THE GREEN ALGAE OF NORTH AMERICA 377 



merits repeatedly pinnate, articulations of the pinnae 3-4 diam. 

 long, of the pinnules 2 diam. Fla., Gulf of Mexico. 



This species was dredged by Menzies early in the last cent- 

 ury, and his single specimen remained undescribed until 1866, 

 when it was taken by J. E. Gray, 1866, p. 70, as the type of the 

 new genus Wiyllodictyon. The original specimen, though over 

 30 cm. long, is evidently fragmentary ; a single, smaller frag- 

 ment, found by Mrs. G. A. Hall, at Jupiter Inlet, Florida, is 

 the only record since Menzies. 5". pulcherrima seems to be the 

 rarest, as well as one of the most interesting of our green 

 algae. 



3. S. RAMOSA Dickie, 1874, p. 316; Murray and Boodle, 

 1888, p. 280, PI. XVI, fig. 3. Stipe, with a few annular con- 

 strictions, above oppositely branched, each branch ending in a 

 sub-elliptical network, about 3X1^ cm.; filaments tripinnate, 

 lower articulations 7-8 times their diam., upper 3-4 times. 

 Bermuda. 



Family 4. DASYCLADACEAE. 



Frond consisting of a long, inarticulate axillary cell, attached 

 by rhizoids below, and of whorls of usually pluricellular, simple 

 or branching ramuli of limited growth ; in fertile ramuli are 

 produced either gametes, or aplanospores which when freed 

 produce gametes. 



Marine plants of warm waters and general distribution. 



KEY TO THE GENERA OF DASYCLADACEAE. 



i. Frond calcified. 2. 



i. Frond not calcified. 6. 



2. Frond with slender stipe and with whorls of branches terminal 



or at considerable intervals. 3- 



2. Whorls of branches contiguous, concealing the axis. 5. 



3. Spores contained in whorled branches, not calcified. 



I. ACETABULARIA. 



3. Spores contained in whorled branches, calcified. 4- 



4. Spores imbedded in a solid mass of lime, but membrane free from 



lime. 3- ACICULARIA. 



4. Spores free, membrane much incrusted. 2. CHALMASIA. 



5. Stem branching, moniliform. 5- CYMOPOLJA. 



5. Stem unbranched, surface continuous. 4- NEOMERTS. 



6. Sporangia terminal ; whorls very closely set. 6. DASYCLADVS. 



6. Sporangia lateral, whorls rather distant. 7. BATOPHORA. 



i. ACETABUI.ARIA Lamouroux, 1816, p. 244. 

 Frond calcified, with perennial root and annual erect axis 



