LA MER UMANE 
£4889 
XVII. Lichenes Amazonici et BEE a Domino SPRUCH. 
By the Rev. W. A. LEIGHTON, B.A., F.L.S. 
(Plate LVI.) 
Read March 15th, 1866. 
THE celebrated traveller Mr. Richard Spruce has entrusted to me a most magnificent 
collection of corticolar Lichens, formed by him during his long and laborious explorations 
in Equatorial America, for examination and determination. The result is comprised in 
the following catalogue, which contains not only very many rare and beautiful species 
already known, but also about twenty-four species previously unknown and undescribed. 
It is both a pleasure and a duty to acknowledge the liberality and kindness of Dr. Wm. 
Nylander, of Paris, in examining and confirming most of those which I consider to be 
new species, —a circumstance which will be duly appreciated by every lichenist who is . 
acquainted with his great knowledge of exotic lichens—unsurpassed, indeed, by that 
of any living lichenologist. 
In the list, I have added to the names certain numbers, which correspond with those 
on the tickets attached to the several sets of these lichens which have been distributed 
by Mr. Spruce, and by a reference to which their possessors will be now enabled to add 
the proper names. Many specimens (which were imperfect, from the attacks of insects 
and other causes) have been wholly omitted, and only those inserted which could be 
fully determined. 
The following account of the region is in the words of Mr. Spruce himself :— 
“I divide that part of Equatorial America explored by me into five great regions, 
depending on natural, and not on political features,—to wit : 
“1. The Lower Amazon (from the mouth to the confluence of the Rio Negro, or about 
1000 miles up). 
“2. The Rio Negro, with its tributaries. 
"6. The Upper Orinoco (i. e. above the cataracts). 
“ These first three regions are all in the Great Plain, which is perhaps nowhere ele- 
Yated 1000 feet above the sea-level. 
À 3 The Perwian Andes. 
“5. The Quitenian Andes. bi Ss 
“As so hep of my plants were gathered on the uncertain frontiers of ee, 
Countries (for instance, in the territory claimed by Brazil on the one hand, and by € 
mela and Nova Granada on the other, and also in the neutral ground en Peru an 
Ecuador), any political grouping of regions could only be very transitory. 
ons of the several localities are here given. 
To save: repetiti 's descripti 
repetition, Mr. Spruce's descrip the tickets attached to the sets. 
The names between inverted commas are those on 
