MARINE ALG2E OF NEW ENGLAND. 127 



Our most robust and coarsest species, not uncommon in Long Island Sound, but not 

 yet recorded north of Cape Cod. The color is dark, and in the water almost black, 

 and the substance is rather spongy, the plant not collapsing when removed from the 

 water, as do most of the New England species of the genus. 



C. Baileyi, Harv. (G. Baileyi, Harv., Ner. Am. Bor., Part III, PI. 

 35 b. — Dorythamnion Baileyi, Naeg.) PI. XI, Figs. 1-2. 



Fronds monoecious, two to four inches high, setaceous, shrub-like, 

 pyramidal in outline, color purplish red, main filaments densely corti- 

 cated, the rest monosiphonous ; main axis percurrent, attached by a 

 disk, pinnate with long, undivided, alternate branches, which are once 

 ' or twice pinnate, the ultimate divisions beset on all sides with rather 

 slender, flexuous, recurved or incurved, fasciculate branches ; cells 

 several times longer than broad ; tetraspores tripartite, sessile on the 

 upper brauchlets ; antheridia in tufts on the upper internodes ; favellse 

 binate. 



Var. laxa. 



Cortications less marked than in the type, branchlets long and slen- 

 der, divisions widely spreading below, fastigiate at the apex. 



On Zostera, stones, sponges, and algae below low-water mark. 



Common from New Jersey to Cape Cod ; Boston Bay, Harvey ; Port- 

 land, G. B. Fuller. 



As is suggested by Harvey in the Nereis Am. Bor., the present species is not only 

 very variable in habit, but it is also difficult to distinguish some of the forms from G. 

 tetragonum. We are inclined to believe that it would be better to consider the pres- 

 ent species as a delicate form of C. tetragonum, in which the cells are longer and more 

 slender, the brauchlets less dense and robust, the color less inclined to blackish, and 

 the substance more delicate. If we are to unite Bhodomela subfusca, B. gracilis, and 

 B. Boehci in one species, as has been done by Agardh, with good reasou as it seems, it 

 would be equally correct to unite C. Baileyi and C.teiragonum, since the difference in 

 habit might result from variations of habitat and season. With us, the form here 

 referred to the typical C. Baileyi is more common than C. tetragonum, and is found on 

 wharves, on Zostera, shells, and stones in rather warm waters and sheltered places, 

 while C. tetragonum frequents places where there is a current of water, or grows on 

 alg?e in somewhat exposed pools. The var. laxa has a diffuse ramification and the 

 cortications are not prominent, and we at one time supposed that it might be the C. 

 Dietzke of the Nereis, as far as we could recollect the specimens of that species in the 

 Harveyau Herbarium at Dublin. In such cases, however, it is not safe to trust to 

 one's memory, and in the present article we are unwilling to express an opinion about 

 C Dietzias. 



Sect. III. Byssoid^:. 



Branching monopodial or dichotomous, cortications present at the base, 

 ultimate branches decompound, very delicate, usually ending in a hyaline 

 hair. 



C. byssoideum, Arn. (G. byssoideum, Phyc. Brit., PI. 262,—Phle- 

 bothamnion byssoides, Kiitz. — Pcecilothamnion byssoideum, Na3g.) 



