58 TUFTS COLLEGE STUDIES, VOL. IV, No. 7 



Page 225 and p. 83 of supplement, tor Key to the Species of 

 Oedogonium,* substitute, 



i. Mac rand rons. 2. 



I. Nannandrous. 59. 

 2. Oogonium opening by a pore. 3. 

 2. Oogonium opening by a lid. 40. 



3. Spore globose. 4. 



3. Spore ellipsoid. 21. 



4. Pore median. 5. 



4. Pore supramedian. 



4. Pore superior. 13. 



5. Membrane of oospore smooth . 6. 



5. Membrane of oospore pitted. 92. 



5. Membrane of oospore spinous. 4. Of. succicum.* 



6. Monoecious. 94. 



6. Dioecious. 7. 



7. Oogonia 22-25 M diam. 2. Oe. ru/fscens. 



7. Oogonia 30.38 M diam. 2. Oe. socialt. 



8. Pore slightly above the middle. 9. 



8. Pore almost superior. n. 



9. Monoecious. 10. 



9. Dioecious. 7. Of. cardiacunt. 



10. Oogonium subglobose or subdepressed-globose. 5. Of. obsoletiim. 



10. Oogonium snbglobose or subellipsoid globose. 



6. Oe. plusiosporum. 



II. Monoecious. 12. 

 II. Dioecious. 8. Oe. franklinianutH. 



12. Oospore 31-41 n diam. ; suffultory cell not swollen. 



9. Of. various. 



12. Oospore 40-48 Mdiani. ; suffultory cell swollen. 76. Of. tyrolicum. 

 13. Oogonium manifestly swollen. 14. 



13. Oogonium little if any swollen. 19. 



14. Membrane of oospore smooth. 15. 



14. Membrane of oospore pitted. 93. 



15. Monoecious. 16. 



15. Dioecious. 12. Of. plagiostotnntn. 



16. Vegetative cells less than 18 M diam. 17. 



16. Vegetative cells 20-30 M diam. n. Oe. Vaucherii. 



89. Oe. Reinschii, fructification unknown, is not included in thin 

 key ; The hexagonal-appearing cells are characteristic. 



t Descriptions of species with serial numbers from 1-74 will be found on 

 p. 229 and following pages of Collins, 1909; species with letters a or b 

 after their serial number are described on p. 84 and following pages of 

 Collins, 1912: species from 75 upare described on the pages immediately 

 following this key. 



