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655 



TERTIARY FAUNA OF FLORIDA 



sulcate in the adult, those on the posterior dorsal slope lower and more rude 

 than those on the body of the shell; the hinge-line is straight, the cardinal 

 area differs from that of A. rustica only by having but a single transverse 

 groove anteriorly between the beaks ; both valves are similarly sculptured, 

 but no adult left valve was collected ; the hinge-line is straight and shorter 

 than the shell ; there are about fifteen anterior and four times as many similar 

 vertical posterior teeth, the proximal ends of the series slightly overlapping; 

 the hinge-line in the specimen figured is forty-six millimetres long, the ver- 

 tical of the beak falls at 8.5 millimetres from the anterior end; inner margins 

 thickened, with short flutings. Lon. 55, alt. 36, diam. 45 mm. 



This fine species appears to be rare, and was found only at Alligator 

 Creek, where two adult right valves, one young pair, and some fragments 

 were obtained. The young has much the outline of A. auricnlata, but is 

 not markedly auriculate. It is proportionately shorter than the adult. The 

 species belongs in the same subordinate group as A. rustica, as shown by the 

 minor characters. 



A single broken valve, probably of this species, is among the material 

 from Shell Creek. 



Scapharca (Anadara) subrostrata Conrad. 

 Area siiliroslnttn Conr. , Proc. Acad. Nat. Sci., vol. i., p. 30, 1841 ; Fos. Med. Tert., p. 



58, pi. 30, fitf. 7, 1845. 



Scii/ihiircii /<-iiniciinf<> Conr., Am. Journ. Conch., v., p. 39, pi. 2, fig. 4, 1869. 

 St'iifi/iiti't'ii subrostrata Conr.. 1'roc. Acad. Nat. Sci. Phila. for 1862, p. 580, 1863. 



Miocene of Maryland in Talbot and Calvert Counties, at Calvert Cliffs, 

 Skipton, Centreville, Plum Point, and other localities; Conrad, Cope, Burns, 

 and Harris. A single valve, stated to be from the Miocene of North Carolina, 

 is in the National Museum. 



This species appears to be rather common. The cardinal area is grooved 

 longitudinally with numerous rather irregular concentric grooves. This is 

 not the A. subrostrata of Sowerby (1847) or f Smith, Quart. Journ. Geol. 

 Soc. Loud., 3, pp. 413, 418, figs. 8, 9. A. callipli'tira Conrad is probably 

 founded on an unusually short specimen of this species. 



Scapharca (Anadara) aresta n. s. 



PLATE 33, KICUKK 2. 



Chesapeake Miocene of Alum Bluff, Calhoun County, Florida; Ball and 

 Burns. 



