MARINE ALGA! OF BEAUFORT, N. C. 475 
these fertile filamentous branches confluent into an hymenium on the apices of which 
the carpospores are borne singly or, rarely, in short chains. 
About 90 species, all marine, mostly in warm and temperate seas. 
Genus Gelidium Lamouroux. 
Gelidium, Lamouroux, 1813, p. 40. 
Frond terete or flattened, pinnately decompound, of tough, firm texture, with thick 
dense rind; central axis composed of a segmented, longitudinal filament, from which 
arise numerous obliquely longitudinal filaments verticillately arranged and densely 
coalescent into a proper cortex, outer rind cellular, with larger cells toward the center, 
smaller ones toward the periphery; central axis with distinct apical cell. Tetrasporangia 
formed in sori immersed in local swellings on both sides of the thallus below the apices 
of ordinary pinne, rotund, cruciately divided; cystocarps immersed in swollen portions 
below the apices of ordinary pinne, usually divided by a longitudinal partition into two 
chambers, one on each side of the flattened thallus, each chamber communicating with 
the exterior bya separate pore, carpospores obovate arising singly from the hymenial layer, 
pericarp raised up from the hymenial layer but joined with it by numerous simple fila- 
ments, antheridia occurring in superficial patches; tetrasporangia and cystocarps occur- 
ring on separate plants. 
About 25 species recognized, many separated by inconspicuous, probably doubtful, 
characters; in warm and temperate seas. 
KEY TO SPECIES. 
Upright branches 1 to 2 cm. tall or less, comparatively thick, flattened, much branched.. 
Bt ay OF coerulescens (p. 475). 
Upright branches: 2 to, 3. 5c cm. .. tall, ‘slender, subterete, sparsely branched... ie isi 2. G. crinale (p. 475). 
1, Gelidium ceerulescens Kuetzing. Pl. XCV, fig. r. 
Gelidium cerulescens, Kuetzing, 1868, Bd. 18, p. 19, pl. 56, f. 2. 
Thallus erect, flattened, arising from a fine, filiform, creeping base, 1 to 2 cm. tall, 0.3 to 0.5 mm. 
wide in widest portion; branching decompound, distichous from the margins, sparse below, more or 
less dense above; texture fleshy gelatinous; color, dark purplish brown. 
West Indies; New Caledonia. 
Very abundant, forming low, dense masses on jetties, walls, shells, and stones at Fort Macon, 
Beaufort, N. C., and along town front from about ro to 70 cm. above low tide line, April to October, 
probably throughout the year. 
This species was identified by Mr. Collins on the basis of a Guadeloupe specimen determined by 
Crouan, and it may perhaps be questioned whether it is really the species described by Kuetzing. 
a. Gelidium crinale (Turner) J. Agardh. Pl. XCV, fig. 2. 
Fucus crinalis, Turner, 1808, pl. 198. 
Gelidium crinale, J. Agardh, 1876, p. 546. 
Gelidium crinale, Farlow, 138a, p. 158. 
Gelidium crinale, De Toni, 1897, p. 146. 
P. B.-A. Nos. 195, 2089. 
Primary frond decumbent, about o.5 mm. in diameter, giving off erect branches, terete or some- 
times slightly flattened, slender, 2 to 7 cm. tall, sparingly branched, sometimes almost simple; color 
purple or yellowish brown. 
Warm and temperate waters generally, occurring on our coast from Maine to Florida. 
Fairly abundant between tide lines on Fort Macon jetties, Beaufort, N. C., April to August, 1908, 
probably occurs throughout the year, abundant on submerged shells in Newport River near ‘Green 
Rock,’’ August, 1906; abundant in Core Sound near Leckly’s Island July, 1908; fairly abundant in Pam- 
lico Sound on shells and posts between tide lines, Ocracoke, N. C., August, 1907; one specimen on 
submerged shell, Pawleys Island, near Georgetown, S. C., August, 1909. 
110307°—21——31 
