198 LINDSAY, ON THE PROTOPHYTA OF ICELAND. 
many works of travel in Iceland, containing sections or 
chapters devoted to its natural history;* and it has been 
visited by British botanists of such distinction as the late Sir 
‘ W. J. Hooker, of Kew, and the present Professor Charles 
Babington, of Cambridge. Its geology and mineralogy have 
been the subjects of some elaborate treatises ; its birds and 
their eggs have had several zealous students and collectors ; 
not a few travellers have made superficial gatherings of phe- 
nogamous plants; but our knowledge of the groups of Cryp- 
togams here referred to is meagre and unsatisfactory in the 
extreme. I propose here to show how meagre, especially for 
the information of British naturalist-tourists, in the hopes 
that they may be stimulated to undertake at least what is the 
comparatively easy work of collection.t 
I. Diatomacee. 
In a ‘ Flora of Iceland, ¢{ which I published in 1861, and 
which included all plants up to that date recorded as having 
been collected in that most interesting island, only one 
Diatom was mentioned ; and even yet I am enabled to sub- 
join a total list (which follows) of only ten species, some of 
which, moreover, are fossil : 
1. Isthmia nervosa, Kitz. (I. obliquata, Ag., in my ‘ Flora,’ 
p- 36). Occurs also on the coast of Denmark, England, and 
Portugal. 
2. Amphora Libyca, Ehrb, Libya, America, and some 
parts of Central Europe. 
3. A. Semen, Ehrb. 
4, Navicula equalis, Ehrb. Occurs also in other parts of 
Northern Europe. 
5. N. constricta, Ehrb. Fossil. 
6. Stauroneis aspera, Ehrb. Occurs in various parts of 
Europe, from Spitzbergen and Norway toCorsica and Sardinia. 
7. S. Liostauron, Ehrb. 
8. Grammatophora Islandica, Ehrb. On the coasts. 
* Since my own visit in 1860, works of travel have been published almost 
annually by British tourists of the “ Alpine Club” class (e.g. by Syming- 
ton, Forbes, Metcalfe, Gould, Shepherd). None of these, however, 
‘are so scientific and of such permanent value as a German work published 
by two of my compagnons de voyage of 1860, Professor Zirkel, of Lemberg, 
Galicia, and Dr. Preyer, of Berlin, viz., “‘ Reisenach Island im Sommer 1860,” 
Leipzig, 1862. 
+ Many remarks on the subject of collection, especially of the Diatomacea, 
will be found in my previous paper, “On the Protophyta of New Zealand,” 
in this Journal, April, 1867, p. 97. 
+ ‘Edinburgh New Philosophical Journal,’ July, 1861, and ‘ Transact. 
Botanical Society of Edin.,’ vol. vii, p. 114. 
