Annals of the Transvaal Museum. 
97 
are found in the rivers ; this country, therefore, seems to be an exception 
to the general rule, for we find an isolated species of crayfish thriving 
where Thelphusidae, Atyidae, and Palaemon occur. 
To what extent can we correlate the distribution of the freshwater 
amphipods with that of the crayfishes ? 
Gammarus occurs in both hemispheres, but appears to be absent 
from the tropics. In the southern hemisphere we find, according to 
Smith (“Freshwater Crustacea of Tasmania ”, Trans. Linn. Soc., 1909), 
such typical Tasmanian Crustacea as Anaspides , Phreatoicus , 
Neoniphargus , Gammarus , and Boeckella , distributed in temperate climes 
together with New Zealand forms, very few of which range into tropical 
zones. Two genera, Chiltonia and Boeckella , characteristic of temperate 
regions, occur in temperate South Australia, Tasmania, New Zealand ; and 
in South America Hyallela , closely allied to Ghiltonia , and Boeckella 
itself, have been found. The peculiar genus Broteas Loven, speaking 
purely from a geographical point of view, seems to take the place of the 
last-mentioned genus in South Africa. 
Taking these i facts into consideration, the discovery of a blind 
freshwater amphipod inhabiting caves in the Transvaal is not without its 
particular interest as indicating conceivably the remnant of a river fauna 
in its last stages of extinction by the present successful combination of 
crabs and prawns. In Madagascar, where the crayfish Astacoides still 
holds its own, we may be witnessing an earlier stage in the extermination 
of an older river fauna, which was similar to, or had much in common 
with, an ancient South African river fauna in which the ancestors of the 
subject of this paper may have had a place. 
It would be as well, before speculating on the derivation of this 
little animal, to consider briefly its relationship to forms found in other 
parts of the world ; for this purpose a short description at this point may 
not be out of place. 
The Rev. Noel Roberts and Mr. J. Hewitt, of the Albany Museum, 
Grahamstown, are responsible for having first brought this animal to light 
and recognized its importance. They obtained examples some eighteen 
months ago from a cave containing a little fresh water at Irene, which is 
not far from Pretoria. Mr. Hewitt very kindly gave me the specimens 
to describe, and, hoping to get a larger series, I went with Mr. Austin 
Roberts to the Makapan Caves, near Potgietersrust. Here we found that 
two large caves supported a great number of these amphipods, besides 
some copepods and ostracods, and we were able to obtain some large and 
excellent specimens ; it is from one of these, a large female, that the 
following somewhat abbreviated description has been taken. 
Description of a Female from the Makapan Caves, Transvaal . — 
Length, 11 mm. ; colour, dirty yellow or pink (according from which 
caves specimens were taken the colour was found to be dirty yellow or 
pink or semi-transparent white). Eyes absent. Body rather compressed, 
smooth, without carina ; rostrum barely perceptible. The last three or 
five segments with spines on posterior margin. 
The first four coxal plates of the pareion segments deeper than 
the rest, the first smallest, the third and fourth deepest ; the fourth plate 
broader than the others ; the side-plates of the fifth, sixth, and seventh 
pareion segments small, those of the fifth and sixth deeply emarginate 
behind apparantly. These coxal plates bear small spines marginally. 
Antennules long, longer than the antennae ; flagellum much longer 
than the peduncle; first joint of the peduncle a little shorter than the 
