118 Loa papionis n.:sp. 
observers simply mention the presence of glandular substance without giving 
any details. 
The mid-gut and rectum correspond to Looss’s description. 
The ano-genital opening is 0-084 to 0-086 mm. from the posterior extremity 
in the while in the 9 the anus is rather more than double this distance away. 
The excretory system. I only once succeeded in finding the excretory pore 
in the 9, and never found it in the it was situated 0-68 mm. behind the 
anterior extremity on the ventral surface. What appeared to be an excretory 
canal was sometimes visible in the substance of the lateral band. 
The genital system in the male. Although a cursory examination reveals 
the presence of five pairs only, seven pairs of pedunculated and symmetrically 
situated genital papillae exist. The first three pairs are preanal, the last three 
postanal, while all six have an oval outline and diminish in size from before, 
backwards (Plate IX, fig. 2, P ± 2 , etc.). The fourth pair are adanal in position 
and slender in shape. I never noticed them in undissected specimens; how¬ 
ever, after removal of the spicules and hemisection of the posterior extremity 
they caught the eye at once in both cases in which this little operation was 
successful (Plate IX, fig. 3, P 4 ); in the undissected state they seem to be 
hidden by the spicules. The seventh pair are also readily overlooked owing 
to their subterminal position on the ventral surface of the sharply curved tail. 
If a number of living males be observed in normal saline, the tail is seen to 
be strongly curved in almost all of them; in fact it never seems to be com¬ 
pletely uncoiled, although the extent of the curve may vary considerably 
during movement. Even after fixation in hot alcohol the curvature persists, 
and in several cases I was unable to see a trace of the seventh pair before 
dissecting the posterior extremity. Sometimes however, one or both of these 
papillae are quite conspicuous in the undissected state; in the first case the 
muscle cells were probably contracting more vigorously on the one side than 
on the other at the moment of fixation, the posterior extremity becoming 
slightly twisted in consequence (Plate IX, fig. 2, P 7 ); in the second case the 
posterior extremity was much less sharply curved than usual. 
At the time, I was unable to reconcile these observations with the descrip¬ 
tions of L. loa available in the literature. Looss describes five pairs of papillae 
and mentions the presence of ‘‘terminal filamentsin both sexes; however, 
lack of material prevented him from deciding whether those of the male were 
distinct papillae or not. Penel (1904) records the presence of two little 
tubercles in this situation, as do Annet, Dutton and Elliot (1901). Penel also 
mentions the presence of small, adanal tubercles; but he gives no details, and 
does not say whether he regarded them as being constant or not. After reading 
Leiper’s paper (1913), these difficulties largely disappear. Both Leiper and 
Lane regard the slender fourth pair as being bilaterally symmetrical and 
constant in L. loa\ Leiper also seems to recognize the seventh pair as being 
pedunculated, and describes other small unpaired genital papillae in ad¬ 
dition. 
