358 Messrs. T’. and A. Scott on some 
Length of this specimen 1°23 millim. (s'5 of aninch). The an- 
tennules are four-jointed and sparingly setiferous ; a filament 
much longer than the antennule springs from the end of the 
second last joint, and possesses what looks like an articulation 
at about a third of its length from the proximal end, where 
also are two setew-like appendages; the basal joint is larger 
than the others and somewhat dilated, the other three are of 
nearly equal length, but the last is much narrower than the 
two preceding ones (Pl. XVI. fig. 10). The antenne are 
long and slender and three-jointed ; the middle joint is longer 
than either the first or the third, and the third is armed with 
a stout and claw-like terminal spine (Pl. XVI. fig.11). We 
have been unable to make out the mouth-appendages. The 
first and second pairs of feet are fairly well developed ; they 
each consist of a stout one-jointed basal part, which bears a 
short and robust two-jointed branch, and, in the second pair 
at least, what looks like a rudimentary second branch ; in 
both pairs the outer two-jointed branches are each armed with 
two powerful terminal claws, while a stylet-like spine springs 
at nearly right angles from the distal half of the outer margin 
of the first joint. In the first pair the lower part of the basal 
joint is considerably gibbous and produced into a stout tuber- 
culiform process ; in the second pair the basal joint is not so 
much dilated as in the first pair, but is furnished with a 
stout stylet-shaped spine on its inferior aspect (Pl. XVI. 
figs. 12 and 13). This spine may represent a rudimentary 
second branch, as already stated. ‘The third, fourth, and 
fifth pairs of feet appeared to be entirely absent, and no 
ova were observed upon or within any of the specimens 
examined. 
Habitat. On Alcyonium digitatum. Firth of Forth, and 
also in the Moray Firth. 
Remarks. Though this organism has been known to us 
for several years, we have not hitherto observed any descrip- 
tion of it in any of the works on natural history within our 
reach. It seems to be a true though a somewhat abnormal 
Copepod, and also we think there can be no doubt that it is 
parasitic on Alcyonium digttatum. The method usually 
adopted by us for obtaining specimens is to immerse fragments 
or whole specimens of the zoophyte in diluted methylated 
spirit, and, after washing them thoroughly, the residue is 
examined ; by adopting this method we seldom fail in ob- 
taining one or two specimens. ‘The parasite does not, how- 
ever, appear to be very common, and may not be generally 
distributed. 
