166 Cc. D. GILLIES. 
THE SPINE MODE OF CENTROPYXIS ACULEATA, 
! STHIN. | 
By C. D. GILLIES, M.sc., 
Biology Department, University of Queensland, Brisbane. 
With Hight Text Figures. 
[Read before the Royal Society of N.S. Wales, June 5, 1918.] 
Centropyxis aculeata, Stein, is regarded as the most 
variable of the testaceous freshwater Rhizopoda, and as it 
is a common form, it lends itself readily to the study of its 
empirical spine mode. For this purpose material from the 
following localities in Queensland was investigated :— 
Brisbane District—Botanical Gardens, Ironside and 
Gold Creek. 
North Coast—Caloundra, Humundi and Bajool (near 
Rockhampton). 
The various gatherings were preserved in weak formalin, 
and in preparing the tables the spines of both inhabited 
and empty tests were counted. 
1. Brisbane Botanical Gardens. (Lagoon near old bird 
house), Figs. 1 and 2. 
Material from this locality was systematically collected 
about the end of each month from May 1916 to December 
1917, and the gatherings were taken from a constant part 
of the lagoon. Gatherings were also made on 12th May 
and 6th October, 1916. 
(a) 12th May, 1916. 
No. of spines Le 2) 3 4, 3) Cem 
Frequency 3 9 9.5 bo Oyoly gee 
Total frequency 33 Mode 2-3 
(b) ? June, 1916. 
Species too scarce for tabulation. 
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