MARINE UNIVALVES 167 
shell, which is almost black, and is wholly 
devoid of the gay trimmings of its rela- 
tives. The columella is ridged by three strong, 
oblique folds, which are very conspicuous. The 
cut represents a small specimen, for dead shells 
are not infrequently found that are fully two 
inches in length, though they are almost always 
somewhat broken. Fresh specimens have a black 
epidermis. 
Mitromorpha aspera, Cpr., the 
Rough Miter-form, Figure 155, is 
really only five millimeters in 
length, but the enlarged picture 
gives the details finely. It has a 
brownish — sur- 
Pace. am dy as 
marked with a 
very distinct 
sieve -like  net- 
Work ote im é 
lines. 
Mitromorpha 
filosa, Cpr., the Threaded Miter- 
form, is shown in Figure 156. 
The little shell is about a quarter 
of an inch in length, and is almost 
black in color. Very distinct 
spiral lines run around it, giving it a threaded 
appearance. 
Fig. 155, x t (*) 
Fig. 156, x T (*) 
