THE YAN YEAN RESERVOIR, VICTORIA. 83 
The Yan Yean collections were fairly rich in the Desmidiaceæ, and it is 
this group which must be examined for the peculiarities which enable one ta 
recognise from what part of. the world the collections were obtained without 
having previously been informed. Even with our present imperfect know- 
ledge, one can almost invariably do this with a rich Desmid collection. 
On contrasting Nordstedt’s valuable contribution to the freshwater Algæ of 
New Zealand * with the present paper, it is at once obvious that Australia 
and New Zealand have much in common amongst the Desmids, including 
many species which are only known to occur in this region. In the 
Yan Yean collections the Australasian types were the following :— 
Pleurotænium mamillatum, G. S. West. 
Micrasterius Hardyi, ©. 8. West. 
Cosmarium Capitulum, Roy & Biss., var. australe, G. 8. West, 
., perfissum, G. S. West. 
. achondroides, G. S. West. 
dorsitruncatum, (Nordst.) G. S. West. 
Murrayi, Playfair. 
turgidum, Bréb., var, oratum, Nordst. 
" amplum, Nordst. 
Hardyi, G. S. West. 
anenum, Bréb., var. medioleve, Nordst. 
Staurastrum assurgens, Nordst. 
sagittarium, Nordst, 
victoriense, G. №. West. 
digitatum, G. 5. West. 
sexangulare, (Buln.) Rabenh., var. productum, Nordst. 
The following species, although not observed in the Yan Yean drainage 
area, are also Australasian types so far as can be judged from our present 
knowledge :— 
Euastrum multigibberum, Nordst. 
Mierasterias suboblonga, Nordst. 
Cosmarium securiforme, Borge. 
Xanthidium bifurcum, Borge. 
gloriosum, (+. 3. West (=X. pulcherrimum, Playfair). 
" multicorne, Borge. 
Staurastrum cruciforme, Playfair. 
23 
" elegans, Borgo. 
Lyalotheca hians, Мог. 
The Australian Desmid-flora is а rich one, probably far richer than that of 
ж О. Nordstedt in Kongl. Sv. Vet.-Akad. Handl. xxii. no. 8 (1882). 
