446 W. N. F. WOODLAND 



The nervous system is similar to that in W. virilis, 

 so far as the two main longitudinal trunks are concerned. 

 The excretory system is also similar hut is much less extensive, 

 especially in the head region, when compared with that of 

 W. virilis. As PI. 24, figs. 19 and 20 show, there are about 

 ten longitudinal excretory channels underlying the subcuticula 

 and two in the medulla, both at the base of the head and in the 

 uterine region. 



The eggs (PI. 24, fig. 21) are of the usual ovoid shape and 

 measure (when mounted in balsam) 34- 7-36- 6 microns in 

 length and 21 •9-25-6 microns in breadth. They are distin- 

 guished from the smooth-surfaced eggs of W. virilis, 

 C. laticeps, the two species yet to be described, and, so 

 far as I know, all other species of Caryophyllaeidae, 

 by the fact that under a magnification of a 1,000 diameters 

 the shell is seen to be covered with minute spines (PI. 24, 

 fig. 21). 



The specific characters of W. acuminata will be stated 

 below. 



Wenyonia minuta, sp. nov. Woodland. 1923. 



Of this species (PI. 24, figs. 22, 23) I possess one stained 

 mounted specimen only. Fortunately the specimen is well 

 stained, and I have been able to make out all the main features 

 of its structure without restaining or sectionizing. This parasite 

 was found in the Nile 8iluroid Chrysichthys auratus, 

 Giinth., at Khartoum, presumably in the intestine. The 

 total length of the body is only 3-5 mm., and the maximum 

 breadth 0-8 mm. It is fully mature, the uterus being filled 

 with eggs. The body is distinctly more flattened than in either 

 of the two preceding species or in C. laticeps, the head is 

 distinctly more of the C . laticeps type, and, as in C. lati- 

 ceps, the post-ovarian region is short ; on the other hand, 

 as in the two preceding species, the genital apertures are 

 situated in the anterior half of the body and the uterus is 

 very long. 



The head measured about 0-88 mm., the testicular region 



