I 
On Carteria Fritschii, sp. nov. 
BY 
H. TAKEDA, D.I.C. 
With ten Figures in the Text. 
I N a paper on Scourfieldia cordiformis , published in the current volume 
of the Annals of Botany, reference is made to a species of Carteria 
which swims usually forwards but occasionally backwards. 1 Since this 
organism has proved to be a new species of that genus, a short account of 
its characteristics, together with a Latin diagnosis, illustrated by some 
careful drawings, will be given below. 
The organism occurred abundantly in the same material as that in 
which Scourfieldia cordiformis was found, and which had been collected 
by Professor F. E. Fritsch at Keston, Kent, in May, 1915, and kept as 
a laboratory culture for over six months. The outstanding features of the 
organism are, firstly, that the outer firmer part of the cell-wall (i. e. the 
structure usually designated as ‘ cell-wall 5 or ‘ cell-membrane ’) is thicker 
than in any other described species of the same genus ; secondly, that the 
inner gelatinous part of the cell-wall (i. e. that part of the cell-wall which 
lies between the outer firmer part and the protoplast, usually referred to as 
‘ space ’) is frequently developed to a marked degree and very often 
unevenly, so that the protoplast does not always conform to the outline of 
the cell. 
The organism varies in shape to some extent, being ovoid to nearly 
spherical, and in some cases obovoid-ellipsoid. When viewed from the end 
the organism usually appears to be circular, but occasionally broadly 
elliptical, the cell being slightly compressed from the side. At the anterior 
end of the cell there is no wart-like papilla, such as is seen in C. obtusa, 
Dill, but the cell-wall forms a slight obtuse angle without any conspicuous 
thickening. The outer firmer part of the cell-wall reaches a thickness of 
about § jut, while the inner gelatinous part is often -very well developed, 
particularly at the posterior end and sometimes at the anterior end of the 
cell. The gelatinous part of the cell-wall occasionally contains some 
colourless granular substance, the nature of which has not been deter- 
mined (Fig. 6). 
1 Ann. Bot., vol. xxx, No. cxvii, January, 1916, p. 157. 
[Annals of Botany, Vol. XXX. No. CXIX. July, 1916.] 
