1909. | OF THE THIRD TANGANYIKA EXPEDITION. 67 
the last pair of legs developed in exactly the same manner as in 
the Kuropean species, is present in a mounted slide containing 
some other Entomostraca, which, according to the label, are 
from Lake Nyasa. The specimen has not yet been examined 
in detail, and is therefore only mentioned here. Dr. Mrazek 
also records a species of this genus, probably the same as that 
here mentioned, from Victoria Nyanza. 
GENERAL REMARKS. 
The working out of the Copepoda of the Tanganyika Ex- 
pedition has involved no. small diticulty and trouble, both as 
regards the selection of the specimens from the samples, and the 
examination and determination of the species, some of which, 
especially of the genus Cyclops, are so closely related to each 
other and to European species, that a very minute and careful 
examination has been needed to make out their true relationship. 
Yet, I think that the labour thereon bestowed may not have 
been in vain. For the final results of my examination have 
turned out to be on the whole very satisfactory, and have indeed 
far surpassed the expectation at first entertained. I hope there- 
fore that the present Report will furnish a not unimportant 
contribution both to the exact definition of species, and to the 
general characterisation of the fauna in the three great Central 
African lakes. 
The number of Copepod-species examined and mentioned in 
the present Report amounts to no less than 38 in all, belonging to 
six different genera. Of these species the far greater number, 
viz. 30, have proved to be new to science, and of the genera two 
have previously been known only from salt or brackish water. 
Finally, one new genus, “rgasiloides, has been established, to 
comprise three species allied to Hrgasilus Nordman. 
The annexed table is intended to show the distribution in the 
three lakes of the species here recorded, and, at the same time, 
the number of species found in each of them. It will at once 
appear from this table that Lake Tanganyika is by far the 
richest in Copepoda, no less than 29 species having been recorded 
from there, whereas a rather limited number of species is found 
in the two other lakes, viz., in Nyasa 11, in Victoria Nyanza 
only 7 species. This agrees pretty well with the results which 
other authors have obtained, in regard to the richness and 
specialisation of forms in that lake, as compared with the fauna 
of the other African lakes. 
In striking contrast hereto stands, however, the apparently 
total absence in Tanganyika of Cladocera. Although I have 
with the greatest care sought for forms of this group in the 
numerous ‘samples from this lake, I have only succeeded in 
finding in one of them a solitary specimen of a Moina, and 
this specimen in all probability has only quite accidentally 
been carried into the lake from some neighbouring stream. 
a 
