EUCOPEPODA FROM TANGANYIKA, 829 
Serious epidemics due to vast numbers of parasites which have 
multiplied under conditions abnormally favourable to them. 
It is worth while to mention that a few other specimens 
belonging to the British Museum have passed through my hands 
without receiving any notice in the general text. This is because 
they were too much damaged to permit of identification or 
description, but they can be referred to the genus Lerneocera 
almost with certainty, and as such are worthy of putting on 
record. They were all taken on Nile fish, and came from three 
separate individuals. One Specimen was taken on a Clarias 
lazera, two more on another Clarias (2 lazera), while two-further 
Specimens are labelled as follows :—“F rom Barbus bynani— 
Damietta Nile, near Samannud. Loat Coll., no. 691.” 
As regards the distribution of these African Species of Lerneidee, 
it is to be noted that while one species has been found only 
in Tanganyika and another only in the Nile, the third form 
occurs in both. There is, then, no indication of that peculiar 
nature and superior richness of fauna which in SO many cases 
characterises the lake. At the same time, we know as yet so 
extremely little of the distribution of these forms in Africa, that 
it would be out of place to lay much stress on the facts which have 
so far coine to light. It is, indeed, a fact that the Tanganyikan 
species, Lerneocera diceracephala, is so fav peculiar that it ma y be 
found necessary to establish a new genus for its reception, while 
the two Nile species are much more typical members of the genus 
Lerneocera. Further, if we deal with the parasitic Kucopepoda 
as a whole, including the Ergasilidee, we still find that the fauna 
of Tanganyika is exceptional and unusually rich in diverse forms. 
Prof. Sars described * a new genus—FHrgasiloides—with three 
endemic species from Lake Tanganyika, and from Lake N yasa, 
only a single species of FErgasilus not further determined, but 
which is probably the same as that recorded by Mrazek from the 
Victoria Nyanza. 
EXPLANATION OF THE PLATE. 
(All figures by about 5.) 
Lerneocera diceracephala. 
Fig. 1. Ventral view. 
2. Lateral view. 
3. View of cephalic arms from above. 
Lerneocera haplocephata. 
Pig. 4. Ventral view. 
5. Lateral view. 
6. View of cephalic arms from above. 
7. Lateral view of specimen infested with \ orticellids. 
Lerneocera temnocephata. 
Fig. 8. Ventral view. 
9. View of cephalic arms from above. 
* P.Z.S. 1909, p. 63. 
oO* 
