TRANSACTIONS OF WAGNER 

 636 



TERTIARY FAUNA OF FLORIDA 



blunt angle, this part of the shell being somewhat produced; right valve with 

 twenty-seven less prominent ribs, of which the posterior dozen have the 

 nodules obsolete or absent and those on the anterior ribs somewhat less 

 marked than on the other valve ; cardinal area short, wide, with the beaks 

 incurved over it ; inner margin of the valves sharply fluted ; hinge-teeth 

 slightly larger and more oblique distally, in general nearly vertical, close set, 

 and about thirty-two in number, not obviously divided in the centre. Lon. 

 27, alt. 27, diam. 22 mm.; Ion. of hinge-line 15 mm. 



This is one of those species on the border-line of groups which make it 

 so difficult to divide the Arks into clear-cut sections ; it has the hinge, cardi- 

 nal area, and discrepant sculpture of Cunearca ; the valves are slightly unequal, 

 and it seems most properly assigned to a place in this section. It is obviously 

 a form ancestral to such species as Area Chemnitzi Phil. (A. bicops Orb., + A. 

 antillarum Dunker, fide Kobelt, + A. Orbignyl Kobelt), which is referred to 

 Anoinalocardia (= Anadard] by Ihering, and is found recent in the West 

 Indies. This species, which has been distributed under the (MS. ?) name of 

 A. rhombica Rawson, is also inequivalve, with discrepant sculpture, and prob- 

 ably should be referred to this section. 



From A. Chemnitzi the present species differs by its larger size, more 

 oblique shape, narrower and more numerous ribs. 



Area filicata Guppy from the Eocene beds of Manzanilla, Trinidad, is 

 probably, though much smaller, a precursor of the above-mentioned species. 



Section Scapharca s. s. 

 Scapharca (Scapharca) lienosa Say. 



Area lifnosa Say, Am. Conch., iv., pi. 36, fig. i, 1832 ; Tuomey and Holmes, 1'leioc. 



Fos. S. Car., p. 40, pi. 15, figs. 2, 3, 1855 ; Kmmons, Geol. N. Car., p. 284. fig. 



204, 1858. 



Scapharca lienosa Meek, Smithsonian Checkl. Miocene Fos., p. 6, 1864. 

 Area florid an a Heilprin, Trans. Wagner Inst., i., p. 97, 1887 ; not of Conrad, Am. Journ. 



Conch., v., p. 108, pi. 12, fig. 2, 1869 (as Anomalocaniici) = A. sccticostata Rve., 



Icon., fig. 38, 1844. 



Miocene of York and James River, Virginia, of Wilmington and Duplin 

 County, North Carolina, and of the upper bed at Alum Bluff, Florida; Plio- 

 cene of the Waccamaw District, South Carolina, the Caloosahatchie River, 

 Alligator and Shell Creeks, Florida ; Tuomey, Burns, Willcox, and Ball. Not 

 known in the recent state. 



