177 
Rhizophidium acuforme (Zopf) Fisch. 
72. Ray, J. Methodus Plantarum. London, 1682. 
73. ,, ,, Historia Plantarum. London, 1686. 
74. Richard, L. C. in “ Catalogue des Plantes du Jardin medicinal de Paris,” 
by F. Marthe, 1801. 
75. Rivini, A. Q. Ordines Plantarum. Leipzig, 1690. 
76. Ruppius, H. B. Flora jenensis. Frankfort, 1718. 
77. Schultz Bipontinus, C. H. Beitrage zur Kenntniss der Cassiniaceen. 
Flora, Bd. 35, p. 129, 1852. 
78. ,, ,, ,, Beitrage zum Syskema der Cichoriacean. 
Durkheim, 1866. 
79. Small, J. K. Flora of South-Eastern United States. New York, 1913. 
80. Small, J. The Pollen-presentation Mechanism in the Composite. 
Annals Bot., Vol. XXIX, 1915. 
81. ,, ,, Notes on the Corolla in the Composite. New Phytologist, 
Vol. XV, 1916. 
82. ,, ,, Anomalies in the Ovary of Senecio Vulgaris, L. Annals Bot. 
Vol. XXX, 1916. 
83. Theophrastus. Enquiry into Plants. With Eng. trans. by Sir A. Hort. 
London,1916. 
84. Tournefort, J. P. Institutiones Rei Herbariae. Paris, 1700. 
85. Vaillantus, S. Methodus Compositarum. Memoires de l’Acad. Roy. 
des Sci., Paris, 1718-1721. 
86 . Vuillemin, P. Tige des Composees. Paris, 1884. 
87. Warming, E. Observations sur la valeur systematique de l’ovule. 
Mindeskrift f. Japet. Steenst., 1913. 
88 . Wernham, H. F. Floral Evolution : with particular reference to the 
Sympetalous Dicotyledons. New Phytologist, Vol. 
XI, 1912. 
89. Wettstein, R. R. v. Handbuch der Systematischen Botanik. Leipzig, 1901. 
RHIZOPHIDIUM ACUFORME (ZOPF) FISCH. 
By W. B. Grove, M.A. 
[With One Figure in the Text]. 
O N Chlamydomonas intermedia, of which a large gathering was 
made at Harborne (in the same cart-rut that is mentioned 
in the following note), there was found in April, 1917, a quantity 
of Rhizophidium acuforme. This parasite has been previously 
recorded by Zopf on a Chlamydomonas- like organism in March 
from an ice-covered pond in Pomerania, but there remained a 
doubt how far it was really distinct from R. glohosum (Braun), 
which occurs on a large number of fresh-water Algae. This doubt 
is dispelled by the present find. 
The cells of the Chlamydomonas are attacked by the zoospores 
of the Rhizophidium, while still in active motion, at any point 
of their circumference ; one to four (or even five or six) may be 
