238 QUEENSLAND SPECIES OF ARCELLA, 



Leidy [(2) p. 177], Kofoid [iD p. 100], and Wailes [(3) p. 129], all 

 refer to its scarcity. 



In this paper are presented the results of a preliminary inquir}^ 

 into the seasonal distribution of the four forms met with in 

 Queensland. The various collections examined were preserved 

 in w^eak formalin, and, for identification and counting, an ocular 

 of medium powder, and a 2 3 objective, usually w^ere found suffi- 

 cient. In this investigation, any Arcelln-tes't not containing the 

 organism was rejected. 



Data. 



(1). Brisbane Botanical Gardens. 



These observations, extending from ^^eptember 29th, 1916, to 

 29th December, 1917, have been made by the monthly examina- 

 tion of material from a lagoon near the old Bird-House. Gather- 

 ings were usually taken about the end of each month, but, on 

 6th October, 1916, and 12th September, 1917, supplementary 

 material was obtained, and, to avoid as much as possible the 

 introduction of disturbing factors, the collections were made 

 near the northern extremity of the major axis of the lagoon, 

 which is elliptical in shape. 



(b)6th Oct, 1916. 

 Actual No. 



counted. Pei'centage. 











16 16 



84 84 



100 100 



(d)28th Nov., 1916. 







43 86 



7 14 







Total ... 50 100 50 100 



