34 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
pressed, pointed and attenuated, the anterior end rounded; hinge with 8 
anterior and 6 very minute posterior teeth, the resilifer subumbonal, 
extremely small. This species has no indication of lunule or escutcheon. 
Length, 4.5; height, 3.5 ; diameter, 2 mm. (Dali.) 
Type in U. S. N. M., No. 111420. Type locality, Station 2923, off 
San Diego, California, in 322 fathoms mud. 
Range. Tillamook Bay, Oregon, to San Diego, California. 
Yoldia sanesia Dali, 1916. 
Proc. U. S. N. M., 52:399. 
Shell small, thin, plump, pale olivaceous, inequilateral, the anterior 
end shorter, the beaks 2.6 mm. behind it; base roundly arcuate, dorsal 
slopes nearly straight, anterior end rounded, posterior end slightly re¬ 
curved, compressed and bluntly rounded; beaks low, inconspicuous, with 
no indications of lunule or escutcheon; hinge with 7 or 8 very minute 
anterior and about 10 posterior teeth, the resilifer subumbonal and minute. 
Length, 6; height, 4; diameter, 2.5 mm. (Dali.) 
Type in U. S. N. M., No. 223578. Type locality, Station 4224, in 
Boca de Quadra, Alaska, in 160 fathoms mud. 
Range. Boca de Quadra, Alaska, to Point Conception, California. 
Yoldia cecinella Dali, 1916. 
Proc. U. S. N. M., 52:399. 
Shell minute, polished, smooth, nearly equilateral, the margins arcuate 
above and below, the anterior end rounded, the posterior more pointed 
and slightly longer; beaks low and inconspicuous, with neither lunule nor 
escutcheon indicated; hinge with 6 or 7 minute teeth on each side of the 
subumbonal, very small resilifer. Length, 5; height, 2.6; diameter, 1.5 
mm. (Dali.) 
Type in U. S. N. M., No. 211424. Type locality, Station 2823, off 
La Paz, Gulf of California, in about 26 fathoms. 
Range. Aleutian Islands to the Gulf of California. 
Yoldia capsa Dali, 1916. 
Proc. U. S. N. M. t 52:400. 
Shell very thin, small, polished, smooth, compressed, the beaks hardly 
rising above the general hinge line; base deeply arcuate, the dorsal margin 
very slightly convex; anterior end rounded, posterior end slightly broader 
and flatter, obscurely pointed toward the dorsal level; beaks slightly an¬ 
terior to the middle line of the shell; hinge with a few very small anterior 
and posterior teeth; the resilifer subumbonal, not projecting. Length, 
4.4; height, 3; diameter, 1.5 mm. (Dali.) 
