6 Distribution of the Smaller Crustacea. _—[Sess. 
several adult males and females, the majority were immature. 
I do not know of a single record of this species from the east 
or south-east coast of England, but Dr Wolfenden has taken it, 
along with other southern forms, in the Faroe Channel. Its 
occasional occurrence in the Moray Firth may therefore be 
owing to the action of currents passing round the north of 
Scotland into the North Sea. I have lately met with what 
looks like a southward extension of the distribution of the 
species on the east of Scotland, several specimens having been 
obtained in a tow-net gathering of crustacea collected off 
Aberdeen on November 11, 1901. This is the first time I 
have met with Hucalanus crassus so far south on the East 
Coast. Hucalanus elongatus (Dana) has also occasionally made 
its appearance in the Moray Firth, as well as another nearly 
allied form—Rhincalanus nasutus, Giesbrecht,—a form which 
I am inclined to regard as identical with Prof. G. H. Brady’s 
Ehincalanus gigas. These probably, like the others, owe. 
their presence in the Moray Firth to the action of oceanic 
currents. 
In a paper in Part IIT. of the Eighteenth Annual Report 
of the Fishery Board for Scotland, I record Coryceus anglicus 
for apparently the first time in the Firth of Clyde. The 
specimens had been obtained in a surface tow-net gathering 
collected on May 29, 1899, in the vicinity of Ailsa Craig. 
At about the time these specimens were obtained near Ailsa 
Craig, Mr I. C. Thompson had been getting the same species 
in abundance off Port Erin, Isle of Man. It is therefore 
probable that these Clyde specimens were stragglers from the 
same swarm that Mr Thompson had met in with, and that this 
swarm had entered the Irish Sea by the North Channel. I 
had once before observed Coryceeus anglicus in Scottish waters 
—viz.,in the Firth of Forth in 1896; and it has more recently 
been captured, but very sparingly, between Lerwick and 
Sumburgh Head, Shetland, in the Moray Firth, and off 
Aberdeen. . 
But besides the occasional introduction of southern species 
within our faunal limits by oceanic currents, other forms 
whose natural habitat is arctic or sub-arctic make their 
appearance at intervals, and sometimes in abundance. These 
are usually found early in the year, and are probably brought 
