228 



TUFTS COLLEGE STUDIES, VOL. II, No. 3 



48. Oospore globose. 



48. Oospore ellipsoid. 

 49. Pore median or slightly above. 

 49. Pore superior. 

 49. Pore inferior. 52. 



50. Membrane of oospore smooth. 



50. Membrane of oospore spinous. 

 51. Oogonium 30-37'^ diam. 

 51. Oogonium 49-53 M diam. 



52. Oogonium subdepressed-globose. 



52. Oogonium subglobose to ellipsoid. 46. 

 53. Membrane of oospore smooth. 

 53. Membrane of oospore spinous. 



54. Oogonia solitary. 



54. Oogonia usually seriate. 59 



55. Spines without order. 

 55. Spines arranged spirally. 



56. Spines scanty ; oogonia subglobose. 4 



56. Spines dense ; oogonia depressed-globose. 

 57. Oogonium 51-64 n diam. ; veg. cells 15-35 /a diam. 



50 

 57. Oogonium 63-78 /u. diam. ; veg. cells 32-59 n diam. 



5i- 



58. Pore median or slightly higher. 



58. Pore superior. 

 59. Membrane of oospore smooth. 

 59. Membrane of oospore spinous. 



60. Membrane of oospore smooth. 



60. Membrane of oospore ribbed. 



60. Membrane of oospore pitted. 

 61. Suffultory cell not swollen. 

 61. Suffultory cell swollen. 



62. Oospore globose. 



62. Oospore ellipsoid. 

 63. Oogonia 14-23 /u diam. 

 63. Oogonia 30-56 /u. diam. 



64. Oogonium opening by a pore. 



64. Oogonium opening by a lid. 

 65. Membrane of oospore smooth. 

 65. Membrane of oospore ribbed. 



66. Oospore globose. 



66. Oospore ellipsoid. 

 67. Division of oogonium medium. 

 67. Division of oogonium inferior. 



68 



68 



68. 

 Oospore nearly or quite filling the oogonium. 



49- 

 58. 

 50. 



53; 

 Oe. H until. 



52. 



43. Oe. Braunii. 

 44. Oe. flavescens. 

 45. Oe. pungens. 

 Oe. echinospermum. 

 54- 

 55- 



47. Oe. irregulare. 

 , Oe. multisporum. 

 56. 



57- 



8. Oe. armigenim. 

 49. Oe. echinatiim. 



Oe. stellatuni. 



Oe. Donnellii. 



59- 

 60. 



Oe. sexangulare. 

 54. Oe. Hystrix. 

 61. 



Oe. Wolleanum. 

 Oe. concatenatum. 

 55. Oe. crassiusculum. 

 56. Oe. Borisianuin. 

 60. Oe. macrandrium. 



63- 



61. Oe. longatum. 

 62. Oe. acrosporum. 



65- 



64. Oe. undulatum. 

 73. Oe. cataractum. 

 63. Oe. cyathigeruin. 

 67. 



69. Oe. pluviale. 

 68. 



Oe. platygynum. 

 69. 



53- 



57- 

 58. 



Ooospore not nearly filling the oogonium. 67. Oe. Areschougii. 



