516 BULLETIN OF THE BUREAU OF FISHERIES. 



Carpogonia and auxiliary cells numerous, formed at the base of special flask -shaped concep- 

 tacles in the thallus, usually closely associated, gonimoblasts numerous, usually 

 arising from a cell formed by the fusion, after fertilization, of all the auxiliary 

 cells 2. CORALUNACE^ (p- 5 22 )- 



Family 1. GRATELOUPIACELE Schmitz. 



Frond usually terete, sometimes angular, flattened or foliaceous, usually laterally, 

 sometimes dichotomously, branched in various ways, nearly always showing a very 

 evident filamentous structure; tetrasporangia scattered over the thallus or confined to 

 special fertile portions, embedded in the cortex or in swollen nemathecia, cruciately 

 divided; carpogonia and auxiliary cells formed on short, special branches of filaments 

 in the inner part of the outer cortex, these branches giving off short lateral branches 

 which inclose the carpogonium or auxiliary cell, forming upright oval or flask-shaped 

 structures, auxiliary cells occurring singly, intercalary in the filamentous branches, 

 branches forming auxiliary cells and, to a less extent, those forming carpogonia, devel- 

 oped in large numbers, intermingled; cystocarps usually small, scattered over the thallus 

 or confined to special portions, usually many occurring near together, embedded in the 

 inner cortex,. forming very slight swellings on the surface, usually surrounded by a more 

 or less developed network of filaments, communicating with the exterior by a pore, 

 gonimoblast arising from the base on a more or less large stalk cell, divided into more 

 or less numerous, compact, successively formed lobes, forming numerous carpospores 

 in compact groups. 



About 1 50 species, mostly in warm seas. 



KEY TO GENERA. 



a. Tetrasporangia formed in nemathecia, cortex parenchymatous, compact, frond foliose, 



borne on a short stalk 3. Cryptonemia (p. 521). 



aa. Tetrasporangia embedded in the outer cortex b. 



b. Thallus terete, angular, or flattened, cortex rather thin, small celled, and compact with- 

 out, large celled and loose within, joining medullary portion by large, scattered, 

 reticulately arranged cells, medullary portion consisting of a -loose network of fila- 

 ments i. Halymenia (p. 516). 



bb. Thallus flattened, cortex rather thick, consisting of compact anticlinal rows of small 

 cells without, looser within, gradually passing over into the medullary portion, 

 medullary portion consisting of a rather compact network of filaments. .2. Grateloupia (p. 520). 



Genus i. Halymenia Agardh. 



Halymenia, Agardh, 1817, p. XIX. 



Frond terete, angular, or flattened, dichotomously or laterally branched in various 

 ways, often bearing proliferations from the margins; structure cellular filamentous, 

 medullary portion consisting of a loose network of thin, segmented, branched filaments 

 traversing the inner tube, cortex usually rather thin, small celled and compact without, 

 large celled and lax within, joined to the medullary portion by large, scattered, reticu- 

 lately arranged cells; tetrasporangia scattered over the frond, embedded in the outer 

 cortex, cruciately divided; antheridia forming colorless patches over the surface of the 

 thallus; cystocarps scattered over the frond, small, inconspicuous, embedded in the 

 inner cortex, forming little or no swelling on the surface, inclosed by a more or less 

 developed network of filaments, communicating with *the exterior by a pore, bearing 



