PH.HOPHYCEA 69 
reserve-material in their protoplasmic contents points 
farther to an incapacity for independent development. 
The so-called zoospores of these species are almost as 
much greater than these in size as the ciliated 
oosphere of Cuéleria is greater than its antherozoids. 
Another aberrant species of Zetocarpus, viz. £. 
pusillus Griff... presents a difficulty of another kind. 
The spores (at least those of the plurilocular spor- 
angia) have no cilia, and are immobile. This latter 
character does not really point to the Tilopteridacce, 
since the unilocular.sporangia of £. pusillus contain 
a number of spores, and, as has been seen, the uni- 
locular bodies in Tilepteridacee have but one spore 
(or oosphere, as the case may be). 
These difficulties primarily concern the classifica- 
tion of ectocarpacee, but their occurrence has a 
special significance to those who desire to interpret 
similar organs in the 7ilopteridacee and neighbouring 
groups. M. Bornet is disposed to give the first 
place in such matters to the morphological characters 
so strikingly alike in Ectocarpacew and Tilopteridaccee, 
and to retain these groups in proximity, pointing out 
that the unilocular, monosporous sporangia and the 
form of the antheridia sufficiently distinguish them 
from the Zctocarpacee. Whether we have to deal 
with a unilocular, monosporous sporangium or with 
an oogonium containing one oosphere in the Tilo- 
pteridacece can only be settled by observation. 
This order is known only from the North Atlantic 
(including Mediterranean) and Arctic Sea. Tilo- 
1 Not E. pusillus of Kiitzing, in which Goebel has observed 
conjugation. The latter is properly called LZ. globifer, as Bornet 
has shown, 
