490 BULLETIN OF THE BUREAU OF FISHERIES. 



Halymenia the thallus wall is denser, being composed of smaller, more closely crowded 

 cells, and the cavity is traversed by numerous more or less densely crowded filaments. 



KEY TO SPECIES. 



Frond flat, leaflike ; i. C. agardhii (p. 490). 



Frond hollow-tubular and gelatinous-membranaceous throughout; laterally decompound 



2. C. enteromorpha (p. 490). 



Frond caulescent, solid and rigid below, dichotomously branched, bearing numerous hollow, 

 gelatinous-membranaceous, obovate, bladderlike lateral branches below the apices 

 3. C. uuaria (p. 491). 



1. Chrysymenia agardhii Harvey. Fig. 34; PI. CII, fig. 2. 



Chrysymenia agardhii, Harvey, 1853, p. i?p, pi. 30 A. 

 Chrysymenia agardhii, De Toni, 1900, p. 538. 

 P. B.-A. No. 746- 



Frond flat, leaflike, 5 to 20 cm. long, about 2 to 5 cm. wide, broadly cuneate at the base and tapering 

 gradually into a rather short stipe, dichotomous or subpalmately laciniate, sometimes simple, sometimes 

 irregularly pinnate by lobes from the margins; segments rather broad, approximate above narrow axils, 

 marginal ones somewhat attenuate toward the base, terminal ones attenuate, obtuse; margin wavy, 

 usually eroso-denticulate ; thallus rather thick, bearing a more or less conspicuous cavity traversed by 

 branched, segmented filaments, which are fairly numerous in some places, sometimes joining the thallus 

 walls, wall composed of one or two layers of very large cells bordered by i to 3 layers of small cortical 

 cells; cystocarps rather prominent, bluntly conical, scattered over the surface of the segments; color 

 bright rose, becoming pale rose or brownish when dry; texture gelatinous-membranaceous. 



Florida. 



Four sterile plants 7 to 18 cm. long, dredged on coral reef offshore from Beaufort, N. C., August, 1914. 



This species resembles Halymenia floridana and H. gelinaria. From the former it is distinguished 

 by its more gelatinous texture and its thicker frond, with larger cells and fewer internal filaments. 

 From the latter it is distinguished by its less gelatinous texture, its thicker frond with larger, more 

 numerous cells, and the absence of papillae on the surface. 



In none of the specimens has there been observed as abundant filaments or as thick a cortex as is 

 figured by Harvey, and the cortical cells have not been observed in vertically seriate rows. Thick 

 sections, however, especially under low magnification ,, may give an appearance similar to that shown 

 in Harvey's illustrations. 



This is the northern, known limit of the species and of the genus. 



2. Chrysymenia enteromorpha Harvey. PI. CIII. 



Chrysymenia enteromorpha, Harvey, 1853, p.. 187. 

 Chrysymenia enteromorpha, De Toni, 1900, p. 545. 

 P. B.-A. No. 386. 



Frond tubular-hollow, terete or flattened, about 5 to 30 cm. tall, 4 to 8 mm. in diameter, arising 

 from, a slightly tapering base, laterally decompound branches elongated, similar to the main axis, con- 

 stricted at their bases, apices obtuse, often narrowed below the apex and terminated by an obtuse 

 apiculum; main branches flattened or terete, ultimate branches and branchlets terete; thallus wall 

 consisting of one or, more rarely, two loose layers of large cells bounded by a single layer of minute 

 cortical cells; cavity of frond filled with soft jelly; tetrasporangia inconspicuous, scattered over the sur- 

 face without order among the cortical cells, cruciately divided; cystocarps small, not very prominent, 

 scattered over the branches; texture delicate gelatinous-membranaceous; color light yellowish to rosy 

 pink. 



Florida and West Indies. 



Two specimens, one tetrasporic, the other cystocarpic, Bogue Beach, Beaufort, N. C., August, 1907, 

 one specimen dredged from coral reef offshore, August, 1914. 



The specimens from Bogue Beach (PI. CIII, fig. i) and the one from the coral reef (PI. CIII, fig. 

 2) differ greatly in appearance, although both seem to come within the range of the species. 



