1904-5.] Free- Swimming Crustacea of Firth of Clyde. 799 
Among the various Crustacean species observed in 1902, the 
seven just referred to were by far the most numerous, and con- 
stituted almost the whole of the contents of several of the 
gatherings in that year. 
The majority of the other species mentioned in the table are, 
for the most part, demersal in their habits, and this may explain 
to some extent their rare occurrence in the collections. 
Stephos Scotti, G. 0. Sars (No. 4), was only observed in a sample 
collected in January. It was at first ascribed to Stephos gyrans 
(Giesbrecht), but was afterwards shown to be a new species. 
S. Scotti, though not very common, appears to have a fairly wide 
distribution, and is one of the species found in Norway by 
Professor G. 0. Sars.* 
Undinopsis bradyi , G. 0. Sars (No. 5). — This species, which 
occurred on several occasions, may be found in the Clyde at 
nearly all seasons, though usually not very plentiful. It is a 
species that has had various names, i.e., Pseudocalanus armatus , 
Bradyidius armatus, and now Undinopsis bradyi. f 
Fuchceta norvegica (No. 6). — This species was observed in only 
one of the samples under consideration. It is abundant in the 
deep water of Upper Loch Fyne. 
Diaixus hibernicus (A. Scott), (No. 7), was noticed several times 
during the year. It is a deep-water species, and is moderately 
frequent in Upper Loch Fyne. It has been found in other parts 
of the British seas, and is also represented in the marine fauna of 
Norway.! 
Diaixus pygmceus (No. 8) is a smaller species than the last, and 
is also a moderately rare form. It has not yet been recorded 
outside of the British islands. 
Isias clavipes (No. 10) is also a comparatively rare species in the 
Clyde. It was only observed in one or two samples collected late 
in the autumn. 
Metridia lucens, Boeck (No. 12), though observed very sparingly 
in the present collections, is widely and generally distributed 
throughout the British seas. 
* Crustacea of Norway, by G. 0. Sars, vol. iv. p. 63, pi. xliii. (1903). 
t Op. cit., p. 32, pis. xix. and xx. 
+ Op. cit., p. 59, pis. xxxix. and xl. 
