208 Auierican Seashelh 



Boreotrophon pacificus Dall Northwest Pacific Trophon 



Figure 46f 



Alaska to off Lower California. 



% 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 



Figure 46a 



Arctic Ocean to Fuca Strait, Washington 



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 



Figure 46b 



Monterey to San Pedro, California. 



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 



Figure 46e 



Alaska to Redondo Beach, California. 



% 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 com- 

 mon from 1 2 to 80 fathoms. 



Genus Trophonopsis Bucquoy, Dautz. and Dollfuss 1882 

 Trophonopsis lastiis Dall Sandpaper Trophon 



Bering Sea to Lower California. 



