22 
MARINE SHELLS OF WEST COAST OF. NORTH AMERICA 
Tritonalia interfossa atropurpurea Dali, 1919 
Proceedings of the United States National Museum , 56 :334. 
This form resembles clathrata, but is more elongate and much less 
distinctly turreted. The color when fresh is a purplish black, which, 
however, fades in the cabinet to a more or less ruddy brown after 
some years. It was discriminated in manuscript half a century ag-Q by 
Dr. P. P. Carpenter, and has been sent out by that name to collectors, 
but so far as I know has not yet been published. Height, 19; diameter, 
7 mm. (Dali.) 
Type in United States National Museum, No. 155286. Type locality, 
Neah Bay, Washington. 
Range. Neah Bay, Washington, to San Diego, California. 
Tritonalia interfossa beta (Carpenter) Dali, 1919 
Proceedings of the Biological Society of Washington , 32 :250. 
Shell resembling 7. barbarensis Gabb but stouter and without the 
recurved spines at the shoulders; reddish-brown, of more than five whorls, 
the nucleus defective, the whorls somewhat turreted by an angular 
shoulder; axial sculpture of (on the last whorl, six, including the ter¬ 
minal varix; on the penultimate whorl, seven) angular ribs, prominent 
at the shoulder and extending to the canal; these are crossed by about 
fourteen densely imbricate spiral cords, subequal and equally spaced, 
with narrow interspaces; terminal varix heavy. Aperture small, the 
margin continuous, the outer lip with four or five low denticles inter¬ 
nally, the pillar smooth, the canal closed, rather short. Height, 22; 
of last whorl, 16; diameter, 10 mm. (Dali.) 
Type in United States National Museum, No. 46728. Type locality 
Monterey, California. 
Range. Known only from type locality. 
Tritonalia foveolata Hinds, 1843 
Proceedings, Zoological Society of London, 127. Zoology of the Voyage of H.M.S. 
Sulphur, Molluscae; PI. 3, figs. 15, 16. 
Testa fusiformi, crassa multivaricosa, transversim creberrime sulcata, 
amims minimis longitudinalibus foveolata, atro-purpureo pallide bifas- 
a, vanci us septenis simplicibus, postice rotundatis, antice margine 
cuta, apertura ovali, coarctata; labro intus obtuse denticulato; labro in- 
terno producto; canali aperto, subrecurve. (Hinds.) 
. . medium s ' ze ’ ^sifortn; spire elevated; whorls six, angulated, 
S1X ° r seven Prominent, rounded, transverse ribs that rise to the 
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