
442 THE AMERICAN NATURALIST. [VoL. XXXVI. 
pale reddish, rose pink (McIntosh), or bright brick red; posterior 
proboscis chamber very small, rounded; in ordinary states 
of contraction central stylet lies immediately behind brain. 
Basis of central stylet slender, about .025—.03 mm. in length 
by .006—.008 in average diameter. Central stylet about .008— 
012 mm. long, or between one-third and one-half as long as 
basis. In general anatomical features the 
species closely resembles C. epialti, which 
is described in detail below. 
Parasitic on the gills of various species 
of crabs when young, migrating to the egg 
UU BU masses of the crab at the approach of 
ey voril ii toria sexual maturity, the young returning to the 
TUM um gills after a short period of development. 
Distribution: Mediterranean Sea, Bay of Biscay, English 
Channel, on Carcinus manas; both north and south of Cape 
Cod, Mass., on Platyonichus ocellatus; France, Bay of Biscay 
(the same or a closely related species) on Xantho fforidus; 
Mediterranean Sea (possibly the same species), on Galathea 
strigosa. 
Carcinonemertes epialti sp. nov. 
This is a much smaller and less slender species than the above 
when sexually mature, and differs from it in regard to the size 
of the posterior chamber of proboscis, in the stylet apparatus, 
and in many other anatomical details, although the differences, 
as will be described below, are not very considerable. 
In general appearance, in color, arrangement of ocelli, cesoph- 
agus, intestine, and brain the two species are very similar. 
C. epialti also lives when sexually mature among the egg masses 
of a crab — in this case Epialtus productus, the common kelp 
crab of the California coast. 
Upwards of one hundred of these little worms were found 
among the eggs of a single crab at Monterey, Cal., Sept. 3, 
1901. In practically all, the sexual products were nearly mature, 
but no eggs were laid in confinement. The worms lived only 
a few days in a dish of sea water and appeared less hardy than 
the species on the Atlantic coast. I was unable to determine 
