212 NEW- YORK FAUNA — MOLLUSCA. 



(EXTRA-LIMITAL.) 



D. variabilis. (Say, 1. c. Vol. 2, p. 305.) Shell triangular : anterior margin obliquely truncated, 

 cordate; suture a little convex; posterior hinge-margin nearly straight ; base a little prominent be- 

 yond a regular curve near the middle. Valves striated longitudinally with scarcely visible parallel 

 impressed lines; basal edge crenate. Length, 0-5; width 0'9. Georgia and Florida. 



D. elevata? (Haldeman, Monog. Lymn.) Shell orbicular; cardinal tooth prominent; lamellar 

 tooth thick ; beaks elevated. CoZor, brownish olive. Length, 0-55; height, 0*5. New-Orleans. 



Genus Capsa, Brug. Shell transverse, equivalve. Valves approximated and close ; right valve with 

 three primary teeth ; a small bifid tooth in the left valve, inserted into a cavity in the opposite 

 one ; no lateral teeth : ligament external. 



C. Icevigata. (Conrad, Conch, pi. 17. Pl. 25, fig. 260 of this book.) Shell oblong, trigonal, con- 

 vex, with minute radiating stris : posterior side compressed; lateral margin flattened; beaks pro- 

 minent. Color : epidermis pale olive ; beaks violaceous ; interior bluish white. Transverse axis, 

 2*2; vertical ditto, 1-5. Florida. 



C. deflorata. (Id. 1. c. p. 70, pl. 17, fig. 1.) Shell small, ovate-oblong, convex, with numerous 

 rugose radiating striae, strongest on the posterior margin, where they are somewhat tuberculated. 

 Color, variable, but generally violaceous, with broad yellowish rays. Florida. 



GENUS SANGUINOLARIA. Lamarck. 



Animal unknown. Shell equivalve, inequilateral, subovate, compressed, rounded anteriorly, 

 subrostrate posteriorly, slightly gaping at the sides. Hinge-margin with two small cardi- 

 nal approximated teeth in each valve : palleal impression with a deep sinus. 



Sanguinolaria fusca. 



PLATE XXXU. FIG. 304. 



(STATE COLLECTION.) 



Psammobia fusca. Say, Jour. Acad. Nat. Sciences, Vol.5, p. 219. 

 P. id. RussEL, Essex Jour. Nat. Hist. Vol. 1, p. 54. 



Sanguinolaria fusca. Conrad, Am. Mar. Conch, p. 34, pl. 7, fig. I. 

 jS. id. Gould, Invertebrata of Mass. p. C6, fig. 42. 



Description. Shell thin and fragile, ovate-orbicular ; beaks small almost central. Surface 

 with concentric wrinkles : anterior margin more narrowed than the posterior, with a slight 

 and obtuse fold passing over the anterior submargin. Teeth slightly diverging, very slender ; 

 the largest grooved. 



Color. Epidermis dusky ; beneath which, brownish tinged with red. 



Vertical axis, 0"8; transverse ditto, I'O. Diameter, 0-3. 



