38 Marine Shells of the Western Coast of Florida 



ish; inequilateral, moderately thick; umbos well above hinge margin, 

 anterior to middle, rounded and obtuse; anterior margin rounded, 

 posterior margin oblique, hinge and ventral margins parallel; strong 

 posterior rostration; sculpture of lamellate or beaded ribs and growth 

 lines, less prominent over umbos and central area; about eight 

 anterior and twelve posterior teeth; margins finely crenate. 

 Dredged from rough bottom about reefs. 



Genus NOETIA Gray, 1857 



Subgenus EONTIA MacNeil, 1938 



Noetia ponderosa^o (Say) PI. 3, fig. 13 



Alt., 42; length, 60; diam., 36 mm. White, thick, heavy; strong, 

 black epidermis; equivalve; obliquely mequilateral; umbos well 

 separated, incurved; sides of hinge area slope obliquely downward 

 to a straight margin; hinge typical; posterior margin almost 

 straight, carinate; anterior and ventral margins rounded. Thirty-two 

 flattened, radiating ribs and fine, concentric intercostal sculpture 

 which is absent from the umbos. Interior smooth, marginal inden- 

 tations correspond with ribs; strong muscular impressions; simple 

 pallial line; no byssus. 



On sand and gravel bottoms, often about rock reefs. Living 

 Gorgonia often attached to shell. 



Family GLICYMERIDAE 



Genus GLYCYMERIS da Costa, 1778 

 Gljcjmeris-i pectiiiata (Gmelin) PI. 3, figs. 14a, b 



Alt., 21; length, 21; diam., 11 mm. Rounded and ribbed, sug- 

 gesting a fan shape; dull white with irregular brown cross-mark- 

 ings; thin, brownish epidermis; equivalve; equilateral; central, 

 small, pointed umbos; margins rounded; about 24 rounded ribs with 

 narrow interspaces, ribs on anterior and posterior parts of shell much 

 smaller than median ribs; fine reticulate sculpture on umbos of un- 



-° From Noe, Noah, fern., Lat., pondcrosus, a weight. 



2^ Gr., glykys, sweet, with meris, share, part; Lat., pecten, a comb. 



