THE NAUTILUS. 21 
bilicus 3.8 mm.; 44 whorls. Whetstone Range. Most speci- 
mens taken this year are larger than the type lot, collected by 
Ferriss and Daniels in 1914. 
Sonorella insignis, n. sp. The shell is much depressed, rather 
solid, openly umbilicate. Band is broad with pale borders. 
Surface roughened by low wave-like ribs in the direction of 
growth-lines, and microscopic incised lines. Aperture small. 
Peristome very little expanded, blunt. Alt. 9.8, diam. 20.5 
mm.; 44 whorls. Whetstone Range. One of the finest Sono- 
rellas collected in 1919, recalling S. dalli by its depressed form. 
MOLLUSCA OF FORRESTER ISLAND, ALASKA. 
UNIVALVEs (Continued from page 69). 
BY GEORGE WILLETT. 
Tornatina carinata Gld. Tornatina culcitella Gld. Cylichna 
alba Brown. These three species were taken occasionally in the 
dredge, the latter being the most uncommon. 
Dentalium pretiosum Nutt. Very plentiful in 10-40 fathoms. 
Dentalium dalli Pils. A few young specimens secured in 50 
fathoms. 
Inmacina pacifica Dall. Appeared swimming in the water in 
great numbers at times during calm weather. Extensively 
eaten by several species of fish. 
Siphonaria thersites Cpr. Abundant in some localities, mostly 
in short moss growing on the rocks considerably above low tide 
line. 
Crassispira perversa Garb. Dredged occasionally in 40-50 
fathoms. 
Crassispira rotula Dall. More plentiful than the last in about 
same depth. 
Crassispira (Suavodrillia) sp.? A specimen dredged is now in 
National Museum. Stated by Dr. Dall to be undescribed. 
Mangilia oldroydi Arnold. Mangilia eriopis Dall. Mangilia 
crebricostata Cpr. A very few specimens of each of these three 
species were taken in the dredge. 
