17 



Spores four, six, or eight, colourless, very large, bent at middle, one sep- 

 tate, with, in many instances, nuclei in the loculi, epispore crenulate ; 

 paraphyses dense, capillary ; hypothecium pale yellow, grumous, 

 subtended by the dense black receptacle. — This is evidently allied to 

 Lecidea marginijiexa (Taylor), although quite distinct. On trees at an 

 elevation of 1000 feet. 



Lecidea fuscolutea (Dicks.), — The chemical reactions are identical, 

 viz., K. thallus, yellow j apothecia, crimson. The hypothecium is darker 

 than specimens from Ben Lawers. — On trees, 1000 to 1500 feet. 



Lecanora chrysosticta (Taylor) is mentioned for the purpose of re- 

 cording the fact of its growing along with the preceding on the bark of 

 the same tree. As regards their internal organization, the two lichens 

 are identical, and it is only when the thallus and thalline margin of the 

 latter are considered, that the question of generic difference is forced 

 upon the attention. The chemical reactions are also identical, and, as 

 showing still further the close organic affinity between the two, there are 

 seen, scattered ou the thallus of the former, spermogones without 

 the thalline margin, while on the latter are seen the same, with an 

 elevated thalline margin. I may have another opportunity of returning 

 to this subject, which is beginning to interest me, inasmuch as I can 

 point to other instances having a similar association. 



Bceomyces pertenuis (Sp. Nova).^ — -Thallus scarcely discernible. Apo- 

 thecia pale buff, concave with a paler border, attached by a central axis ; 

 spores eight, exceedingly minute, elongato-elliptical, apparently simple, 

 although there are occasional indications of a septum which a ^ objective 

 cannot distinctly resolve, in nearly single file in asci, which scarcely 

 differ in size or thickness from the ordinary paraphyses. A section pre- 

 sents the characteristic appearance of lichens of this genus. In such an 

 extreme case as this, it is necessary to remark that I have carefully dis- 

 criminated between the oil globules that are seen in the paraphyses of 

 one or two of the species of this genus and these minute spores, which 

 still preserve their outline when free of the asci, and which, by the aid 

 of a better objective, I find now are nearly constantly three septate. — On 

 trunks of trees, apparently those of some species of tree fern. 



Squamaria thaumasta (Sp. Nova). — Thallus greyish white, tesselato- 

 areolate, consisting of roundish umbonate particles, closely set together, 

 and yet quite distinct; cephalodia large, reddish brown, cracked in a 

 radiating manner, and roundly lobed at the circumference ; apothecia 

 small, elevato-sessile, concave, reddish brown, rugose, with an elevated, 

 smooth, inflexed border ; spores eight, colourless, broadly elliptical, 



