THE SHELL-FISH OF THE COAST. 27 
Natica (Pl. 1, Figs. 1, 4), one of whose best repre- 
sentatives is the common globular shell, of about 
the size of an apple, which is found almost every- 
where along the beach. The natics, with strong 
carnivore propensities, are markedly predaceous in 
their habits, moving about rapidly in their sandy 
homes in quest of food, which they usually find in 
the shell-fish buried at some little depth beneath 
the surface. The making of the larger round holes 
which appear in such perfection on the shells of 
many of the bivalves is commonly attributed to the 
Natica, but the exact amount of guilt attaching to 
this creature has never yet been determined. The 
NATICA EXTENDED. 
Naticas have certain peculiarities of structure which 
it will be well to notice. You will observe, if you 
have succeeded in finding more than the empty 
shell, that the animal is completely retractile, and, 
further, that it has cased itself in by means of a 
horny lid or ‘ operculum,’ which is attached to the 
under surface of the creeping disk or foot. This 
foot is greatly produced in front, where it is re- 
flected back in the form of a hood, covering the 
