330 THE PLANT PHYLA 
(a) Sporophylls open, ovules and _ seeds 
naked (gymnospermous). 
(1) Gametophytes dioecious; sperms cili- 
ated and motile; sporophytes pro- 
ducing microspores and megaspores 
in spiral or whorled sporophylls, or 
these aggregated into cones. 
Phylum 12. CycapopuHytTa. 
(2) Gametophytes dioecious; sperms not 
ciliated, not motile; sporophytes 
with sporophylls in cones. 
Phylum 13. SrroBILopHyta. 
(b) Sporophylls closed, ovules and seeds 
covered (angiospermous). 
(1) Gametophytes dioecious; sperms not 
ciliated, not motile; sporophytes 
with sporophylls in flowers. . 
Phylum 14. ANTHOoPHYTA. 
In the following systematic enumeration many of the families 
are merely named in their sequence, without any characteriza- 
tion or examples. Moreover the characterizations of all groups 
are necessarily very brief and general. The examples cited are 
of the more common genera, or those of particular interest to 
the student. 
Phylum I. MYXOPHYCEAE. The Slime Algae 
Usually blue-green, poorly developed cells, or filaments 
Class 1. ARCHIPLASTIDEAE (Cyanophyceae). “Blue 
Greens.” Without nuclear mem- 
brane. (Sp. about 2,000.) 
Order CoccoGonaLes. Green or greenish; unicellular. 
Family 1. Chroococcaceae. Cellsrounded.—Chroo- 
coccus, Gloeocapsa, Merismopedia. 
Family 2. Chamaesiphonaceae. Cells elongated.— 
Chamaesiphon. 
Order HormoGonaues. Mostly green or greenish; fila- 
mentous. 
Family 3. Oscillatoriaceae. No heterocysts.—Oscil- 
latoria, Lyngbya. 
