OEDOGONIUM 53 
Genus III. Oedogonium Link. 
1820, p. 5; Pringsheim 1858, p. 68; Wittrock 1874, p. 6; Hirn 1900, p. 72; Collins 
1909, p. 223; Prolifera Vaucher 1803, p. 14;, Vesiculifera Hassall 1845, p. 195; 
Cymatonema Kuetzing 1849, p. 375; Androgynia Wood 1872, p. 196; Pringsheimia 
Wood 1872, p. 195; Conferva (early authors). 
Filaments single, unbranched; vegetative cells cylindrical, or some- 
times capitellate, nodulose or undulate; basal cell with holdfast; terminal 
cell obtuse, apiculate, or hyaline; all vegetative cells, except the basal 
one, capable of division; oogonia and antheridia produced by direct 
division of vegetative cells. 
KEY TO THE SPECIES, VARIETIES, AND FORMS OF 
OEDOGONIUM 
ievecetative cellsundulate ormodulose... 9.28.58 0 egos. esac dns cne dan: 2 
iran eetdiie Cellupunetate Or Sranulate: |.) wens edelein odie. sce bebses 6 
ieee Veceratmvercellidistinetiyscapitellate....45-esn ..«sseeeeidedses onesceen. 7 
PeVieserabivercelllieygimdrCalinen ) vers cok Hannes en . | eee nce owes asc 35 
1. Vegetative cell subhexagonal or subellipsoid....... 236. O68. reinschii* 
aso Wh a OCC ENTS 2 0 6600 (2, Lo ys 3 
Ps Aaa mye hyoligle sane eh ee ee GR pL Vic Se 4 
Se Diameter ot oogonium IS—23u... 0424... 26 osc ue gees 105. Oc. sphaerandrium 
3. Diameter of oogonium 48-57. -..............---:- 96. Oc. nodulosum 
3. Diameter of oogonium 64-74u......... 96a. Oe. nodulosum var. commune 
Ae Diametermowoogonianml 44-0644... -....-anneneo ate. Ser sceose.: 
4. Diameter of oogonium 58-68u...119a. Oe. undulatum var. americanum 
5. Dwarf male 36—46u in length.......... 119b. Oe. undulatum f. senegalense 
ee Owanrhamale A8—/Owanlengthess. 4.0 4..<..22:1s40ee- 119. Oc. undulatum 
6. Diameter of vegetative cell 6-Su............ 155. Oe. elegans 
6. Diameter of vegetative cell 9-13u........... 84. Oc. minus 
6. Diameter of vegetative cell 16-22u.......... 85. Oc. punctatostriatum 
A, Wiftitlvonnr Chine Toi Ra een 5 cme oN eneU an tk ee re rr 8 
NH ME Glvyaislptincll ag Ae PRT ee Staves sank h a eee «koe kG eis ote he Ba irae Gone 17 
ieee eproductive structures impertectly known... 0.3... 0. cc kee dee eens 34 
Bi, DROVES SS o cre a ae cece a MERIT © ete ec Sen a an eee 9 
SEE MOTOR CIOS are WR r at Saker, tattrn wiarinc in. an 5 sashes voto ale: «tae oe 11 
PEO it1O Ol COPONITIMDASAL Jo. 6 lig gis he ees ss ss 78. Oe. infimum 
9. Division of oogonium inferior........ 1s a eee 77. Oe. inversum 
Cee Dvr OMeOrOoOZOniuimapmolediaines.t0. sm sy ctlens asco aes cae eee cv a owteee sos 10 
9. Division of oogonium supramedian or superior..... 89. Oe..mitratum — 
10. Oogonium 26-29u in diameter... 79a. Oe. howardii var. minus 
10. Oogonium 29-32u in diameter............... 79. Oc. howard 
10. Oogonium 32-36 in diameter............... 81. Oe. latiusculum 
11. Oogonium opening by a pore.......... 20a. Oe. hirnii var. africanum 
PME Ott mOMenim Vea LG oro. oc bese bene cme dist eee deanna saide as 12 
ee OiaimeLvemomoo soni LOZ. 5. ooctsice a oe ceases vce ed one eM Eas 13 
Zee Dice terOMmOOP ONT O4—4 Ou . sis 5 cede aes som on weds 6 ows eee 16 
Lee Div tSIOf OMOOLONiMl MECIAME. 5 .ccce cmos Seb neu sngued ovo osiee es ehee ble 14 
eee mAMOn OL COSI SUPLAMEeCIAN.:....... 56 eg een dence eea tees eine cee’ 15 
14. Oogonium subdepressed-globose............. 86. O8c. capitellatum 
145 Oorontum-angular-globose............5.-.-- 87. O8c. quadratum 
id= Msameterioft oogonttum 15=20n.......... 065.2050 55 210. Oc. virceburgense* 
ise Osameter of oogonia, I8—Bap.. 2... ne cn ee es es 105. Oc. sphaerandrium 
jee Oirameter, Of OOSOMilM 2O-2ou.... .- ns. cess se ee oe 211. Oe. spurium* 
*Species so marked have incomplete descriptions and are included in what is 
perhaps their probable position in the genus, using such characters as are available. 
