CEEAMIACEAE. 533 



sexual origin -where one would naturally expect cystocarps of sexual origin. 

 The resemblance of the vegetative characters of Ceramothamnion to those of 

 undoubted species of Ceramium, the occurrence of antheridia, the failure to 

 find proved procarps and cystocarps, and the resemblance of the supposed 

 polysporangia to the cystocarps of Ceramium, form a combination of circum- 

 stances that suggests the possibility that the alleged polysporangia of Ceramo- 

 thamnion are in reality cystocarps. (Phyc. Bor.-Am. 845 and 1899 ; 2193, as 

 Ceramium tenuissimum pygmaeum.) 



Centroceras clavulatum (Ag.) Mont, is the commonest and perhaps the 

 most variable Bermudian representative of the Ceramiaceae, growing on rocks 

 and on various larger algae in shallow water, or, in surf -beaten places between 

 the tide-lines. Its capillary brownish red or dingy red dichotomous fastigiate 

 filaments form tufts or loose mats commonly 0.5-4 inches high. The filaments 

 are corticated throughout and may be distinguished from corticated species of 

 Ceramium by having the somewhat rectangular cortex cells in regular longi- 

 tudinal rows. In the younger parts at least, each node bears a whorl of teeth 

 or short mostly 2-celled spines, by which character also it is easily distinguished 

 from its Bermudian relatives. In the length, shape, and abundance of these 

 spines, the plant varies greatly according to habitat, and distinctions of species 

 based on these characters have been attempted. (Phyc. Bor.-Am. 1948, as 

 Ceramium clavulatum.) 



Family GRATELOUPIACEAE. 



Halymenia bermudensis Collins & Howe, has a membranous, violet-red, 

 rather firm or slightly gelatinous, usually stipitate frond that is variable in 

 form, mostly suborbicular, cordate, or obovate, and 2-10 inches broad, sub- 

 entire or sparingly or copiously lobed or proliferous, the lobes ovate or con- 

 formable. Under a microscope, the medullary filaments viewed through the 

 cortex are seen to be interspersed with a few coarser filaments, having more 

 homogeneous refringeut contents and radiating from substellate, ganglion-like 

 enlargements. (Phyc. Bor.-Am. 2050.) Apparently endemic. 



Halymenia pseudofloresia Collins & Howe, has a membranous deep red or 

 violet-red frond that is gelatinous in younger parts, becoming firmer with age, 

 suborbicular, ovate, cuneate-obovate, or commonly very irregular in general 

 outline, 3-10 inches long, deeply, irregularly, or subpalmately lobed, or often 

 showing cuneate-based substipitate marginal proliferations, the main expansion 

 or axes A-3 inches broad, the lobes or proliferations commonly lanceolate, ser- 

 rate, biserrate, or subpinnately lobulate or bilobulate, the teeth mostly acumi- 

 nate-deltoid, the medulla, under a microscope, occasionally showing a few incon- 

 spicuous stellate ganglia. (Phyc. Bor.-Am. 2099.) Apparently endemic. 



Halymenia echinophysa Collins & Howe, has a membranous lilac or grayish 

 vinaeeous gelatinous frond that is suborbicular in general outline and 47 

 inches wide, deeply, irregularly or subpalmately lobed or divided, the lobes 

 irregularly obovate or suborbicular, mostly 1-2* in. broad, their margins 

 sinuate- or erose-dentate or sparingly sublobulate. Under a microscope, some 



