ARCHER — ON TWO NEW SPECIES IN SAPROLEGNIEiE. 141 



or even solitary; they mostly terminate a filament, and rarely occur along 

 its length. In this respect they differ, so far as I know, from those of 

 other Saprolegnieae recorded, except S. androgyna above described ; but, if 

 I am right, this form not only falls under a distinct genus from that just 

 described above, but, even if the evidence were in favour of their belong- 

 ing to one genus, they are abundantly specifically distinct in that the 

 present plant is dioecious, the former monoecious, and that on a seemingly 

 novel plan. Moreover, A. cornuta is altogether distinct, owing to the 

 remarkable horn-like extensions, numerous and often long, and occa- 

 sionally bifid, which are presented by this form : on one occasion a 

 curious depressed and equally lobed form of these cornua presented itself 

 (fig. 4, the second oogonium to the right near the base). This reminds 

 one somewhat of the form of the oogonium in CEdogonium Itzigsohnii 

 (de Bary) ; and to those who have seen that plant in fructification 

 the comparison will at once call to mind the figure of this peculiar lobed 

 extension. I, of course, mean to institute no further comparison be- 

 tween them. This new species, too, seems thus quite distinct from 

 Achlya dioica by the character mentioned. A. dioica has globular oogo- 

 nia, destitute of cornua, and are seemingly always solitary — in fact, so 

 far as they go, quite like those of Saprolegnia monoica, except that they 

 are smaller. The projecting cornua call to mind the similar but smaller 

 ones of Aphanomyces stellatus (de Bary) ;* but, setting aside the evi- 

 dence of this plant belonging to the genus Achlya, all the species of 

 Aphanomyces described are monoecious, that is, furnished with lateral 

 male branchlets emanating from another part of the filament. As 

 regards Saprolegnia asterophora (de Bary), f even setting aside, as in 

 the previous comparisons, the evidence as to the generic location of this 

 plant in Achlya, it is again well distinguished by being dioecious, whilst 

 Saprolegnia asterophora is, like Aphanomyces stellatus, monoecious. It 

 is, besides, different from all these forms mentioned by its larger and 

 coarser size, as well as often producing several oospores in the oogonia, 

 whilst all the species referred to very rarely produce more than a single 

 oospore. 



* Jahrbiicher fiir wiss. Bot.,"Bd. ii., p. 178, t. xix., 1-1; 

 f Loc.cit., p. 189, t.xx., 25-27. 



VOL. V. 



