WITH NOTES ON OTHER SPECIES. 119 



antheridia are otherwise similar to these. The antheridia which attach themselves to 

 a given oogonium may or may not arise from the same hypha with it, though such is 

 perhaps more often the case. 



The precise systematic position of the species is perhaps open to discussion, but 

 it presents points of resemblance and probable relationship with both the last and the 

 following species. 



AcHLYA POLYANDRA Hildeb. ('67). 



Syn. : A. gracilipes DeBary ('88). 111.: Hildebrand, '67, PI. XVI, Figs. 7-11. 



DeBary, '88, PI. X, Figs. 2 and 6. 

 PI. XVm, Figs. 78-81. 



Hyphse stout, long. Zoosporangia often not abundant, secondary ones rare, 

 nearly cylindrical. Oogonial branches usually very long and often recurved at the 

 tip, racemose. Oogonia terminal, globular, with smooth and unpitted walls. 

 Antheridial branches arising chiefly from the oogonial branches not far from the 

 oogonia, often branched. Antheridia one to several on each oogonium, short-clavate. 

 Oospores five to twenty-five, usually ten to fifteen, in an oogonium, centric, their 

 average diameter 27//.. 



Massachusetts — Amherst. Europe. 



First obtained in spring from Algse from a temporary rain-pool in a depression 

 in a grassy field, this species appeared later in a culture from ConfervcB and Yau- 

 cherice, taken from a running brook. Its numerous oospores, very long oogonial 

 branches, usually recurved at their tips, with the branched antheridial threads 

 arising from them and bearing small and short antheridia, distinguish it from related 

 forms. It appears to be rare with us, as I have never seen it from any other locality 

 than Amherst, and only twice there. 



It is especially interesting as having been the subject of a misunderstanding 

 which has led to a confusion in synonymy that I have here attempted to correct. It 

 was undoubtedly this species which Hildebrand described ('67) as A. polyandra. 

 As has been already pointed out, DeBary gave the same name ('81) to a distinct 

 species which he recognized as differing from Ilildebrand's description, but thought 

 to be probably his species. At the time of the completion of the paper quoted, 

 DeBary had probably never seen this form, as his later paper ('88) states that he 

 first obtained it in January of 1881, the year of the publication of the earlier one. 



A. p. s. — VOL. XVII. p. 



