158 REV. W. A. LEIGHTON ON THE LICHENS OF ST. HELENA. 
obliterato; hypothecium incolor; sporæ 8, incolores, ellipsoideæ, utroque apice 
loculum.prebentes; gelatina hymenea iodo intense cærulescens. 
Ad saxa volcanica. B. 
Sometimes I have fancied that the polar nuclei of the spores are united by a minute 
tube similar to the nuclei of the spores of the tribe Placodei; but I have failed in perfect 
vision, so as to speak with full certainty on this peculiarity. The chemical reaction of 
the thallus is K +,C +. 
See Plate XXXV. fig. 4 a, section of apothecium ; 5 a, spores magn. 1200. 
