THE MARINE ALG.E OF NEW ENGLAND. 67 



Exs. — Alg. Am. Bor., Farlow, Anderson & Eaton, No. 95. 



On stones at low tide. 



Eastport, Maine ; Cape Ann, Mass. 



We have referred to the present species a rather large form found abundantly in 

 September, 1877, at Eastport, near Dog Islaud, where it grows with Chordaria flagel- 

 liformis, which it somewhat resembles in habit. It is much coarser than D. fcenicu- 

 laceus, and of a darker color, and the branches are long and flagellate, and furnished 

 with comparatively few secondary branches. The Cape Ann specimens are smaller 

 and approach nearer D. fceniculaoem. The Eastport form can hardly be regarded as 

 an extreme state of D. fccniculaceous, but whether it is really the I). Mppitroides of Are- 

 schoug admits of some doubt, as Areschoug describes his species as being only six or 

 seven inches long. According to Areschoug, the conjugation of zoospores has been ob- 

 served in this species. 



Family ECTOCARPE.E. 



Fronds filamentous, monosiphonous or sometimes partly polysipho- 

 nous, cortex rudimentary or wanting ; sporangia either in the continu- 

 ity of the filaments or external, sessile or stalked ; unilocular sporangia 

 globose or cuboidal ; plurilocular sporangia muriform (formed of uuiner- 

 ous small rectangular cells densely aggregated in ovoidal or lanceolate 

 masses) ; growth trichothallic. 

 Fronds polysiphonous above, monosiphonous below, densely beset above 



with very short horizontal branches Myriotrich la. 



Fronds generally nionosiphonous throughout, branches free, opposite or 



alternate Ectocarpw. 



MYEIOTBICHIA, Harv. 



(From fivpiog, a thousand, and 6pt§, a hair.) 



Fronds olive-brown, filamentous, at first consisting of a single row of 

 cells, which by transverse and longitudinal division afterwards form a 

 solid axis; branches short, closely approximated, radiating in all direc- 

 tions, formed by outgrowths from the superficial cells of the axis ; uni- 

 locular sporangia spherical, borne on the axis between the branches; 

 plurilocular sporangia unknown; main axis and branches ending in 

 hyaline hairs. 



A genus comprising three species which are hardly distinct. They form small tufts 

 or fringes on different Plucosporecv, especially on Sci/tosij^wn , and are recognized by the 

 numerous short branches which in some cases almost cover the main axis and cause 

 it to resemble a Stigonema. The development of the frond is given in detail by Na*geli 

 in Die neuern Algensysteme. 



M. clav^formis, Harv., Phyc. Brit., PI. 101. (If. Harveyana, N;eg. 

 partim.) 



Fronds half an inch to an inch in length, club-shaped in outline, axis 

 clothed throughout with branches, upper branches longer than lower 

 and bearing secondary branches. 



