106 LINDSAY, ON THE PROTOPHYTA OF NEW ZEALAND. 
perhaps, than we should @ priori have been led to expect 
in the circumstances. 
A second feature of interest is the large proportion of 
forms which are not only common fresh-water species in 
Britain, but are cosmopolite, occurring in most different 
parts of the world, under great variety of climate, latitude, 
and elevation, including the heights of the Himalayas and 
Andes. ‘This category embraces, e. g., Synedra radians, 
S. Ulna, Stauroneis gracilis, S. anceps, S. Phenicenteron, 
Pinnularia viridis, P. borealis, Cocconema lanceolatum, Colle- 
tonema vulgare, Epithemia gibba, Navicula claviculus.* 
Equally important and even more encouraging to the local 
botanist is the fact that a superficial collection, hurriedly 
made by a traveller in a most limited area, near a capital 
town, contains three new species, viz., Cymbella Lindsayana, 
Stauroneis scaphuleformis, and S. rotundata, or 2°72 per cent. 
These are necessarily, so far as we yet know, restricted in 
their distribution to New Zealand: though the analogy of 
other species renders it at least probable that they,will yet be 
found to possess a wider range. 
Of the 110 species enumerated in the foregoing list, none 
are recorded in the latest general catalogue of Diatoms (in 
English)—that of Ralfs, in Pritchard’s ‘ Infusoria’ (4th ed., 
1860)—as having been previously found in New Zealand: 
while in the earlier ‘ Synopsis’ of Smith (1853 and 1856) 
only three are so recorded, viz., Epithemia Sorex, Pinnularia 
viridis, and Cocconema lanceolatum. 
A knowledge of the geographical distribution—of the 
nature of the habitats—of the botanical relations of Diatoms 
in other parts of the world in which they have been thoroughly 
studied—cannot fail to assist the local botanist in his search 
for, and examination of, New Zealand forms. Hence no 
apology seems necessary for introducing here the following 
general observations : 
I doubt whether any other group of plants has a wider 
geographical range than the Diatomaceze +—whether any will 
* Smith’s “ Synopsis,” vol. II., preface, xxvii. 
+ It is a well-recognised Jaw, admirably discussed by Alph. De Candolle 
as regards plants, that “the lower any group of organisms is, the more 
widely is it apt to range” (Darwin, ‘Origin of Species,’ 4th ed., 1866, 
p. 481); and the late Prof. Gregory, of Edinburgh, who distinguished him- 
self during the latter years of his life by his devotion to the theory of the 
Diatoms of Scotland, remarks, “These organisms are far less affected by 
climate and temperature than larger plants or animals, since many of the 
very same species are found in every latitude and in every country......and 
there is absolutely no difference between the exotic and the British forms ” 
(‘ Proceed. Botan. Soc. Edin.,’ 1855, p. 71). 
