204 DR. M‘INTOSH, ON THE CARCINUS M@NAS. 
stomachs it becomesa complete Distoma. Such fishes, again, 
as the Lophius piscatorius, that prey upon their fellows, may 
also become the future hosts of this parasite egg, as the 
following example will show. Two years ago I cut from the 
stomach of a large Lophius, in company with nine Flounders, 
a Cottus bubalis about a foot long, with an abdomen extra- 
ordinarily distended, a state due to the presence of two entire 
specimens of the Carcinus menas, each upwards of two inches 
across the carapace, in its stomach, besides the partly digested 
débris of others. 
In two cases an Ascaris was found amongst masses of liver 
removed from the C. menas, and carefully preserved for in- 
vestigating the former parasite. The first was unfortunately 
lost before a minute examination was made; the second, 
about three quarters of an inch in length, is shown magnified 
by a dissecting lens in fig. 9. It presents the usual ascaroid 
structure, the head, seen x 80 diam. in fig. 10, having 
four short and blunt spikes at the sucker tip, and there being 
a transparent membranous collar a little behind the proboscis. 
The central canal was opaque for the anterior fifth, then 
presented the curiously coiled aspect of a rope with its 
strands, which appearance, however, became indistinct near 
the tail. The posterior dorsal portion of the body of the 
worm curved rapidly downwards, and terminated in a well- 
marked caudal appendix (fig. 11, x 80 diam.). Just in front 
of the little tail was a very distinct rounded body (fig. 11, a), 
with a double outline and granular contents, and there were 
. indications in the same region of one or two others of similar 
formation. There was a small papilliform projection at the 
tip of the tail. The intestinal canal was chiefly filled with 
granules, and there were many oil-globules in the general 
cavity of the body. 
It is possible that this worm, swallowed with fragments of 
a fish, may have perforated the digestive cavity of the crab 
and lodged in the liver ; but appearances were not in favour 
of the supposition in either of the specimens. Besides, were 
this mode of entrance common with such forms, the Tetra- 
rhynchi, Echinorlynchi, and others, would sometimes be found 
elsewhere than simply amongst the débris of fishes in the 
stomach, for instance, of the Cancer pagurus, caught by bait 
in the usual manner. ’ 
