104 
Parasites of the Zebra 
and surrounds the genital cone. The appendages of the genital cone are in 
the form of broad oval plates, fused together in the middle line. 
This form evidently belongs to the group of species which includes C. auri- 
culatum, Looss, C. elongatum Looss and C. insigne Boulenger, agreeing with 
these in the general formation of the head and in the structure of the male 
bursa and its appendages. Apart from minor characters it differs from these 
species in the shape of the oesophagus with its enlarged anterior extremity 
and the greater development of the oesophageal funnel. 
Fig. 5. Cylicostomum zebrae sp. n. A. Bursa of male from right side. B. Posterior extremity 
of female, ventral view, x about 75. 
Cylicostomum Montgomeryi sp. n. 
Specific Diagnosis. Cylicostomum. A small species, females 4-5-6-5 mm., 
males 4-3-6 mm. in length. The greatest thickness of the body is 0-28 mm., 
decreasing to 0-2 mm. at the level of the commencement of the intestine. 
The head is 0-08-0-09 mm. broad, not separated from the body by a con¬ 
striction to form a neck. 
The mouth is oval, the dorso-ventral axis being a little shorter than the 
lateral. The mouth collar is thick and depressed at the margins (Text-fig. 6). 
The lateral papillae are prominent, the submedian slender with leaf¬ 
shaped appendages. 
The anterior leaf-crown consists of about 18 slender, pointed leaves, the 
posterior leaf-crown of twice that number of rather similar but shorter 
elements (Text-fig. 6). 
The mouth-capsule is characterised by its peculiar bilateral symmetry, 
its dorsal and ventral walls being considerably higher (0-032 mm.) than the 
lateral walls (0-022 mm.); this absence of radial symmetry makes an optical 
