THE MARINE XLGM OF NEW ENGLAND. ^ 69 



would, however, incline one to consider that the antheridia in this genus were not 

 proper male bodies. 



Some of the species of Ectocarpus described by Harvey in the Nereis were founded on 

 sterile specimens, but, at the present day, algologists agree in thinking that the pres- 

 ence of sporangia is necessary for the determination of species of Ectocarpus, and we 

 have, accordingly, omitted the Harveyan species founded on sterile plants as being 

 inadequate. 



Subgenus STREBLONEMA, Derb. & Sol. (Entonema, Reinsch). 



Primary branches procumbent, creeping iu or over the substance of 

 other algae ; secondary and fructifying ramuli erect. 



E. Chordaria, n. sp. 



Filaments much branched, irregularly nodose, about .02 ram in diam- 

 eter, sunk in the tissue of the host-plant; hairs and fertile branches erect, 

 the former, projecting above the surface; unilocular sporangia on short 

 stalks, solitary or clustered, oval, about .07 mra broad by .14 mm long; 

 plurilocular sporangia unknown. 



Parasitic in the fronds of Ghordaria divaricata, Leathesia tuberiformis^ 

 and other Phceosporece. 



Wood's Holl, Gloucester, Mass. ; Newport, E. I. 



A common but insignificant species which grows iu the cortical portion of different 

 PhcBosporew, especially Chordaria divaricata, and usually in company with Bulbocoleon. 

 It forms dark-colored spots on the surface of the plant in which it is growing, and, on a 

 hasty microscopic examination, would pass unnoticed, so great is the resemblance of the 

 sporangia to those of Chordaria. Our plant resembles & sphcericum, Thuret, but differs 

 from the Mediterranean forms of that species in having oval, not spherical, sporangia, 

 which are often clustered. The filaments, too, are composed of very irregular-shaped 

 cells, and are never moniliform as in well-developed specimens of S. sphcericum. It 

 may, however, be the case that what we have considered specific marks are only local 

 variations. It may also be asked whether the present species is not the form of S. 

 fasciculatum, Thuret, which bears unilocular sporangia. At present only the plurilocu- 

 lar form of sporangium is known in that species as it occurs in Europe. 



E. reptans, Crouau, Florule du Finistere, p. 161; Kjellman, Bidrag 

 till Kann. Skand. Ect. Tilop., p. 52, PL 2, Fig. 8. 



Filaments forming circular spots on the host-plant, primary branches 

 very densely branching, so that they almost form a membrane, fur- 

 nished with numerous erect branches, which are .5-7 mm high and grad- 

 ually taper to a hyaline hair; cells at base about .01 mm broad; plurilocular 

 sporangia arising from the primary filaments, sessile or on short stalks, 

 ovate-acute, .012-20 mm broad by .038-76 mm long. 



On Phyllitis and Dictyosiphon. Summer. 



Newport, E. I. ; Europe. 



A larger species than the preceding and growing more superficially, so that the fila- 

 ments may be said to creep over the surface rather than in the substance of the host- 

 plant. Owing to the dense branching of the prostrate filaments and the abundance 



