382 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



OlKOPLEURA. 



In 1913 Oikopleura dioica was represented in all our 

 standard hauls throughout the year. The first record in 

 the thousands was on February 20th- (2,670), and from 

 March 10th to November 7th, the numbers were usually in 

 the thousands. The maximum was 34,000 on July 24th. 

 The September increase was not so great as usual, the 

 largest haul being only 9,200 on the 29th. This record 

 differs from that in 1912, when the greatest hauls were in 

 March and September. 



Various Larvae. 



Echinoderm larvae were unusually abundant in 1913. 

 Absent in January, they appeared suddenly in our nets on 

 February 6th, to the number of 3,040, and attained their 

 maximum of 51,200 as early as February 13th. Other 

 large hauls were 24,080 (February 20th), 17,000 

 (February 27th), 24,360 (March 10th), and 27,150 

 (March 13th). The numbers dropped to zero by the middle 

 of April, but Echinoderm larvae were present occasionally 

 from this time on to the end of October, and on July 17th 

 there was a large haul of 30,000 Twice in September the 

 numbers reached the thousands (7,400 on the 11th, and 

 4,000 on the 18th). 



Polychaet larvae were present in most of our hauls 

 in 1913. The largest number obtained in one standard 

 haul was the very high figure of 115,080 on March 3rd. 

 The next highest records are 32,000 on April 10th, and 

 40,000 on April 15th. 



The "Mitraria" Polychaet larvae, as usual, were 

 absent in summer, began to appear sporadically in autumn, 

 increased during winter and reached their maximum in 

 March (7,200 on March 10th, 5,900 on March 22nd, and 



