Lecidea. 45 



Subg. IX. Psora (Hall.) Th. Fr. Thallus squamulosus aut 

 squamaeformi-areolatus aut e verruculis demum in isidia acere- 

 scentibus constans. AjJotJiecia laetius colorata aut atra. S])orae 

 simplices, decolores, parvae aut minores. 



Psora Hall., Hist. Stirp. Helv. III (1798) p. 93 pr. p. Mass., Ric. Licli. 

 Crost. (1852) p. 90 pr. p., Mem. Lich. (1855) p. 123; Koerb., Syst. Germ. (1855) 

 p. 175 (em.); Miill. Arg., Princ. Classif. (1862) p. 40. Lecidea A. Psora Th. 

 Fr., Lich. Scand. (1874) p. 411. 



47. L. breviuscula NyL, Licli. Nov.-Gran. ed. 2 (1863) p. 

 339, Lich. Nov.-Grran. Addit! (1867) p. 321 (mns. Paris.). Psora 

 hrevmscula Miill. Arg., Lich. Beitr. (FL 1882) p. 494. 



Thallits squamulosus, aut fere foliaceus, squamis incisis la- 

 ciniatisve, laciniis crenulatis et insico-crenulatis aut demum.mar- 

 gine fere isidioso-laceratis, partim sublinearibus, circ. 0,5 0,3 

 millim. latis, circ. 5 1 millim. longis, adnatis, demum plus mi- 

 nusve imbricatis, planis aut convexiusculis, stramineo-glaucescen- 

 tibus aut stramineo- vel olivaceo-pallescentibus, inferne et ad 

 ambitum hypothallo vulgo bene evokito byssomorpho fusco aut 

 pallido instructus. Apothecia circ. 0,8 2 millim. lata, testaceo- 

 fuscescentia, aut pallida, convexa aut planiuscula, immarginata 

 aut margine demum evanescente exclusoque. Hypothecium fulve- 

 scens aut testaceo-pallidum, KHO non reagens. Sporae 8:nae, 

 oblongae aut fusiformi-oblongae aut ellipsoideae, long. 0,oo5 

 0,010, crass. 0,ooi5 0,oo2 millim. [ 0,oo45 millim., observante 

 Nyl., Lich. Nov.-Gran. p. 3391. 



Ad corticem arborum pkiribus locis prope Lafayette et Sitio 

 (1000 metr. s. m.) in civ. Minarum, n. 337, 338, 795. Valde est 

 variabilis et verisimiliter in L. parvifoliam Pers. (Nyl., Lich. 

 Nov.-Gran. ed. 2 p. 339) transit. Thalliis superne strato cor- 

 ticali instructus, 0,0 5 0,0 3 millmi. crasso, pellucido, decolorato, 

 chondroideo, ex hyphis formato subverticalibus, ramosis, conglu- 

 tinatis, membranis incrassatis, lumine cellularum angusto, oblongo 

 aut fere parenchymatico. Infra zonam gonidialem adest stratum 

 medullare tenue tenuissimumve, hyphis intricatis, sat leptoderma- 

 ticis, in hyphas hypothallinas continuatis. Hypothallus ex hyphis 

 circ. 0,0 4 millim. crassis, maxima parte fasciculatis et fere rhi- 

 zinas formantibus, at parum conglutinatis, membranis sat tenui- 

 bus, lumine sat lato, cellulis elongatis. Gonidia globosa, diam. 



