216 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



(1) Their 28 gatherings in one year did not show the 

 organism to be present. 



(2) Our 650 gatherings in one year showed that it was 

 present during eleven months, and was fairly abundant 

 (up to 7,753 per haul) during most of the year. 



In the following list we have separated the records of 

 Ceratium tripos within Port Erin Bay from those taken 

 in the open sea, and we give a curve for each locality 

 (fig. 7). In most cases where hauls were taken in both 

 places at the same time a larger number of individuals 

 occurred within the bay ; but on the other hand the 

 largest number collected (7,753, on September 12th) was 

 in a haul from the open sea. 



Distribution of Ceratium tripos, per net 

 throughout the year: — 





Bay. 



Open Sea. 







Bay. 



Open Sea 



Jan. 18 .. 



100 . 



— 



June 1 



. 1,500 . 



— 



Feb. 5 .. 



900 . 



— . 





15 .. 



300 . 



— 



22 .. 



750 . 



— 





27 .. 



. 2,000 . 



— 



26 .. 



300 . 



— 



July 



5 .. 



375 . 



— 



Mar. 26 .. 



500 . 



— . 





12 .. 



. 2,500 . 



— 



29 .. 



3,000 . 



1,000 





17 .. 



. 4,375 . 



— 



April 1 . . 



— . 



1,900 





31 .. 



. 2,750 . 



— 



2 .. 



— . 



2,000 



Aug 



10 .. 



. 1,000 . 



— 



4 .. 



— . 



550 





12 .. 



. 2,000 . 



— 



5 .. 



— . 



1,622 





13 .. 



. 2,000 . 



— 



6 .. 



500 . 



— 





14 .. 



. 1,000 . 



— . 



8 .. 



— . 



590 





15 .. 



. 1,000 . 



— 



9 .. 



2,750 . 



1,119 





16 .. 



500 . 



— 



10 .. 



1,850 . 



1,310 





17 .. 



100 . 



— 



11 .. 



— . 



1,125 





19 .. 



375 . 



— 



13 .. 



3,000 . 



300 





20 .. 



500 . 



— 



15 .. 



300 . 



633 





21 .. 



37 . 



725 



16 .. 



1,000 . 



709 





22 .. 



800 . 



— 



17 .. 



3,000 . 



— 





23 .. 



325 . 



142 



18 .. 



2,000 . 



469 





24 .. 



— . 



147 



19 .. 



— . 



792 





26 .. 



— . 



75 



22 .. 



2,000 . 



188 





27 .. 



— . 



383 



23 .. 



1,000 .. 



250 





28 .. 



400 . 



716 



24 .. 



750 .. 



1,049 





29 .. 



— . 



98 



25 .. 



250 . 



412 





30 .. 



300 



— 



26 .. 



250 .. 



529 





31 .. 



150 . 



375 



27 .. 



1,125 . 



659 



Sept 



2 .. 



— . 



290 



May 8 .. 



1,000 . 



— 





3 .. 



. 2,200 . 



1,028 



18 .. 



1,750 . 



— 





4 .. 



— . 



289 



24 .. 



2,000 . 



— 





5 .. 



50 . 



— 



