468 BULLETIN OF THE BUREAU OF FISHERIES. 



to spore-bearing filaments directly or in conjunction with auxiliary cells; auxiliary cells 

 present, except among Nemalionales, associated with the carpogonium or occurring 

 separately in the thallus, sometimes not developed until after fertilization; tufts of spore- 

 bearing filaments (gonimoblasts) , formed as result of fertilization, entire or divided into 

 several parts (gonimolobes) ; each filament giving ris to a single nonmotile spore 

 (carpospore) from each of one or more of its apical cells; gonimoblasts naked or 

 inclosed by sterile jackets, forming cystocarps opening by apical pores. 



KEY TO ORDERS. 



a. Gonimoblasts formed directly from the fertilized eggs i. NEMALIONALES (p. 468). 



co. Gonimoblasts formed with the interposition of auxiliary cells b. 



b. Auxiliary cells usually united with carpogenic branches into definite procarps, cystocarps 

 usually immersed in the frond, gonimoblasts not attached to a basal placenta 



2. GIGARTINALES (p. 476). 



66. Mother cells of auxiliary cells united with carpogenic branches into definite procarps, 

 the auxiliary cells usually formed only after fertilization, cystocarps not immersed 



in the frond, gonimoblasts attached to a basal placenta 3. RHODYMENIALES (p. 482). 



666. Auxiliary cells occurring separately in the thallus, not united with carpogenic 

 branches into procarps, cystocarps usually immersed in the frond, gonimoblasts 

 usually attached to a basal placenta 4. CRYPTONEMIALES (p. 515). 



Order i. Nemalionales Schmitz. 



Nemalioninae, De Toni, 1897, p. 34. 



Gonimoblast formed directly from the fertilized egg itself," consisting of an upright, 

 small, or more or less expanded, branching tuft, whose branches in some cases fuse with 

 neighboring cells of the thallus or with specially formed auxiliary cells. 



KEY TO FAMILIES. 



Gonimoblast a compressed tuft of segmented branched filaments, whose terminal cells form 



carpospores, external or immersed, not inclosed by a sterile jacket. . i . HELMINTHOCLADIACE^E (p. 468). 



Gonimoblast a widely expanded tuft of segmented branched filaments, some segments fusing 

 with neighboring cells; the apices of these fertile filamentous branches confluent into an 

 hymenium from which the carpospores arise f 2 . GELIDIACE^E (p. 474). 



Family HELMINTHOCLADIACE/E (Harvey) Schmitz. 



Nemalionaceae Howe. 



Thallus filamentous, terete, or compressed, variously branched, usually gelatinous, 

 sometimes incrusted with lime; structure conspicuously filamentous, central axis usually 

 present; asexual propagation by monospores, dispores, tetraspores, or polyspores; anther- 

 idia scattered or clustered on the apices of short, filamentous branches, often developing 

 from ordinary vegetative cells, each producing one or a few spermatia; carpogonia borne 

 at the apices \of short specialized or unspecialized, filamentous branches; the fertilized 

 egg gives rise directly to a tuft of segmented, branched filaments (gonimoblast) whose 

 terminal cells (and sometimes subterminal ones also) form carpospores; sporocarp 

 external or immersed, usually naked, sometimes surrounded by a few sterile filaments; 



Doubt may be thrown on this point by the work of Svedelius (1915). showing the presence of auxiliary cells in Scinaia. 

 The retention of this genus in the Nemalionales would, however, break down the distinction between the Nemalionales and the 

 Gigartinales, necessitating their combination into a single order characterized (?) by the presence or absence of auxiliary cells. 

 It seems, as far as our present knowledge goes, therefore, that Scinaia and other genera having these structures should be trans- 

 ferred to the Gigartinales, and that the Nemalionales should be retained as now understood, including the genera lacking 

 auxiliary cells. 



