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bouring families, but having some affinities with the 
Scahbregmide, Opheliidee and Maldanide. 
PARASITES. 
I.—A considerable number of specimens of Arenicola, 
from the Lancashire coast near Blackpool, were found to 
contain small ovoid bodies attached to, or imbedded in, 
the muscles of the anterior region. These proved to be 
Distomid cercariw which had migrated into this position 
and encysted there. Hach is about half a millimetre 
long and a third of a millimetre broad and is surrounded 
by a moderately thick eyst-wall. In each specimen the 
two suckers, the muscular pharynx, the two limbs of the 
intestine, about a dozen flame cells and the rudiments of 
two of the reproductive organs (testes %) may be distin- 
guished. These would remain encysted in <Arenicola 
until the worm was eaten by the final host (probably a 
fish or a bird), in which the cerearia would be liberated 
from the cyst and would grow into a ** fluke.” 
I1.—In other specimens Coccidia are occasionally 
very abundant in the walls of the stomach, intestine and 
nephridia. They are much more common in A. grubia 
than in A. marina. They are spherical or ovoid cells, 
each about 0°14 mm. in diameter when fully grown, with 
a vesicular nucleus containing a large nucleolus. <A few 
eysts, 0'2 to 0°25 in diameter, each containing a few 
thousands of rounded spores (sporozoites) have been met 
with on the outer surface of the gut or attached to the 
muscles of the body wall. Each spore is 3 to 4 in 
diameter, and consists of a thin covering of protoplasm 
enclosing a (comparatively) large nucleus. 
As the lugworm is a common food of fishes (especially 
of flat fish), a knowledge of its parasites is desirable, as 
