nutters: i.wconx .wn calaxaura. 181 



mons. The internodes are 4-10 mm. in length (usually about 6 

 mm.), .75-1.5 mm. wide and .5-1.25 mm. thick, each internode 

 slightly wider at the distal than at the proximal end. The lower 

 internodes are terete, slightly rugose and furnished with a very few 

 long hairs which in some specimens are scattered and in others are 

 verticillately grouped at the lower nodes. The uj^per internodes vary 

 to a considerable degree in the several plants. In some they are 

 quite terete, in oth.ers flattened and about twice as wide as they 

 are thick. The upper internodes are entirely glabrous and marked 

 with transverse striations. 



The medullary portion of the frond is composed of intertwined 

 filaments, 7-12 mic. in diameter. The parenchymatous layer con- 

 sists of about three layers of elliptical, spherical or slightly angled 

 cells, the innermost about 65 high by 40 wide, the outer ones 20-30 

 mic. high. 45-55 mic. wide. The assimilatory filaments are borne 

 upon the middle layer of the parenchymatous cells, their stalks in- 

 tervening between the cells of the outer layer. Two or three of 

 these filaments may be borne upon a single cell of the parenchyma- 

 tous layer. The filaments are typically three-celled. The basal cell 

 is about 17 mic. high by 7-10 mic. wide, forked at the summit. It 

 comm.only bears two distal cells. These are narrowly or widely 

 elliptical or ovate, rounded at the distal end or shortly mucronate, 

 and have hemispherical chromatophores which fill about the distal 

 one-third of the cells. Among these filaments are the few long 

 hairs mentioned above, which are straight, unbranched, about 700 

 mic. long and 10 mic. thick. They are very rare in the upper parts 

 of the frond and not abundant anywhere. 



Galaxaura mauiana sp. nov. 



PLATE XXIV. FIG. 20. 



Fronde at 6 cm. alta e caudice brevissimo hirsuto prolificationi- 

 bus plurimis iteratim furcatis inferne teretibus superne subcom- 

 planatis aut paene teretibus, inferne hirsuta fills rectis plerumque 

 simplicibus aut fere glabra, superne subglabra transversim striata ; 

 tela assimilatoria filis curtis plerumque cellulis ternis vel quarternis 

 compositis cellula proxima singula ultimas aut binas aut ternas 

 ferente ovates rare apiculatas 35-46 mic. longas, 20-27 mic. crassas, 

 chromatophoro conspicuo complanato praeditas qui partem quartam 

 cellulae supremam implet instructa. 



