CELIDIUM. 



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Genus III. CELIDIUM, TuL 



Gen. Char. Apothecia epithalline, very minute (microscopic), 

 pulvinate and immarginate, contiguous, and thickly associated in 

 maculiform heaps ; sometimes all, sometimes only the central 

 ones, confluent. Thecae clavate, four- to eight-spored. Spores 

 simple or locular, ovate and oblong, pale. Spermogones globose, 

 unilocular, generally seated in the centre of the maculae. Sper- 

 matia slender, straight, short. Pycnides unknown. Parasitic on 

 the thallus and apothecia of various foliaceous Lichens. (Name 

 from ktjXlSlov, a macula or spot, in allusion to the aggregated or 

 confluent apothecia.) 



1. Celidium stictaeum. Maculae orbicular, black, con- 

 tinuous, frequently excavated in centre. Spores oblong- 

 elliptic, quadrilocular. Spermogones globose and minute, 

 aggregated and sometimes confluent, on the maculae, or on 

 the apothecia of the Lichen on which the species is parasitic. 

 Spermatia very slender and straight. 



This species is the var. pleurocarpa of Sticta pulmonaria 

 according to Schserer, and it constitutes the black, fungous, 

 abortive condition of the apothecia in that species. We 

 have seen fine specimens of this state of the fructification of 

 S. pulmonaria from the Forfarshire woods, and it does not 

 appear to be very uncommon in Britain. The spores of the 



