CRYPTOGAMIA FUNGI. 133 



Hab. On the under surface of the living leaves of the 

 stinking crane's-bill, in autumn. 



The leaves of this herb continue green until winter has at 

 least fairly set in, and in that season the under surface 

 may be observed marked with excavated dots, which have 

 no relation to this, or any other parasite. They are the 

 remains of the ruptured glands containing the essential oil 

 whence the plant derives its strong disagreeable odour ; 

 and that they are so, is easily proved by rubbing such 

 leaves between the fingers, when they will be found per- 

 fectly scentless. 



3. D. alnea, small, gregarious but distinct, glossy black, sub- 

 -drcular, flattened, roughish. GREV. Crypt. Fl. 1. 146. f. 2. Xy- 

 loma alneum, PERS. Syn. 108. MOUG. and NEST. No. 78. HOOK. 

 Scot. ii. 9. GREV. Fl. Edin. 368. 



Hab. On both surfaces of the living leaves of the alder, 

 generally occupying a half or a smaller portion of it, but 

 sometimes scattered over the whole. 



4. D. Heraclei, rugose and somewhat tubercular, confluent, 

 Wack, opaque ; internally black with white cells. SPRENG. Syst. 

 Veg. iv. 417. 



Hab. On the under surface of the leaves of the common 

 cow-parsnip, in autumn, not common. 



5. D. Alchemilla, " filaments very minute, extremely fine, 

 branched ; at length bearing subdistinct black tubercles ; produ- 

 cing a pale spot on the leaf." Asteroma Alchemill^ GREV. Fl. Edin. 

 369. 



Hab. On living leaves of the lady's-mantle, frequent. 



This, when mature, consists of black minute raised points, 

 or very short lines, clustered on pale circular spots of the 

 leaf^ and external to the epidermis. The points are irre- 

 gularly arranged, but they are most closely set in the cen- 

 tre, and assume altogether an obscure star-like form. 



68. PHASCIDIUM. 



1. P. coronatum, black, smooth, convex, the base circular, broad, 

 the apex dimpled and margined : diameter 1 line. GREV. Crypt. 



