NO. 1264. ILLUSTRATIONS OF AMERICAN SHELLS— BALL. 541 
Section ACTINOTROPHON Ball, 1902. 
BOREOTROPHON ACTINOPHORUS Dall. 
This is Tixrphm actlnop/wriis Dall, lS8i), dredged hy the IT. S. S. 
Ilhihe ojft' Barbados, Santa Cruz, and Martinique, in 14(» to 248 fath- 
oms. It is figured in the Blake report, and with its two whorls of 
channeled spines can not be mistaken for any other species. 
This completes the list of known East American species, which will 
doubtless be enlarged when more dredging is done on our southern 
coasts. 
The northwest coast of America is very rich in species, but the mon- 
ographs of Sowerby and Tryon are so unsatisfactory that they ati'ord 
little help, and confound perfectly discriminable species together. The 
following list is made out from the species in the National Collection, 
where there is preserved an unparalleled series of the group from this 
region. I begin with the species referable to Trophonopsis. 
Section TROPHONOPSIS Dautzenberg. 
BOREOTROPHON TENUISCULPTUS Carpenter. 
This elegant and variable form was described by Carpenter in 1866, 
from the Pleistocene of Santa Barbara, California. It now ranges 
from Estero Bay, near San Luis Obispo, California, northward to the 
Aleutian Islands. It is the Trophoi} xuhseivafus Sowerby, 1880, de- 
scribed from Vancouver. It is found in the north from low water to 
10 fathoms, but the Californian specimen was dredged in 92 fathoms. 
I have not found it west of Unalaska and it is very rare south of 
Cape Mendocino. It has the usual mutations, the whorls either 
rounded, Avith close fine imbricate spiral sculpture, or with a coronated 
angle at the shoulder. The northern specimens are larger and heavier 
than those from the south and less disposed to be spinose, but the 
change, geographically, is gradual. 
BOREOTROPHON SCITULUS Dall.' 
Described in 1891 from specimens dredged off Unalaska, in Bering 
Sea, at a depth of 225 to 309 fathoms. Its range in deep water prob- 
ably extends to San Pedro Channel, California. 
BOREOTROPHON KAMCHATKANUS, new species. 
Shell small, solid, yellowish white, with about five whorls; nucleus 
lost; subsequent whorls with (on the fifth twenty -one) low, rude, rib- 
like varices, crossed b}^ four or five obscure revolving cords, of which 
two are visible behind the sutures; in front of the suture is a sloping 
space somewhat constricted, at the shoulder is a cord, followed b}^ 
others with wider interspaces and toward the canal more feeble; the 
' Figured in Proc. U. S. Nat. Mus. XVII, 1895, pi. xxvii, fig. 5. 
