22 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
teriorly, interior of the rostrum without a longitudinal septem. Length, 
27.5; height, 10.5; diameter, 4.5 mm. 
Type in U. S. N. M. Type locality, off Point Conception, California. 
Range. Aleutian Islands to San Diego, California. 
Leda gomphoidea Dali, 1916. 
Proc. U. S. N. M., 52:396. 
Shell elongate, inequilateral, smooth, polished, the rostrum obliquely 
rounded-truncate, the anterior side rounded and shorter; beaks small, but 
pustule like, 5 mm. from the anterior end, the prodissoconch distinct; 
teeth small and numerous, about 25 in front of and 35 behind the small 
oblique resilifer; posterior basal and dorsal margins nearly straight, the 
escutcheon narrow, long impressed, and straight. Length, 17.5; height, 8; 
diameter, 4 mm. (Dali.) 
Type in U. S. N. M., No. 212889. Type locality, Station 3346 off 
Tillamook Bay, Oregon, in 786 fathoms. 
Range. Known only from the type locality. 
Leda extenuata Dali, 1897. 
Plate 28, fig. 3. 
Nat. Hist. Soc. Brit. Col. Bull . No. 2:8; pi. 2, fig. 2. 
Shell elongated, arcuate, slender, compressed, of pale olive color, 
with a smooth but not brilliant periostracum; surface sculptured with 
delicate concentric hardly elevated ridges; beaks acute, small, a flat ridge, 
medially depressed, extends from them to the end of the elongated, 
obliquely truncate, rostrum; there is no lunule, but between the rostral 
ridges a depressed smooth space might be regarded as an escutcheon; 
valves very inequilateral, the beaks % 4 of the distance from the anterior 
to the posterior end; interior white, smooth with an elevated ridge un¬ 
equally dividing the rostral channel; chondrophore small directed back¬ 
ward ; hinge plate very narrow, bearing extremely oblique, long, narrow, 
laminar teeth, of which 9 are anterior and 12 posterior. Length, 17; 
height, 6; diameter, 3 mm. (Dali.) 
Type in U. S. N. M. Type locality off Dixon Entrance, British 
Columbia, in 1569 fathoms ooze. 
Range. Alaska to British Columbia. 
Leda spargana Dali, 1916. 
Proc. U. S. N. M., 52:397. 
Shell small, elongate, inequilateral, pale olivaceous, compressed; pro¬ 
dissoconch conspicuous, otherwise the beaks are low, and about 4 mm. 
from the anterior end of the shell; sculpture of low concentric ridges, 
stronger anteriorly, sparser toward the beaks, and obsolete on the dorsal 
