78 Mr Greville on the Genus Erineum. 
Schweiniz, in their excellent Conspectus Fungorum. A part 
of their character only belongs to the plant in question, as well 
as a portion only of the description. The other species is also 
peculiar to the birch, and hence the error of conceiving the two 
species to be different states of one plant, E. hetulae is almost 
invariably found on the superior surface of the leaf, is of a deep 
blood-red colour, and very irregular in form ; sometimes almost 
covering the leaf, at other times so spotted and scattered, that it 
has the appearance of having been dashed on by accident. The 
colour becomes dingy in old age, but does not change as the 
above named authors suppose. Viewed with a pocket lens, the 
plant appears finely granulated, and the tubes under a high 
power various in figure, turbinate, capitate, and often hammer- 
shaped, with the summits truncated. So intense is the colour, 
that the tubes, under the highest power of a compound micro- 
scope, retain a considerable portion. 
Erineum hetulinum has its spots or tufts mostly on the under 
surface, and the colour changes from white to a dark ferrugi- 
nous, or even tobacco colour. The tubes have some resem- 
blance in their form, but are smaller and more eccentric. The 
whole plant also is never so confluent as the other^ nor is it 
so completely emersed. E. hetidce seems to prefer those leaves 
which have been some time expanded and more exposed to the 
sun, while the other is fond of shade and younger leaves. 
Summer is the best season for finding this splendid Erineum, 
and it is by no means uncommon. At Ravelrig toll, near Edin- 
burgh, I have noticed it three successive seasons. 
Erineum joojowZmwm, Pers. 
Plate III. Fig. 4. 
E. hypophyllum maculaeforme immersum rufescens, tubis defor- 
mibus congregatis crassis sub-ramosis apicibus irregularibus 
erosis, — Gr. 
Erineum populinum, Pers. Syn. Fung. p. 700. 
JDe Cand. Syn. FI. Gall. p. 15. 
Albert, et Schrv. p. 371. 
Moug, et Nest. No. 100. 
Hab. In foliis Populi treraulae ; aestate. 
A singular species, changing from a purplish to a rich dark 
brownish-red colour. Spots distinct, entirely immersed, round- 
