46 Palaeontographica Americana 46 



Area lineolata Conrad, Fos. Med. Tert., p. 61, pi. 32, fig. 3, 1845; not of Roeraer. 1836. 



Area siMineolata Orbigny, Prodr. Pal., 3, p. 125. 



Area a-quicostata Conrad, Fos. Med. Tert., p. 60, pi. 31, fig. 6, 1845; Tuomey and Holmes (?), 



Pleioc. Fos. S. Car., p. 44, pi. 16, figs, 3, 4, 1856. 

 Area brevidesma Conrad, Fos. Med. Tert., p. 62, pi. 32. fig. 5, 1845. 

 Scapliarea (Area) plieal lira Conrad, Acad. Nat. Sci. Phila., Proc. for 1862, p. 579, 1863. 

 Seapharea (Scapharea) pliealura Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 643, 644, 



1898. 



"Trapezoidal, ventricose; ribs about 31, rounded, approximate, rough with coarse 

 concentric •minkles; umbonial slope rounded; posterior margin oblique, ciu-ved; basal 

 margin slightly tumid posterior to the middle; posterior extremity acutely rounded; series 

 of cardinal teeth narrow, obsolete about the middle of the hinge line ; within sulcated. 



'.'Loc. Occurs with the preceding species. [Neuse River, Craven co., N. C] 



"The furrows within corresponding to the ribs are very distinct in this species, and 

 the marginal teeth very long and profound posteriorly." — Conrad, 1845- 



"This is a considerably larger species than A. improcera, more rounded and with a 

 tendency to nodulation of the ribs. I am somewhat doubtful if the shell figured by 

 Tuomey and Holmes is to be identified with it. It has a very close resemblance to A. 

 arata Say, and is much larger than any specimens oi plicatura I have seen. The sculp- 

 ture of the two valves m. plicatura is markedly discrepant, which is not the case in im- 

 procera. In this, the former more nearly approaches A. transversa, but the latter has 

 reverted to the rhombical form of improcera. 



"jf. * *This species \_A. transversal has the rounded nodulous ribs and discrepantly 

 sculptured valves of A. plicatura, with the more rhombic form and solidity of A. impro- 

 cera, with both of which it is doubtless genetically connected." — Dall. 



Dimensions. — Lon. +13,-24; alt. +4,-21; diam. 23 mm. 



Occurrence . — Upper Miocene of Duplin County, North Carolina, of the Sumter Dis- 

 trict, South Carolina, and of De Leon Springs, Florida; Pliocene of the Waccamaw beds 

 of South Carolina. — Dall. Pliocene of the Waccamaw beds of South Carolina and the 

 Croatan beds of North Carolina. — C. U. Museum. 



Area subsinuata Conrad 

 Plate X, Figures 2:, 22 



Area subsinuata Conrad, Fos. Med. Tert., p. 62, pi. 32, fig. 6, 1845. 



Scapliarea (Area ) subsinuata Conrad, Acad. Nat. Sci. Phila., Proc. for 1S62, p. 5S0, 1863. 



Scapliarea (Scapliarea) subsinuata Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 645, 1898. 



"Subrhomboidal, inequivalved, slightly sinuous, or subreflected posteriorly; disk 

 flattened; ribs about 34, square, little prominent, narrower than the interstices; concen- 

 tric wrinkles somewhat imbricated; umbonial slope rounded; posterior slope somewhat 

 flattened, not depressed; posterior margin straight, oblique, extremity rounded; basal 

 margin nearly straight; summits prominent, distant; cardinal area with angulated 

 grooves; series of teeth narrow, the teeth fine, interrupted towards the extremities of the 

 series. 



"Loc. Near Newbem, N. C." — Cotirad, 1S45. 



