CLASS PELECYPODA 
17 
slope rounded, posterior extreme bluntly pointed; escutcheon large, trans¬ 
versely striate; lunule not differentiated but similarly striate, sculpture 
of fine sharp, concentric grooves with wider interspaces, less arcuate than 
the incremental lines; chondrophore small, triangular, not projecting, with 
22 anterior and 16 posterior hinge teeth on the cardinal border. Length, 
15.5; height, 10.5; diameter, 7.2 mm. 
Type in U. S. N. M. Type locality, Puget Sound, near Port Orchard. 
Range. Puget Sound, Washington. 
Leda navisa Dali, 1916. 
Proc. U. S. N. M. f 52:395. 
Shell elongated, arcuate, inequilateral, with slender recurved rostrum 
and well marked smooth impressed escutcheon but no lunule; base con- 
vexly arcuate, rostrum obliquely truncate, anterior end evenly rounded; 
beaks obscure, 5.5 mm. from the anterior end; sculpture of numerous 
sharp concentric low ridges, with wider flat interspaces, obsolete toward 
the rostrum; anterior teeth about 12, posterior about 20, the resilifer 
minute subumbonal, not projecting; interior chalky, a small medial ridge 
near the end of the rostrum. Length, 16; height, 7; diameter, 5 mm. 
Type in U. S. N. M., No. 208770. Type locality off Farallon Islands, 
California, in 191 fathoms mud. 
Range. Farallon Islands to San Diego, California. 
Leda amiata Dali, 1916. 
Proc. U. S. N. M. t 52:395. 
Shell light olivaceous, elongated, compressed, the posterior dorsal 
margin nearly straight; beaks low, polished, about 3.5 mm. from the 
anterior end, showing the whitish prodissoconch; the smooth surface con¬ 
tinues for a short distance when the sculpture changes to sharply evenly 
lamellose with slightly larger interspaces wider on the rostral area which 
is defined by the angular turn of the lamellae which stop short at the sharp 
margin of the long escutcheon; interior porcellanous, with 12 anterior 
and 16 posterior teeth, the resilifer minute, subumbonal, hardly projecting. 
Length, 11.3; height, 4.5; diameter, 3 mm. (Dali.) 
Type in U. S. N. M., No. 209252. Type locality, Station 4351, off San 
Diego, California, in 488 fathoms mud. 
Range. Known only from the type locality. 
Leda penderi Dali, 1910. 
Plate 39, figs. 4, 5. 
Canada Geol. Surv. Mem. 14N., No. 1143, p. 9, pi. 1, figs. 3, 4. 
Shell small, solid, equivalve, nearly equilateral; the posterior side 
slightly longer, lighter or darker olivaceous in color, tumid, with the 
