SEA-FISHERIES LABORATORY. 291 



we shall allude to in the rest of this discussion by their 

 generic names. "We have again made out detailed lists 

 of the occurrences on every occasion in '09, but we do 

 not think it necessary to publish these : a comparison 

 with last year's results will probably suffice. 



Pseudocalanus is again one of the most abundant 

 forms. It is present throughout the year, and is repre- 

 sented in nearly every gathering, and in many months by 

 high numbers, for a Copepod. The greatest numbers 

 caught in single hauls reached over 3,000 on occasions in 

 January, February and March, 7,000 in May, 5,000 in 

 June, 9,200 in July, 19,250 in August, 14,000 in Septem- 

 ber, and 23,200 and 16,900 in October, 8,100 in November 

 and 4,000 in December. These numbers are rather higher 

 than .those of last year and not quite so high as those of 

 '07. .Many of the monthly averages, per net, run into 

 thousands, and for October the number is 8,990. In the 

 earlier part of April it seems to be more abundant in the 

 deeper nets, and later in the month is more on the surface. 



Calanus (see PI. B, fig. 4) is present throughout 

 the year, although in some months only a few individuals 

 were caught at a time. The numbers remain low, for the 

 most part units and tens, during the first four months, 

 and then on May 27th run up suddenly to 1,500. This 

 was probably an exceptional swarm that entered the Bay, 

 as next day the same net caught 95 only. In June the 

 numbers were generally in the hundreds, and twice (18th 

 and 19th) exceeded a thousand. July was much the same, 

 with 1,500 on the 6th and 2,000 on the 21st; August and 

 September showed units and tens and occasional hundreds, 

 while October had 1,800 on the 16th and 4,200 on the 

 18th. The end of the year like the beginning gave low 

 numbers only. This agrees fairly well with previous 

 years, but the increase in early summer is here later than 



