OEDOGONIUM 55 
Wiclikois OOSPOnesSimOOUls vee ercicl. salcitiss setts sis re cee cee nace ehldn esa’ 40 
Wielitotsoosporerscroniciwlateres. 1. nes dac-s 0% ce oe ce wen vealoctutenee sel 49 
WralllkoroOsporerechuatevcec css Accs 4 c.cbciie ds comes eccssvasdece cone cuca 50 
ARE LOMO CCIOUS HMR nG Faience rors cie ee e ise beste steeceua meee es 41 
At) ED TOCCIOMS meets See nian ae cis oF ueeiEe aieinis lad miler ace cas wes ate ones 44 
DiamMeTreMOMOOUZOMUM SAC Ks ss cSe a cieloss soc sles ese nbseeccdecneod® 42. 
Diameter of oogonium 32-38y.........5.20.05.:.+. 1. Oe. laeve 
42. Filament irregularly curved................ 2. Oe. curvum 
APM ATO eH CESLG ATM ie Mier ieee Geir Si © ccs cla Sale we dcreelune sos 43 
Ooronimim 25=28 Xe 26S ek seal ese See eae 3. O08. cryptoporum 
Oogonium 18-25 X 18-26h............. 3a. Oe. cryptoporum var. vulgare 
AAS Diameter OmoosomilUumme Arete ss Gos See cn scree cess cis Seale cans 
AAP eM iaIMetet OlMOOCOMUM lA (—OoMe os es. sacks Sons cee cee cn eeeneeees 47 
AAS e Diametemot OOsOnitin SU=GO.. 265-8. Se ive oss ces bs sek ou slne ones 48 
Drametemotmecetative cell o-lOue eee oct cies sce 6c are vache cbse sans wets 46 
Diameter of vegetative cell 8-I3u..... 4b. Oe. rufescens var. lundellit 
46. Diameter of vegetative cell5-Qu 4a. Oe. rufescens var. exiguum 
46. Diameter of vegetative cell 8-10u........... 4, Oe. rufescens 
Diameter of vegetative cell 9-llu..... 218a. Oe. inerme var. mentiens* 
Diameter of vegetative cell 11-l4u................ 5. Oe. calcareum 
AS OOSPOLEHS OOM a oS TOON. i. a. cincinnati eee 6. Oe. sociale 
AStaOOSPOLCISd TOS) NUL ROL. snes cesta oe pac 218. Oc. inerme* 
IMOnOECIOUSSe seers ore oe ac ce ese a caw en emeee st 7. Oe. cymatosporum 
Dioecious (very rarely monoecious)............... 8. Oe. magnusit 
50. Diameter of vegetative cell 9-l4u........... 9. O68. suecicum 
50. Diameter of vegetative cell 14-16z, 
9a. Oe. suecicum f. australe 
Oospore scrobiculate, 22-27y in diameter.......... 217. Oc. moniliforme* 
Oospore scrobiculate, 43-48y in diameter, 
66a. Oe. argenteum f. michiganense 
Oosporeismoo umes teres: ool snss5 82 dae shapes otc At oe sens oe ees 52 
HUME LOTOCCIOUSHEE Eee SS 5.05 Sak 300 55 LER oa wa ieeiagaig sina 6 hae. 53 
SDE DIO CCI OUSHE rat Se see aS oS ROE coe gee mans Ha eae gas 58 
52. Both monoecious and dioecious............. 10. Oe. varians 
IRoserapiiitictabovesimedianuted<<ta40ar an oso ee some snake he eed tnaes s 54 
RoremearlvastiperlOtr anes seGtiois > Tat oe hoes bent ad nie Geyser .'s 56 
Pore variable between these two positions.................00 ee eeeeeeee 57 
je Diameter ob oogonitum 34-450" 0.0 .aeen. 2.....-s-- 5. Rae Seed 55 
54. Diameter of oogonium 46-55u............... 11. Oe. urbicum 
Oospore depressed-globose, 30-34 K 28-32u........ 12. Oe. obsoletum 
Oospore regularly globose, 30-39 * 30-39y......... 13. O8c. plusiosporum 
Dow Oospore sl—4l x -30—-4) ae. seas es 10. Oe. varians 
bom Oospore.40 48) 40-482. Phase es ees 14. Oe. tyrolicum 
Terminal cell narrowed and often setiferous....... 225. Oe. inflatum* 
Terminal cell neither narrowed nor setiferous...... 11. Oc. urbicum 
Sis, [torre a, Iniimel evel ovonyasanleye behalf 5.5 ante Ces EERO hee eerie ene 59 
DEP OL HNe Ailes MCI OL Mewar kin ess tree ae ste asst owe bess 006 60 
58. Pore variable between these two positions....................05-. 62 
Vegetative cell 1-3 diameters long.... 15b. Oe. cardiacum f. pulchellum 
Vegetative cell 3-7 diameters long................ 15. O8c. cardiacum 
60. Diameter of vegetative cell 8-12u........... 16. Oe. franklinianum 
60. Diameter of vegetative cell 12-l6u.......... 10. Oe. varians 
Hae Diametenommeretanive cellil4—80 oe see es oie’ eee ee ace 61 
Oospore depressed-globose, 31—42u in diameter, 
15d. Oe. cardiacum var. minus 
Oospore subglobose, 42-49u in diameter........... 17. Oe. glabrum 
Oospore globose, 43-58u in diameter.. 15a. Oe. cardiacum f. interjectum 
Oospore ellipsoid-globose, 40-52u in diameter, : 
15c. Oe. cardiacum var. carbonicum 
62. Oospore not filling oogonium................ 225. Oe. inflatum* 
62. Oospore completely filling oogonium........ 18. O6¢. lautumniarum 
*See footnote, page 53. 
