A NEW NEMATODE, CYLINDROPHARYNX ORNATA, FROM 
THE ZEBRA, WITH KEYS TO RELATED NEMATODE 
PARASITES OF THE EQUIDAE 1 
By Eloise B. Cram 
Zoological Division, Bureau of Animal Industry , United States Department of 
Agriculture 
Cylindropharynx ornata, sp. it. 
Two males and one female of this species were found in material collected 
from Equus grevyi at Bethesda, Md., in 1907, one male among specimens col¬ 
lected from the feces by Dr. E. C. Schroeder and the other two among specimens 
collected post mortem by Dr. M. C. Hall. The worms were collected from 
one or both of two zebras presented by the King of Abyssinia to Ex-President 
Roosevelt and turned over by him to the Department of Agriculture. 
Size: Male 9.9 mm. in length and 0.4 mm. greatest breadth. Female 10.0 mm. 
in length and 0.5 mm. greatest breadth. 
Head—Mouth collar. —Depressed at margin; marked off from rest of the 
skin by a constriction; it is considerably higher dorsally and ventrally than 
laterally. 
Head papillae. —Submedian papillae very striking in appearance, a distal 
leaf-shaped portion being separated by a constriction and bent inward from the _ 
tall digitiform proximal portion. 
Lateral papillae not conspicuous; do not project beyond mouth opening; their 
extremities are trifurcated, as noted by Boulenger (l) 2 in C. brevicauda. 
Mouth capsule. —This shows the great length characteristic of the genus; in 
the male 250/*. in the female 300/* long. The diameter of the anterior third of 
the capsule is markedly greater than that of the posterior two-thirds, giving the 
appearance of a bulbous swelling. In the male the diameter of the anterior 
portion was 140/*, of the posterior portion 83/t; in the female 166/t and 99/t res¬ 
pectively. The ratio of greatest width to length of capsule was therefore 1:1.8 
in both sexes. The capsule is lined with the usual transparent chitinous layer, 
which in the anterior bulbous portion projects into the lumen in what appears 
as a ring-like thickening. The walls of the mouth capsule are thick, their diam¬ 
eter being 11/e in the anterior portion and 16/* in the posterior portion. 
Dorsal oesophageal gutter. —This does not project into the buccal capsule. 
Leaf crowns. —The external leaf crown in this species, as in the three pre¬ 
viously described, consists of six elements, all clearly projecting beyond the 
mouth opening. The four occupying the submedian positions are delicate, 
relatively small, and sharply pointed leaves; the two which are situated laterally 
are much broader; their tips are bent toward the exterior. The inner surface of 
these leaves is grooved, giving the appearance of three ridges with two troughs 
between them; these are divergent toward the base of the leaf. Boulenger ( 1 ) 
noted that the corresponding leaves of C. brevicauda were notched in a similar 
manner and suggests that this may indicate that the leaf resulted from the fusion 
1 Received for publication Mar. 27, 1924. 
* Reference is made by number (italic) to “ Literature cited,” p. 672. 
Journal of Agricultural Research, 
Washington, D. C. 
( 661 ) 
Vol. XXVIII, No. 7 
May 17,1924 
Key No. A-72 
