MISS E. S. BARTON ON THE GENUS ТОВВТХА ВТА. 225 
in this respect Fucus ceranoides, L. ; and T. trialata is a diœcious species, of which I 
have only found the oogonia. Тһе material of T. Ми’гауата at my disposal is not in 
good enough condition to enable me to decide anything definitely with regard to its 
reproductive organs; but, since I have found traces of oogonia in the conceptacles and 
nothing that argues in any way the presence of antheridia, I am inclined to regard it as 
another dicecious species. Thus, of the three species of which it is possible to speak 
decidedly, two are dicecious and one hermaphrodite and dicecious, while no species has 
as yet proved to be moncecious. 
Antheridia.—The antheridia grow on comparatively thick branched hairs, and since 
they are often found growing out near the base of these hairs (cf. Thuret, Etudes Рвус. 
tab. xxi. fig. 5), which have themselves hardly reached the height of the antheridia, the 
conceptacle has the appearance of being lined with antheridia, seated each on a separate 
stalk (Pl. LV. fig. 10). Itis on this account, and because the hairs rarely bear more than 
_ two or three antheridia, that it is difficult in any but the oldest conceptacles to be assured 
of the fact that the antheridia of Turbinaria, like those of all other Fucaceous algæ, grow on 
branched hairs, and an empty one is sometimes difficult to distinguish from the hyaline 
branch of the hair which bears it. In some cases the nuclei are very plainly visible 
(Pl. LV. fig. 10а). 
Oogonia.—I have been unfortunately prevented from tracing the development of the 
oogonia through want of good material for the subject, since in all the receptacles which 
I have examined the oogonia have shrivelled so much that it is impossible to make out 
more of their structure than the fact that they contain only one oospore ; but, as I am 
hoping, through the kindness of Mr. Thurston, of Madras, to receive material more suited 
for the investigation of the conceptacles, I may be able at some future time to furnish a 
description of the oogonia of this genus. 
Paraphyses.—Besides the branched hairs which bear the antheridia, there are 
unbranched paraphyses in the fertile conceptacles exactly resembling those in the 
vegetative conceptacles described above; and since in the latter case these filaments 
arise as outgrowths of the cells lining the base of the cavity, I assume that the develop- 
ment of these unbranched paraphyses takes place in the same manner. 
Finally, I have to thank the Department of Science and Art for its kind permission 
to work in the laboratory at South Kensington, and I am specially indebted to Dr. Scott 
for his guidance and help throughout the morphological part of this investigation. For 
material I am indebted to the British Museum and to Madame Weber van Bosse; and 
personally to Mr. Murray, who has kindly revised the systematic portion and assisted me 
in determining new species. Mr. Batters has helped me to decide as to the nature 
of the filaments in the vegetative conceptacle. 
