4 OTTO VERNON DARBISHIRE, (Schwed. Südpolar-Exp. 



Lecidea agellata nov. spec. 

 (Plate i. fig. 3.) 



Thallus flori lactis sordide concolor, tenuis sed firmus, continuus, rimoso-areo- 

 latus, K — , saepius sterilis, ut Rhizocarpon geographicum geographice margine nigro 

 divisus; apothecia non frequentia, nigra, immersa, lecideina, plus minus rotundata, 

 0.5 — 1.0 mm magnae; epithecium carbonaceum; parathecium et hypothecium decolor; 

 sporae octonae uni- ad polyseriatim dispositae. hyalinae, unicellulares, 10 — 14x6 — 8 u 

 magnae; spermogonia et soralia non visa; habitat ad saxa, Falkland Islands, Port 

 Louis. 



Notes: This species appears to be not far separated from Lecidea cyanea (ACH.) 



Tu. Fr. which is known from Kerguelen. A very characteristic feature of our new 



speeies is the frequent absence of apothecia and still more the chart-like division of 



the thallus not unlike that met with in Rhizocarpon geographicum. When thallus 



meets thallus a thick black margin is formed and growth seems to come to an end. 



"Flori lactis concolor" stands for cream-coloured, "agellata" for divided into small 



fields. 



Lecidea protracta nov. spec. 



(Plate 1, fig. 4.) 



Thallus flori lactis concolor, aut quasi parce flavescens, crassiusculus, continuus 

 et glaberrimus, aut rimosus ut limus desiccatus, K externe intense flavescens et interne 

 albescens; hypothallus colori chalybeius; apothecia rara, nigra, lecideina, emergentia. 

 marginata et dein quasi immarginata, plana, 0.5 — 1.9 mm lata; epithecium et para- 

 thecium carbonaceum; hypothecium decolor; sporae octonae, polyseriatim dispositae, 

 hyalinae, unicellulares, 8 — 14x4—6 ,» magnae; spermogonia et soralia non visa; ha- 

 bitat ad saxa, Falk I and Islands. 



Notes: The greater portion of this cream to yellow coloured thallus is smooth 

 and exhibits no areolation. In places the areolation becomes very marked but it 

 does not resemble the true areolation met with in most crustaceous plants but it is 

 rather like the breaking up into aréoles found in dried up mud or clay. Another 

 characteristic feature is the steel blue hypothallus or margin. It is so well developed 

 that frequently the thallus which is rather thin nearer the margin appears itself steel 

 blue owing to the hypothallus below becoming visible through the upper layers. In 

 contact with the thallus of another lichen individual a thick dark green ridge is 

 formed and growth ceases. 



Lecidea lapillicola nov. spec. 



(Plate 1, fig. 5, 6.) 



Thallus effusus, 0.5 — 0.7 mm crassus, contiguus vel parce et irregulariter rimoso- 

 areolatus, albido-coerulescens aut substrato subconcolor, K flavescens aut — , hyphis 



