MYCOLOGICAL NOTES 315 



Melampsokidtum alni Diet, in Engl. u. Prantl, Nat. Pflanzenf. 

 1900, I. i. 551. Melampsora alni Thiim. in Bull. Soc. Imp. Nat. 

 Mosc. 1878, liii. 226. 



Mr. Boyd h<is informed me that he occasionally finds, as at West 

 Kilbride, Ayrshire, in woods where Melampsoridium hetulinum is 

 abundant, a few leaves of Alnus also affected by a Melampsora-Y\ke 

 fungus ; there is also in Herb. Kew. a similar specimen, with uredo- 

 spores only, from Aberdeen. It was at first thought that this was 

 merely the fungus on the Birch which had strayed accidentally to the 

 Alder, but, in view of the fact that the parasite named above has 

 been found on Alnus incana and other species in Siberia, Japan, and 

 Ecuador, it is possible that it may be found here also ; it is desirable 

 that it should be looked for further in suitable districts. The 

 differences from M. hetulinum are very small, except for the host- 

 plant, but so far as they go the British spec'mens seem to be in 

 agreement with them. ^^__ 



The dangerous parasite next to be noticed differs from the others 

 contained in this series in being an exotic species : — 

 Placophomopsis, gen. nov. 

 Pycnidia iis Phomopsidis subsimilia, at solidiora et subiculo 

 vel stromati tenui, quasi Placosphceriam in memoriam revocanti, 

 insidentia. Sporuke alia? fusoidese, alias filiformes hamataeque. 

 Placophomopsis Heveae, sp. unica. 



Subiculo effuso, ex hyphis atrobrunneis valde ramosis 2-3 p crassis 

 efformato, stratum continuum atrum inter peridermium corticemque 

 sistente, quo denique peridermium excutitur. Pycnidiis dense in 

 subiculo gregariis, subinde seriatis, atris, depresso-globosis, 200- 

 400 /x diam., poro vel rimula apertis ; contextu crassissimo, parte 

 exteriore atro-brunnea, interiore olivaceo-brunnea. A-sporulis ellip- 

 tico-fusoideis, plerumque utrinque subacutatis, interdum apice rotun- 

 datis, biguttulatis, maturis 7-8x2 fi, sporophoris subulatis, rectis 

 curvulisve, apice acutis, 15-18 X 2 -2 j //, ferine achrois suffultis : 

 B-sporulis filiformibus, saepe curvatis v. hamatis, 20-30 x |-1 p, 

 sporophoris brevibus suffultis. 



Hab. in truncis Hevece brasiliensis, in plantario imperiali, Kam- 

 pala, Uganda (alt. 1260 m.), Oct. 1920— leg. Snowden, no. 672. 



This fungus, which Dr. E. J. Butler, Director of the Imperial 

 Bureau of Mycology, kindly communicated to me, is presumably the 

 pycnidial stage of a Diaporthe, and possibly of Diaporthe Hevece 

 Petch (Ann. "Roy. Bot. Gard. Peraden. 1906, iii. 3; Diseases of 

 Rubber Tree, 1921, p. 263. Sacc. Syll. xxii. 381). The pycnidia 

 are at first completely hidden, then they cast off little fragments of 

 the periderm and become visible through the hole, but without pro- 

 jecting. Afterwards the periderm is thrown off in sheets 2-3 cm. 

 broad, but it never becomes blackened externally. Ultimately the 

 pycnidia fall out, leaving little pale depressions in the subiculum. 

 A- and B-spores may be found in separate pycnidia, but, if in the 

 same, the A-spores usually predominate. The texture of the wall 

 is especially thick, being composed of 10-12 layers of dense pseudo- 

 parenchyma, of which only the outer two or three are dark brown. 



