THE MARINE ALGiE OF NEW ENGLAND. 177 



are tropical, Australia being especially rich in species. The genus is dividiMl into a 

 nmubcr of snl>«;tMU'ra, an<l is coniu'ctetMiy liostrychia an«l Tirnioma with Polyxlphouia. 

 The totrasporrs are in t<tiihiilia lu)nio on the hair-like branihlets, while in Boxtryrlna 

 they are in the ji(»lysii>honons branches, ami in Tirnioma the stiehidia are ibrnied from 

 the llattene«l an<l seareely altere<l branches. The eystotarps are borne on short lat- 

 eral branrhes, which are nsnally slightly prolonj^ed beyond the base of the cystoearii. 

 The plaernta of Dasi/a ditVers somewhat from that of I'olysijihotiia anil onr other gen- 

 era of Jihodomtha: The sjiores are jiyriform, bnt are borne on rather lon«; branthinj^ 

 lilaments which surround the cari>ogenic cell at the base of the conceptacle, and 

 which rise high up in its interior instead of being nearly sessile around the carpo- 

 genic cell, as in I'olysiphonia. The development of the cystocarp has been studied in 

 detail by Jauczewski in D. cocciiu-a. The fronds are either tilamentous or more or less 

 tlattene«l, and, as in the case with most of the siiborder, are formed from a monosiph- 

 onous axis, from the cells of which whorls of tilaments are given oil", which in tho 

 older parts of the frond become parallel to the axis and replace the sijihons of Pol y- 

 Htphouia. In most of the genus there are also secondary siphons and corticating cells, 

 and either at the tip or throughout the frond tufts ttf delicate, dichotomous, m<»nosiph- 

 onous branchlets, which are colored and not hyaline, as in the hairs of some other 

 genera. 



D. ELEGANS, Ag.j Sp. Alg. [lihodonema elcf/ans, ^lartens. — Dafti/a 

 pediccUiitaj Air., Syst. ; Bailey, in Am. Joiini. Sci., Vol. Ill, p. 84.)— CAe- 

 niUe. PI. XV, Fig. 1. 



Exs. — Alg. Am. Bor., Farlow, Anderson & Eaton, Xo. 51. 



Fronds dicecions, villous, lake-red, six inches to three feet long, cylin- 

 drical, attached by a small disk, alternately 1-3 pinnate, with a percur- 

 rent axis, densely clothed throughout with tufts of purple, cai)illary, 

 nionosiphonous, dichotomous branchlets, sections of branches showing 

 five cells around the axial cell j antheridia densely covering the lower 

 cells of one of the divisions of the branchlets ; tetraspores in two or 

 three rows in linear-lanceolate or ovate pointed stichidia on the branch- 

 lets ; cystocarps sessile on very short branches ( pedicels) which are 

 borne on the main branches. 



On Zostera, wharves, «S:c., below low-water mark. 



Common from Cape Cod southward ; Adriatic Sea. 



A beautiful species, known to lady collectors by the name of chenille, at once recog- 

 nized by its long, cylindrical, branching fronds, densely fringed with fine lake-colored 

 filaments. It is found throughout the year. In drying it adheres closely to paper. 

 The antheridia are much like those of Polysiphonxa rariegata, but are longer. The 

 species extends to the West Indies, but appears to be more c(mimon in Long Island 

 Sound than elsewhere. There is in the collection of the Peabo<ly Academy of Salem 

 a very large specimen, said to have been collected at Ipswich Beach, Mass., but tho 

 locality must be regarded as doubtful. At any rate, tho species is quite unknown 

 ' Isewhere north of Cape Co<l. 



Suborder CORALLINE/E, Decaisne. 



Fronds rose-colored or puri)le, calcareous, horizontally expanded or 

 ' rect and branching, crustaceous, foliaceous, or filiform, continuous or 



