174 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Equally spirally lirate throughout, lip scarcely sinuous, with about a 
dozen minute internal denticles; purple-black, or chocolate color, without 
and within. Length, 5-6 mm. (Tryon, Manual of Conchology.) 
Small, diamond-shaped, but rounded periphery, spirally threaded. 
(Carpenter.) 
Type in British Museum. Type locality, Santa Barbara, California. 
Range. Monterey to San Pedro, California. 
Mitromorpha aspera Carpenter, 1865 
Journal de Conchyliologie, 13. Tryon, Manual of Conchology, 6; PI. 25, fig. 61. 
Testa parva, tenui rufo-fusca, gracili, angusta, fusiformi, epidermide 
tenui induta; anfra. nucleosis 2 laevibus, vertice contorto; normalibus 
(t. adolescente) 4 elongatis, fenestratis, suturis distinctis; costulis radi- 
antibus circiter 13 angustis, acutis, et costulis spiralibus, in spira 3, an- 
fractu ultimo circiter 10, angustis, acutis, radiantes superantibus, eleganter 
decussata; intersectionibus subnodulosis, interstitiis quadratis; apertura 
elongata, antice effusa; labro postice vix sinuato. Long., .11; long, spir., 
.69; lat., .08 poll. (Carpenter.) 
Elongated, with coarse fenestration. (Carpenter.) 
Spirally lirate and longitudinally closely costulate, the intersections 
forming a roughly asperated surface; reddish-brown. (Tryon, Manual of 
Conchology .) 
Type in British Museum. Type locality, Monterey, California. 
Range. Monterey to San Pedro, California. 
Mitromorpha gracilior Hemphill, 1884 
Tryon, Manual of Conchology, 6: 317; PI. 25, fig. 62. 
Decussation not so deep, so that the surface is smoother, the tubercu- 
lation smaller; sometimes the clathration of the body-whorl is only seen 
on the upper portion, the longitudinal costulae becoming obsolete below. 
Length, 4-5 mm. (Hemphill.) 
Type in Hemphill Collection. Type locality, San Diego, California. 
Range. Forrester Island, Alaska, to San Diego, California. 
Mitromorpha gracilior intermedia Arnold, 1903 
Paleontology of San Pedro, California, 223; PI. 4, fig. 10. 
Shell small, mitre-shaped; apex rounded; whorls six; slightly convex; 
whorls ornamented with about four equidistant, sharp, raised spiral lines, 
and numerous rounded, transverse ridges which are most prominent on 
angle of whorl; ridges obsolete, or nearly so, on body-whorl; suture 
[1741 
