312 Mr. R. I. Pocock on 



XLII. — Notes on some Ethiopian Species of Ischnurinse con- 

 tained in the Collection of the British Museum. By R. I. 

 Pocock. 



Since I published some notes upon the African Ischnurinae 

 contained in the collection of the British Museum *, a con- 

 siderable number of accessions to this group have been made, 

 and amongst them are some examples, apparently repre- 

 senting species, which not only are new, but are of additional 

 interest inasmuch as they bridge over the differences between 

 the genera Opisthacanthus, Opisthocentrus, and Gheloctonus. 

 Thus the two species from Madagascar, with their deeply 

 excised frontal border, large brachial process, and (especially 

 in Madagascar iensis) large and prominent lateral eyes, falls 

 between the South-American Opisthacanthus and the South- 

 African Opisthocentrus, but may further be recognized from 

 both by the presence of a well-developed median row of 

 spicules upon the lower surface of the tarsi. Since, however, 

 traces of this row are visible in some of the South-African 

 specimens examined by me, it is, perhaps, not wise at present 

 to regard it as a character of generic value. Nevertheless the 

 same character is perhaps the only distinctive feature between 

 the genera Hormurus and Iomachus. So, too, with regard to 

 Cheloctonus. The examination of the specimen described as 

 crassimanus shows that two of the characters relied upon, 

 namely the absence of upper anterior crest on the humerus 

 and the marginal position of the lateral eyes, can scarcely be 

 regarded as of more than specific importance. The shape of 

 the hand, too, though striking enough, is shown by analogy to 

 be hardly of generic value ; so that I am now of opinion that 

 the three genera under discussion may be looked upon as 

 identical. Consequently the African genera of Ischnurinae f 

 may be recognized as follows : — 



a. Feet thickly clothed below with two rows of 



long stout bristles Ischnurus, Koch. 



b. Feet sparsely clothed below with paired spines 



or bristles. ' 



* Ann. & Mag. Nat. Hist. (6) xii. pp. 316-320 (1893). 



t Collectors in South Africa who are not acquainted with the genera 

 of Scorpions may readily recognize the Ischnurinae from the Scorpioninse 

 (Scorpio and Opisthophthalmus), to which they are most nearly allied, by 

 the flatness of the body and claws and the weaker compressed tail. The 

 group ranges from Gaboon and Mombasa southwards over the whole of 

 the continent. 



