ON CRUSTACEA. 
277 
food. But when the tide ebbs, it returns with it by swimming, 
because it is then afraid to be left upon the sand, and has no 
further prey to expect. Most generally it swims and walks 
forward ; but should it be seized by any sudden fear, it 
escapes by swimming sideways, and even backwards. During 
the winter it disappears from the coast and retires into the 
depths of the sea. It returns in spring, and the female, in 
consequence of the eggs which she then carries, is very much 
esteemed as food. It is reported that this crustacecum some- 
times issues from the water, to seek its subsistence on the 
strand. A great number of them are taken daily during the 
summer at Charleston. 
“ All the portuni which inhabit our sea,” (the coast of 
Nice) says M. Risso, “live united in society, and each species 
chooses a dwelling conformable to its wants and habits. The 
bimacula tm takes up its sojourn in the region of the cortici- 
ferous polyparia. The puber and plicatus prefer rocks seve- 
ral hundred feet under water. The depuralor delights in 
pebbly plains, always mixing with the columns of little clupete , 
such as the anchovy and pilchard. Another, imperfectly de- 
scribed by Rondelet, whose name it bears, conceals itself 
under the mud. The guttatus inhabits the middle of the 
algae, which grow at a considerable depth ; and the P. longipes 
frequents the holes of the compact limestone which edges the 
coasts. The portuni feed on mollusca and small Crustacea, 
which they break to pieces, and grind by means of the osselets 
of their stomach. Their flesh has not the same taste in all 
the species, and it is only those which live in the rocks that 
are made use of as food ; the others serve as bait for fish. 
“Many of these Crustacea are tormented by little aselottse, 
which insinuate themselves under their corslet, and attach 
themselves upon their gills. The female portuni have many 
births in the year, and deposit each time from four hundred to 
six thousand little globular and transparent eggs, which dis- 
