23 American East Coast Arcas 23 



Area lignitifera Aldrich 

 Plate V, Figures 3 , 4 



Area {Barbalia) lignitifera Aldrich, Nautilus, vol. 22, p. 75, pi. 5, figs. 6, 7, Dec. 1908. 



"Shell small, thin, extremities rounded, moderately convex, beaks small and flattened; 

 surface marked by many radial riblets crossed by irregularly spaced lines of growth; a 

 depressed area running from beaks to base nearly central; valves smooth internally, but 

 showing faint lines corresponding to some of the riblets. Hinge line long, slightly curved; 

 the hinge carries four close-set teeth anteriorly, next a short vacant space, and then ten 

 to thirteen small teeth, larger and more nearly parallel to the hinge line as they approach 

 the posterior. 



"Lon. 5 mm.; alt. 3 mm. 



"Loc.VLiTY. Six miles east of Thomasville, Ala., Wood's Bluff horizon." — Aldrich, 

 igo8. 



Occurrence. — [Sabine] Eocene of Alabama. — Aldrich. 



Area Aldriehi Dall 



Plate V, Figure 5 



Barbatia (Cucullaria) Aldriehi Dall, Wagner Free lust. Sci., Trans., vol. 3, pt. 4, p. 630, fig. 19, 

 1898. 



"Shell small, elongate, thin, somewhat pointed behind, rounded in front, moderately 

 convex, with low, prosogyrate beaks; cardinal area very narrow and elongated, widest 

 in front of the beaks; stirface evenly sculptured by fine equal, flattish radial riblets, sep- 

 arated by narrower grooves and crossed by irregularly spaced impressed lines; inner mar- 

 gin of the valves smooth or slightly fluted in harmony with the ribs, especially behind ; 

 beaks in the anterior fourth ; hinge-line about two-thirds the length of the shell ; hinge 

 anteriorly with four oblique, rather close-set teeth, separated by a wide gap from the 

 posterior teeth, which are about six in number, smaller proximally, and parallel with the 

 hinge-line. Lon. 8.3, alt. 5, diam. 4 mm. 



"A single specimen of this interesting shell was obtained, adding a new group to the 

 list of Eocene forms found in the Claibornian. The hinge is somewhat like that of Area 

 {Cucullaria) Caillati Deshayes, but wants the central vertical denticles. The form is 

 more like that of A. gracilis, Desh., but wider and more regular." — Dall, 1898. 



Occiirre7icc. — Claiborne sands, Claiborne, Alabama. — Dall. 



Area taeniata Dall 

 Plate V, Figures 6, 7 



Barbatia (Cucutlaria) taeniata Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, p. 631, pi. 25, 

 figs. 1, la, 1898. 



"Shell thin, elongated, arcvtate, mesially compressed, in general inflated; the beaks 

 near the anterior fifth; anterior end rounded, short; posterior higher, produced, and 



