SEA-FISHERIES LABORATORY. 107 



total of twenty-six. In June, although the species present 

 had fallen to nineteen, the number noted was high, and 

 the bulk of the plant life consisted of Eucampia and 

 Rhizosolenia. In August and September the Diatoms 

 continued to be very abundant and the species represented 

 were nearly as numerous as in May. In October there 

 was a marked decrease in numbers and the species had 

 fallen to twenty. An apparent recovery was found to 

 have taken place in November, and the number of 

 Diatoms taken in the three hauls was fully twice that 

 found in the three hauls for October. During October 

 and November there were more Diatoms in the vicinity of 

 Walney than at the other two stations, and the central 

 region contained the least. It will be noted that the hauls 

 taken in October yielded 3J, 17 and 5 cubic centimetres 

 of organisms respectively, yet the numbers of Diatoms 

 were completely inverted, as the following figures show : 

 (3J) 24*300; (17) 7*450; (5) 12700. 



Species of Ceratium were present in eight out of the 

 nine monthly hauls. They appeared to be entirely absent 

 in the whole area in January and at Station I in 

 February. It will be noticed from the tables that from 

 the month of June to the end of the series, these organisms 

 were more abundant at Station I than at either the second 

 or third. It is evident that there is a distinct maximum 

 period in August. Specimens of Peridinium were much 

 scarcer than those of Ceratium, and apparently reached 

 their maximum point a little earlier in the year. 



Noctilnca has been recorded in our reports for some 

 years as occurring in large numbers along the North 

 Wales and Lancashire coasts during the summer and 

 autumn months. 



The specimens found in the hauls for January, 

 February and March were probably survivors from the 



