ABSTRACT OF PAPER ON DESMIDIEZ4. 323 
Cosmarium cyclicum, Lundell, var. ampliatum ; var. nov.—The 
original is exceedingly rare in England. It has a deep, narrow 
constriction, whereas the N.Z. variety has a wide, gaping con- 
striction. The frond is marked with radiating gemmules. Dia- 
meter 50 p. 
Cosmarium nndulatum, var B, var. nov.—A doubtful variety, 
chiefly distinguished by its minute size, but this is variable. 
Length about 33 p. 
Cosmarium tenue, spec. nov.—Very minute ; length only 15 p; 
somewhat resembling C. bioculatum, but having no isthmus and a 
deep narrow constriction. 
 Stauvastrum eustephanum, var. emarginatum ; var. nov.—lIt is diffi- 
cult to give an abstract description of this little plant. In side 
view it resembles nearly S. spinmosum ; in end view it shows a tri- 
angle with emarginate sides, and, as if placed on the face of the 
triangle, a star of six rays. The rays are bifurcate. and the 
angles of the triangle are produced into sharp awns. Length of 
sides of triangle, exclusive of awns, 25 p. 
Staurvastyvum clepsydva, Spencer; spec. nov.—The author has 
been allowed by Dr. Spencer to include in his paper this plant, 
which appears to be a new species resembling S. dejectum, but 
differing in the broad junction of the segments, which junction 
is about half the width of the trond. Bodies which are probably 
zygospores of this plant were observed ; they have fewer spines 
than those of S. dejectum. 
Triploceras tridentatum, Maskell, var. cylindvicum; var. nov.— 
Differs from the original (Trans. Vol. XIII.) in having greater 
thickness and circular section. Probably both plants ought to 
be relegated to the genus Pleuvotenium. Rabenhorst rejects 
Bailey’s name Triplocevas. 
All these plants are ficured i in an attached plate. 
Besiees the above nine plants, thirty others are included in 
the paper which are believed to be identical with species 
described from elsewhere. 
Part II. contains notes on some of the Desmidiez included 
in the auther’s paper in Vol. xIII. of the Transactions. 
A note is devoted to the distinctions of Micrasterias votata and 
M. denticulata, which the author considers too slight to separate’ 
the plants, and to the differences observable in the New Zealand 
form. First, this is invariably a good deal larger than the 
English plant, the diameter of the former being from 320, to 
400 uw against 270 mw for the latter ; secondly the teeth are more 
numerous and sharper; thirdly, the terminal lobe of the New 
Zealand plant is deeply cleft at its end, and has at each side of 
the cleft two short spines. This latter character, indeed, would 
make it approach nearer to M, fimbriata, were it not for the total 
absence of spines on the teeth of the intermediate lobes. Four 
figures, showing the differences referred to, are oven in the 
second plate attached to the paper. 
‘Notes are also given as to the motions observed on one occa- 
