Ethiopian Species of Ischnurin se . 317 



little doubt that they are specifically identical with the type of 

 trichiurus described by Gervais, as is shown by the strong 

 terminal spine-armature of the superior keels of the second 

 and third caudal segments. In both the vesicle is smooth 

 and the carapace distinctly excised in front. 



Secondly, a female from Tette measuring 147 millim., of 

 which the tail is 68 and the carapace 18 (pectinal teeth 18 or 

 19) ; a second specimen of the same sex from Umfuli River, 

 Mashunaland, 1200 feet alt. (G. A. K. Marshall), which 

 measures 140 millim., the carapace being 16 and the tail 68 

 (pectinal teeth 16). These two specimens, which appear 

 specifically identical, are doubtless referable to the_ form 

 recorded by Peters from Tette as troglodytes. According to 

 Kraepelin this species of Peters is identical with trichiurus of 

 Gervais ; and the former would recognize only one species of 

 this genus. According, however, to the material available to 

 me for examination, there may be two South- African species 

 in addition to the new one here described as paucidens ; these 

 may be recognized as follows : — 



c. Keels on the lower surface of the fifth caudal seg- 

 ment furnished each with about five strong spini- 

 form teeth ; the rest of the characters as cited 



under b 2 . Congo paucidens, sp. n. 



b. Keels on lower surface of fifth caudal segment fur- 

 nished much more thickly, though less strongly, with 

 teeth, there being upwards of 12 teeth on the median 

 keel and 8 or 9 on the lateral. S. Africa. 

 a 2 . Anterior border of carapace angularly excavated, 

 the triangular sclerite small ; first caudal segment 

 with distinctly crenulate upper crests; the second 

 and third, especially the secoud, with the terminal 

 granule of the upper crests much enlarged ; vesicle 



smooth trichiurus, 



b 2 . Anterior border of carapace shallowly emarginate ; [(Gerv.). 



first caudal segment smooth aud not crested above ; 

 the terminal granule of the upper crests on the 

 second and third segments only very slightly 

 enlarged troglodytes, Pet. 



Genus Iomachus, Poc. 

 lomachus politus, sp. n. 



Colour blackish brown above j tail entirely dark ; legs pale 

 at the base j lower surface of trunk fulvous ; maxillary pro- 

 cesses of first and second legs infuscate. 



Upperside of trunk entirely smooth and polished ; sterna 

 of abdomen also quite smooth ; carapace a little longer than 

 the first three segments of the tail. 



Tail slender and very short, only a little more than twice 



