Bd. IV: il) THE LICHENS. I 7 



Notes: The very small scaly thalli seem to be an important feature in this spe- 

 cies and the brownish apothecia. The plants are very small and only become pro- 

 perly visible when the lens is applied. 



Parmeliella major nov. spec. 



(Plate 3. fig. 30.) 



Thallus minute foliaceus, aut squamosus, adpressus, saepius ad 10 mm latus 

 marginem granulatus, pallide fuscescens usque ad marginem, superne bene corticatus, 

 laevis, subtus ecorticatus, albidus sed rhizinis instructus nigricantibus; gonidia nosto- 

 cacea; apothecia urceolata, semper bene emergentia, stipitata et basi constricta, primo 

 margine proprio obscuro instructa sed dein emarginata et disco concavo (primo 

 piano) instructa nigro-fusco aut quasi nigro; interne parathecium et hypothecium 

 obscuriusculum; sporae octonae, hyalinae, unicellulares, polyseriatim dispositae, 

 18 — 20x6 — 7 /( magnae; spermogonia nulla visa; habitat ad corticem arborum, 

 Tierra del Fuego, Harberton. 



Notes: This species is at first sight not unlike the previous one, but the colour 

 of the apothecia is different, the portions of the thallus are larger, there is no pro- 

 nation at the margin and finally the margin of the apothecia of Parmeliella minor 

 is thicker and more persistent than that of our present species. 



Verrucaria exquisita nov. spec. 



Thallus tenuissimus, intense ferrugineus, rimoso-areolatus, plus minus continuus, 

 hypothallo superimpositus nigro tenuiissime laciniato; gonidia protococcoidea; apo- 

 thecia pyrenoidea, nigra, tota immersa, plana, 0.1— 0.15 mm lata, vix visibilia; epi- 

 thecium carbonaceum; parathecium et hypothecium hyalinum; asci breves, 54 a alti 

 et 28 fi lati; sporae octonae, hyalinae, unicellulares, 12—14x5 ft magnae; spermo- 

 gonia null visa; habitat ad saxa, South Georgia, Pot Harbour. 



Notes: This is one of the smallest lichens I know at least of the lithophilous 

 plants and it was only by means of the Zeiss Binocular Dissecting Microscope that 

 I discovered it at all. An ordinary lens is insufficient to do more than just reveal 

 its existence. Though so small the more central portions of the thallus are very 

 clearly rimoso-areolate and not merely diffract. The thallus, that is to say, is well 

 developed and quite distinct from the searching hypothallus which is black whereas 

 the thallus proper is a brick red or strongly rust coloured. The apothecia are very 

 small and remain embedded in the thallus never rising above it. 



3 — 112885. Schwedische Südpolar- Expedition igoi—içoj. 



