On a New species of Melanotacnimn. Rudolph Beer. 335 



in the "Beitrage zur Kryptogamenflora dcr Schweiz," who 

 transferred it to the genus Melanotaenium. 



Melanotacnium An was first described by Cooke (1872) under 

 the name of Protomyces An. It was found by Dr Paxton in 

 May, 1872, upon the leav^es and petioles of Arum maculatum 

 growing at Chichester. The same fungus was found in Denmark 

 in 1876 by Rostrup who named it Ustilago phimbca. Thirteen 

 years later Pirotta (1889) rediscovered this fungus growing upon 

 the leaves of Biaruin tcnuifolium and, believing its affinities 

 to be nearest to de Bary's genus Melanotaenium, he named it 

 M. plumbeum (Rostr.) Pirotta. Rostrup in " Ustilagineae Da- 

 niae" (1890) accepted this nomenclature. Lagerheim (1899) 

 found the fungus growing upon the leaves of Arum maculatum 

 at Pardailhan and he referred to it under the name of Melano- 

 taenium Ari (Cooke) Lagerheim. In more recent writings, such, 

 for example, as "Danish Fungi," revised by J. Lind (1913) and 

 Schellenberg's (1911) "Beitrage zur Kryptogamenflora der 

 Schweiz," and also in Jaap's "Fungi Selecti Exsiccata," issued 

 by Magnus in 1903, the name Melanotaenium Ari (Cooke) Lager- 

 heim is retained. Through the kindness of Miss Wakefield and 

 Mr J. Ramsbottom I have been enabled to re-examine Cooke's 

 original type-material of this fungus as well as other specimens 

 collected elsewhere at various times. I find the spores to be 

 quite different in character from those of either Protomyces or 

 of any member of the Ustilaginaceae. Their membrane is com- 

 paratively pale in colour and is more complex in structure than 

 is the case with that of either of these groups. It consists of an 

 inner layer (endospore) and a comparatively thick outer coat 

 (exospore) which swells up vigorously in strong sulphuric acid. 

 Moreover, the outer coat is perforated by several narrow germ- 

 pores. It was not found possible to determine more nearly the 

 details of the structure of this fungus or its spores in herbarium 

 specimens, and the true systematic position of the fungus must 

 be left undecided until fresh material becomes available. 



M. Selagincllae Henn. et Nym. (Hennings 1900) was found in 

 Java growing upon the stem and bases of the leaves of Selagi- 

 nella. Its spores are chestnut brown in colour and later black; 

 their membrane is covered with wart-like outgrowths and they 

 measure ly-igfj. in diameter. 



M. Jaapii Magn. was found by Jaap in 191 1 near Vienna 

 growing upon Teucrium w.ontanum, and a short description of 

 this fungus was given by Magnus (191 1) in the same year. It 

 forms swellings upon the base of the stem or the upper region 

 of the root and in one case it was found to occur higher up the 

 stem of the plant. In sections it could be seen that the hyphae 

 of the fungus run in the intercellular spaces and send haustoria 



