CHAETANGIACEAE. 513 



G-alaxaura flagelliformis Kjellm. is similar to the foregoing, but has more 

 elongate branches and the longer assimilatory filaments are tufted, crowded, 

 or irregularly disponed without any obvious tendency to a whorled arrange- 

 ment. It probably represents the tetrasporic phase of G. squalida Kjellm., 

 with which it occurs at Bethel's Island (Collins 8i86). In the West Indiet^, 

 G. subverticillata and G. flagelliformis seem sometimes to intergrade, as do 

 also their probable sexual phases, G. rugosa and G. squalida. 



Galaxaura squalida Kjellm. has usually a smooth firm cortex, though 

 parts of the surface often bear few or numerous free assimilatory filaments. 

 It occurs on rocks and washed ashore at Hungry Bay, Gravelly Bay, Bethel 's 

 Island, etc., forming greenish, reddish green, or finally whitening tufts or 

 clusters mostly 2-4 inches high. It has terete, regularly dichotomous branches, 

 about 16 in. wide or a little more, commonly collapsing or flattened towards 

 the apices on drying. (Phyc. Bor.-Am. 1882.) 



Galaxaura marginata (Ell. & Soland.) Lamour. has a dark red, grayish 

 red, or greenish red thallus that is for the most part strongly flattened even 

 when living. Its sexual phase (G. occidenialis BjzTrg.) has a firmer cortex and 

 often a more shiny surface than the tetrasporic plant, and from certain parts 

 of its epidermis, especially at or near the margins, there grow out few or 

 numerous papilla-like cells, making darker roughened areas, barely visible 

 under a hand-lens. (Phyc. Bor.-Am. 1930, as Brachycladia marginaia.) 



Galaxaura obtusata (Ell. & Soland.) Lamour. has a coarse, terete, smooth 

 dichotomous thallus 2-5 inches long, its segments ^-ut inches in diameter, 

 usually constricted and jointed at either end, and often tapering towards 

 either end. It is more rigid and fastigiate than G. squalida. and its forkings 

 are wider-angled. It occurs unattached in fish-ponds, etc. near Tucker's Town, 

 where it is often less calcified than when growing under normal conditions in 

 deeper water, as met with in the West Indies. (Phyc. Bor.-Am. 1881.) 



Family GELIDIACEAE. 



Wrangelia penicillata (Ag.) Ag. is one of the delicate feathery or 

 ''mossy" red seaweeds. Its tufts reach a height or length of 2 to 6 inches. 

 Its usual color is a dull red or brownish red, becoming blackish with age or 

 partial decay. The thread-like, almost microscopic, branchlets are in regular 

 whorls, as may be determined with a hand-lens, and towards the sometimes 

 subcircinate apices of the main branches they are often tufte.l or subsecund. 

 The species occurs in warm shallow bays, as at Spanish Point, Ely's Harbor, 

 Achilles Bay, and Harrington Sound. (Phyc. Bor.-Am. ISSfi.) 



Naccaria corymbosa J. Ag. bears some resemblance to the above in gen- 

 eral habit, but is a rather smaller plant, mostly 1 to 2 inches high, is less 

 likely to darken on drying, and the branch system is alternate throughout. 

 The ultimate branchlets are so short, minute, and crowded as to be demon- 

 strable only with a compound microscope. The larger branchlets that are 

 visible with a hand-lens are slender and taper-pointed, and do not have the 

 tufted-plumose appearance of the corresponding branchlets of Wrangelia 



34 



