SEA-FISHERIES LABORATORY. 307 



December, January, February and March, when there 

 were never more than a few hundred in a haul. It is well 

 represented from April to November inclusive, and gets 

 above 3,000 in a haul in April, May, June, July, August 

 and September. The greatest hauls were : — April 13th, 

 4,600; April 19th, 5,600; May 27th, 3,600; June 22nd, 

 3,600; July 3rd, 3,350; July 31st, 3,000; August 2nd, 

 3,000 ; 'August 23rd, 3,350; September 11th, 5,300; 

 September 18th, 7,600; September 25th, 3,500. 



The smoothed curve representing monthly averages 

 shows a rounded elevation extending from April to July, 

 and reaching its highest point, a little over 3,000, in 

 June; a slight fall in August and a higher and much 

 sharper peak in September, reaching a maximum of 

 nearly 5,000. Comparing this with the two previous 

 years, we find that there is ver}^ close agreement with '07, 

 even to such details as the amount of the greatest catch 

 obtained in April, 5,500 per net in '07 and 5,600 in '09. 

 There is, however, the great rise to 7,600 in September 

 this year, which agrees with the September maximum of 

 7,000 in '08. So that, finally, this year combines the 

 maxima of '07 and '08. The winter minimum remains 

 constant for the three years. 



Oceanic and Neritic Species. 



In the tables below the attempt is made to^ determine 

 whether the plankton in Port Erin Bay during the last 

 three years has been more Neritic or more Oceanic in 

 character. We regard as Oceanic species those that 

 typically inhabit the open ocean, although they may also 

 be found in coastal waters, and which have no fixed or 

 resting bottom stages in their life-history, and are, in 

 short, holoplanktonic (Haeckel) Nerilic sjtccies are those 

 typically found in coastal and comparatively shallow 



