210 WEST AMERICAN SHELES 
We have two other species somewhat 
resembling the Cowries. The first is 
named Hrato vitellina, Hds., the Veally 
Erato, Figure 225. The shell is pear- 
shaped, or rather, balloon-shaped, and 
is quite smooth. It is of a dark reddish- 
brown color, though the toothed margin of the 
aperture is white. The ordinary length of the shell 
is about half an inch. Specimens are not nu- 
merous. 
Erato columbélla, Mke., the Dove Erato, ‘) 
Figure 226, is very small and delicate, but 
well worth searching for. As shown in the 
figure, it has a visible, but short spire, and Fiz. 226 
a long aperture with toothed lips. These are 
white, but the back is olive-brown. Dead shells 
may be rather frequently found, but living speci- 
mens have been dredged from considerable depths. 
Cerithiopsis tuberculata, Mont., the 
Tubercled Horn-shell, Figure 227, has a 
small shell, about the length of the cross 
shown in the figure. The spire consists of 
six or seven whorls, well sculptured, and of 
a dark brown color, and the sutures are conspicu- 
ous. There are several other small specimens of 
this genus, all of which will be mentioned in the 
List. 
Bittium filosum, Gld., the threaded Bit- 
tium, Figure 228. This fine little mollusk 
may often be found at low tide, by turning 
over stones and searching carefully for lit- 
tle shells. Tiny hermit-crabs are liable to 
Fig. 227 
Fig. 228 
