12 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
often nicked or broken. Length, 40; diameter at aperture, 2.6; at apex, 
1 mm. (Tryon and Pilsbry, Manual of Conchology.) 
Type not known to writer. Type locality, Puget Sound. 
Range. Stephens Passage to Panama Bay. 
Dentalium (oerstedtii Morch) numerosum Dali, 1897 
Tryon and Pilsbry, Manual of Conchology, 17:25; PI. 10, figs. 70-73. 
The general proportions and curvature are as in typical D. oerstedtii, 
but the sculpture is less coarse; tertiary riblets soon appear on the concave 
as well as the other sides of tube, and toward the middle a varying number 
of threads of a fourth order are interposed; toward the aperture all sculp¬ 
ture becomes flattened, and the total number of riblets and threads is de¬ 
cidedly greater than in typical oerstedtii. The specimens are glossy. Length, 
41.5; diameter of aperture, 3.5; of apex. 0.6 mm. (Dali.) 
Type in United States National Museum, No. 87559. Type locality, 
Coronado Islands. 
Range. Coronado Islands south to Panama and the Galapagos Islands. 
Dentalium watsoni Sharp and Pilsbry, 1897 
Tryon and Pilsbry, Manual of Conchology, 17:113; PI. 21, fig. 44. 
Shell slightly curved, long, extremely slender, not much tapering, thin, 
white; surface shining, wholly free from longitudinal sculpture, the 
growth-lines fine and inconspicuous. Aperture circular, hardly oblique. 
Anal orifice small and circular, simple; no slit or notch. Length, 31; 
diameter at aperture, 1.6; at apex, 0.75 mm. (Pilsbry and Sharp.) 
As straight as D. rectius Carpenter, but very much more slender. It is 
more curved than the closely allied D. aequatorium from off Ecuador, and 
slightly larger at the aperture. ( Pilsbry.) 
Types in United States National Museum, Nos. 107702 and 107706. 
Type locality, off Tillamook Bay, Oregon, in 786 fathoms. 
Range. Tillamook Bay, Oregon, to San Diego, California. 
Dentalium fisheri (Steams) Pilsbry, 1897 
Tryon and Pilsbry, Manual of Conchology, 17:36; PI. 6, figs. 61-65. 
Shell cylindrical, becoming square toward the apex, not much tapering, 
and nearly as wide at the apex as at the aperture; moderately arcuate; 
comparatively solid and strong. White with riblets, gray, lusterless. Sculp¬ 
ture of four strong angles at and near the apex, where it is square; these 
angles rapidly decreasing in prominence until at the first third of the shell’s 
length the section is almost round. Very near the apex each of the four 
