ANGIOCARPOUS LICHENS. 



ANGIOCARPI, Fries. 



Apothecium closed, perforated by a pore, or irregularly 

 dehiscing ; nucleus included, subglobose, ascigerous. 



In this order of lichens the apothecium is more or 

 less globose, resting upon or immersed in the thallus, 

 either formed from the thallus itself, or distinct, and 

 consisting of an outer covering or shell {perMecivm), 

 varying in colour, black, red, or pale, either entirely en- 

 veloping the nucleus, or dimidiate, and situate on the 

 upper or exposed portion. This outer shell or perithecium 

 is (probably in all cases, though not always distinguish- 

 able,) lined with a tunic or membrane, more or less tough 

 and consistent, and either black, brown, or pale and 

 nearly colourless, which completely encloses the nucleus. 

 The nucleus is internally white, or slightly coloured brown, 

 more or less transparent, gelatinous, consisting of hyaline 

 tubes or filaments {cisci) of various forms, each ascus con- 

 taining 8 sporidia, varying in shape and size in different 

 species. Intermixed wdth the asci are generally para- 

 physes, usually considered as abortive asci. When mature, 

 the sporidia escape from the ru])tured asci through the 

 pore or perforation at the apex of the perithecium. 



Such appears to be the normal condition. In some 

 plants, how^ever, hitherto arranged under the genera of 

 this order, (as Verrucaria niveo-afra, rudis, aphanes, leuco- 

 cepJiala, and others,) there are no asci, the sporidia being 

 innumerable and free, agglutinated into a mass, which 

 dissolves as in many fungi. It may be questionable 

 whether these should be ranked as Lichens coiTcctly, or 

 whether they should be regarded as fungi, either distinct or 

 parasitic on the crusts of Lichens : but this must be 

 decided by future and more favorable and extended ob- 

 servations. 



