H. A. Baylis 
425 
hexagonal in outline, with straight anterior border. Dorsal lip with two simple 
lateral papillae; ventro-lateral lips each with one papilla towards the ventral 
side. Dentigerous ridges nearly marginal, with very small teeth. Oesophagus 
about ~ of total length, with a maximum thickness (near the posterior end) of 
0-35 mm. A short intestinal caecum present, about 0-4 mm. long, springing for¬ 
ward from a little behind the junction of oesophagus and intestine. Excretory 
pore at 0-95 mm., and nerve-ring at 0-8 mm., from the anterior end. A pair of 
cervical papillae, not prominent, just behind the nerve-ring. Vulva behind 
the middle of the body, dividing the total length in the proportion of 6 : 5. 
Vagina runs back as a muscular tube for about 3 mm. before widening into the 
uterus, which gives off six branches, running parallel to each other posteriorly. 
The coils of the ovarian tubes extend back to 13 mm. from the caudal end, 
and forward to a little behind the vulva. Ova nearly spherical, measuring 
0-08-0-1 mm. in diameter. Male unknown. 
Host: Zamenis gemonensis , var. caspius . 
Locality: Macedonia. 
Fig. 7. Polydelphis ivalcrstoni. The head; dorsal view. 
Note. In the foregoing account no attempt has been made to give a 
complete list of the Ascarids of snakes. Some forms recorded under the name of 
Ascaris have been intentionally omitted, which cannot be assigned to either 
of the genera Ophidascaris and Polydelphis , or of which no description exists 
which is adequate for the determination of their position. 
The nomenclature of the hosts has been, as far as possible, revised and 
corrected with the aid of Boulenger’s Catalogue of the Snakes in the British 
Museum (1893-1896), and the writer’s best thanks are also due to Dr Malcolm 
Smith for his help in this direction. Synonyms have been eliminated from 
among the names of hosts, except where it seemed an advantage to retain them, 
in which cases they have been enclosed in square brackets. 
REFERENCES. 
Baird, W. (1860). Description of some New Species of Intestinal Worms in the Collection 
of the British Museum. Proc. Zool. Soc., London, p. 446. 
-(1861). Description of some New Species of Intestinal Worms in the Collection of 
the British Museum. Ann. and Mag. Nat. Hist. (3) vu. p. 228. 
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