i6 DISCOVERY REPORTS 



Involucrellum dome-shaped, lying directly over the excipulum, brown-blackish, of ± uniform thickness 

 (45-60 /<). Periphyses numerous inside ostiole and upper part of excipulum; their walls gelatinized, 

 only the slender lumina visible, simple or sparingly branched, 30-45 x i -5 fi. Usually no paraphyses are 

 present, but in some perithecia there are a few delicate branching hyphae i •5-5-0// thick traversing the 

 mucilage between the asci. Asci clavate or ventricose-clavate, 50-65 x 20-30//, with gelatinous walls 

 up to 5// thick. Spores irregularly 2-3-seriate in ascus, 8, with wall about o-6// thick, variable in size 

 and shape, ellipsoid to broadly ellipsoid, (12-5-) i4-i8(-2o) x (7-o-)8-ii (-13)//. Pycnidia indicated 

 by minute punctations or brownish spots, saccate or almost flask-shaped in section, simple, 180-240// 

 deep, 75-90// across, with colourless wall, not carbonized around ostiole. Fulcra exobasidial, subulate. 

 Pycnoconidia bacillar, straight, 3'0-3-5 x o-6-o-j fi. 



Chemical reactions : surface of thallus and medulla KHO-, CaClaOg-, KHO(CaCl202)-, CgH4(NH2)2-, 

 I-. Hymenial mucilage I + wine-red, ascus-contents and spores yellowed. 



Vainio's ' V err near ia glaucoplaca' represents an uncommon growth-form of the species, for which 

 reason I prefer to use ' elaeoplaca ' as the specific epithet, the type specimen of the latter being the normal 

 state. The designation V. elaeoplaca i . glaucoplaca (Vain.) M. Lamb, n.comb., may be used for the form, 

 occasionally met with in damper situations, in which the thallus is composed of a number of separate, 

 contiguous, juvenile and uncracked thalli separated by dark brown lines, giving the impression of a 

 thallus consisting of large dark-edged areolae. This is well shown on Vainio's pi. i, fig. 5. The F.I.D.S. 

 specimen no. 1801 from Goudier Islet is partly referable to this form. 



In very wet situations the thallus is more continuous (the cracks not usually anastomosing to form 

 complete areolae) and usually with a pronounced red or pink tinge. In a fresh-water pool in the penguin 

 rookery at Hope Bay I was able to trace the transition from the normal brown areolate condition on 

 stones on the upper drier banks of the pool to the reddish more continuous state in the pool itself. 



V. elaeoplaca is very characteristic of inundation surfaces wetted bv nitrogenous snowmelt water in 

 springtime. The photographs on PI. Ill, figs, i and 2, were taken on Goudier Islet. In fig. i it is seen 

 lining a natural gutter in the granodiorite rocks down which a steady seepage of water occurs during 

 the melting of the islet's snow cover. Fig. 2 shows it forming a zone around the margin of a snowmelt 

 water pool, and also bordering the run-ofl^ channel from the latter. The snowmelt water is highly 

 nitrogenous from the excreta of birds (gulls, skuas, Chmiis alba, etc.). Although the species is restricted 

 so closely to inundation surfaces, the duration of actual inundation during the year is comparatively 

 short, lasting from late October, when the snow accumulated during the winter commences to melt, 

 till about the end of November, when in normal years the upper part of the islet should have become 

 snowfree. 



Geographical Distribution. Apparently endemic to the coast of Graham Land and adjacent 

 islands. Previously recorded from west Graham Land: Palmer Archipelago, Moreno Island, Bob 

 Islet (Vainio, loc. cit.) and Goudier Islet (Hue, loc. cit.). 



Verrucaria famelica Darbishire (Fig. 3/; PI. IV, fig. 3) 

 1912, p. i8, pi. 3, fig. 33. 



Not found in the present collections. Known only from the type locality: South Shetlands, Nelson 

 Island, coll. C. Skottsberg, 1 1. i. 1902. The following redescription of the species is based on a syntype 

 specimen preserved in the Kew Herbarium. 



On non-calcareous fine-grained rock. Thallus interruptedly covering an area of 2-5 x 2-0 cm., 

 brown-blackish, thin (up to o-i mm. thick), eflFuse, indeterminate, not continuous, but composed of 

 small confluent patches around the perithecia, with the substratum visible between ; continuous or here 

 and there slightly cracked, matt. A very fine blackish dendritic-reticulate hypothallus is visible with 



