292 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Guinardia.^— The numbers for 1914 are lower than 

 usual, the maximum being only 1,740,000 on June 11th. 

 This year agrees with every other recorded year in having 

 the Guinardia maximum in June. The highest numbers 

 for the autumn were only 8,400 on October 12th, and 

 8,500 on the 18th. 



Lauderia. — -The maximum of this genus has been 

 sometimes in April and sometimes in May. This year it 

 was in the latter month, with 3,600,000 on May 4th, and 

 the high monthly average of 831,800. Absent after 

 June 1st until September 28th, the numbers then rose 

 again to 88,000 on October 15th, and fell to zero by 

 November 19th. 



We give here, for comparison with those published 

 in other years, the table showing the monthly averages of 

 the above seven genera of Diatoms. 



1914. 



Biddul- 



Chaeto- 



Coscino- 



Rhizoso- 



Thalassi- 



Guin- 



Laud- 





phia. 



ceras. 



discus. 



lenia. 



osira. 



ardia. 



eria. 



Jan. ... 



10,075 



8,195 



7,397 



55 



2 



132 



69 



Feb. ... 



22,233 



36,124 



8,257 



7 







560 



9 



Mar. ... 



45,100 



625,606 



49,839 



2,642 



2,969 



4,331 



162 



April... 



9,972 



2,355,146 



329,406 



93,167 



8,114 



55,100 



373,193 



May ... 



2,652 



20,832,575 



17,285 



417,112 



108,131 



89,762 



831,800 



June ... 



26 



15,731 



430 



2,013,916 







333,356 



378 



July ... 



26 



15,085 



42 



1,240,334 







3,996 







Aug. ... 



6 



374 























Sept. ... 



85 



206,032 



25 















12 



Oct. ... 



26,140 



820,602 



38,002 



1,638 



3,329 



3,113 



12,579 



Nov. ... 



406,100 



110,187 



37,292 



420 



217 



3,462 



275 



Dec. ... 



33,000 



29,500 



8,584 



17 







10 







The increase and diminution of the several forms, 

 month by month, is shown almost as clearly as it would 

 be by a curve. 



DlNOFLAGELLATA . 



The monthly averages for Ceratium and Peridinium 

 in 1914 were as follows : — 



