144 AMERICAN JOURNAL 



AMPHIDESMID^S. 



Genus SEMELE, Schumacher. 

 Semele, Schum., Essai. pp. 53, 165, 1817. 

 Amphidesma, Lain., Hist. An. s. Vert. v. p. 489, 1818. 

 Semele rubrolineata, Conrad. 



&'. rubrolineata, Conr., Journ. Phil. Acad. Sci., vii, p. 239, 

 pi. xviii, f. 11, 1837. 



S. simplex, Ad. and Rve., Moll. Samarang, p. 81, pi. xxiv, 

 f. 11, 1850. Rve., Conch. Icon., sp. 53, teste Conrad. 



Not S. rubrolineata of California authors. 



The shell which, is above identified by Mr. Conrad and Geo. 

 W. Tryon, Jr., in the catalogue of Tellinidce, Am. Journ. Conch., 

 iv, appendix, p. 122, is not the shell latterly known under that 

 name by California naturalists, which appears, as follows, to be 

 undescribed. 



Semele rubropicta, n. s. 



Shell usually pure white and brilliantly polished within, but 

 occasionally with a faint yellowish or pinkish flush when very 

 deeply colored externally. Inner margin, except on the hinge- 

 line, always pure white. Outside, covered with a thin yellowish 

 green or olive, epidermis usually wanting, color yellowish white, 

 with rose-pink and pure white rays, color stronger on the lines 

 of growth. Sculpture consisting of incised lines radiating from 

 the umbones where they become obsolete ; crossed by rounded, 

 smooth, concentric ridges rather sharply defined by concentric 

 grooves. These ridges are usually regular but sometimes bi- 

 furcating. In perfect specimens the radiating lines and grooves 

 are so sharp that their intersections appear as if punctured. 

 Ligament pit deep and excavated, cardinal and lateral teeth 

 moderate. Anterior end much produced, rounded, margin 

 rounded below, posterior end very short, almost truncated ; 

 shell rather inflated. Lunule deeply impressed, narrow, lanceo- 

 late, short. General form subquadrate. Umbones inconspicu- 

 ous, usually tinged with yellow. Hinge-line below the lunule 

 with a purple spot. Interior marked with extremely faint radia- 

 ting lines. Posterior portion of the inferior margin produced. 

 Shell thick and solid. Alt. 1-35 in. Lon. 1-55 in. Diam. -7 

 in. Lunule "24 in. 



Habitat. Beach at Soquel, Monterey Bay, two or three 

 valves, Dall ; San Pedro, Cooper ; Neah Bay, one worn valve, 

 Swan. 



