C. L. Boulenger 
328 
in which these organs are provided with three pointed processes instead of the 
normal two (Text-fig. 4). This character is therefore one which should be used 
with caution in differentiating the various species of Cylicostomum. 
18. Cylicostomum pateratum Yorke and Macfie, 1919. 
( C . cymatostomum Kotlan, 1919.) 
A single female specimen of this species was found in the colon of a horse 
from Sargodha, Punjab. The worm was 11 mm. in length, and in its various 
measurements agreed well with the original examples described by Yorke and 
Macfie, being distinctly smaller than the Hungarian specimens recorded by 
Kotlan under the name C. cymatostomum and which, according to Ihle (1920 b), 
should be referred to C. yateratum. The species has hitherto been recorded 
from Europe only. 
Fig. 4. Cylicostomum pseudo-catinatum Yorke and Macfie. Genital appendages of an abnormal 
male individual, ventral view, x 460. 
19. Cylicostomum nassatum (Looss, 1900). 
20. Cylicostomum nassatum var. parvum Yorke and Macfie, 1918. 
With the exception of C. insigne, this is the commonest species of Cyli¬ 
costomum met with in horses in the Punjab. The small variety is more abund¬ 
antly represented in my collections than the type form, the females of the 
two varieties are however sometimes difficult to distinguish. 
21. Cylicostomum insigne (Boulenger, 1917). 
C. insigne was the commonest species found in the Punjab, it was obtained 
from almost every horse dissected in Lahore, frequently occurring in very 
large numbers. I am able to add somewhat to my account of the species 
published in 1917. 
The distribution of the worm in the body of the host is peculiar: adult 
specimens were found to be almost completely restricted to the posterior part 
of the colon, only rarely occurring in the anterior region of this organ; larvae, 
on the other hand, were found abundantly in the caecum, usually encysted 
in the sub-mucosa, rarely free, in the latter condition being also occasionally 
met with in the anterior colon. 
