106 OUR CARCINOLOGICAL FRIENDS. 
our coast, the two commoner being Lepas anatifera, 
in which the stalks grow to a length of from four 
to six inches, and Lepas fascicularis, in 
which, as the name indicates, a consid- 
erable number of individuals are closely 
bunched together or fasciculated. The 
former species, found on the bottoms of 
Lepas Fascic- ships, is probably not indigenous to the 
ue yegion. It is an erroneous notion, which 
is shared by many, that the barnacles in any way 
injure the holds of vessels to which they may be 
attached. They merely impede navigation through 
the resistance which their enormous numbers offer 
to the water, and hence the necessity of keeping 
vessels clear of their colonies. An effective method 
of removal, frequently practised by sailing-masters, 
is to drive a barnacled vessel into fresh water, where 
the animals soon die and drop off. 
Belonging to the same order of animals as the bar- 
nacles proper are the acorn-shells, those crater-like 
eminences that are found so abun- 
dantly encrusting rocks at about 
high-water mark, and scarcely less 
abundantly on the surfaces of shells, 
drift-wood, ete. They have the same 
general structure as the goose bar- 
nacle, but are devoid of the stalk or peduncle, and 
are hence known as ‘sessile’ barnacles. Where 
attached to a rock they leave a peculiar circular 
stamp of lime, which is not infrequently taken for 
a coral impression. 
The shell of the acorn is usually conical in out- 
ACORN-SHELL (Bal- 
anus balanoides). 
