KE VISED LIST OF MARINE ALGiE. 121 



stem solid, ramuli tapering at both extremities 



Naccaria 



81. Axis composed of loosely woven, elongated verti- 



cal filaments, peripheral filaments composed of 

 large pear-shaped cells. Fronds undivided, 

 beset with nmiierous simple or slightly branched 

 tapering branches ... ... Helminthocladia 



Axis composed of oblong cells, smTomided by 



, slender, long-jointed filaments, from which the 



dichotomously radiating peripheral filaments 



arise. Fronds very much and irregularly 



branched Helminthora 



82. Branches much contracted at the base Chondria 



Branches not contracted at base 83 



Fronds red-brown, hollow below, branches 



tapering to both extremities, spores arranged 



in irregular masses Gloeosiplionia 



83. Fronds rose-red, stems slender, ramuli simple, 



subulate, acute, apices not involute, cystocarps 

 stalked alternate with the ramuli Bonnemaisonia 



Fronds dark-red, much branched, rather robust, 

 superficial cells small, polygonal, irregularly 

 placed, apices of branches not involute, tetras- 

 pores in the young branches or palmately 



' divided receptacles (stichidia) Bliodomela 



Fronds purple or brownish purple, superficial 

 cells quadrate, apices of the branches strongly 

 involute, tetraspores in swollen pod-like 

 branches (stichidia) Bostrjjcliia 



Fronds purple or red, occasionally blackish, 

 articulated either throughout or at least in 

 the young branches, the articulations longi- 

 tudinally striate 84 



