download pdf

208 Auierican Seashelh
Boreotrophon pacificus Dall Northwest Pacific Trophon
Alaska to off Lower California.
Figure 46f
% to I inch in length, similar to multicostatiis, with the spire % the
length of the shell, canal twice as long, with 12 to 14 ribs which are shoul-
dered further below the suture. Suture slightly indented. Fairly common at
low tide in Alaska. Occurs in very deep water farther south.
Boreotrophon dalli Kobelt Dall's Trophon
Arctic Ocean to Fuca Strait, Washington
Figure 46a
2 inches in length, spire /4 and canal nearly 34 the length of the shell.
5 whorls globose, crowned at the shoulder with 12 to 20 short spines per
whorl. The ribs over the whorl are moderately to obsoletely developed.
Rare in about 30 to 50 fathoms.
Boreotrophon triangulatus Carpenter Triangular Trophon
Monterey to San Pedro, California.
Figure 46b
Nearly i inch in length, 7 whorls, with 8 delicate axial ribs which bear
rather short erect protuberances on the shoulder. Nuclear whorl smooth,
followed by squarish whorls which bear ribs from suture to suture, and which
are smooth in between. Siphonal canal rather short. Grayish white with
enamel-white aperture. B. peregrimis Dall is the same. Formerly confused
with Forreria (Austrotrophon) cerrosensis cerrosensis and its form, p'mnatiis
Dall, and its subspecies catal'mensis Oldroyd. The latter group has longer
spines, longer siphonal canal and the ribs are only on the periphery of the
early whorls.
Boreotrophon orpheus Gould Orpheus Trophon
Alaska to Redondo Beach, California.
Figure 46e
% to I inch in length, resembling pacificus but with a spire Yi the length
of the shell, and with 3 strong, but small, spiral cords showing in the spire,
but with about the same number and type of axial ribs. It resembles an im-
mature stuarti, but has more and smaller ribs and its whorls are not so sharply
shouldered on top nor so strongly cancellate in the spire. Moderately common
from 1 2 to 80 fathoms.
Genus Trophonopsis Bucquoy, Dautz. and Dollfuss 1882
Trophonopsis lastiis Dall Sandpaper Trophon
Bering Sea to Lower California.