THE ALGAE OF BERMUDA. 69 



7. Branching irregular, branches patent. 4. E. coniferus. 



7. Branches subsecund, ramuli long, pectinate. 5. E. Sandrianus. 



8. Plurilocular sporangia fusiform, unilocular unknown. 



1. E. confervoides. 



8. Plurilocular sporangia short-conical, unilocular ovoid or subspherical. 



2. E. siliculosus forma arctus. 

 9. Plurilocular sporangia variable, always blunt or truncate. 



6. E. Duchassaingianus. 

 9. Plurilocular sporangia acute. 10. E. Rallsiae. 



1. E. CONFERVOIDES (Roth) Le Jolis, 1863, p. 75; Kuckuck, 1891, 

 p. 19, fig. 3; Ceramium confervoides Roth, 1797, p. 151. Floating, 

 Gibbet Island, March, Hervey. Somewhat variable, but mostly 

 of the typical form. 



2. E. SILICULOSUS (Dillw.) Lyng. forma ARCTUS (Kiitz.) Kuckuck, 

 1891, p. 18; P. B.-A., No. 1922; Ectocarpus arctus Kiitzing, 1843, 

 p. 289; Corticularia arcta Kiitzing, 1855, p. 23, PI. LXXX, fig. II. 

 On sand covered rocks, below low water mark, Gibbet Island, March, 

 Harris Bay, April, Hervey; floating, Tucker's Town, April, Harring- 

 ton Sound, May, Collins. E. acanthoides Vickers, Barbados, No. 95, 

 seems to be the same plant. We have not found in Bermuda the 

 typical form of E. siliculosus, which is common on both sides of the 

 North Atlantic. 



3. E. MITCHELLAE Harvey, 1852, p. 142, PL XII. G; P. B.-A., 

 No. 1921; E. mrescens Thuret in Sauvageau, 1896, p. 18 of reprint. 

 Harris Bay, Heron Bay, Jan., St. David's Island, Feb., Harrington 

 Sound, Shelly Bay, March, Hervey; Shelly Bay, Harrington Sound, 

 Cooper's Island, April, Collins. A common species, growing on corals, 

 larger algae, aquatic phanerogams, and on submerged twigs of live. 

 Tamarisk. Plurilocular fruit apparently always abundant, mega- 

 sporangia and meiosporangia in about equal numbers. The former 

 have not been recorded for the Atlantic coast of North America, 

 where the species is common, but were found in California, and dis- 

 tributed as 'P. B.-A., No. 671. When growing on any hard substance, 

 rhizoidal growth is usually insignificant; on Castagnea, Helmintho- 

 cladia etc., the rhizoids are strongly developed, penetrating well into 

 the tissue of the host. 



4. E. CONIFERUS Borgesen, 1914, p. 164, figs. 131-132. Shelly 

 Bay, April. Hervey, among E. Mitchellae. This species was quite 

 recently described from the Danish West Indies, and its occurrence 

 at Bermuda is of interest, indicating that it may be found at other 

 stations in the Atlantic. 



