100 



somewhat darkened and with scarcely developed receptacles, 

 but otherwise of about the normal habit. 



Phyllophora memhranifolia (Good. & Woodw.) J. Ag. Tetra- 

 sporic. 



Champia parvula (Ag.) Harv. Plants 3-4 cm. high, apparently 

 sterile. This species is ascribed to summer by Davis. 



Delesseria sinuosa (Good. & Woodw.) Lamour. A battered 

 tetrasporic plant. 



Polysiphonia elongata (Huds.) Harv. Plants 10-15 cm. long, 

 fibrillose, apparently sterile. 



Melobesia Lejolisii Rosan. On leaves of Zostera. 



Dermatolithon piistulatum (Lamour.) Fosl. On leaves of Zostera, 

 with the preceding. 



Mr. Latham sent in for determination several collections also 

 that were made in the month of March and so are perhaps not 

 properly to be referred to as "midwinter" algae, but two of these 

 collections were so little later than the month of February that 

 they are of some interest in this connection. The first of these 

 March specimens were picked up on the "Sound shore" on 

 March 5, but are believed to have washed in "with the great 

 storm of March i." Omitting the common Fucaceae and a few 

 others already mentioned, those of March 5 were 



Halothrix lumhricalis (Kiitz.) Reinke. On Zostera leaf, fertile. 



Pufictaria latifolia Grev. Sterile. 



Desmarestia viridis (Miill.) Lamour. 



Chondrus crispus (L.) Stackh. Tetrasporic and cystocarpic. 



Phyllophora memhranifolia (Good. & Woodw.) J. Ag. Tetra- 

 sporic and cystocarpic plants. The "nemathecia" of this 

 species are in structure very suggestive of Actinococcus sub- 

 cutaneus (Lyngb.) Rosenv., parasitic on Phyllophora Brodiaei. 

 In form, however, they are strikingly different from the sub- 

 spherical thalli of Actinococcus suhcutaneus and a microscopical 

 examination seems to indicate that they are integral parts of the 

 Phyllophora thallus rather than parasitic organisms. The re- 

 cently established facts as to alternation of generations in the 

 Florideae, together with the obvious structural resemblances 

 just alluded to, suggest a further consideration of Reinke's idea* 



* In Darbishire, On Actinococcus and Phyllophora. Ann. Bot. 13: 264. 1899. 



