257 
Original Articles. 
ON PTYCHOGRAPHA, Nyl., A NEW GENUS OF LICHENS. 
By tue Rev. J. M. Cromarze, F.L.S. 
(Tas. 150.) 
Tre occurrence of a new genus amongst the many new species and 
Varieties that are yearly being added to our British cetreyia sate 
of sufficient interest to render a short notice of it desirable. 
oe indeed but few tribes in which, in so far at least as Grea 
ne. 
The systematic place of this genus is immediately after Xylographa, 
Which at first sight it closely resembles. From this, however, as we 
#8 from all the other Graphidei, it is well recognised by the above 
er. tylographoides, Nyl., in Flora, 1874, p. 315. Thallus effuse 
A » Sreyish-white, internally with the gonidia subglomerated. 
Pothecia black, lanceolate, prominent, above somewhat plane, the 
it gitudinal 
ne, colourless, ellipsoid,’ simple, 0.011-14 mm. long, scr auth 
aa thallus spreads itself extensively over the substratum in the 
a, Manner as that of Xylographa parallela, of which, when 
= ig and on a mere cursory inspection, it was su to be 
Yel Ya condition with the apothecia as in var. pallens f. elliptica, 
y h differi _ colour. re 
Fe 
4 cclum, &c., as above noted, very distinct from that or any — 
*Pecies of Xylographa, and on sending a specimen to Nylander for 
N.S. Von. 3. [Szrremper, 1874.] ee 
