10 MR. B. M. GRIFFITHS ON THE 
8. CRUCIGENIA MINIMA (Fitschen), Brunnthaler. (Pl. 1. fig. 12.) 
This minute species also oceurred in very small numbers in Whiteknights 
Pool. It resembles Tetrastrum staurogenieforme, but differs from it in the 
complete absence of spines and the smaller size and the looser arrangement 
of the cells. It has not been recorded previously for this country. 
9, RADIOFILUM CONJUNCTIVUM, Schmidle. (PI. 1. fig. 10.) 
The alga was found in small quantities in Bulmershe South Pool. The 
mucous investment is exceedingly delicate and transparent. The median 
transverse lines of the cell are distinctly seen. Colonics consisting of as 
many as fifty cells oceur, but in most cases the number is about half that. 
The alga has been recorded for the South of Europe and for Australia, but it 
has not previously been found in this country. 
10. Ceratium HinvNDINELLA (O. F. Müller), Schrank. 
Each of the pools had its own form of this very variable species. The 
three-horned form occurred in Bulmershe North Pool and in Whiteknights, 
but the two forms were not absolutely identical. In Bulmershe South Pool 
the two-horned form was found. In each case the particular form was 
present without any intermixture with the other. 
In conclusion, I wish to thank Mr. J. Rushbrook of Bulmershe Court for 
his kind permission to collect from Bulmershe Pools, and Mr. Guy Hargreaves 
of Whiteknights Park, and Mr. Hearst of Foxhill for permission to collect 
from Whiteknights Pool. I should like also to thank Mr, L. Sutton and 
Mr. M. H. F. Sutton for their help regarding the latter pool. 
Department of Botany, May, 1921. 
Armstrong College, 
University of Durham, 
LITERATURE QUOTED. 
GRIFFITHS, D. M. 1912,—Alge of Stanklin Pool, Wores. Proc. Birmingham Nat. Hist. & 
Phil. Soc. vol. xii. No. 5. 
1916.— August Heleoplankton of North Worcestershire Pools. Journ. 
Linn. Soc., Bot. vol. xliii. pp. 423-432. 
Grove, W. B., and others. 1920.—Flagellates and Alge of Birmingham District, by 
W. B. Grove, M. Bristol, and N. Carter. Journ. Bot., lviii. 
Suppl. III. pp. 1-5. 
SMITH, G. M.  1920.—Phytoplankton of Inland Lakes of Wisconsin. Part 1. Wisconsin 
Geol, & Nat. Hist. Survey, Bulletin No. 57. 
WESENBURG-LUND, C. J. 1908.—Plankton of Danish Lakes. Copenhagen. 
” 
