127 
with a smooth, glistening, dark purple mantle. Here for the first time 
were discovered good fruiting spe'cimens which determined the 
hitherto doubtful generic position of the plant. The chlorophyll is 
usually more or less centrally contracted in each cell. There is no 
evidence of twin nuclei, a fact which, with the color and the genicu- 
late feature of the filaments, makes a distinct specific character. 
Mesocarpiis^ Hassal. M. crassus, n, sp. — Vegetative cells robust, 
measuring, with slight variation, 50/i in diameter, 5-10 times as long 
as wide; fruiting cells very nearly, or perfectly straight; zygospores 
smooth, spherical, 65/i in diameter. 
Floating in extended, pale yellow- green masses on ponds near St. 
Augustine, Florida, In every way much larger than the" largest of 
described species, and the articulations proportionately longer. 
Staurospernmm^ Ktz. ^S". gracillimnm^ Ktz. 
I.akes near Winter Park, Florida. 
Bambusina, Ktz. B. gracilescens, T^ord. (Plate li., Figs. 13-14). 
This is described in my Desmids of the United States as a variety of 
B. Brebissonii. Whether viewed as such or as a distinct species, it 
was an interesting discovery to find fine fruiting specimens frequent 
in a pond near Winter Park, Florida. 
Diameter of cells, 14;'; length, 23//; apices, 8/^; zygospore, 15//. 
An observation made by Rev, H. D. Kitchel, and by myself, on 
' gatherings from the same marsh pond is worthy of special note. 7'he 
plant conjugates, not like one of the Desmidiacese, but, like one of the 
Zygnemaceae, in longer or shorter series; often when the zygospores 
are nearly matured, the cells of one side separate and cause the other 
side to bend backward in a reversed, semi-circular form. We found 
^he fruiting specimens in many stages of conjugation, first putting 
\ out separately narrow gelatinous connecting tubes, then these uniting 
and forming complete conjugation, next the chlorophyll passing out 
of the cells, flowing together in the tube, and gradually developing 
the zygospore, until fully matured. 
Judging by these specimens, the correctness of the generic position 
of Banibusina may be questioned. 
Sphcerozosma^ Corda. S, pulchrum^ Bail, var. constrictum, //. 
var. (Plate lt., Fig. 12). — Cells half as long as wide, with a decided 
constriction in each lobe between the axis and the apex. Diameter, 
Lake near Kissimme, Fla. 
S. vioniliforme^ Lund. (Plate li., Fig. 11). — Diameter 20/i; length 
of cell 4o>u. 
Lake near Kissimme, Fla. 
Cosmarium, Corda, C. Eloisianum^ Wolle. A species hitherto 
found only in Minnesota now turns up also in Splitrock Pond, New 
Jersey. 
Alictasterias, Ag. M. verrucosa, Roy. (Plate li., Fig. 10.)— In 
outline this species agrees with forms of M. denticulata (Breb) Ralfs., 
but differs from these and all other described forms by the remark- 
able row of credulated, circular or oval basal inflations crossing from 
side to side, larger towards the centre, gradually growing smaller 
towards the margins. The original, typical plant was found in Scot- 
