GLONIOrsis — DICHAENA. 43 



Hi/sterographium eurvatum, Behm, Krypt.-Flora, Ilyst., 

 p. 17. 



Hijsterium naviculare, Walbr., Fl. Crypt. Germ., ii. p. 441. 



On dry branches of rose, bramble, sloe, and hawthorn. 



When growing on rose stems the ascophores are mostly 

 parallel, but on other plants they frequently stand at all 

 angles. 



Specimen named by Fries examined. 



DICHAENA. Fries, (figs. 10-12, p. 22.) 



Mostly gregarious and clustered in irregular patches, at 

 first closed, roundish or elongated, then opening by an elon- 

 gated slit, blackish brown ; asci obpyriform or broadly fusi- 

 form, 4-8-spored ; spores elliptical, at first one- then many- 

 celled, colourless, grouped without order in the ascus ; para- 

 physes slender. 



Dicliaena, Fries, Summa Yeg. Scand., p. 403; Sacc, Syll., 

 ii. p. 771. 



The species included in the present genus are true para- 

 sites, growing on the living bark of the host-plant. Although 

 some of the species, as D. quercina, are exceedingly common, 

 y T et the fruiting stage is rare, and in some species unknown. 



Dichaena quercina. Fries, Elench., ii. p. 142 ; Sacc, 

 Syll., ii. (figs. 10-11. p. 22.) 



Ascophores grouped into dense, irregular patches, of vari- 

 able size, J— 5 cm. across, blackish-brown, form variable, 

 blackish brown, roundish at first, then elongated, ends ob- 

 tuse, flattened, dehiscing by a longish slit, ^-1 mm. long, 

 ^ mm. broad, membranaceous; asci broadly obpy r riform, 

 sessile ; spores 8, broadly elliptical, at first one- then many- 

 celled or parenchymatous, hyaline, 22-25 X 8-10 /x, inordi- 

 nate; paraphyses filiform, about 2 fx thick, agglutinated 

 together. 



Opegrapha quercina, Pers., Annal. Bot., vii. p. 31, t. 3, f. 4. 



On oak branches, on the living bark. 



A very common species, but usually barren. 



The supposed pycnidia form of this species resembles the 

 ascigerous form in habit ; the pycnidiophores are smaller, 



