THE MARINE ALGJS OF NEW ENGLAND. 71 



other algaB. It is distinguished from our other species by the short, broad, and sessile 

 Bporaugia. In the type the branching is opposite and compact, and the corticating 

 filaments are sometimes so numerous, especially in the Newport specimens, as to lead 

 one to admit the validity of Kii tzing's genus Cortioularia. But in other cases the cor- 

 ticating filaments are few in number. 



E. confervoides, (Roth) Le Jolis. (Ectocarpus siliculosus, Phyc. 

 Brit., PL 102 ; Ner. Ain. Bor., Vol. I, p. 139.) 



Filaments erect, two to twenty inches long, loosely entangled at the 

 base, becoming free and feathery above; branches alternate or secund, 

 gradually tapering; cells of larger branches .04-5 nn in diameter; pluri- 

 locnlar sporangia ovate-acute or acuminate, sessile or stalked, sometimes 

 rostrate average size of sporangia .025-40 mm broad by .15-40 mra long; 

 unilocular sporangia oval or ellipsoidal, .023-30 ,rm broad by .035-50 mm 

 long. 



a, var. siliculosus, Kjellman. (Ectocarpus viridis, Harv., Ner. Am. 

 Bor., Vol I, p. 140, PI. 12 b and c.) 



Plurilocnlar sporangia subulate or linear-subulate, sessile or sub- 

 sessile, frequently rostrate. 



/9, var. hiemalis, Kjellman. (Ectocarpus Memalis, Crouan.) 



Plnrilocular sporangia elongated, conical or snbacuminate, .08-15 ram 

 long by .02-3 mm broad, generally rostrate. 



Very common on algre and wood work along the whole coast. 



Var. «, most common south of Cape Cod. 



Var. /?, Wood's Holl, Mass J 



The largest, most variable, and most common summer species of our coast, aud 

 found in nearly all parts of the world. It has been subdivided by Kiitzing into a 

 large number of species, which are scarcely to be recognized from his descriptions 

 and plates. Formerly some of the different forms of E. littoralis were referred to 

 the present species, but the true E. littoralis is now recognized as belonging to the 

 subgenus Pylaiella. Those interested in tracing the synonymy of E. confervoides 

 should consult Kjellman's Bidrag till Kannedomen om Skandinaviens Ectocarpeer 

 och Tilopterider, Stockholm, 1872. As seen on our own coast, what we have called the 

 typical E. confervoides forms tufts of indefinite extent on wharves, and especially on 

 the larger algse, varying in length from a few inches to a foot and a half long. It 

 frequently fringes the fronds of Chorda filum with its soft, silky tufts. In the type 

 the plurilocular sporangia, which are much more common than the unilocular, are 

 ovate-acuminate, and only occasionally rostrate. In the variety silictilosus the pluri 

 locular sporangia are long and comparatively very narrow. The variety Memalis is 

 found in the winter and spring, and has plurilocular sporangia, which are almost 

 always rostrate and somewhat cylindrical in form, so that they may be said to resem- 

 ble those of the subgenus Pylaiella. The color of the present species when growing 

 js a light brown approaching yellowish, which in drying often turns to a yellowish- 

 green, especially in the variety sHiculosns, of which herbarium specimens might be 

 mistaken for Cladophora?,. The winter forms are deeper brown than those found in 

 summer. E. amphibius, mentioned in the supplement to the Nereis as occurring near 

 New York in brackish water, is a form of the present species. 



