40 SPECIES OF ALG.E. 



v. Diameter of veg. cells 13-14/4 pyriforme, 95 



v. " " " " 16-20/4 irregulare, 79 



v. " " " 27-30/4 crrssiusculum, 80 



o>. Oogonia opening by a pore (x). 



w. " " " " lid (00). 



#. Pore above the middle (y). 



x. " below " " oospore with 4 spiral ridges . Huntii, 85 



7. Oospore longitudinally costate Wolleanuip, 82 



z. Diameter of oogonia 45-50/4 by 60-75/4 . . . Boriseanum, 81 

 z. " " " 70-83/4 by 90-105/4 . . . concatenation, 81 

 5. " " " 29-32/4 by 33-38/4 .... scxangularc, 82 

 00. Oospore longitudinally costate, filling the oogonium, 



acrosporum, 83 

 00. " not " " (bb\ 



bb. Terminal cell setiform ciliatum, 84 



bb. " not setiform obtruncatum, 84 



<rr. Oospores ellipsoid oogonia opening by a pore in the middle, 



Hystrix, 87 



cc. " globose (^/). 



^/. Oogonia opening by a pore at the middle . echinospermum, 86 

 dd. " " " " " above the middle (ee). 



ee. Spines of oospores conical (//). 



ff. Diameter of veg. cells 2.5-5 times as long as wide . stellatum, 85 

 ff. " " " " 1-2 times as long as wide . Donnellii, 85 



ff. " " " '' 6-14 "/ u " " " . echinatum, 86 



gg. Oogonia not or scarcely swollen (hk). 

 gg. '" manifestly swollen (). 



hh. Diameter of oospore 22-52/4 by 38-62/4 .... capillarc, 87 

 ^//. " 47-49/4 by 50-66/4 .... stagnate, 87 



. Oospores globose or subglobose (jj). 

 it. " ellipsoid or oval (00). 



_#. Oogonia opening by a pore (kk). 



jj. <% " " " lid; oospore globose , . Pringsheimii, 90 



kk. Pore in the middle; membrane of veg. cells and of oogonia spirally 



punctate puncto-striatum, 90 



kk. Pore in the middle; membrane not punctate . . rufescens, 89 

 kk. Pore above the middle (//). 



//. Oospore filling or barely filling the oogonia (mm). 

 II. Oospores not filling the oogonia (nn). 



mm. Oospore globose, filling the oogonium, diameter 25-29/4 by 24-30/4 



Franklinianum, 89 



