Cceoma. 261 



On Menurialis perennis. 

 May and June. 



Biology. — This is stated by Rostrup and Nielsen to be the 

 .(tcidium of Melavipsora ireinulce from Populus tremula and alha. 

 I repeated their experiments by placing the teleutospores from P. tre- 

 mula on Mercurialis peimnis on several occasions, but was unable 

 to confirm their statement. The Cceoina pinitorqiium, which these 

 authors also state to be connected with a form of M. tremulce, has 

 not yet occurred in Britain. 



In October, 1887, however, during the annual excursions of the 

 Woolhope Club, I gathered a number of leaves of Populus alba, on 

 Dinmore Hill, with a Melampsora on them. In April and May, 1888, 

 I infected with this Melampsora some plants of Mercurialis perennis, 

 which had been growing for several }ears in my garden at King's 

 Lynn, and produced first the spermogonia, and then the perfect Cieoma. 



Cseoma alliorum. Link. 



Spermogonia flat, yellowish, in circular groups. Sori amphigenous 

 in circular or elliptical clusters. Spores subglobose or ellip- 

 tical, punctate, yellow, 17-25 x io-20/x. 



Synonyms. 



CcEonia alliatum. Link (?), " Sp. Plant.," vol. ii. p. 43. 

 Uredo alliorum, D. C. Cooke, " Micro. Fungi," 4th edit., 

 p. 217, in part. 



On Allium nrsinum, oleraceum, vineale. 



Biology. — Schroter thinks this species, or at least the form of it 

 that occurs on A. olej-aceutn, is connected with Melampsora populina 

 (" Krypt. Flor. Schl.," vol. iii. p. 363). 



Coeoma orchidis. Alb. and Schw. 



Spermogonia on yellowish spots. Sori generally irregular, flat, 

 often confluent. Spores subglobose or ovate, punctate, yellow, 

 15-25 X 10-20/U.. 



Synonyms. 



Winter, loc. cit, p. 256. 



Uredo confluens, var. orchidis. Alb. and Sclnv., " Consp.," 

 n. 122. 



