196 Transactions of the Royal Society of South Africa. 
particular class of host, in a defined zoo-geographical region, find their 
nearest relatives not in that region in which they themselves occur, but in 
the same class of host living in other zoo-geographical regions. 
Five such faunal groups from Amphibia are now more or less well known, 
viz. European, North American, Asiatic, Australian, and South African. 
In each region we find, in hosts of this class, trematodes corresponding 
or closely corresponding with representatives in the other regions. The 
group in the European region, as the longest known and most extensively 
investigated, shows the greatest number of genera ; in point of numbers, 
the American group, to which a good deal of attention has been given of 
late years by Stafford and others, follows closely on the European. The 
Australian, Asiatic, and South African groups show smaller numbers, partly, 
perhaps, because less completely worked up. The facts at present seem to 
indicate that in Asia, Australia, and South Africa the number of representa- 
tives may be further, more or less extensively, added to by subsequent inves- 
tigations. Besides the frogs, other classes of hosts, as mammals, birds, and 
reptiles, show faunal groups of parasites with relations analogous to those 
exhibited by the group from frogs, as the small collection of trematodes 
I have from mammals thus far go to show, viz. Paramphistomidae and 
Fasciolidae from sheep and cattle, for example. Leaving the latter in the 
meantime out of account, and confining ourselves to the groups from frogs, 
we find : Opisthioglyphe endoloba, occurring in the intestine of European 
and South African frogs, is represented in North America by Glypthelmius 
quieta and in Australia by Dolichosaccus trypherus and Dolichosaccus 
ischyrus, which also live in the proximal part of the intestine of their hosts. 
The three European species of Pneumonoeces, found in the lungs, are 
represented in America by no less than six species (P. longiplexus 
Stafford, breviplexus Stafford, P. varioplexus Stafford, P. similiplexus 
Stafford, P. medioplexus Stafford, and P. complexus Seeley), while they 
are represented in Asia by Pneumonoeces capyristes Klein, in Australia 
by P. australis. The only representative of Pneumonoeces I have thus 
far come across was a specimen given me by my chief, Dr. E. J. Goddard ; 
it was removed from the lungs of Rana fuscigula. Unfortunately it was 
damaged, and did not lend itself to specific determination. 
The Gorgoderinae, represented in European frogs by the two genera 
Gorgodera and Gorgoderina, comprising between them, according to Ssinitzin, 
five separate species, all living in the bladder of frogs, are represented in 
America by four species of Gorgoderina and one of Gorgodera. No species 
of Gorgodera has yet been described from Asia, and thus far I have not 
yet found any in South Africa, but the genus is represented by one species — 
G. australiensis (Johnston) — from Australia. The European Brachycoelium 
crassicolle R., found in the intestine, is represented in America by B. hospi- 
