2 8o THE TANGANYIKA PROBLEM. 



quite well known, I have not dealt with them in the pre 

 sent work.* 



Limnothelphusa metadata was found in the deep water o 

 Tanganyika, and the particular specimens examined and 

 described by Mr. Cunnington were obtained to the south 

 and west of the lake in water varying in depth from 500 

 to 600 feet. They were brought up in the dredge 

 clinging to Neothauma shells and other objects, and 

 were very active. I have, however, obtained the crab 

 throughout the lake. 



Platythelphusa armata was obtained by me only off 

 the west coast of Tanganyika in nets and dredges 

 which were being worked in water of about 20 fathoms. 

 The prawns were found occasionally throughout the lake, 

 and in the following descriptions of the above specific 

 types I have but slightly adapted the material contained 

 in the papers of Messrs. Cunnington, Caiman and Milne 

 Edwards. See bibliographs of expeditions at end of 

 volume. 



Limnothelphusa maculata t (Fig. I.). 



Regions and sutures on carapace moderately marked. Postero-lateral regions 

 exhibiting an irregular series of small, slightly oblique and granular ridges. Post- 

 frontal crest distinct, with median notch and partial lateral interruptions, but not 

 extending to margins. Antero-lateral margins shorter than postero-lateral, armed 

 with 2-3 spines, in addition to that at the outer angle of the orbit. Second joint of 

 antenna extending to under border of front, and bearing a short flagellum. Cheli- 

 peds in the male unequal, subequal in the female ; merus rather short, trigonous, 

 with spine on outer margin ; carpus with two spines on inner margin. Ambulatory 

 legs rather long and slender. Colour (in spirit) light yellowish-brown, with dark 

 brown or reddish spots. 



* It should be noted further that the same species of Thelphusa which are found 

 about the shores of Nyassa and other great African lakes, occur also about Tanganyika, 

 but since these crabs are practically terrestrial, I have omitted them from the Tangan- 

 yika list. 



t Cunnington, " Pro. Zoo. Soc," Part III., 1899, p. 698. 



