l68 THE SAPROLEGNIACEAE 



spores 3-12 in a sporangium, encysting themselves at the mouth of the 

 sporangium; oogonia formed inside the host cells, irregularly cylindrical 

 with perpendicular projections; eggs one or few; antheridia not ob- 

 served." 



EUROPEAN SPECIES NOT FOUND IN AMERICA 



Aphanomyces coniger Petersen. Bot. Tidsskr. 29:387. 1909. Also in 

 Ann. Myc. 8: 525, fig. 3b and f. 1910. 



This species, rather recently described, has not yet been found in 

 America. The following is adapted from the original: 



Hyphae 5-1 5[a thick; oogonia without pits, the wall brown and 

 with great rounded protuberances, which are more or less conical in 

 shape; diameter of oogonia with processes 30-40;!., processes alone about 

 8[l; eggs single, i6-3o(?)yL thick;* antheridial branches in part androg- 

 ynous, in part diclinous from a distance, in this respect resembling 

 A. laevis. Resembling A. stellatiis in the oogonial protuberances, but 

 not to be referred to that species. Observed only once on the tegument 

 of a nymph of one of the Phryganeae. 



The zoospores were not seen to emerge and Petersen is in doubt 

 in referring it to Aphanomyces. It seems very likely that it is an 

 Aphanomyces, however, as remarked by Minden. Granting the species 

 to be in this genus, it is not obvious to me that it differs from A. stel- 

 latiis. The slight differences in the measurements given do not seem 

 important, and no other discrepancies appear. 



Aphanomyces norvegicus Wille. Videnskab. Skrifter. Ser. I, Math. Na- 

 turw. Klasse No. 3, p. 9, figs. 14-27. 1899. 



This species, reported only from Norway, is, like A. phycophilus, 

 parasitic on the Conjugatae {Spirogyra, Zygnema, and Mougeotia). It 

 differs from that species in having the mycelium wound outside the algal 

 threads as well as running inside, and in the brown (not hyaline) wall of the 

 oogonium, which is strongly papillate. The oogonia are nearly always 

 borne outside the host. For full description see Minden ('12, p. 561). 

 This also has not been found in America, and in our opinion further study 

 is required to establish it as certainly distinct from A. phycophilus. The 

 size of the eggs is not given by Wille. 



Aphanomyces helicoides Minden. Krypt. F'l. Mark B. 5: 559. 1912. 



It is very probable that this is not different from A. laevis as there 

 is a strong tendency for the antheridial branches to coil in our Chapel 

 Hill form of that species. 



*The original says 16-70^, an evident error. We guess at ,^0m as that would be about 

 right from the size of the oogonia. 



