Art. LI.—Description of a new species of Thysanothecium collected by Mr. Buchanan during his recent expedition to the Southern Alps.

By Charles Knight, F.R.C.S., F.L.S.

of about 4,000 feet. It belongs to the genus Thysanothecium of which there were only two species previously known, both of which were found in Western Australia by Mr. Drummond, the Colonial Botanist. It is worthy of notice that the New Zealand plant was gathered on a glacier, while those in Western Australia grew on burnt-up timber. As these Lichens are exceedingly interesting to botanists I have made drawings and drawn up description form Mr. Buchanan's specimen, and have named it Thysanothecium Buchanani in recognition of that botanist's valuable contributions to the botany of the Southern Alps.

Thysanothecium buchanani, sp. n.

Thallus in duabus partibus formatus. 1° Pars horizontalis lobulato-squamulosa e viride lurida, squamulis in crusta granulosa areolata congestis. 2° Podetia erecta brevia in apothecia foliacea dilatata (alt. circa 6 mm.).

Apothecia sciphi compressi instar plicata, nonnihil in limbum planum producta, rigida apice inflexa et granulosa, disco testaceo-rufescenti receptaculum thallinum reticulatum omnino tegenti; hymenium incolor excipulo proprio luteolo strato gonimico imposito enatum, paraphysibus rectis capillaribus septatis adglutinatis apice non dilatis. Sporæ 8næ una serie dispositæ sphericæ incolores diam .013 mm.

Corticale receptaculi stratum ex elementis filamentosis directis ad laterem constitutum.

Supra molem nivium frigoribus conglaciatam in summis montibus (“Aspiring Range”), alt. 4,000 pedes.

Explanation of Plate XVII.