508 BULLETIN OF THE BUREAU OF FISHERIES. 
Fronds forming a very fine capillary mat or fringe, composed of creeping’ filaments with short 
erect branches, primary filaments decompound, erect, short branches, slender, curved, tapering slightly 
toward the apices, borne in two rows, coming to lie approximately in one row; pericentral cells 8 to 10, 
segments 1.5 to 2 diameters long in the primary filaments, about 1 diameter long in the branchlets; 
tetrasporangia occurring singly in single, straight, unbroken rows of 20 to 30 in erect, short branches; 
antheridia often borne on every segment for about one-third the length of the branch, beginning about 
the middle and extending toward the apex; cystocarps usually borne Prey on short stalks; texture 
velvety; color purplish red. 
Florida and West Indies; Mediterranean. 
Abundant on Fort Macon and Shackleford jetties, Beaufort, N. C., throughout the year, on other 
alge, especially Padina vickersie, and sometimes on the Polyzoan Bugula turrita, fruiting August and 
September, probably throughout the summer and autumn. Fairly abundant on Dictyota dichotoma, in 
sound near inlet, Wrightsville Beach, N.C., July, 1909. Fairly abundant on shells and other alge, in 
sound near inlet, Pawleys Island, near Georgetown, S. C., August, 1909. 
This species will not be mistaken for any other occurring in this region, being easily recognized by 
its appearance of a creeping Polysiphonia, forming purplish red, velvety mats or fringes composed of 
horizontal filaments with upright branches. The species is dicecious. Often all the filaments observed 
on a single specimen of the host were either sexual (both male and female) or tetrasporic, but sometimes 
both tetrasporic and sexual plants occurred together. 
This is the northern known limit of the species and of the genus. 
Genus 7. Dasya Agardh. 
Dasya, Agardh, 1824, p. XXXIV. 
Frond erect, terete, radially constructed, laterally and radially somewhat irregu- 
larly branched, long and short branches intermixed; structure cellular or filamentous- 
cellular, with a circle of five (very rarely four) pericentral cells, naked or inclosed by a 
more or less dense rhizoidal cortex, apical growth sympodial, the entire frond or the 
younger parts densely covered by spirally arranged, repeatedly forked, colored tricho- 
blasts; tetrasporangia in whorls (usually of five sporangia) at each segment of special 
lanceolate branchlets (stichidia) arising as young branches of the trichoblasts and 
attached to these by monosiphonous stalks, covered by special cover cells when young, 
uncovered when mature, triangularly divided; antheridia arising as branches of the 
trichoblasts, lanceolate-conical, ending in a sterile apex, borne on a monosiphonous 
stalk; procarps numerous near the growing apices of more or less developed lateral 
branches; cystocarps ovate-globose or urn-shaped, borne laterally on smaller branches, 
pericarp rather thin, opening by a conspicuous terminal carpostome, gonimoblast com- 
posed of dichotomously branched filaments radiating from a basal placenta, forming 
oval or club-shaped carpospores singly or, rarely, in shcrt chains of two to three spores 
from their terminal segments. 
Thirty to forty species, in warm seas. 
Dasya pedicellata Agardh. Pl. CX, fig. 2. 
Dasya pedicellata, Agardh, 1824, p. 211. 
Dasya elegans, Harvey, 1853, p. 60. 
Dasya elegans, Farlow, 1882, p. 177, pl. 15,f. 1. 
Dasya elegans, De Toni, 1903, Pp. 1201. 
A. A. B. Ex. No. 51 (Dasya elegans). 
P. B.-A. No. 54s, Fasc. A, No. XXIII (Dasya elegans). 
Fronds moderately robust, flexuous, terete, 4 to 90 cm. long, about 0.6 to 6 mm. in diameter in 
main stems, arising singly from a small basal disk, branching lateral, decompound, sparse or profuse, 
lower portions of the main stem and larger branches naked, smaller branches, and sometimes almost 
the entire plant, very densely covered by conspicuous, monosiphonous, dichotomous, flaccid tricho- 
blasts going out on all sides from the cortical layer, not tapering toward the apices; pericentral cells 
