PRESIDENTIAL ADDRESS. 117 
this species I have found larval nematodes, Spiroptera (7?) 
sp. 
The known nematodes of FE. norvegicus (Australian 
records!) are therefore :—Strongyloides papillosus, Capul- 
larva annulosa, C. schmidti, Hepaticola hepatica’, Tricho- 
somoides crassicauda!, Trichinella spiralis, Heterakis spu- 
mosa', Oxyuris obvelata’, Heligmosomum braziliense’, 
Strongylus sp., Gongylonema neoplasticum, Protospirura 
murist and Spiroptera ?..sp. | 
Of E. rattus (including E. rattus alexandrinus) :—Capul- 
laria annulosa, C. papillosa, Hepaticola hepatica’, Trichuris 
muris!, Trichosomoides crassicauda, Heterakis spumosa', 
Oxyuris obvelata’, Gongylonema neoplasticum, Protospir- 
ura muris', Physaloptera circularis, Spiroptera rattr, and 
Filaria sp. 
Of Mus musculus :—Capillaria bacillata, Hepaticola hep- 
atical, Trichuris muris', Trichosoma muris-muscult, Tricho- 
nella spiralis, Heterakis spumosa', Oxyuris obvelata', O. | 
tetraptera’, Strongylus lemni (2), Ollulanus tricuspis, Gon- 
gylonema musculi, G. neoplasticum, Protospirura muris', 
and Spiroptera quadrialata. Johnston records Gongylo- 
nema sp. for Australia. 
These lists give 13 species for H. norvegicus, 12 for EH. 
rattus (and E. alexandrinus), and 14 for Mus musculus. 
Seven species are common to EH. norvegicus and EF. rattus. 
M. musculus shares 5 species with EL. norvegicus and 6 with 
£. rattus, whilst 5 are common to all three rodents. 
In Australia, E. rattus and M. musculus have five 
species of nematodes in common, and share four of these 
with #. norvegicus. 
Of these nematode parasites of rats, two for different 
reasons are of world-wide interest, a third is of some par- 
ticular interest to members of this Society, whilst a fourth 
