72 Rhodora [APRIL 
З р, certainly much larger than those which appear in fig. 8 (pl. 79). 
In the formalin material it was impossible to distinguish any details 
with respect to the flagellae of these spores, or to determine what 
becomes of any of the motile cells. Perhaps they are the micro- and 
macro-zoospores mentioned by Oltmanns,' as described by Reinhardt.’ 
Although Characium eylindricum is characterized by so many fea- 
tures, visible nucleus, two chromatophores, oil globules, absence of 
pyrenoids, peculiarity of attachment, and peculiarities of reproduction, 
at variance with what have been accepted up to this time as generic 
characters of Characium, it does not seem advisable to make a new 
genus for this form, without further study of living material. 
Reinsch ? has described a minute alga, Dactylococeus Hookeri, which 
he found growing attached to the small crustacean, Cyclops bicaudatus, 
collected in the neighborhood of Erlangen, Germany, in 1872. In 
1874 he found another form, Dactylococcus De Baryanus, growing 
on the same crustacean, Cyclops bicaudatus, collected in the same 
region. In the summer of 1877 he found the latter form, Dactylo- 
coccus De Baryanus, on “a somewhat smaller species" of Cyclops from 
pools a few miles west of the southern end of Lake Michigan. Again 
in the following summer, 1878, he discovered Dactylococcus De Bary- 
anus, on Cyclops bicaudatus and оп a species of Lepidurus,* taken 
from the water mains of the city of Boston. As Mr. F. S. Collins 
regards both of these species of Dactylococcus as belonging to the 
genus Characium, it is of interest to note what Reinsch ? has described 
for the reproduction of Dactylococcus De Baryanus, the species which 
he found here in the vicinity of Boston. He describes as the earliest 
stage of development a slow-moving, green amoeboid cell of about 
25 u diameter, with red stigma. When these cells are elongated 
they have at the anterior hyaline end a single vibratile flagellum 
terminated by a bead-like thickening. After a short time these cells 
lose their power of movement, attach themselves to the surface of the 
1Oltmanns, Dr. Fr., Morphologie und Biologie der Algen, Jena, 1904, Bd. 1, p. 175, 
quoting. 
? Reinhardt, L., Entwickelungsgeschichte der Characien, Protok. d. Sekt.-Sitz., 
d. 5. Vers. Russ. Naturf. u. Arzte in Warschau, 1876.  Jahresber. 4, p. 50. 
3 Reinsch, P. F., Contributiones ad Algologeam et Fungologeam, p. 78, pl. 11. 
4 In referring to the crustaceans found in the water mains of the city of Boston, 
Reinsch says, "Am 20 Juni waren die meisten untersuchten Thierchen (Cyclops 
bicaudatus und einer Lepidurus-species, von der deutschen verschieden) mit Parasiten 
besetzt." Inasmuch as Lepidurus is not known to occur east of the Great Plains, 
it is impossible to say what crustacean is referred to here, 
5 Reinsch, P. F., Beobachtungen über entophyte und entozoische Pflanzenparasiten, 
Botanische Zeitung, 1879, p. 38, pl. 1, figs, 21-24. 
