4.76 WILLIAM NICOLL. 
The species in question was first obtained on August 21st, 
1907, from the middle part of the intestine of Anthus 
obscurus (rock pipit), which is by far the commonest bird 
inhabiting the rocks along the shore in this district. The 
parasite, however, is by no means frequent, for out of eleven 
pipits shot during August to October only two specimens 
were obtained—one adult and one immature. <A. point of 
interest is that the two birds from which those specimens 
were obtained contained several other parasites, in particular 
two species of Spelotrema and a number of Cestodes. The 
other birds contained only a few examples of Spelotrema 
claviforme and an occasional Cestode. Several other rock- 
frequenting birds, e.g. Saxicola cnanthe and Mota- 
cilla flava, were examined in the hope of finding more 
specimens of the parasite, and towards the middle of October 
another single example was found in the intestine of Mota- 
cilla. This second example did not entirely agree with the 
first, but at present they may be regarded as one and the 
same species. ‘lo avoid detailed comparison the specimen 
from Anthus will first be described, and the main features 
of difference in the specimen from Motacilla will then be 
indicated. 
The general shape is that common to the genus. The 
lengthis 1-6 mm.; the breadth is fairly uniform—52—57 mm. 
Almost the whole surface of the body is covered with minute 
straight spines which have the peculiarity that they Just 
barely pierce the cuticle. This feature is shared by the 
other members of the genus, and would appear to be charac- 
teristic. 
The oral sucker is not quite at the extreme anterior end of 
the body, but is a short distance from it. Its length is shghtly 
greater than its breadth, and it has an elongated slit-lke 
aperture. his again appears to be characteristic of the 
genus. In this species the aperture is slightly expanded 
posteriorly and narrows toa fine point at the anterior end. 
The sucker measures ‘20 by ‘18 mm. ‘The ventral sucker is 
globular, with a circular aperture, and measures only ‘16 
