THE ALGAE OF BERMUDA. 71 



differs somewhat from the typical, but not enough to raise any ques- 

 tion as to identity. Our form comes nearer to the type from New 

 Guinea. The only marked difference is in the basal portion of the 

 plant growing on C 'odium. "When growing on Sargassum it formed a 

 more or less definite basal layer, from which short rhizoids issued, 

 entering the host. On the Codium there is no definite basal layer, 

 but a compact bundle of irregular rhizoidal filaments, narrower than 

 the assimilating filaments, with few chromatophores, and cells up 

 to 10 diam. long. The lower ends of these rhizoids separate more or 

 less, and spread among the utricles of the host. This difference is 

 explainable by the difference in structure of the hosts. On the Gala- 

 xaura the rhizoids are less conspicuous. Plurilocular sporangia, simi- 

 lar to those figured by Heydrich, were abundant. 



S. E. LUTEOLTJS Sauvageau, 1892, p. 25, PI. II, figs. 14-19. On 

 Didyopteris Justii, South Shore, Aug., Collins. The lower part of the 

 frond inhabits the tissue of the host; the upper part forms a fine down 

 on the surface. 



9. E. PARASITICUS Sauvageau, 1892, p. 28, PL III, figs. 20-23; 

 Streblonema parasiticwn (Sauv.) De Toni, 1895, p. 575. In Haly- 

 mcnia pseudofloresia, Jan., Hervey. Mostly endophytic; the plants 

 from Maine, distributed as P. B.-A., No. 1337, were chiefly external, 

 the difference being probably due to the firmer tissue of the host 

 in the latter case, Cystoclonium purpurascens. 



10. E. RALLSIAE Vickers, 1905, p. 59; 1908, PI. XXXII; Borge- 

 sen, 1914, p. 169, fig. 133; P. B.-A., No. 2172. On Helminthocladia 

 calvadosii, Old Ferry, April, Hervey. The main filaments are occa- 

 sionally stouter than in the Barbados and St. Thomas material, up to 

 40 /j. diam., but usually not over 30 n, in lesser divisions down to 20 /*, 

 in hairs to 10 p. There is a system of descending filaments, irregular 

 and twisted, but otherwise like the erect filaments, extending for quite 

 a distance in the tissues of the host; plurilocular sporangia agree in 

 form, dimensions and position with Borgesen's figure. 



STREBLONEMA Derbes & Solier. 



S. SPHAERICUM Derbes & Solier in Castagne, 1851, p. 100; Sauva- 

 geau, 1897, p. IS, figs. 2-3 (of reprint); Kuckuck, 1899, p. 28, figs. 

 6-7. In Castagnea Zostcrac, Cooper's Island, April, Collins. With 

 uni- and plurilocular sporangia; generally in company with Myrio- 

 irichia, which it much resembles. 



