1921] Marine Molluscan Shells of Beaufort 131 



Less common than the next (Coues), vice versa J, outer beach. 



This is the American variety of Linne's A. noae. 



Three or four smaller ribs between the large ones. 

 Area umbonata Lamarck. C J 



Figure 56. 



Occasional, outer beach. 



This is the American variety of the European A. imbricata. 



Large and small ribs alternating, somewhat reticulate. 

 Area (Barbatia) reticulata Gmelin. J 



Figure 13. 



Two fragments of posterior portion of valve; inside. 

 Area (Noetia) ponderosa Say. S C A J 



Md. Geo. Sur., Pho. -Pleistocene, pi. 64, figs. 1-6, and figures 51 and 1019. 



Common, inside and out (see Aller). 



Specimens very much elongated posteriorly are rarely met. They approach 

 the ancestral form A. limaula Conrad. I have figured one of these speci- 

 mens, figure 54. (See also Coues.) 

 Area (Scapharca) secticostata Reeve. S C J 



Figures 55 and 119. 



Occasional, outer beach. 



My specimens are worn but do not look fossil. 

 Area {Scapharca) ineongrua Say. S C J 



Figures 52, 53 and 1021. 



The most abundant of the genus, outside. 

 Area (Scapharca) transversa Say. C O A J 



Dall, U. S. Nat. Mus. Bull. 37, pi. 56, fig. 2; and figs. 50 and 076a. 



Fairly common inside. 



Could some of Coues' A. lienosa have been this species? The name has often 

 been applied to A. secticostata. 

 Area (Scapharca) eanipeehiensis Dillwyn. S C A J 



Dall, U. S. Nat. Mus. Bull. 37, pi. 56, fig. 16; and figs. 49 and 181. 



Common, inside. 



Specimens approaching the elongate South Carolina variety A. atnericana 

 (with 35 ribs), are seldom found. 

 Atrina rigida (Dillwyn). S A J 



Arnold, Sea-beach at Ebb-tide, p. 432, fig. 1. 



Uncommon outside, occasional inside. (See also Aller.) 



This is the long-spined form. 

 Atrina serrata (Sowerby). S C? J 



Rogers, Shell Book, p. 410, fig. 1. 



Fairly common on mud flats, commoner outside. 

 Pteria radiata Leach. 



Reeve, Conch. Icon., Avicula, pi. 6, fig. 10; and pi. 7, fig. 14. 



One pair of attached valves, 11 mm. along hinge line. 

 Pteria eximia Reeve. 



Reeve, Conch. Icon., Avicula, pi. 16, fig. 62, and figures 7 and S. 



Common on sea fan (Leptogorgia virgtdata) in shallow water. Found on parts 

 of the sea-fan which are black and bare of zooids, with the long wing di- 



