SAI'KOLEGNIA 25 



3. CXigonia often in chains but mostly single; not tending to separate; antheridia present 



on some (usually tew) of the oogonia, diclinous See Isoachlya loriilnidcs (p. 82) 



3. Oogonia mostly in chains; not separating; antheridia none / S. lorulosa (14) 



or very few, aridrogynous or diclinous ) •^- >'"0€tica (p. 67) 



) 5. variabilis (p. 67) 



\see also Isoachlya (p. 81) 



3. Oogonia not nornialU- in chains, antheridia jiresent on all or nearly all the oogonia 4 



3. Oogonia not normally in chains, antheridia absent or present on only a part (rarely 



as many as 75%) of the oogonia, mostly androgynous 10 



3. Oogonia not in chains; antheridia present on only about a third of the oogonia, 



diclinous 5 cruMna var III (p. 70) 



4. Antheridia all or nearly all diclinous 6 



4. Antheridia all or mostly androgynous 5 



5. Oogonial stalks bent and often coiled; oogonial wall unpitted or the pits few and in- 



conspicuous 5-5- spiralis (p. 71) 



\ S. fiircata (p. 72) 



5. Oogonial stalks not coiled or much contorted, oogonial wall usually with pits which are 



often conspicuous 7 



6. Spores of two kinds, large and small V anisnspora (4) 



6. Spores not of two kinds 9 



7. Aiitheridial branches present and not rising from immediately below the oogonia; 



antheridia on all or nearly all the oogonia 8 



7. Antheridial branches normally absent; antheridia cut off from the top of the oogonial 

 stalk S. hypogyna (13) 



7. Antheridial branches at times absent; if present arising from immediately below the 



oogonium (antheridia always present) seeAplanes Treleaseanus (p. 79) 



8. First oogonia mostly terminal on main hyphae, often oval; eggs large, mostly 30-33^ 



thick .*). litoralis (10) 



8. Oogonia commoi.ly on jhort. lateral branches; eggs \ery large, 30— 52M thick 



S. mcgasperma (11) 

 8. Oogonia commonly on short, lateral branches, spherical with a neck, eggs usually five 



or more in an oogonium, 16-22^1 thick S. monoica (7) 



8. As in 5. monoica, except that the eggs are usually less than five in an oogonium and 



mostly 25-27M thick S. monoica var. glomerata (8) 



8. As in S. monoica but no oogonia produced except in a solution of lucin and levulose 



5. monoica var. vexans (9) 



8. As in S. monoica except that the oogonia have longer stalks and few or no pits, and that 



the vegetative threads are longer and more slender . . .S. monoica var. montana (p. 75) 



9. Oogonial wall without pits ("except where the antheridia touch); eggs 20-26^ thick 



S. diclina (i) 

 9. Oogonial wall without pits (excei)t where the antheridia touch): eggs averaging 3011 



thick 5. Kauffmaniana (2) 



9. Oogonial wall with numerous pits; eggs 12-22.5^1 thick 5. stagnalis (p. 70) 



9. Oogonial wall with less numerous pits; eggs mostly 25-27/^ thick S. delica (3) 



9. Oogonial wall with few pits; eggs 17-27^ thick 5. critstosa var. II (p. 69) 



9. Oogonial wall with few pits; eggs 12-22^ thick S. critstosa var. I (p. 69) 



10. .\ntheridia usually on not more than 15% of the oogonia, often very few or none; 

 oogonia often found in old sporangia and then cylindrical; eggs mostly about idn 

 thick 5 ferax (5) 



