SHEELS WiIlLHOUT CANALS 229 
Amauropsis purpurea, 
Dall, the Purple Moon- 
shell, Figure 249, has a 
purplish shell, though the 
patches of enamel near the 
aperture are white, while 
the periostracum is olive, 
with darker streaks. It 
reaches a length of two 
inches, and it is found in 
northern waters, as far as 
Point Barrow. 
Fig. 249, x $ (#) Sigarétus débilis, Gld., 
the Frail Sigaretus, has a delicate, pure white 
shell, very flat, with a small spire and a very large 
aperture. The surface is beautifully sculptured by 
fine rays crossing the lines of growth. Its breadth 
is an inch or more, and its home is in the south. 
Eunaticina oldroydii, Dall, Oldroyd’s Natica, 
resembles Figure 247 in shape, but is much thin- 
ner and more delicate, and is marked with almost 
microscopic seulpturing. It has been dredged at 
several places along the California shore, but is 
still a rare species. My specimen from Monterey 
measures 35mm. in height. 
Velutina levigata, Linn., the Light 
Velvet-shell is our next species, and its 
little shell is shown in Figure 250. The 
color is ight brown, and the aperture is — Fis. 250 
nearly circular. In fresh specimens a velvet-like 
epidermis covers the shell. It lives in northern 
waters. 
