l"*l-ij Setcliell: Tlir Slcinaia Assemblage 111 



GLOIOPIILOEA J. G. Ajiarflh 



Cylindrical, uneonstrietod, diehotojiious jiiaiits. with axial strand 

 arising from a. much depressed puHclion r( (/dationis and giving off 

 dichotomons filaments excnrrenf oblif|nely upwards, whose outer ends 

 form at first a layer of utricles intermixed with colored cells, later, 

 however. ])y the continued growtli of the latter developing into a cortex 

 of anticlinal rows of fasciculate moniliform anticlinal tilaments inter- 

 mixed with more or less collapsed utricles at different levels; mono- 

 ecious or dioecious ; antheridia forming a continuous covering over 

 large portions of the frond; cystocarps scattered and irregularly 

 aggregated, arising in the inner layers of the cortex, pyriform, open- 

 ing outwardly through a narrow carpostome ; gonimoblasts free, aris- 

 ing from a few celled placenta, abjointing spores in succession; 

 periderm of few layers, pseudoparenchymatous or closely filamentous. 



As defined and described by J. G. Agardh (1870, p. 29), 6-7010- 

 phloea is a genus to be distinguished from Scinma by the structure of 

 the cortex. This is true of the adult frond where the cortex consists 

 of more or less closely placed anticlinal filaments whose inner cells 

 are large and rounded and whose outer cells are gradually smaller. 

 A study of the development of the cortex, however, shows that it 

 passes through a Scinaia-like stage. At first the outer cells are trans- 

 formed into utricles, but the cells below the utricles give off branchlets 

 which grow out between the utricles and ultimately form the anticlinal 

 I'ows described by Agardh. The utricles first formed collapse and are 

 to be detected only in thin sections and upon very careful examination. 

 Younger parts and young specimens, especially on the cystocarpic 

 plants of the dioecious species, have the appearance of being true 

 members of the genus Scinaia. It is possibly a question whether it is 

 better to retain the genus Gloiophloca or not. lint, on the whole. I 

 think it better to retain it for the present at least. The species of 

 GloiopJiloea show the cymose method of branching of the peripheral 

 filaments in a pronounced fashion. The terminal cell becomes a utricle 

 and does not divide farther. The later branchlets grow up around 

 the utricle, overtop it and may, in lurii. become utricles, to Ix' ovei'- 

 topped in turn by their lateral branches. The utricles are gradually 

 compressed and become inconspicuous on account of their lack of 

 color, thus giving the appearance of a cortex of anticlinal filaments. 



The cystocarps have the structure of those of Scinaia as Agardh 

 has stated. The antheridia occupy more extended areas than those of 

 any species of Scinaia thus far known, and in certain speci&s which 

 are dioecious they cover the whole plant. In structure they agree 

 with those of Scinaia. 



