126 



WEBEE-VAN BOSSE ON THE 



A small fragment, attached to Gelidiopsis variaUUs. In the 'Siboga ' paper I liope to 

 point out that Schmitz was perfectly right, when he supposed that Boscliera africmia, 



n. nlnrnprnlata beloncred to the same ojenus. I have therefore 



Bonder, and Tolypiocladia glomerulata 



made use in this paper of Sender's older generic name 



i^CiA LW I^X^V. o^x^v. Q 



Heeposiphonia, Naegeli. 



1. HepvPOSiphonia prorepexs (Harv.), Sclim. 



w 



Harvey^ Phycol. Australica, tah. 185 (B). 



Chagos Archipelago. 



Distribution. Algoa Bay ; AVestern Australia. 



After describing the present plant, Harvey adds : " This alga was first described from 

 Algoa Bay, where it occurs on corallines. The Australian plant is more slender, with 

 fewer tube's, bat otherwise the same." The mrposipJionia on Dasyopsis Geppii has 

 8 pericentral tubes ; it stands therefore nearest to Harvey's Australian form. My 

 material is too scanty to make out whether these forms are specifically distinct from 

 the Algoa plant, as some authors have thought probable. 



Oligocladtjs, Weber-van Bosse. 

 1. Oltgocladus Puainii*, n. sp. (Plate 14. fig. 31.) 



Thallo filiform! repente, ramis normaliter dorsaliter exeuntibns, erectis, endogenis, 

 ramulos unilaterales ferentibus. Filo constante ex uno ordine cellularnm central! 

 et ex quattuor ordinibns cellularum pericentralibus. Trichoblasti desunt. Pilis 

 latis 120-200 fi, ramulis 12-80 ^. Organis fructificationis ignotis. Ehizoidis 



unicellularibus. 



Coetivy, reef, on Dasyopsis aperta ; in alcohol. 



The alga that I have named Oligocladus Prainii belongs to the subfamily of the 

 Herposiphone^e, and is very nearly allied to the new genus Oligocladus, provisionally 

 described in *i.nnales du Jardin Botanique de Buitenzorg,' 1910, p. 31. The specimens 

 were found growing among the penicilli of Dasyopsis aperta and are barren; the 

 determination is therefore not quite certain, but in anatomical structure these algae so 

 closely resemble 0. BoldingUi, Web. v. B., that I feel almost sure that they belong 

 to this genus. I may also add, that in a few long branches I have seen a con- 

 densation of protoplasm in two cells of each segment. This reminded me of the 



sporangia 



in each segment in Oligocladus Boldinghii, but in the present 



I 



could not detect the slightest trace of division in the protoplasm. They were, however, 

 too young, and I must leave it to future investigators to settle the question. 



0. Drainii is a creeping filamentous alga with four pericentral cells, dorsally placed, 

 endogenous branches, and unicellular exogenous ventral rhizoids. Thus far it is like 

 O. BoldingUL It differs from this alga in having no trichoblasts, but a naked, straight 



^ E 



of Sir David Prain, in remembrauce of a lovely walk in tlie Botanical Gardens at 



honour 



Calcutta. 



r^ 



