Charles L. Boulenger 105 
section of the head in a lateral view present a totally different appearance to 
that viewed dorso-veil trail v (Text-fig. 6 , a and b). 
There is no dorsal gutter. The oesophageal funnel is poorly developed. 
The oesophagus is slender with an average length of 0*33 mm. Cervical 
papillae are present at the same level as the excretory pore, 0*24 mm. from 
the anterior extremity. 
Female. The vulva is 0-13 mm., the anus 0*06 mm. from the posterior 
extremity of the body. The tail region behind the anus is narrow and ends 
in a fine point. 
Male. The bursa is 0-25 mm. broad when viewed from the dorsal or ventral 
surface, the dorsal lobe is of medium length (0-12 mm.). The dermal collar 
is poorly developed and almost flat on the ventral surface of the genital cone. 
The latter is short, its appendages are similar to those of C. tetracanthum 
(Mehlis), i.e. ovoid in shape with a short blunt point on the posterior margin. 
Fig. 6. Cylicostomum Montgomeryi sp. n. Anterior extremity. A. Dorsal view. B. Lateral 
view, x about 350. 
In the structure of its mouth capsule this form differs from all other known 
species of Cylicostomum with the exception of C. faldferum (Cobbold, 1882), 
a parasite of the Elephant -now placed in a separate genus Murshidia Lane, 
1914. In the latter species, however, the bilateral symmetry extends to the 
elements of the leaf-crown; this is not the case in C. Montgomeryi , where 
these structures are radially arranged. 
m 
Genus Craterostomum gen. n. 
Type species: C. tenuicauda sp. n. Closely allied to Triodontophorus 
Looss, differing from this genus by the absence of teeth projecting into the 
mouth-capsule. 
Craterostomum tenuicauda sp. n. 
Small, rather robust worms; the type specimens consist of three females 
only, 4-5*5 mm. in length. The cuticle of the body is transversely ringed. 
Body with a maximum breadth of nearly 0*4 mm., reduced to 0*28-0*32 mm. 
at the level of the termination of the oesophagus. 
