106 
Queensland Trematodes 
are, in consequence, in many cases identical with, or very closely related 
to, those which occur in the same or similar birds in Europe and Asia. 
This is well illustrated by the common occurrence of such widely dis¬ 
tributed parasites as Echinostomum revolution (Froelich) and Noto- 
cotijlus attenuatus (Rud.). 
With one exception ( Allopyge antigones S. J. Johnston) all the trema- 
tode parasites hitherto described from Australian birds have been 
referable to already known genera. The same applies to the species 
described in the present paper with the exception of two liver-flukes 
from the stone-curlew and white ibis. Though closely related to corre¬ 
sponding European forms ( Platynosomum ) they display characters 
sufficiently distinctive to warrant their being regarded as members of 
a separate genus. 
The most characteristic feature of the Australian bird Trematode 
fauna is the comparative frequency with which Echinostomes and Holo- 
stomes occur. Specimens of these two groups have been collected from 
eighteen and a dozen different birds respectively. 
In addition to the species described here a number of other forms 
have been collected but either on account of immaturity or imperfect 
condition they do not admit of sufficiently accurate determination and 
description. Amongst these may be mentioned an interesting form 
from the Spur-wing Plover, apparently a member of the Lepodermatidae, 
and a species of Prostliogonimus from the peewit ( Grallina picata). 
DISTOMATA. 
Family Opisthorchiidae. 
Opisthorehis obsequens n. sp. 
(Plate VI, fig. 1.) 
About fifty specimens of this form were obtained from the liver of 
a brown hawk ( Hieracidea berigora). A few immature specimens 
(about 1 mm. long) were also obtained from the liver of Hieracidea 
orientalis. The adult specimens vary in size from 2'6 to 5'1 mm. The 
maximum breadth, which occurs in the post-acetabular region, varies 
from 0‘8 to l - 2 mm. An average specimen measures 3'7 X l'O mm. 
The body is very much flattened and the edges are crenated. The 
anterior end is considerably attenuated but the posterior end is rounded. 
Frequently, however, a small knob-like tip projects from the posterior 
end. There are no cuticular spines. The oral sucker is almost terminal 
