductor scars subequal, pallial sinus small, angular ; 

 there is usually no radial striation, but the inner margins of both species are 

 minutely crenulate. Length (elongate specimen) 29, height 23, diameter 14 

 mm. ; of a short specimen, length 28, height 24, diameter 16 mm. Some speci- 

 mens reach a length of 33 mm., and one of these shows a few obsolete radial 

 striae on the anterior portion of the disk, but as these appear only on one valve 

 they are probably pathological. Among some fifty other valves no other shows 

 any radial sculpture. 



Chione (Chamelea) rhodia n. sp. 

 PLATE 55, FIGURE 10. 



Oligocene of the Ballast Point silex beds near Tampa, Florida, Dall ; and 

 of the Oak Grove sands, Santa Rosa County, Florida, Burns. 



Shell small, solid, inequilateral, the beaks at the anterior sixth, high, 

 pointed, decurved, over an impressed, cordate, striated lunule of moderate 

 size ; escutcheon elongated, large, smooth in the left valve, bordered by a keel 

 at which the concentric sculpture ceases ; anterior slope short, concave, pos- 

 terior arcuate, both ends bluntly rounded, base evenly arcuate; sculpture of 

 concentric lamellae more elevated on the posterior slope, with wide concentri- 

 cally striated interspaces and no radial sculpture ; hinge well developed, pallial 

 sinus angular, nearly reaching the middle of the shell, adductor scars subequal ; 

 inner margins minutely crenulate. Length 18, height 17, diameter 10 mm. 



Though this species is only represented by a small amount of material, it 

 seems a well-characterized form. 



Genus ANOMALOCARDIA Schumacher. 

 Anomalocardia Schumacher, Essai, pp. 44, 134, 1817; Venus fluctuosa L. ; Gray, P. Z. S., 



1847, p. 183. 

 Triquetre Blainville, Diet. Sci. Nat, x., Tableau, 1818; Malacologie, p. 557, 1825 (not 



