32 Sclerostomes of the Donkey 
Habitat : Zanzibar, caecum of donkey. 
This species is evidently closely allied to C. insigne and belongs to the 
group of species which includes this form and C. elongatum, C. radiatum and 
C. auriculatum. It is distinguishable from C. insigne by the character of the 
genital appendages, by the number and shape of the leaves of the internal 
leaf-crown, and the presence of a highly chitinized oesophageal funnel. 
Fig. 5. Cylicostomum adersi sp. n. Lateral view of male bursa, x 75. 
REFERENCES. 
Boulenger, C. L, (1917). Sclerostome Parasites of the Horse in England. II. New Species 
of the Genus Cylichnostomum. Parasitology, ix. 420-438. 
Looss, A. (1901). The Sclerostomidae of Horses and Donkeys in Egypt. Rec. Egypt. Govt. 
School of Med. I. 24-136. 
Railliet, A. (1915). L’Emploi des Medicaments dans le Traitement des Maladies causees 
par des Nematodes. Rep. 10th Internat. Vet. Cong. London, 733-749. 
Railliet, A. and Henry, A. (1902). Sur les Sclerostomiens des Equides. C. r. Soc. Biol. 
54, 110-112. 
EXPLANATION OF LETTERING. 
A.d.c. Appendage of the dermal collar. 
G.c. 
Genital cone. 
A.g.c. 
Appendage of the genital cone. 
I.l.c. 
Internal leaf-crown. 
Ca. 
Wall of mouth capsule. 
L. 
Ventral lip of the genital cone. 
C.p. 
Cervical papilla. 
L.p. 
Lateral head-papilla. 
D.c. 
Dermal collar of the genital cone 
M.c. 
Mouth collar. 
D.g. 
Dorsal gutter. 
Oes. 
Oesophagus. 
D.r. 
Dorsal ray of the bursa. 
O.f. 
Oesophageal funnel. 
D.t. 
Dorsal tooth. 
P.b.p. 
Prebursal papilla. 
E.p. 
Excretory pore. 
Sp. 
Spicule. 
E.l.c. 
External leaf-crown. 
S.m.p. 
Submedian head-papilla. 
