68 COLLINS AND HERVEY. 



CLASS PHAEOPHYCEAE. 



FAMILY ECTOCARPACEAE. 

 PYLAIELLA Bory. 



P. FULVESCENS (Schousboe) Bornet, 1889, p. 5, PI. I; P. B.-A., No. 

 2076; Conferva fulvescens Schousboe ms ex Bornet. On sand-covered 

 rocks by lighthouse, St. David's Island, May, 1913, Hervey. The 

 plant agrees fully with Bornet's figure as to form and dimension of 

 horizontal filaments and sporangia; the erect filaments are in part 

 simple, as figured by Bornet, in part like those figured by Sauvageau, 

 1896a, fig. 1, being recurved near the tips, and bearing numerous 

 longer or shorter branches, mostly on the outer side of the curve. The 

 unilocular sporangia are rare, but well developed. P. Hooperi, 

 Barbados, Miss Vickers, seems hardly distinct. In comparing the 

 description of P. fulvescens by Bornet with that of Pylaiclla sp. 

 (Ectocarpus Hooperi Crouan) on the following page, the chief dis- 

 tinctive character of the latter would seem to be the Rhizoclonium- 

 like ramuli near the base; such ramuli were occasionally seen in the 

 Bermuda plant, but were not at all abundant. 



ECTOCARPUS Lyngbye. 



1. Lower part of frond endophytic. 2. 



1. Not endophytic. 3. 



2. Only slightly endophytic, in Dictyopteris Justii; largely free; pluri- 

 locular sporangia cylindrical. 8. E. luteolus. 



2. Mostly endophytic, in Halymenia; plurilocular sporangia ovoid. 



9. E. parasiticus. 



3. Erect filaments arising from prostrate, branching filaments. 4. 



3. No distinct prostrate filaments. 5. 



4. Erect filaments with plurilocular sporangia near base, no other branch- 

 ing. 7. E. elachistaeformis. 



4. Erect filaments freely branched, bearing sporangia throughout. 9. 



5. Plurilocular sporangia seriate on upper side of branches, near base. 6. 



5. Plurilocular sporangia variously placed, not seriate. 8. 



6. Plurilocular sporangia cylindrical. 3. E. Mitchellae. 



6. Plurilocular sporangia ovoid to conical. 7. 



