PARASITES OF A CHAPMAN's ZEBRA. 445 



the anus is narrowed suddenly to form a point. The figures 

 show that the relative proportion of the ovi-projector to the 

 vagina is about the same in both species. The ventral promi- 

 nence and other curves in this region of C. golcU appear less than 

 those of C. 2yseuclo-catinatum. 



Boulenger gives the distance between the anus and vulva of 

 C. goldi as about 90/^-100/^, and for the same in C. pseudo- 

 ccUinatum Yorke and Mactie give 45/a-85/x. Thus the anus 

 and vulva are almost the same distance apart in, at least, some 

 members of the two sj)ecies. 



Mcde. The two descriptions of the posterior regions of the 

 males of C, goldi and C. jyseudo-catinatutn are identical in many 

 important points. 



The median dorsal lobe of the bursa is short and almost semi- 

 circular in both species. In both, the dermal collar is well 

 developed on the anterior and posterior (venti'al and dorsal, 

 Yorke & Macfie) surfaces. The pre-bursal papillae are well deve- 

 loped in both. 



The genital cone of both species is similar in having its 

 appendages in the form of very thin delicate plates (slight 

 elevations, Yorke & Macfie) each provided with two slender 

 fi.nger-shaped processes. Of these two processes the inner one 

 is the larger in both species. The figure of the genital cone of 

 C. goldi is indeed veiy similar to that of G. pseudo-catinatum. 



In C. pseudo-catinatum the main trunk of the posterior ray of 

 the bursa and its second lateral branch are each provided with a 

 small accessory branch. Boulenger makes no mention of any 

 accessory branches in his description of G. goldi, but his figure 

 of a lateral view of the bursa shows an indication of one on the 

 second lateral branch of the posterior ray, though nothing is seen 

 on the main posterior ray. In the lateral view of the bursa of 

 G. pseudo-catinatum the accessory branch of the main postei'ior 

 ray is not shown. 



Boulenger makes no mention of the spicules of G. goldi, so it 

 it is not known whether they resemble or difier from those of 

 C. psetulo-catinatimi Avhich are figured by Yorke and Macfie. 



This comparison of the two species, made only from descrip- 

 tions and figures, was made more difficult by the different 

 methods of treatment employed by the difi"erent writers. Never- 

 theless enough has been shown to prove that there are some 

 features of very great similarity, if not of identity, in G. goldi 

 and G. pseudo-catinatum. 



CyLICHNOSTOMUM ZEBRiE, sp. n. 



Specific diagnosis : — 



Gylichnostomum zehrm is one of the largest of the Cylichno- 



stomes, being slightly larger than G. elongatum, but smaller than 



G. auriculatum, which is the largest of all members of the family. 



The male of G. zehroi measures 13-13-5 mm. in length and has a 



