SEA-FISHEEIES LABORATORY. 153 



Carnarvon Bay it is only represented twice, being com- 

 mon in September; elsewhere it is commonest in autumn. 

 In the Red Wharf Bay area, as at Stations 5-7, C. inter- 

 medium is the summer and autumn form, and is replaced 

 by C. longipes in winter and early spring. C. tripos 

 occurred in small numbers in some of the Nansen net hauls 

 in July and December, and was present in small numbers 

 in Carnarvon Bay in January. It does not appear in any 

 other gatherings. 



Noctiluca. 



Ostenfeld* states that though no resting stage is 

 known, this organism probably survives unfavourable 

 conditions in an altered state, perhaps at the bottom of 

 the sea. It seems impossible to account for its distribu- 

 tion otherwise. 



This year it appeared first in our records in June, 

 at places so far apart as the north of Cardigan Bay 

 (June 4th) and Nelson Buoy (June 12th), being fairly 

 abundant at both places. 



By July it had spread over most of the district, being 

 present on various dates, often in quantity, in Tremadoc 

 Bay, Carnarvon Bay, Red Wharf Bay, Liverpool Bar, 

 Nelson Buoy, and No. 1 Hydrographic Station. On the 

 29th of this month it was present in enormous quanti- 

 ties, colouring the sea for miles along the north coast of 

 Wales, and round the Liverpool N.W. Lightship. On 

 this day it occurred, for the only time during the year, 

 in the Nansen net samples, at Stations 6 and 7. It never 

 occurred at Station 5 or at Station 14. It was still 

 common in many parts of the district in August, and 



* Cons. Perm. Internat. : Resume des Observations sur le Plankton ; 3me 

 partie, 1913. 



