96 
Cercariae 
Connolly has removed schakoi from the 8. African list, for the shells do agree 
very well with Jickeli’s description and figures of schakoi. 
Most of the larger specimens of Isidora schakoi Jickeli, collected from the 
Golf Links at Potchefstroom, were found to be infested with an interesting 
eye-spotted cercaria, Cercaria frondosa. This cercaria is about 0-6 mm. in 
length, the tail being about twice the length of the body. The body is 
elliptiform and possesses oral and ventral suckers. The body of this ephemeia 
is somewhat heavily coloured, particularly in the fully developed cercaria. 
This makes the internal organs hard to define. The younger specimens possess 
a pair of deeply pigmented eye-spots, just posterior to the oral sucker and on 
either side of the gut. In the older cercariae, which are really beautiful, these 
eye-spots are seen to branch out in all directions and present the appearance 
of leaves. In well developed forms this pigment is continued down the sides 
of the gut, suggesting that it is connected in some way with an elementary 
nervous system. On either side of the gut, chains of cystogenous vesicles may 
be seen in some of these cercariae. In some instances these chains are seen 
to branch. After staining with various stains, the body of about one in five 
of the cercariae is more darkly stained than the others, and, as this appearance 
is fairly constant, it is possible that the two forms represent different sexes. 
The eye-spots can be seen through the semi-transparent wall of the rediae. 
These rediae are slightly motile, and possess an oral sucker at one extremity. 
A varying amount of coloured matter can be seen in the rediae outside the 
girt. They also possess two very small appendages on either side, not far 
from the oral extremity. 
CERCARIA GLADI1. 
Two specimens of Isidora schakoi from the Golf Links at Potchefstroom 
contained sporocysts and daughter-sporocvsts without the formation of 
rediae. These sporocysts contained a cercaria with oral and ventral sucker, 
no pharynx at the commencement of the oesophagus and two flat prongs at 
the extremity of the tail. The body was 0-2 mm. in length and breadth, the 
tail without the prongs 0-15 mm. in length and the prongs 0*25 mm. The 
prongs were not so long as those of Cercaria secobii from Pietermaritzburg 
(see (American) Journ. of Parasitology, March 1917), and presented the 
appearance of drawn swords. These prongs were constantly longer than those 
of the cercaiia which produces Bilharziasis in the Transvaal. The cercaria, 
for which I have suggested the name, Cercaria gladii, probably represents the 
cercarial stage of the trematode parasite of some of the frogs, crabs, small 
birds or cows that frequent these parts; though examination of a number of 
the crabs has failed to throw any light on its possible life-history. 
I have collected several specimens of Limnaea natalensis from this same 
pool at Potchefstroom, but have found them free from infection with cercariae. 
The specimens of Limnaea natalensis that I obtained from the Hex river at 
Rustenburg were the finest I have seen; here, I also obtained some large 
Planorbis jifeijferi, which I have not encountered at Potchefstroom. 
