160 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Type in United States National Museum, No. 110626. Type locality, 
U.S.S. “Albatross” Station 2980, in 603 fathoms. 
Range. Tillamook, Oregon, to Gulf of California. 
Admete woodworthi Dali, 1905 
Nautilus, 18:123. 
Shell small, thin, whitish, with a yellowish-brown periostracum, five 
normal, sculptured, and one smooth, turgid nuclear whorl, gradually in¬ 
creasing, subtabulate by a prominent spiral thread at the shoulder while 
young, rounded at the last whorl, with 8 or 9 obscure riblets on the upper 
part of the spire, which are obsolete on the last whorl and a half; spiral 
sculpture of rounded threads, with wider flattish, somewhat irregular in¬ 
terspaces; periostome continuous with a slight notch or sulcus near the 
end of the nearly straight pillar, and with no umbilicus; there are two 
obscure plaits on the pillar, which is not marked by any umbilical chink 
or fissure; aperture with the external sculpture modifying the margin, but 
no lirations. Lon. of shell, 9; of aperture, 4; max. diam., 4.5 mm. (Dali.) 
Type in United States National Museum. Type locality, Monterey Bay, 
in 10-45 fathoms. 
Range. Monterey Bay, Santa Barbara Islands. 
Family OLIVIDAE 
Genus OLIVELLA Swainson, 1840 
Shell polished, small; spire produced, acute, suture canaliculated; aper¬ 
ture narrow behind, enlarged anteriorly; columella plicated in front; 
callous posteriorly. Operculum horny, thin, half ovate, with apical nucleus. 
Olivella is distinguished from Oliva by the small size of the shell, its more 
produced spire, the presence of a large, thin, horny operculum, and the 
want of eyes. (Tryon, Structural and Systematic Conchology.) 
Type. Olivella undatella Lamarck. 
Distribution. North Carolina, West Indies, West Coast of America, 
Senegal, China, Philippines, Australia, Polynesia. Fossil: Pleistocene, 
Pliocene. 
Olivella biplicata Sowerby, 1825 
Plate 26, figs. 20, 20a 
Tankerville Catalogue, Appendix 33. Tryon, Manual of Conchology, 5; PI. 34, fig. 58. 
Testa ovali, griseo-fulvescente, longitudinaliter substriata, laevi; spira 
subacuminata, sutura, subfusca; columella laevi, superne callosa, ad basim 
biplicata; apertura, columellae basi, cinguloque basali violaceo tinctis. 
Long., 1; lat., 6/10 inc. (Sowerby.) 
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