THE MARINE ALG^ OF NEW ENGLAND. 77 



angles, and frequently opposite. In S. cirrhosa the sporangia are generally scattered 

 on the secondary branches, while in S. radicans they are often clustered on the main 

 branches. In both cases the pedicels are usually one-celled. In both species the 

 propagula are so variable in outline that they cannot be described in few words, but 

 those of S. cirrhosa are more robust than those of S. radicans. 



Sphacelaria dedalea, Eeinscb, Contrib. ad Alg. et Fung., p. 22, PL 30, described from 

 the coast of Labrador, does not correspond to any form known to us from New England. 



CH^ETOPTERIS, Kiitz. 



(From xcutt], a hair, and Trrepic, a fern.) 



Fronds olive-brown, filamentous, branching; branches opposite, dis- 

 tichous, apical growth as in Sphacelaria ; rhizoidal filaments very numer- 

 ous, densely interwoven, so as to form a false cortex ; plurilocular spor- 

 angia borne on the branches, shortly pedieillate, unilocular sporangia 

 " globose on the tips of short special filaments " (Areschoug). 



A genus founded on the old Sphacelaria plumosa of Lyngbye. It differs from Spha- 

 celaria in the false cortication of the main branches by the interlacing of rhizoidal 

 filaments, and from Cladostcphus by the opposite, not whorled branches. The genus 

 does not rest on a firm basis, for it occasionally happens in some of the species of Spha- 

 celaria that the rhizoidal filaments form a rudimentary cortex. Chcetopieris squamulosa, 

 Klitz., is made by Geyler the type of a new genus, Phloiocaulon. 



C. plumosa, (Lyngb.) Kiitz. {Sphacelaria plumosa, Lyngb., Phyc. 

 Brit., PI. 87. — Chwtopteris plumosa, Kiitz., Phyc. Gen., p. 293; Tab. Phyc, 

 Vol. 6, PI. 6, Fig. 1 ; Areschoug, Obser. Phyc, Part HI, PI. 2, Figs. 4 

 and 5.) 



Fronds two to six inches long, tufted, rigid, attached by a small disk, 

 main branches sparingly branched, secondary branches plumose ; pluri- 

 locular sporangia numerous, secund on the upper side of short special 

 branches, shortly stipitate, elliptical in outline ; unilocular sporangia 

 globose, terminal on short branches. (Areschoug, 1. c) 



Prince Edward's Island, Mrs. Davis, and northward ; Northern Eu- 

 rope. 



A beautiful species, common in Northern Europe and Greenland, but not yet found 

 farther south than Prince Edward's Island on the American coast. It may, however, 

 be expected at Eastport and our northern border. 



CLADOSTEPHUS, Ag. 



(From k\ doc, a branch, and oreQoc, a crown.) 



Fronds olive-brown, branching, secondary branches (leaves) whorled, 

 apical growth as in Sphacelaria; main stems densely corticated by 

 growth of rhizoidal filaments, secondary branches (leaves) naked, hairs 

 borne in tufts just below the apex of branches ; unilocular and pluri- 

 locular sporangia on special branches (leaves), stipitate. 



