90 MARINE 



tiful alga of a rod-brown color. It is found washed ashore, or in deep 

 tide-pools, south of Cape Cod. (Plate XXIX.) 



R. larix. Frond cylindrical, robust, six to fourteen inches high ; 

 branches of unequal length standing out horizontally all around the main 

 stem ; clusters of branchlets growing spirally around stem and branches. 

 Found on the northern California coast. (Plate XXIX.) 



M. floccosa. Frond four to ten inches high ; less robust tnan R. 

 larix ; stem and branches flat and divided in one plane ; branches alter- 

 nate ; ultimate brauchlets somewhat incurved ; color black. In fertile 

 plants the terminal branchlets are gathered in a mass. Found on the 

 California coast. (Plate XXIX.) 



GENUS Chondria 



Plants of this genus are distinguished by having the ultimate 

 branches attenuated at the base. 



C. dasyphylla. Frond four to eight inches high ; general outline 

 pyramidal ; branches alternate on main stem ; stem and branches cov- 

 ered with short, club-shaped (blunt at top, attenuated at base) branch- 

 lets ; cystocarps, or spore-cases, adherent to branchlets or on short 

 stalks ; color light or dull brown. It grows in tufts, and is common 

 from New York to Cape Cod. (Plate XXX.) 



C. tenuissima. This species is similar to C. dasyphylla, but is more 

 slender, and the branchlets taper at both ends instead of being club- 

 shaped. 



C. striolata. A species similar to C. tenuissima. The branchlets 

 bear secondary branchlets, and the cystocarps are on short stalks. It is 

 plentiful in Long Island Sound. 



SUBORDER CEEAMTEJE 



GENUS Callithamnion 



These are very beautiful and delicate plants, growing in small, 

 soft, silky tufts, bright red in color, with darker dots along the 

 much-branched filaments. There are many species, and they are 

 common on the northern shores of both oceans ; but the different 

 species are not easy to distinguish with the naked eye, and so but 

 a few of them are described below. The special characteristics by 

 which the genus may be recognized are : fronds filamentous, of 

 cobweb fineness, one inch to six inches long, much branched, 

 and closely crowded at the top ; brilliant red color. 



C. atnericanum. Frond three to six inches long, densely tufted ; 

 filaments of extreme fineness ; main branches alternate ; much branched ; 

 main and secondary branches have pairs of branched ramuli along the 



