Bd. IV: il) TUE LICHENS. 3 



Lecidea interrupta nov. spec. 



(Plate i, fig. i.) 



Thallus tenuis, laevis, flavescens, indistincte areolato-rimulosus, continuus et hinc 

 inde interruptus, K intense flavescens; hypothallus thallo concolor aut distincte nigri- 

 cans, thallo lichenis alieni tactus semper nigricans; gonidia protococcoidea; apothecia 

 nigra, lecideina, elevata, margine proprio distincto instructa, 0.5 ad 0.8 mm lata; epi- 

 thecium et parathecium carbonaceum; hypothecium decolor; paraphyses ad 1 j.i latae; 

 asci 40 — 50 « longi et 15 — 20 /j lati; sporae octonae, polyseriatim dispositae, hyali- 

 nae, unicellulares, 10 — 13.5 (rarius ad 20) x 5—6 f.i magnae; spermogonia et soralia 

 nulla visa; habitat ad saxa, Falkland Islands, Port Stanley. 



Notes: This species is well characterised by the regularly interrupted thallus. 

 Here and there, possibly where the thallus is rather young, the substratum is quite 

 exposed and the thallus interrupted. This happens most frequently in smaller plants. 

 In many cases the margin of the thallus in these interrupted portions is fringed by 

 a very fine dark line. The hypothallus is always clear when we have the real mar- 

 gin of the whole lichen before us. It is then quite dark and it may extend a con- 

 siderable distance. In contact with other lichens of the same or of another species 

 a thick black margin is formed which of course is very usually the case. This thick 

 black separating margin reminds one at first of the new Lecidea agcllata. Rliizo- 

 carfon geographicum is generally found growing on the same substratum. 



Lecidea capistrata nov. spec. 

 (Plate 1, fig. 2.) 



Thallus crassiusculus, sordide albidus aut parcissime flavescens, substrata arenaceo 

 quasi concolor, continuus et hinc inde distincte areolato-rimosus, K — ; apothecia im- 

 mersa saepius aspicilioidea, lecideina, nigra, sed margine proprio albido instructa 

 quasi capistrata, rotundata aut saepius difformia, 0.5 ad 1.5 mm lata; epithecium 

 nigricans; parathecium et hypothecium decolor; sporae octonae, polyseriatim dis- 

 positae, hyalinae, unicellulares, 10 — 15 x 6 — 8 [i magnae; spermogonia et soralia non 

 visa; habitat ad saxa arenacea, Falkland Islands, Port Louis. 



Notes: The immersion of the apothecia is a marked feature of this species. The 

 young apothecia are surrounded by the white proper margin containing no gonidia. 

 The appearance is thus at first that of a species of Aspicilia. Later on the apo- 

 thecia rise up rather and coming into contact with neighbouring apothecia become 

 rather misshapen and are no longer round in form. This species occurs on rocks 

 along the shore. 



