1898-1902. No. 21.] LICHENS. 11 



Notes: This new species is characterised by a thin but distinctly 

 areolate and greyish thallus and a very clearly marked hypothallus of 

 a darkish colour, which ist almost effigurate at the margin. It thus 

 differs from Catillaria subalpina, TH. FB. (Lich. Scand. p. 583). The 

 size of the spores and the structure of the apothecium are also typical 

 features. 



Catocarpon depression. (Tab. 1, fig. 3). 



Diagnosis: Grusta tennis, vel crassior, continua, partim albo- 

 coerulescens et rimoso-areolata, partim albida vel dilutissime rubescens 

 et effusa, hypothallo nigro. Apothecia ad 1.5 mm. lata, primum im- 

 mersa, rhargihe distincto cincta pallido, demum erurnpentia et elevata, 

 immarginafa, convexa, nigra; epithecium, parathecium et hypothecium 

 nigrum ; sporae octonae, hyalinae, bicellulares, halone distincto circum- 

 datae, 15 16 X 78 mi. magnae (halone non incluso). Habitat ad saxa. 



Notes: This is a very distinct species, and it appears new. It 

 resembles Catocarpon chioneum (NORM.) TH. FR., but it differs atleast 

 in having a distinct hypothallus, in the apothecia not being flat, and 

 not having a thickish margin, and in the spores being bigger than is 

 the case with C. chioneum. 



Pertusaria determinanda. (Tab. 2, fig. 1). 



Diagnosis: Grusta .5 ad 1.0 mm. crassa, rimoso-areolata, albella 

 vel roseola; verrucae fertiles irregulariter globosae, ad 1.5 mm. latae et 

 ad 1.2 mm. altae, apicibus depressae, ostiolis apotheciorum usque ad 10, 

 punctiformibus, fuscescentibus instructae; sporae octonae, elongatae, 26 

 30 X 810 mi. magnae. Habitat ad saxa. 



Notes: This new Pertusaria differs from Pertusaria rhodoleuca, 

 TH. FR. (Lich. Scand. p. 306) and P. xanthostoma by its smaller and 

 octone spores. It also resembles P. pocillaria, CUMMINGS (Alaskan Lich- 

 ens p. 101, pi. 9) but the spores of the latter are much larger. 



Placodium splendens. 



Diagnosis: Crusta adpressa, quasi foliacea, dense squamulosa, et 

 adscendens, aurantiaca. K -f- intense purpurascens, infra rhizinis destituta 

 et colore albida, utrinque corticata, strato corticali plectenchymatico di- 

 stincto, supra et infra ad 30 mi. crasso. Apothecia ad 2.5 mm. lata, 

 concoloria, lecanorina, primum margine cincta distincto, demum sine mar- 

 gine distincte viso, plana; sporae octonae, polari-dyblastae, apicibus ro- 



