292 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
February, practically absent in March, April, May, 
June, and the greater part of July. A few hundreds 
turned up on July 26th, it ranges up to 3,000 in August, 
50,000 on September 8th, and 30,000 on October 4th. 
After that it diminishes rapidly to about 1,000 on several 
dates in October and November, 5,000 on December 24th, 
some hundreds in January, dying away in tens and units 
in February. The maximum of this species is in 
September, and the minimum in May. 
AcartiA.—A. clausi, although usually regarded as 
an oceanic species, is present in Port Erin Bay in all 
months of the year; it is, however, generally not 
abundant. It is in the thousands from May on to the 
end of the year, but the highest numbers in the bay 
gatherings are only 23,000 on July 18th and 21,000 on 
October 15th. A few hauls in the open sea, however, 
give higher numbers, viz.:—36,200 at Station I on 
April 19th; 30,000 in mid-channel on August 25th; and 
280,410 taken in the shear-net at Station I on 
August 13th. 
These are the six most important species of 
Copepoda numerically, and if arranged in the order of 
their abundance with their totals for the last two years 
they will come as follows :— 
1910. 1909. 
OUERONG SANUS is ay eer se etd ee ee 872,678 465,066 
Pseudocalamius Clongawus..cissscecesacnarcssees 368,326 309,973 
Acar ti@retauss sents cheer eee 340,631 63,373 
POTACOLAWUS PATUUS os dea xosdsceee ss steeaneeees 217,633 54,120 
Temor td: LONGUCOT NAS isnctrnak ben sewn sanaraamtoee es 147,043 62,659 
Calanus helgolandtcus..0.s.c.ccccscensssestseer 15,418 21,412 
With the exception of Calanus, the numbers are all 
larger than in the previous year; but the order is in 
nearly all cases the same. The total in the case of 
Oithona is greatly increased, and far outnumbers all 
the rest. Acartia also shows a notable increase. 
