182 J. E. S. MOORE. 



the facts of (listributio)i that they wouhl be, directly in conflict 

 with all those geological speculations respecting the interior of 

 Africa that have been hitherto more or less generally held. 

 In the paper to which I have referred^ it was seen that the 

 Typhobias belong to^ and are, one of the most remarkable 

 constituents of the 5'wasi-marine or Halolimnic section of 

 the Tanganyika fauna. They consequently share, along with 

 the other members of this group, the strange geographical 

 isolation which is its distinctive mark. 



Like nearly all the Halolimnic animals, Typhobia is found 

 pretty abundantly in Tanganyika, occurring in some places in 

 the most astonishing profusion, but, so far as it is at present 

 known, the mollusc is found living nowhere else in the world. 

 I first obtained the empty shells of T. Horei on the long sandy 

 beaches near the south-west corner of the lake, and subsequently 

 on the southern shore of the deep Kituta Bay. They were 

 readily recognised by the head men of the villages, who told 

 me they had never seen the Gastropod alive, but only the shells 

 when washed up empty along the beach. From this statement 

 of the natives, and from the spinous character of the shells, 

 I thought it probable that they would be found living on mud, 

 but I was unable to find them in the muddy reaches among 

 the Kinyamkolo Islands, in depths of fifty to one hundred feet, 

 nor indeed in any portions of the lake that were of similar 

 depth. It was not until I had extemporised a primitive deep- 

 water dredging apparatus that I obtained the Gastropod alive.^ 



In June, 1896, we were on the west coast of Tanganyika 

 and on the southern shores of Cameron Bay, and here I was 

 able to obtain the strong bark rope used by the Wafipa fisher- 

 men for their nets. As these nets are hauled by rows of men 

 on the ropes at either end, the ropes themselves are strong 

 enough to drag a heavy net with all its weights and stretchers 

 over several hundred yards of ground; and with them I was 



Log. cit 

 ^ My ordinary dredges were smashed almost at once by the sharp rock- 

 ridges which protrude through the muddy floor of the lake. For this deep 

 water I used a native basket, weighted down with stones. . ,. 



