of the Fishery Board for Scotland. 
273 
Mid- Water-Net. 
Fird appearance. — 13th February. 
Last appearance. — 5th September. 
Most plentiful. — These were almost the only times in which this form 
appeared. 
Another abundant species both in the open sea and inshore. It is 
interesting to note that in the majority of instances it occurred chiefly in 
the bottom-net, thus apparently showing a certain sensitiveness to 
atmospheric conditions or temperature. 
Acartia longiremis, Lilljeborg. 
Mid-Water-Net. 
Found in the net on 8th March and 5th September. 
Bottom- Tow- Net. 
First appearance. — 23rd June, numerous. 
Last appearance. — 24th November, myriads. 
Most plentiful. — From 24th June to 24th November, numerous or in 
myriads, as a rule, each time. During this period it occurred very 
frequently. 
Surface- Tow- Net. 
First appearance. — 21st January (?) certainly on 21st February. 
Last appearance. — 10th December. 
Most plentiful. — In August, September and October, many or numerous, 
each time, as a rule. Very few of this species were procured in 
May and June, but on the whole it occurred very frequently. 
A most abundant species in St Andrews Bay, where it affects in a 
marked manner the upper and lower regions of the water respectively, 
only once occurring in the mid- water-net — though in large numbers. The 
maximum period both at the surface and bottom seems to be in 
autumn. 
Acartia bifilosus, Giesbrecht. 
First and last appearance in the surface-net on 5th September. 
Halitemora longicornis, O. F. Miiller. 
Mid-Water-Net. 
This form was procured only three or four times. 
Bottom-Tow- Net. 
First appearance. — 8th March. 
Last appearance. — 5th December, in swarms. 
Most plentiful. — From 23rd June to 5th December, numerous (or myriads 
of) specimens procured, as a rule, each time. The occurrence of 
this species was extremely frequent. 
Surface-Tow-Net. 
First appearance. — 8th March. 
Last appearance. — 30th October, many. 
Most plentiful. — In August and September, many, generally, each time. 
Very few in June and July. Not so common in the mid-water-net 
as in the bottom-tow-net. 
This ubiquitous species occurs in profusion throughout the greater 
part of the year, and covers the entire area examined both within and 
without the Bay. Like some of the previous forms it is most abundant 
s 
