172 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
cept the plaits) and inside of the outer lip frequently deep brown. Length, 
66.5; width, 23.5; length of body-whorl, 46.5; of aperture, 33.7 mm. 
(Berry.) 
Type in Berry Collection, No. 298. Type locality, off Del Monte, 
Monterey, California, in 12 fathoms. 
Range. Monterey to San Diego, California. 
SECTION THALA H. & A. Adams, 1853 
Mitra solitaria C. B. Adams, 1852 
Panama Shells, 44. Proceedings of the United States National Museum, 13; PI. 15, 
fig. 14, 1890. 
Shell rather slender, fusiform; of a deep blackish-brown, less deep in 
the aperture, and quite pale on the plaits; with very numerous small trans¬ 
verse ribs, which are obsolete anteriorly, and which are granulated by 
revolving striae, that are obsolete in the interspaces posteriorly, and are 
strongly developed anteriorly, with microscopic incremental striae; apex 
acute; whorls ten, moderately convex, slightly shouldered above, with 
moderately impressed suture; aperture long, with a rather short canal; 
labrum thick, with numerous sharp plaits inside, with a sinus near the 
posterior end; columella with four plaits. Length, .69; breadth, .23; length 
of aperture, .24 in. (C. B. Adams.) 
Type in Amherst College. Type locality, Panama. 
Range. Point Loma, California, to Panama. 
Mitra orcutti Dali, 1920 
Nautilus, 33:103. 
Shell small, white, mottled with yellow-brown, with five whorls of 
which the white smooth blunt nucleus comprises one; suture distinct; 
whorls moderately convex; spiral sculpture of (between the sutures four, 
on the last whorl, about a dozen) strong, rounded, close-set cords closely 
undulated behind the periphery by numerous low narrow axial riblets with 
about equal interspaces; the cords in front of the periphery are not un¬ 
dulated, but extend to the end of the canal; there are also very fine axial 
striae in the interspaces; aperture narrow, simple, the pillar with two 
plaits, the canal hardly differentiated. Height of shell, 5.6; of last whorl, 
2.6; diameter, 2.7 mm. (Dali.) 
Type in United States National Museum, No. 334567. Type locality, 
La Jolla, near San Diego, California. 
Range. Known only from type locality. 
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