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ALASKA GEOLOGY 
GASTROPODA 
Chrysodomus sp. 
Tritonium sp. Grewingk, Beitrag NW. Am., p. 290, 1850. 
Locality. — Popof Island, 3372; Makushin Bay, Unalaska (Gre¬ 
wingk) . 
Very poor casts of a species resembling C. fornicatus Gray were 
obtained. 
Chrysodomus sp. 
Locality. — Popof Island, 3563. 
A slender species with strong spiral ridges resembling C. liratus 
Martyn was obtained, in fragmentary specimens. 
Tritonofusus sp. 
Locality. — Popof Island, 3372, 3563. 
Fragments of a species recalling T. stimpsoni Morch were ob¬ 
tained. 
Volutharpa? sp. 
Locality. — Popof Island, 3372. 
A poor cast of what may be a Volutharpa or a short stout Buc - 
cinum was obtained. 
Buccinum? sp. 
Locality. — Popof Island, 3372. 
A specimen containing in a very tough matrix the five upper whorls 
of what may be a small species of Buccinum was collected. The 
nuclear whorls are smooth, the later ones sharply evenly spirally 
grooved with about three channels to the millimeter, and, on the 
shoulder, a succession of short low nodulous waves axially directed. 
The suture is appressed but distinct. The height of the specimen 
visible is about 8 mm. and the maximum diameter 7 mm. 
Trochita alaskana sp. nov. 
pi. X, figs. 2, 6. 
Shell of moderate size, and about four convex whorls separated by 
a well-defined suture, beneath which they are sometimes a little con¬ 
stricted, but always more or less convex, with the surface obliquely 
and rather irregularly striated; individuals vary in form from quite 
elevated to moderately conical; the periphery of the whorl is at the 
same time the periphery of the base, there being no overhanging 
margin or keel as in Calyptrcza ; base smooth, concave, the umbilical 
region imperforate or covered by the reflexed columellar margin; 
