124 REPORT OP COMMISSIONER OP PISH AND FISHERIES. 



rather long and slender, opposite, in twos or occasionally in fours, gen- 

 erally distichous, widely spreading, once or twice pinnate, ultimate 

 divisions opposite or secund, long and slender; tetraspores cruciate, 

 sessile on the upper side of the secondary branches ; favellee binate. 



Exs. — Alg. Am. Bor., Farlow, Anderson & Eaton, ISTo. 89. 



On wharves and algae below low- water mark. Spring. 



From New Jersey northward. 



A common and very beautiful species, more abundant in Long Island Sound than 

 farther northward. It varies considerably in the compactness of the branching and 

 the tenuity of the cells. The species with which it is likely to be confounded is 

 C. Pylaiscei, as already indicated. The long and slender secondary branches are less 

 regularly placed than in some other species of the subgenus, and they are not always 

 distichous nor opposite, although that is generally the case. We have also seen a 

 specimen on which both tetraspores and cystocarps were found together. 



0. plumula, Lyngb., Phyc. Brit., PL 242. 



Fronds two to four inches long, main branches alternately decom- 

 pound, secondary branches opposite of in fours, distichous, short, 

 recurved, pectinate on the upper side with 1-3 pinnated branchlets j 

 tetraspores cruciate, shortly pedicellate on the branches. 



On wharves and on shells in deep water. 



Long Branch, IS". J., Savvey ; Orient, L. I., Miss Booth; on steamboat 

 wharf, Newport, R. I. ; dredged in 8-10 fathoms, Gay Head, W. G. F. ; 

 off Block Island, Professor Eaton. 



A rare species on the American coast, and known in but few localities. It is found 

 occasionally on wharves just below low-water mark, but more frequently on shells iia 

 from five to ten fathoms. It is tolerably abundant off the Devil's Bridge, near Gay 

 Head, where it is found in company with Lomentaria rosea. It is one of the most easily 

 recognized species of the genus found on our coast. The branches are beautifully 

 symmetrical and distichous, two opposite branches being given off from each cell, or 

 occasionally there are four in a whorl, two being smaller than the others. The 

 branches are recurved and furnished on the upper side only with 1-3 pinnate 

 branchlets. 



Subgenus PLEONOSPORIUM, Na3g. 



Fronds erect, pinnate, cortication wanting ; antheridia cylindrical on 

 the upper branches; favellse terminal, involucrate; tetraspores poly- 

 sporic. 



C. Borreri, Ag., Phyc. Brit., PI. 159. 



Fronds dioecious, densely tufted, monosiphonous, with a few rhizoidal 

 filaments at the base, filaments one to four inches long, capillary, main 

 branches several times pinnate, branches beset in lower part with 

 usually simple, elongated branchlets, distichously pinnate above, ulti- 

 mate ramifications broadly ovate or triangular in outline, branchlets 

 naked below ; antheridia cylindrical ; tetraspores sessile on the upper 



