NOTICES OF BOOKS. 875 
Subsection II. Macrandrous Species. 
a. Oospores iting (1 species). 
b. Oospores s 
a. Oogonia “tat or but cheny tumid (3 species). 
B. Oogonia manifestly tu 
aa. Oospores globose or "bling (7 species). 
species of (Zdogonium, whose organs of fructification not being suffi- 
ciently known to the ‘author, they cannot be relegated to their proper 
position in the sien scheme or plan of arrangement. Of these 
e more desirable and welcome would have been figures at least 
known, and, therefore at same time, indicating the lacune in our 
knowledge as respects them. 
Genus 2, Butsocuzte, (Ag.). ee 
Section I. Oogonia globose or subglobose, pet (except B. 
aaae in which the oogonia are erect, . latvor, Prings., erect 
art males Cima rcaniD unicellular a pene) 
B. Dwarf males bicellular, spermogonium ‘ 
a. goer cell (tips) a of the dwart males akariee than the spermo- 
10 species), 
b. Basal ‘ell (stipes) of ate dwarf males longer than the spermo- 
gonlum (2 speci 
C. Dwarf males bicelialas ‘spermogonium “outer” (2 species). 
Section II. Oogoni aieliipecital or subellipsoidal ; oospores the sam 
form as the oogonia it completely filling them, epupen jofustediealle 
costate, cost more or less crenulate; septum of the supporting cells 
situated i in their i part (seemingly absent in B. pygmaum, Prings.), 
upper supporting cell (in optical vertical section) 5 iil lower 
pentagonal, more rarely (when oogonia erect) tetragon: 
Subsection 1. Monoicous Species (6 species). 
Subscetion II. Dioicous Species. Nannandrous and gynandro- 
sporous. Dwarf maies straight stipitate; spermogonia * outer,” 
es cellular. 
A. Supporting cells wanting septum = species). 
B. Supporting cells possessing a se 11 species). 
To the foregoing are added (parcial descriptions of two species 
whose organs of fructification are _ sufficiently known to the author, 
hence their precise position uncert 
Subordinate to the ‘ aaa: ‘distinetions as indicated above, 
those characters appertaining to the species which come into play to 
discriminate between rg and arranged in the sequence of com- 
