[361 ] 
VIII. The Lichens of Ceylon collected by G. H. K. Tawarrss, Esq., PhD., F..R.S., F.L.S., 
Director of Royal Botanic Garden, Peradeniya, Ceylon. Examined and determined 
by the Rev. W. A. LEIGHTON, B.A., F.L.S., F.B.S. Edin. 
(Plates XXXVI. & XXXVIL) 
Read January 21st, 1869. 
I HAVE the honour to lay before the Society the results of the examination of an 
extensive and important collection of lichens, made with singular skill and judgment by 
Dr. Thwaites, in the central province and southern portions of the island of Ceylon. The 
collection is apparently a fairly complete one, although, without doubt, many additions 
may still be reasonably expected to be made to some of the tribes and genera by future 
and further researches. As it is, it affords very many lichens hitherto undescribed and new 
to science. . With a very few exceptions, the lichens all grew on the barks of various trees. | 
Mr. Thwaites (in litt. Dec. 13, 1868) says, “ The localities here most favourable for 
lichens are open forests, or the margins of dense forests. Except the Thelotremata, most 
of which affect the bark of old tree-trunks, the greater number of our epiphytal species 
grow best upon healthy young trees, whose bark is sometimes quite covered with lichens, 
adding, I think, greatly to their beauty, and apparently not impairing their health. 
“The range of elevation in which most of our species of lichens occur, is from little 
above sea-level to 4000 feet; many ascend much higher, and even to 8000 feet ; but at 
the last-named elevation the number of species is comparatively small." 
The epiphyllous lichens, of which a large quantity has been forwarded to me, are as yet 
unexamined, and I hope to lay them before the Society in a future paper. 
The following Table will exhibit a synoptical view of those comprised in this paper :— 
SIN eri Pigi a. 1 Pasnara =, as viv ws iint 4 
i A „une 5 Coccocarpia «civic... 2 
Collemei .......... { DEDE vite 1 et isses un 2 
Caliciei { BRübetins eee 1 ola ee vi 6 
i : : 
d dde M THREE TS d : | Ureolena ,........... 1 
Sphærophorei ...... Sphærophoron .......... 1 — € À Dirina serler ea nnn 
Beomyeel.......... A oo. ce A 1 PENES eR 9 
Cladonia.. i... in: la oo a 3 Thelotrema ved V bd aod 2] 
tereocaulei ........ Stereocaulon............ 1 Be ,.,.... 7 
Rolla six Boss Sy. 2:73 ee 1 mieu 103. 4A 1 
Dena Pe eae ji E 3 Tu { œnogonium .......... 5 
Romaka i.i. poss M NE : BNMNE OA Graphis a a is Each 11 
: . Nephromum .........- raphis................ ¿ 
Peltigerei.......... picem ^ urea ee ue 1 | Helminthocarpon ........ 1 
f Asteristion ............ 1 a ODDS rue 1 
BB urere 9 Graphidei .... ...... < Platygrapha ........ e. Y 
BR cu IJOSMBE VU C eere 1 | Arthonia ...:.......... 4 
POR ci es 7 Glyphis.......,........ 5 
| Physeia.. 2o | Chiodecton ............ 4 
Gyrophorei ........ Unmbilisatla “nc. «6 1 ica ZEE oes 17 
B A PME 22... 2 -Pyrenocarpei ...... DO ¿si 
Trypethelium .......... 5 
PNE re, 199 
