SEA-FISILERIES LABORATORY. 303 
If we except the three specimens found in the bay on 
June 25th 
there is an interval of fully three months in which no 
and these may also have been stragglers— 
specimens of this species were captured. During this 
period it may be that the last of the 1907 invasion died 
out, and that the numbers that begin-again in August, 
and reach the maximum of 300 on September I11th, 
represent this year’s invasion—which, however, 1s 
obviously much less abundant than in 1907, when the 
maximum reached 2,500, on September 12th in an 
ordinary tow-net attached to the shear net, which may 
probably be treated as equivalent to the “ weight” net 
ranging down to 10 fathoms. 
CLADOCERA IN LIOS. 
Evadne nordmanm first makes its appearance in the 
surface net at Station III on April 11th (a single specimen 
only), in the weight net at Station I on April 13th, and 
in the surface net in the bay on May 26th. It rises to a 
maximum of 12,500 on June 10th, and then rapidly falls 
off, and continues to be represented by very small numbers 
on occasions only throughout July and August. 
Podon intermedium makes its appearance in the bay 
on May 26th with 300 specimens in the surface haul. The 
numbers fall off during June, and remain small in the 
ordinary fine surface nets in July, August and September. 
The only high numbers are when the new net caught 
1,200 at Station III on August 12th, when the Yungel trawl 
caught 2,400 on August 8th and 5,796 on August 18th at 
Station III, and when the coarse net caught 1,500 at 
Station I on September 11th and 1,800 in the bay on 
September 14th. The last occurrence for the year was on 
October 24th. 
