102 
Parasites of the Zebra 
The spicules are shorter (0-78 mm.) and more slender than those of the 
type species and are provided with less powerful terminal hooks. 
As pointed out by Leiper, the species closely resembles (■. brcricauda, the 
chief points of difference being: the smaller mouth-capsule, the more slender 
oesophagus, the elongated caudal region of the female and the structure of 
the bursa and the genital cone in the male. 
Genus Cylicostomum Railliet and Henry, 1902. 
Cylicostomum zebrae sp. n. 
Specific Diagnosis. Cylicostomum. A fairly large, robust species repre¬ 
sented in the collection by three specimens, onlv two of which are adults, one 
female and one male, measuring 9-8 and 8*5 mm. in length respectively. The 
maximum thickness in both sexes is about 0-8 mm. Both worms have con- 
Fig. 3. Cylicostomum zebrae sp. n. Anterior extremity in lateral view, x about 125. 
siderably shrunk during fixation as is shown bv the ratio of length to breadth, 
during life they must have been considerably more elongated than the figures 
show. The head is broad (0*27-0*3 mm.), not separated from the body by a 
neck constriction. The mouth collar is relatively low and depressed at the 
margins except in the neighbourhood of the lateral papillae. The latter are 
large and very prominent, forming a conspicuous feature in a dorsal or ventral 
view of the head (Text-fig. 4). 
The submedian head papillae are long, with leaf-shaped terminal appen¬ 
dages. 
The mouth is oval in shape, the longer axis being directed dorso-ventrallv. 
The external leaf-crown consists of about 32 pointed leaves, the elements of 
the internal leaf-crown are very inconspicuous and very small, appearing as 
a ring of fine striae immediately in front of the mouth-capsule (Text-fig. 3). 
The mouth capsule is short measuring 0*07 mm. in length, with a breadth 
n * its walls are thin except in the posterior region where they are 
