466 REPORT OF THE HARVARD AFRICAN EXPEDITION 
which are well developed, are considerably larger than the papillae, which are 
minute and inconspicuous. The buccal cavity is very shallow and into it there 
projects a very definite, although at times obscured, cuticularized spine, about 
6.5u long, which arises from the floor of the mouth. The oesophagus, of the typical 
trichostrongyle type, widens only slightly posteriad. It is about one-twelfth 
of the body length in the male and about one-ninth of the body length in the 
female. The nerve ring embraces the oesophagus anteriorly in the first quarter 
(0.28 mm. to 0.32 mm. from its anterior end), and at the same level the excretory 
tube opens by a fine duct on the ventral surface. Cervical papillae were not 
observed in the material at hand. They may be present as minute acicular points, 
which are stated by Leiper to project 0.4 mm. behind the nerve ring. 
Male. 12 to 13.4 mm. long with a maximum thickness of 0.28 mm. The 
bursa consists of two symmetrical lateral lobes united by a small unindented 
lobe, dorsally. The lateral lobes are figured, seemingly over the entire internal 
surface, with macular markings arranged to form a delicate mosaic design, and 
their posterior margins are finely scalloped by the cuticular striae which are quite 
conspicuous in this region. The small dorsal lobe is supported by a single dorsal 
ray, of proportionately reduced dimensions, which bifurcates near the middle of 
the lobe. Each of the bifurcations terminates in two minute digits which are 
slightly curved and extend to the margin of the lobe. The lateral lobes are sup- 
ported by six rays of which the latero-ventral and ventro-ventral, as seen in the 
normal condition of the bursa, appear to be closely approximated, but when the 
lobes are spread out it is seen that the tips of these rays are well separated. The 
three lateral rays are parallel; the postero-lateral is the smallest and the medio- 
lateral the stoutest. The externo-dorsal ray, the basal origin of which could not 
be definitely determined, is very slender. A pair of exceedingly minute prebursal 
papillae are also present. 
The spicules are equal in size, about 0.31 mm. in length, and brown in color. 
Each is composed of a proximal and terminal portion. The proximal portion, 
about 0.18 mm. long and 0.025 mm. broad, is adorned with one or two, somewhat 
twisted, longitudinal crests or ridges, and appears to be tubular in form. The 
distal portion is filiform and flexible, often being bent, as Leiper described, in the 
form of an interrogation mark. The tips of the spicules are not united by a 
membrane. The genital cone les ventral and just anterior to the dorsal lobe 
of the bursa. It is ornamented with tubercle-like papillae, but details of this 
structure could not be seen in the material available. 
Female. 18 to 22 mm. long with a maximum diameter of about 0.30 mm. 
near the middle. The terminal part of the intestine is narrowed to form the rec- 
tum with cuticularized lumen which opens at a point where the body is 0.12 mm. 
wide, about 0.37 mm. from the posterior extremity. The body narrows gradually 
to form a conical tail. The vulva is without salient lips and, in a specimen 
19.3 mm. long, is situated 4.5 mm. from the posterior extremity. The long uteri 
open through divergent muscular ovejectors into a short vagina. The eggs are 
ellipsoidal and have thin shells which measure from 66 to 73u long by 40u 
wide. 
