172 



ON CORTICIUM OAKESII. B. Sr C. 

 By the Editor. 



This communication is, to a certain extent, a continuation of the 

 remarks at p. 136, on Corticiam amorphum. For many years the 

 above fungus Las been distributed in the United States, and else- 

 where, under the name of Corticium Oakesii, B. & Br. It was 

 jDublished by Ravenel in his " Fungi Caroliniani," fasc. iii., No. 

 32, under that name, and the description occurs in " Grevillea," 

 VoL 1, p. 166, where it is said to look at first " like a little Cyphella 

 or Fezizay In fact it so closely resembles Corticium amorphum, 

 Fr., in external features, that Fries has not hesitated to include it 

 as a synonym under Corticium? amorphum, in the new edition of 

 his " Epicrisis" (p. 648j. That this is an error, will presently be 

 shown. Since the previous communication, we have examined a 

 specimen of this fungus published by Bavenel many years ago, and 

 a more recent specimen kindly furnished for the purpose by Mr. C. 

 H. Peck. Our conclusion is that it is congeneric with the Aleuro- 

 discus amorphvs of Rabenhorst. 



That it is not identical with C. aviorphum may be inferred from 

 its external features. The disc is never so brightly coloured, it is 

 more decidedly hairy, and though occurring on the bark of various 

 trees, it has not been found on any Conifer. All these points are 

 presumptive in favour of its being distinct. 



Internally the structure is just that of C. amorphum, there are 

 the same incipient asci, the same nodulose paraphyses, and large 

 sporidia. In this instance the presumed sporidfa are elliptic instead 

 of globose, about 025 X -014 mm. in size. Hence there is good 

 reason for believing that Corticium Oakesii is congeneric with Cor- 

 ticium amorphum, but a distinct species, which should bear the name 

 of Aleurodiscus Oakesii. 



We are not convinced that the whole structure of these two 

 species is yet completely revealed or understood. It seemed to us 

 on examining the specimens from Ravenel, that we could detect on 

 the surface of the disc the tips of threads bearing minute spicules, 

 and a number of minute oval bodies, which resembled conidia or 

 basidiospores, whilst the substratum of the hymenium presented 

 the structure already alluded to. This, however, requires confir- 

 mation, but it is not improbable that the disc may produce conidia 

 which give to it that peculiar glaucous appearance — which is seen 

 in both species — when somewhat fresh. Specimens should be ex- 

 amined in the moist condition, so that no soaking in water is re- 

 quired, and if conidia are present they may be detected seated on 

 the spicules. There is some difficulty in accounting for these 

 minute bodies, and their origin and function, except on some such 

 hypothesis. 



The Rev. M. J. Berkeley remarks that a similar Corticium occurs 

 in India, which may prove to be a third species of Aleurodiscus. 



