1897.] Botany. 65 
The arrangement of our genera within the families may be as follows: 
Family 2.— Oscillariacee. 
A. Cells green or greenish; usually two or more filaments in each 
sheath; Schizothrix, Porphyrosiphon, Hydrocoleum, Dasyglea, 
Microcoleus. 
B. Cells green or greenish ; filaments solitary in the sheaths, or sheath- 
less; Plectonema, Symploca, Lyngbya, Phormidium, Oscillaria, 
Arthrospira, Spirulina. 
. Cells colorless; filaments without sheaths, or nearly so; *Lepto- 
trichia, *Beggiatoa, *Bacillus, *Pasteurella, *Clostridium, *Cor- 
nilia, *Vibrio, *Spirillum, *Pacinia, *Bacterium. This series is 
parallel to B, and perhaps may eventually be merged into it. Cer- 
tainly Spirulina and Spirillum are closely related, if, indeed, they 
are not identical. 
Q 
Family 3.— Nostocacee.—Nostoc, * Leuconostoc, *Staphylococeus, *Mi- 
crococcus, Wollea, Anabzena, *Streptococcus, Aphanizomenon, No- 
dularia, Cylindrospermum. 
Family 4.—Scytonemacee.—Microcheete, Scytonema, Hassellia, Toly- 
pothrix, Desmonema. 
Family 5.—Rivulariacee.—Calothrix, Dichothrix, Polythrix, Isactis, 
Rivularia, Gleotrichia, Brachytrichia. 
Q foe i LT 1 ~ 
1 i i 
Family 6. , Stigonema, 
It will be observed that the “ Bacteria” are confined to the first, 
second and third families, by far the greater number occurring in the 
Oscillariacee. 
The “Slime Moulds” (Mycetozoa) are not here regarded as proto- 
phytes. These interesting and often very beautiful organisms I am 
reluctantly compelled to consider as falling outside of the dominion of 
Botany; and much as I dislike to do so, I am assured that we must 
surrender their study in the future to our zoological friends —CHARLES 
E. Bessey. 
