298 Zahlbruckner : New North American lichens 



Caloplaca amabilis A. Zahlbr. sp. nov. 



Sect. Eucaloplaca. Thallus epilithicus, squamulosus, squam- 

 ulis plus minus congestis, substrato haud arete adpressis, rotun- 

 datis, subangulosis vel irregularibus, minutis, 0.3-0.8 mm. latis, 

 convexiusculis, glaucis vel glauco-aeruginascentibus, nitidulis, ad 

 marginem nonnihil paulum adscendentibus et turn anguste albo- 

 marginatis, superne corticatus, cortice pseudoparenchymatico, cel- 

 lulis minutis, sat pachydermaticis, luminibus rotundatis, decolore, 

 in parte suprema cinerascente et KHO violaceo ; gonidiis palmel- 

 laceis, cellulis 10-15 I 1 latis, infra corticem stratum sat crassum et 

 continuum formantibus ; medulla albescente, ex hyphis intricatis, 

 non amylaceis formata. Apothecia erumpentia, demum sessilia, 

 minuta, 0.25-0.3 mm. lata; disco primum dilute luteo, demum 

 fulvo vel fulvo-aurantiaco, ceraceo, convexo, nitidulo, epruinoso; 

 margine tenui, subintegro, mox depresso ; excipulo tenui, ex hy- 

 phis tenuibus radiantibysque formato, gonidia haud includente; 

 epithecio angusto, fulvo-aurantiaco, pulverulento, KHO purpureo; 

 hymenio «decolore, I violaceo-coeruleo ; hypothecio decolore, ex 

 hyphis intricatis formato, strato gonidiifero superposito ; paraphy- 

 sibus densis, simplicibus, tenuiter septatis, apicem versus con- 

 stricto-septatis ; ascis hymenio subaequilongis vel parum brevion- 

 bus, oblongis, ad apices cuspidato-rotundatis et ibidem membrana 

 incrassata cinctis, 8-sporis ; sporis in ascis biserialibus, obliquis, 

 decoloribus, ellipsoideis, oblongo-ellipsoideis vel ovalibus, apicibus 

 rotundatis, polari-diblastis, isthmo distincto, 9— 13/^ longis et 5.5- 

 7 fi latis. 



On basaltic rocks and boulders. 



Caloplaca elegans brachyloba A. Zahlbr. var. nov. 



Sect. Gasparrinia. A typo distat lobis brevibus, ad I tarn. 

 longis, digitato-incisis. 



On loose blocks of tuff and basalt. 



Xanthoria modesta A. Zahlbr. sp. nov. 



Thallus tenuissimus, efifusus, siccus glauco-cinerascens, opacus, 

 madefactus laete viridis, foliaceus, lobis minutis, ad 0.5 mm. laW 

 vel minoribus, substrato plus minus adpressis vel ad margmes 

 leviter ascenderttibus, congestis, inciso- vel digitato-lobatis, lob« 

 valde brevibus, ad margines hinc inde granulatis, granulis thallo 

 concoloribus, rhizinis mil lis, utrinque pseudoparenchymaticus, 

 cellulis leptodermaticis mediocribus, superne anguste infuscatus c 

 KHO (sub lente visus) purpurascens ; gonidiis palmellaceis, majus- 

 culis, 9^12 /£ latis, laete viridibus, in thallo crebris. Apothecia 

 minuta, ad 0.2 mm. lata, rotunda, dispersa vel raribus approxim- 

 ate sessilia; disco e piano demum modice convexo, aurantiaco, 

 epruinoso, KHO purpureo; margine thallino tenuissimo, thallo 



