May 17, 1924 
A New Nematode 
663 
Gyalocephalus capitatus in what Yorke and Macfie (7) regard as the posterior 
terminations of the internal leaf crown, but wilich Ihle ( 3 ) considers separate 
processes of the posterior border of the mouth capsule wall. These internal 
elements of Cylindropharynx ornata originate considerably behind the anterior 
margin of the mouth capsule, and on reaching that margin are bent inward as 
described above. 
Oesophagus. —Short and broad, in the female having a length of 747/t and 
greatest breadth 216/*; in the male 581/* and 166/* respectively. The nerve ring 
is situated near the anterior extremity. The excretory pore lies at the union 
of the posterior and middle thirds of the oesophagus; the cervical papillae are 
situated a short distance anterior to the pore. 
Intestine. —This shows pseudo-annulations throughout its length, which are 
especially striking in the anterior part. Leiper (4) indicated this in the figures 
of C. brevicauda and C. longicauda. 
. Posterior extremity of the male. —The breadth of the worm decreases 
only very slightly and the dorsal lobe of the bursa is short, so that the posterior 
end of the worm appears very blunt. The dorsal ray is 202/* long, tapers to a 
long, sharp point, and midway from base to tip gives off an external branch, which 
is bifurcated in its distal half, the inner finger-like process being slightly shorter 
than the other (fig. 5). There are no fine, hair-like projections on the dorsal rays 
such as are shown in figures of both C. rhodesiensis and C. brevicauda. The 
bursa is finely striated, its margin showing very fine serrations; the lateral lobes 
do not embrace the genital cone. The genital cone is short (100/*) and stout. The 
dermal collar is well developed on the ventral but not on the dorsal surface of the 
cone. The genital appendages are very striking and of very elaborate nature 
(fig. 6). A central portion, which lies directly under the lip of the genital cone, 
consists of two globular projections, each bearing a papilla-like point; these two 
are connected in the middle line by a thumb-like projection. On each side of these 
central structures there projects a large, irregular-shaped extension, its posterior 
line wavy, its free end a finger-like process, and on the anterior margin a knob¬ 
like projection. These two structures show variation in position, in one male 
being at right angles to the long axis of the cone (as figured) and in the other the 
angle being only half that. This variation may indicate that these are clasping 
organs, therefore motile and capable of changing their relative position. In 
addition to these complex appendages of the cone, the dermal collar bears an 
indefinite number of long, delicate, sharply pointed, flexible processes on its 
lateral and dorsal surfaces. The arrangement of these seems quite irregular. 
The spicules are long (790/*) and stout, their extremities sharply pointed and 
strongly barbed (fig. 7). 
Posterior extremity of the female. —The vulva is 1411/* and the anus 
330/t from the tip of the tail. Posterior to the anus there is an abrupt thickening, 
then the tail tapers to a sharp point. Covering the anus there is a lip-like struc¬ 
ture of papilliform appearance (fig. 8). 
Diagnosis. —This worm is more closely allied to Cylindropharynx rhodesiensis 
than to either of the other two species in the genus, but differs from it in its 
smaller size, in the much greater width of the mouth capsule in proportion to its 
length, in the point of origin of the internal leaf crown elements being considerably 
farther back and in their distal ends being bluntly rounded, in the presence of 
very elaborate genital appendages, and in the different shape of the spicules. 
A comparison of the four species of the genus is seen in the key on page 668. 
