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 rise 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. ................. 1. NEMALIONALES (p. 468). 
aa. Gonimoblasts formed with the interposition of auxiliary cells..............2.2.20-0-0-cceceeee 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). 
6b. Mother cells, ef auxiliary, cells united with carpogenia wbranphes 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). 
bbb. 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... ...........6.002 00000000 4. CRYPTONEMIALES (p. 515). 
Order 1. Nemalionales Schmitz. 
Nemalionine, 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 asterile jacket. .1. HELMINTHOCLADIACE& (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..............-..0.00 0000000 2. GELIDIACES (p. 474). 
Family HELMINTHOCLADIACE& (Harvey) Schmitz. 
Nemalionacee 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; 
2 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. 
