THE GREEN ALGAE OF NORTH AMERICA 365 



7. ANADYOMENE L,amouroux, 1816, p. 365. 



Frond membranaceous, stipitate, membrane consisting of 

 cells of two shapes, the larger, elongate cells forming a 

 branching framework, radiating from the base and paltnately 

 divided ; smaller roundish or ovoid cells issuing from the frame- 

 work and filling its intervals, forming a continuous membrane ; 

 in some species the membrane is of two layers of these smaller 

 cells. Zoospores formed in large numbers in the smaller cells, 

 escaping through an opening. Marine. 



The branching is beautifully symmetrical in the fronds of this 

 genus, showing plainly under a pocket lens, or even to the 

 naked eye. We have two species, one found throughout the 

 warmer Atlantic, the other recorded once only, at some point, 

 not definitely known, in the Gulf of Mexico. 



KEY TO THE SPECIES OF ANADYOMENE. 



I. Ribs of a single series of cells, each cell bearing above normally 

 three or more similar cells, paltnately arranged. 



i. A. stellata. 



i. Ribs composed of several contiguous series of cells, branching only 

 at considerable intervals. 2. A. Menziesii. 



1. A. STELLATA (Wulfen) Agardh, 1822, p. 400; Vickers, 

 1908, p. 21, PI. XXI ; P. B.-A., No. 169 ; A. flabellata Harvey, 

 1858, p. 49, PI. XLIV.A. Fronds often tufted, up to 10 cm. 

 diam., usually ovate or reniform in outline, in older plants often 

 much lobed ; of a single thickness of cells ; the stipe produced 

 into palmately arranged clavate cells, forming similarly dividing 

 series throughout the frond ; interspaces filled with smaller 

 oblong cells, issuing at right angles to the ribs, and forming a 

 continuous membrane. Fig. 125. Fla., W. I. 



Mediterranean, So. America. 



J. G. Agardh, 1886, p. 125, mentions two forms; f. normalis 

 and f. luxurians, the former with slenderer, longer, clavate or 

 cylindrical rib-cells; the latter with stouter, shorter, .ovoid 

 cells ; but he considers the latter form merely a luxuriant state 

 of the former. 



2. A. MENZIESII Harvey, 1858, p. 50; Grayemma Menziesii 

 J. E. Gray, 1866, p. 51, PI. XLIV, figs, i and 2. Frond up to 

 25 cm. diam., margin lobed, the stout ribs terminating in the 

 lobes ; rib formed of a bundle of parallel short-jointed filaments, 

 the marginal ones giving out radiating branches of smaller 

 cells, which form the membrane between the ribs. 



Dredged in 40 meters in the Gulf of Mexico, iu 1802, by 

 Archibald Menzies ; not since recorded. 



