174 FAUNISTIC NOTES. 



observers, certain differences present themselves, some striking, others 

 trivial. That considerable and varied changes in the Floating Fauna do 

 take place is suificiently obvious, and they are doubtless strongly 

 influenced by conditions of climate and currents. Garstang (9) briefly 

 deals with the inter-relations of the Plankton ; but very little accurate 

 information on this point is available, and no explanation has yet been 

 given of the periodic appearance and disappearance of certain forms. 

 Thus, Xodiluca is recorded by Bles (1) as superabundant in 1891, scarce 

 in 1892. Browne (7) comments on its abundance in 1893 ; Garstang (9) 

 does not mention it for 1893 or 1894. I have only found a few in- 

 dividuals in December, 1895, a season quite at variance with the notes 

 of other observers. Mvg</icea, in 1895, appeared about the middle of 

 August, as expected from previous notes ; but it remained constantly 

 present, or nearly so, up to the middle of December, two months later 

 than in other years. 



As regards Copepods, I have found Oithona spinirostris and Coryceiis 

 anglicus continuously from August to December, both inclusive, the 

 former in diminishing numbers as the winter approached. Bourne (3) 

 records both these species as occurring in the spring only ; but, in another 

 paper (4), refers to them both as being extremely abundant in the open 

 sea in July. The non-appearance oi Paracalanus parvus (Glaus) is note- 

 worthy. 



With regard to other forms, Browne (7) has dealt in some detail with 

 the more important features of the Plankton for September, and in 

 comparison with a former period, so that there is but little for me to 

 add, nor have I any other definite information of a similar season with 

 which to make comparison. 



Some reference is, perhaps, necessary to the observations of Prof. 

 Mcintosh, at St. Andrews (10). My own scanty notes accord, as far 

 as they go, with his exhaustive record ; but certain ditlerences, probably 

 due to locality, are conspicuous. In winter Ctenophores appear to be 

 abundant, and of maximum size, at St. Andrews, but no trace of them 

 exists at Plymouth. This is only one case in point. 



The Tow-nettings were taken outside, and usually within a few miles 

 of the Breakwater, at various depths from the surface, to about fifteen 

 fathoms, but without any definite system. In this connection it is 

 interesting to note that certain organisms usually rare, and first found 

 in the open waters of the Channel, in the neighbourhood of the Eddy- 

 stone, were this year abundant, and found comparatively close in shore. 

 Tornaria (Bourne, 2) was fairly evenly distributed in the inshore and 

 open-sea areas; i)o/io/w7?i penetrated as far as the Sound; while Muggicea 

 was abundant within it. 



August. — This month is perhaps the best in the year, or, maybe, it 



