40 THE NAUTILUS. 
he found growing in the mud, standing perpendicular, only about an 
inch being visible at very low tide. They are heavily bearded near 
the edge, partially covered with a light brown epidermis (which is 
several shades lighter than the epidermis of this same species which 
grows in the south), and considerably eroded near the unbones. All 
the shells living in the mud here are somewhat eroded. These mon- 
sters have an uncanny look ; they are hermits when they grow old, 
do not live in clumps or groups as they do when young, or as My- 
tilus edulis does. Often I have seen a solitary M. modiolus upon a 
pile or log, which was entirely covered with M. edulis. They grow 
from ;; inch to 8 inches in a single year. It takes muscle to re- 
move one of the huge creatures from a rock or pile when it has 
fastened itself with brown byssal threads, which it spins with its 
huge tongue-like foot, from a sticky secretion formed at the base of 
the foot. They are said to live six hundred feet deep down in the 
ocean. Pupuras are death on mussels. 
Placunamomia macroschisma Desh. is found here in great num- 
bers. They live upon the under side of rocks which lie wholly in or 
part in water. A chisel is necessary to separate them from the 
rock, and even with this the pear-shaped byssal plug is rarely ob- 
tained entire. The interior of the upper valve is of a lovely sea- 
green and nacreous. The edges of the valves are thin and crumble 
at the least touch, which renders them difficult to clean and send 
away. If they grow upon other shells they are not so easily broken, 
but are much stronger. I have a fine specimen which I found 
growing in an old shell of Cardium corbis Mart. I obtained the 
byssal plug and both valves entire. The shells sometimes grow 
upon each other; when thus found, a perfect specimen is more read- 
ily obtained than from a rock. These shells are often mistaken for 
an oyster, especially by those unlearned in shell lore; they do re- 
semble the variety known as O. expansa, though they are much 
larger and have the byssal opening and plug, which the oyster does 
not have. These bivalves are much handsomer than their southern 
cousins Anomia lampe. ‘The animal is a bright orange, and is quite 
beautiful. To be prepared for the cabinet they are dipped in very 
hot water and the animal removed with a tiny steel chisel prepared 
for the purpose, then gently closed. This shell requires careful 
handling. 
I saw a Lunatia lewisii Gld. eating a Cardium corbis very much 
larger than itself. I stopped this predatory proceeding, took both 
