39 Amkkican Kast Coast Arcas 39 



of the Sopchoppy limestone, and of the Oak Grove sands, Santa Rosa County, Florida. 

 — Dall. Oligocene of Oak Grove and Bailey's Ferry, Florida. — C. U. Museum. 



Area staminata Dall 

 Plate IX, Figures 4, 5, 6 



Scapharca {Scapharca) staminata Dall, Wagner Free Inst. Sci., Trans., vol. 3, pt. 4, pp. 641, 642, 



pi. 31, figs. II, 13, 189S. 

 Scapharca staminata Maury, Bull. Am. Pal., vol. 3, pp. 369, 372, 1902. 



"Shell of moderate size, plump, rhombic, with well-elevated, hardly sulcate, sHghtly 

 prosoccelous beaks, situated in the anterior third of the length; left valve with twentv- 

 eight or twenty-nine radial ribs, the posterior of which are smooth and almost rounded; 

 those on the middle of the valve are squarish, with wider channelled interspaces, and 

 rippled or furnished with transverse nodulation above, which grows stronger and more 

 crowded anteriorly; the ribs are not sulcate or dichotomous, and hardly differ on the 

 two valves; hinge-line straight, rather long, and with conspicuous angles at the ends; 

 anterior end of the valve rounded, base nearly parallel with the hinge-Hne, posterior end 

 somewhat produced; beaks narrow, cardinal area with from three to five sets of lozenge- 

 shaped groovings; hinge strong, the teeth in two adjacent series, somewhat oblique, 

 smaller mesially, at the anterior end of the hinge sometimes more or less broken into 

 granules; inner margin of the valves fluted, interior radially striate. Lon. of a large 

 valve 47, alt. 37 mm.; lon. of figured shell 39, alt. 30, diam. 28 mm, 



"This species differs from A. santarosana, which occurs in the same beds, by its 

 more rhombic form, proportionately longer hinge-line, and unsulcate ribs. It is also a 

 larger and less elegantly sculptured shell. A. staminca Say, of which staminata may 

 prove to be an Oligocene race, has a proportionately longer hinge-line, is more sharply 

 truncate behind, and more obliquely rounded in front, the beaks are less elevated and 

 wider, the ribs anteriorly are only sparsely and feebly nodular, while the aspect of the 

 whole shell is less elegant." — Dall, 1898. 



Ribs twenty-six to thirty. 



Dimensions. — Lon. + i6,-33; alt. +8,-30; diam. 42 mm. 



Occurrence. — Oligocene of the lower bed at Alum Bluff, and perhaps at Roberts, Es- 

 cambia County, Florida. — Dall. Oligocene of the lower bed at Alum Bluff, and Bailey's 

 Ferry, Florida. — C. U. Museum. 



Area staminea Say 



Plate IX, Figures 7, 8, 9, 10, n, 12, 13 



Area <itaniinea Say, Am. Conch., 4, pi. 36, fig. 2, 1832. 



Area elevata Conrad, Fos. Med. Tert., no. i, cover, 1840. 



Area caltiplcura Conrad, Fos. Med. Tert., pp. 54, 56, 59, pi. 29, fig. 2, 18^)0. 



Area triquetra Conrad, Acad. Nat. Sci. Phila., Proc, vol i, p. 305, 1843; Fos. Med. Tert., p. 59, 



pi. 31, fig. 2, 1845. 

 Scapharca {Area) catlipleura Conrad, Acad. Nat. Sci. Pliila., Proc. for 1862, p. 579, 1863. 

 Scapharca (Area) triquetra Conrad, 1. c, p. 580. 



