THE MARINE AL(LE OF NEW ENGLAND. 73 



attenuate; articulations of the branches twice or thrice as long as broad, 

 of the ramuli once and a half as long; propagula elliptic-oblong or 

 linear, quite sessile and very obtuse, transversely striate, several to 

 gether." (Harvey, 1. c.) 



Nantucket, Miss Mitchell. 



Only known from the description and plate in the Nereis. 



Subgenus PYLAIELLA, Bory. 



Both forms of sporangia formed from the cells in the continuity of 

 the branches, and not by a transformation of special branches. 



In the present subgenus one might, at first sight, be inclined to include E. siliculosus 

 var. hiemalis and E. lutosus, but in those species the sporangia are rather situated at 

 the end of branches, which are prolonged beyond the sporangia in the form of hairs, 

 than in 4 he continuity of the branches themselves. 



B. littoralis, Lyngb. {Ectocarpus Jinnies, Ag. — Pilayella littoralis, 

 Kjellman.) 



Filaments tufted or irregularly expanded at the base, two to ten 

 inches long; branches numerous, usually opposite, given off at wide 

 angles, erect; cells .02-4' mc broad; plurilocular sporangia irregularly 

 cylindrical, very variable in size; unilocular sporangia formed of from 

 two to thirty contiguous cells, .02-3 mm broad ; fertile branches monili- 

 form. 



Var. robustus. {Ectocarpus Farloioii, Thuret, in Farlow's List of 

 the Marine Algae of the United States, 1876.) 



Filaments three or four inches long, densely branching; branches 

 robust, opposite or irregular ; cells .03-5 m ' n in breadth ; fertile branches 

 short and rigid, often transformed through nearly their whole length 

 into unilocular sporangia, which are stout and cylindrical, only slightly 

 moniliform at maturity ; cells .04 mm broad and ,03-4 ram in length. 



Very common along the whole coast. . 



Var. robustus in exposed places from JSfahant northward. 



A very common species on our coast, which, although offering numerous forms, can- 

 not, as it seems to us, be well specifically divided. When growing on wharves, where 

 it is very common, or on other wood work, it forms expansions of indefinite extent 

 from which rise tufts several inches long. The basal or prostrate portions branch 

 very irregularly, and the cells are infested with Chytridia and other parasites. If 

 sjjecies of Ectocarpus could be formed from sterile specimens, the basal portions of E. 

 Mttoralis would offer a rich field to the species-maker. What is called var. robustus 

 lias not yet been found south of Cape Cod, but is common on the northern coast on 

 Fuci and other algae exposed to the action of the waves. The original E. Farlowii was 

 founded on sjteciinens collected by Mr. Higbee, at Salem, in November, 1874, and pro- 

 nounced by the late M. Thuret, in a letter dated April 26, 1875, to be distinct from E. 

 littoralis. In the Contributions ad Algologiam et Fungologiam, PL 20, Reinsch 

 figures, under the name of Ectocarpus anticostiensis, a form which, as far as can be 



