SEA-FISHERIES LABORATORY. 287 
OIKOPLEURA. 
The common short-bodied Appendicularian of our 
seas which we are calling Ovkopleura dioica presents 
again the same form of distribution-curve throughout the 
year. It is present in every month, but is only abundant 
from April onwards nearly to the end of the year. The 
largest hauls were obtained in May, June and July, and 
again in September and October. The smoothed curve 
taken from the monthly averages shows a rounded 
elevation extending from April to July, and rising to its 
highest point, 6,000 specimens per haul, in June; and 
a second less extensive maximum in September and 
October, rising in September to over 5,500 specimens. 
Some individual hauls were, however, much higher than 
these figures. The two largest are 16,200 on June 24th 
and 14,900 on October 7th. All the above refer to Port 
Erin Bay. The hauls in the open sea outside do not 
materially affect the curve for the year, but the following 
exceptional hauls may be noted :— 
April 14th Off Port St. Mary Coarse and fine nets 14,100 specimens. 


, 15th Station IIL. ..... 3 = 15,650 ‘ 
» 15th As Otter net A = 15,100 
» .Ldth mr Otter net B = 8,300 oy 
» 19th A Coarse and fine nets = 17,600 
CLADOCERA. 
This is, in the main, a summer group in our seas 
represented by the two common neritic forms Evadne 
nordmannt and Podon intermedium. In 1910, both 
ranged from the middle of March to the middle of 
October, rather a wider range than usual. With the 
exception, however, of a remarkable haul of 1,600 
Evadne in the coarse net, at Station I, on April 19th, 
