Bd. IV: II) THE LICHENS. 5 



internis instructs valde conglutinatis jodo caerulescentibus ; hypothallus effusus thallo 

 concolor; apothecia emergentia et bene elevata, nigra, difformia, contigua, mutua 

 pressione angulosa, 0.5-1- mm lata, ab initio margine instructa, etiam persistente; 

 epithecium et parathecium carbonaceum; hypothecium vulgo decolor aut parte in- 

 ferior! fuscescens; asci 9 u lata; sporae, octonae, hyalinae, unicellulares, 12-14x3-5 ," 

 magnae; spermogonia et soralia non visa; habitat ad lapillos camporum, South Georgia. 

 Notes: This species is not unlike Lecidea auriculata Til. Fk. but the spores of 

 the latter are smaller. At first sight our plant appears to possess no thallus at all 

 but a more careful examination soon reveals that the thallus is only of the same 

 colour as the substratum. There is no regular areolation but as the thallus becomes 

 older chinks are formed but not in the regular way generally met with. I have no 

 doubt however that the chinks in our species have the same function as the more 

 regular structures met with in other crustaceous species namely that of rapidly ab- 

 sorbing water. 



Biatora lavae nov. spec. 



(Plate 1, fig. 2) 



Thallus crassus, granuloso-convolutus, carnosus (i. e. carni concolor); hypothallus 

 nullus distinctus; apothecia emergentia, elevata et quasi stipitata, lecideina, immargi- 

 nata, convexa, rufescentia; epithecium rufescens; parathecium et hypothecium decolor; 

 sporae octonae, hyalinae aut pallidissime virescentes, unicellulares, 12-14x8-9.» 

 magnae; spermogonia et soralia non visa; habitat ad lavam, Graham Land, Faulet 



Island. 



Notes: A small specimen of this plant only was met with and its special interest 

 lies in the nature of the substratum. The species of Biatora are not characteristically 

 epilithic or endohthic plants but mainly choose wood or moss and earth as their 

 substratum. But in this new species we have a species growing on the bare lava 

 in the cold regions of Paulet Island. 



Bacidia tuberculata nov. spec. 



(Plate I, fig. 8.) 



Thallus crassior, rimoso-areolatus, superficialer luberculo-granulosus, cinereus, 



marginem obscurior; gonidia protococcoidea; apothecia lecideina, nigra, emergentia, 

 elevata, primo concava aut planiuscula, margine crassiusculo instructa, dein convexa, 

 saepius confluentia et difformia, margine quasi distincto instructa, ad 0.5—1.0 mm 

 lata; epithecium nigrum; parathecium et hypothecium carbonaceum; paraphyses ad 

 2 ft latae, sed apicibus nigricantibus multo crassiores; asci 50 u lati, parietibus m- 

 structi 3—4 n crassis; sporae octonae, fasciatim dispositae in ascis, hyalinae, 6-10- 



