10 OTTO V. DARBISHIRE. [SEC. ARCT.EXP.FRAM 



Lecidea purissima. (Tab. 1, fig. 1). 



Diagnosis: Crusta crassiuscula indistincte areolata, albicla vel di- 

 lutissime flavescens, partibus albidis discontiguis sed hypothallo nigro 

 impositis, hypothallo nigro instructa. Apothecia usque ad 1 mm. lata, 

 primum immersa et thallo subaequantia, marginata, nigra, deinde quasi 

 elevata, subsessilia convexa et immarginata; epithecinm nigrum; hypo- 

 thecium decolor; asci inflato-clavati; paraphyses simplices; sporae octo- 

 nae. hyalinae, 12.5 mi. 15 mi. longae, 56 mi. latae. Habitat ad saxa. 



Notes: This species is characterised by the smaller or larger 

 white portions of the thallus which are not continuous, but which are 

 superimposed on an hypothallus of dark colour. Externally it much 

 resembles a specimen of "Lecidea alpicola, WAHL. Port Kennedy, Dr. 

 WALKER 25." in the Herbarium at Kew. But this is really Catocarpon 

 chionophilum, TH. FR., and its spores are in fact two-celled, black and 

 measure 22 36 X H 18 nii. Our species differs from Lecidea macro- 

 carpa (DC.) TH. FR. by its smaller spores. I think that it is a new spe- 

 cies. But as I mention later on the Lecideas of the world require re- 

 vising monographically. 



Lecidea solitaria. (Tab. 1, fig. 2). 



Diagnosis: Crusta tenuissima, fere obsoleta, albida, hypothallo 

 nullo distincto; Apothecia dispersa, ad 1 mm. lata, nigra, margine con- 

 colori cincto, demuin immarginata, convexa; epithecium nigrum; hypo- 

 thecium decolor; paraphyses non-articulatae; sporae octonae, non-unise- 

 riatae, subglobosae, 5 X 6.4 mi. magnae. Habitat ad saxa. 



Notes: From the description this plant appears to be not unlike 

 Lecidea ultima, TH. FR., but in the latter the hypothecium is darker, 

 the paraphyses are articulate and the spores. uniseriate. It also in some 

 respects resembles the "crusta fere mdla" - forms of Lecidea auricu- 

 lata, TH. FR. but the persistent margin of the latter is a distinguishing 

 feature. 



Catillaria. sanguinaria. 



Diagnosis: Crusta tenuis, cinerascens, minute rimoso-areolata, 

 margine fusco-nigricanti, hypothallo albido, fere effigurato, centre rimoso- 

 diffracta et fere papillosa. Apothecia minuta, ad .3 mm. lata, papillis 

 immersa, nigra, margine albido cincta, convexa, lecideina; epithecium, 

 parathecium et hypothecium nigrum; sporae octonae, halone nullo, 16 X 6 

 mi. magnae, bicellulares, hyalinae. Habitat ad saxa. 



