136 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Chaetangiaceae 



Plants of moderate size, erect and bushy, soft but not slippery, some- 

 times partly calcified; structurally multiaxial, the ultimate filaments 

 turned outward to form the assimilatory cortex, with the outer cells 

 sometimes closely associated to form a continuous epidermis; asexual re- 

 production by monosporangia or tetrasporangia ; carpogenic branches three 

 celled, borne on inner forks of the cortical, or on the subcortical, filaments; 

 cystocarp becoming surrounded by a pericarp of slender crowded filaments 

 arising from the lowest cell of the carpogenic branch, discharging through 

 a pore at the surface. 



KEY TO GENERA 



1. Smooth and completely uncalcified 2 



1. Smooth or pilose, but if smooth always more or less calcified . 

 Galaxaura 



2. Outer cortex of a more or less coherent layer of chiefly colorless 

 cells forming a distinct epidermis Scinaia 



2. Original utricular surface cells soon interspersed with, and ulti- 

 mately displaced by, anticlinal moniliform filaments . Gloiophloea 



GALAXAURA Lamouroux, 1812 



Plants bushy, of moderate size, fairly soft to firm and wiry, dichot- 

 omously or somewhat pseudoalternately branched; pilose, the cortex in- 

 side of the zone of assimilatory filaments somewhat calcified, or, smooth 

 and without free assimilators, lightly to moderately calcified at the sur- 

 face, sometimes segmented by the absence of calcification at the forks; 

 structurally composed of a medulla of slender colorless filaments which 

 gives rise by lateral branches to an inner more or less filamentous cortex 

 of large colorless cells, the outer cortical cells large in some species, co- 

 hering and forming an epidermal membrane, in some smooth, in others 

 bearing one-celled spinulose projections on these outer cortical cells, or, 

 the cortical cells not coherent and bearing long assimilatory filaments; 

 spermatangia formed in conceptacles ; carpogenic branches three celled, 

 formed on the inner cortical filaments, the cystocarp surrounded by a 

 pericarp of slender filaments, discharging by a pore at the surface. 



The genus Galaxaura is a perennially troublesome one. There is little 

 difficulty where the sexual and asexual plants are alike, though even here 

 the supposed alternate phases have histological differences. It appears 

 probable that the sexual and the asexual plants are in some other species 

 grossly dimorphic, as probably in G. subverticillata and G. rugosa, or G. 

 cylindrica and G. lapidescens, in others not so evidently dimorphic, as in 



