of the Fishery Board for Scotland. 259 
small and apparently two-jointed secondary branch, which is articulated to 
the inner edge of the basal joint ; the basal joint is furnished with three 
strong terminal setz of moderate length, plumose on the distal half.; the 
_ ag branch is armed with a few small terminal spines (Pl. XVII, 
g. 37), : 
The first maxillipedes are small and apparently composed of two joints, 
of which the end-joints are the smallest, each maxillipede is armed with 
two moderately strong terminal claw-like spines, and as they are slightly 
curved inwards, they form, with the end-joint, a moderately powerful hook 
(Pl. XVII, fig. 38). 
The second maxillipedes, which are larger than the first pair, are each 
composed of five joints, the first and second joints are of moderate size but 
the three end ones are small, the terminal claw-like spine is longer than 
the entire length of the three end joints (Pl. XVIIL., fig. 23). 
Lhe thoracic feet_—The first four pairs of thoracic feet are all somewhat 
similar, they are each composed of a stout two-jointed basal part, which 
bears two sub-equal three-jointed branches at its distal end; the outer 
branches are armed on the exterior margin with several small, slender 
spines, while the inner margins of both branches are furnished with 
plumose setz (Pl. XVIIL, figs. 24 and 25). The fifth pair consist each of 
a single uniarticulated lamelliform branch, about three times longer than 
broad ; each branch is provided with six small plumose sete-—one near 
the middle of the inner margin and five arranged round the apex (PI. 
XVIIL,, fig. 26). 
The ovisacs are very large and contain numerous ova. No males have 
yet been observed. 
Halitat.—On the gills of a scarcely full-grown Lobster, captured by 
Mr. H. C. Williamson in Bay of Nigg, near Aberdeen, June 30th, 1900. 
Remarks.—Though Nicothoé astact appears to be moderately frequent 
on the gills of Lobsters captured on various parts of the English coast, I 
do not know of any previous authentic record of its occurrence in Scottish 
waters ; Edward of Banff, who was so successful a collector of Crustacea, 
though he records the common Lobster in his list of Moray Firth species, 
does not appear to have observed the Copepod parasite which is so 
intimately associated with that Crustacean. Mzcothoé astacz is no doubt 
frequently overlooked, and if a careful examination were made of the 
' lobsters captured on our shores the distribution of the parasite in the 
Scottish seas might be found to be co-extensive with its host. 
The Nicothoé seems to be a remarkably sluggish animal. Milne-Edwards 
—quoted by Dr. Baird*—states that ‘‘they allowed themselves to be torn 
to pieces without making the least movement or quitting their hold,” 
and further, that though “ taken carefully off the gills of the lobster with 
all possible precautions not to injure the animals, and placed in a glass of 
sea-water, though watched for several hours, and though they lived during 
that period, as might be seen by the peristaltic movement of the intestine, 
they made no attempt themselves at locomotion.” I may add that my 
son has kept specimens of (Vicothoé alive for five weeks in ordinary sea 
water, which was changed about once a week, and though they were care- 
fully watched during that time he never saw them make any attempt to 
move about, and the only indication that they were alive was the 
persistence of their semi-transparent pinkish colour and the peristaltic 
movement of the alimentary canal. The parasite is usually brightly 
coloured, and, as it is of moderate size, is readily observed in situ when 
that part of the lobster’s carapace which covers the gills is removed. 
* British Entomostraca, p. 304. 
