ON THYSANOTHECIUM. 257 



On Thysanothecium, a new genus of Lichens, by C. 

 Montagne, D.M., and the Rev. M. J. Berkeley, 

 M.A., F.L.S. 



(With a Plate, Tab. X.) 



The remarkable production here characterised formed part 

 of an extensive collection of Swan River Cryptogams sent to 

 Sir W. J. Hooker by Mr. Drummond. The older indivi- 

 duals, though their affinity to the great division of Lichens 

 is very evident, bear a very striking resemblance to Cantha- 

 rellus undulatuSy Fr. Unfortunately no sporidia have been 

 detected ; the series of specimens is, however, too perfect to 

 allow of the supposition that it is merely a strange form of 

 some well known genus. 



Thysanothecium, Mont, and Berk. 



Apothecia terminalia, libere enata, primitus orbicularia plana, 

 margine sinuoso integro, demum flabellari-expansa, obliqua, 

 maxima, lobata, lobis oblongis. Discus tandem iraraar- 

 ginatus (excipulo nullo receptus) thallo subconcolor, palli- 

 dus, strato gonimo impositus. Asci imperfect!. Thallus 

 duplex ; verrucee sparsse a quibus surgunt frondes verticales 

 tereti-compressae, cartilagineo-corticatee, rimoso- plicatse 

 solidae, intus filamentosse.— Had. ad ligna adusta necnon ad 

 terram nudam in regione Australasiae, Swan River dicta. 

 Thysanothecium Hookeri. — Drumm. n. 69, 70. 



The genus has somewhat the habit of Ramalina, to which 

 ^ is analogous, in the position of the proligerous lamina and 

 the nature of the thallus, but it is very different in the mode 

 of evolution and the form of the apothecia. These are 

 formed at an early period on the tips of the fronds, and they 

 aright then be taken for those of a Stereocaulon. They may 

 be distinguished, however, by the absence of an excipulum. 

 They lose gradually their orbicular form, and are developed 

 unequally, so as at last to appear fixed to the thallus by 

 a single point of their circumference, the remainder being 

 vol. v. u 



