of the Fishery Board for Scotland. 
275 
Oitkona spinifrons, Boeck. 
Bottom-Tow-Net. 
First appearance. — 18th July, a few. 
Last appearance. — 11th October. 
Most plentiful. — From 18th July to 11th October, many specimens, as 
a rule, each time. This form was not very common. 
Surface-Tow-Net. 
Only found in this net on the following dates : — 31st July, 31st 
August, 26th September, and 15th October, a very few each time. 
Oithona spinifrons was procured most abundantly in the bottom-tow- 
net, and while it extended from July to September yet attained 
its maximum in the former month. Its frequency in the bottom-net is 
interesting, for Prof. Brady observes 'so far as I know it haunts exclu- 
sively the surface of the sea, being taken only in the towing-net.' * The 
species has a wide distribution round the British si * ores and the North Sea 
generally. 
Thalestris rufocincta, Norman. 
A single example occurred in the bottom tow-net on 15th September. 
Gyclopina littoralis, Brady. 
First appearance. — 19th July. 
Last appearance. — 22nd August. 
It was captured only thrice, and always in the bottom-net. 
Dactylopus tisboides, Claus. 
In the bottom-tow-net, E.S.E. of Bell Rock, 9th August. It has not 
yet been observed within the limits of the Bay. 
Cladocera. 
Pleopis polyphemoides, Leuckart. 
First appearance. — 14th July. 
Last appearance. — 3 1st July. 
It was captured thrice, and only in the bottom-net. 
Evadne nordmanni, Loven. 
This form only occasionally appeared in the bottom-tow-nets in March 
April, and May, but it was otherwise in June and July, since it then 
became much more abundant, though less so in the surface-nets than 
in former years in the latter month (July). It occurred in August and 
September in both bottom- and surface-nets, more frequently in the latter 
than the former. The brood-pouches of the females were still in full 
activity. During October it was present only once or twice respectively 
in the bottom- and surface-nets. None were observed in the surface-nets 
in November and December, and none in the bottom-net in the former 
month. A single example, however, was captured in the bottom-net on 
the 5th December. 
The abundance of this species considerably augments the food of the 
post-larval fishes. 
Parasita. 
Caligus rapax, M. Edw. 
Mid- Water- Net. 
First appearance. — 11th March. 
* Op. cit. p. 91, 
