114 MR. R. I. PococK ON THE SCORPIONS [Mar. 18, 



2. A Revision of the Genera of Scorpions of the Family 

 Buthidce, with Descriptions of some South-African 

 Species. By R. I. Pocock, of the British Museum 

 (Nat. Hist.). 



(Plates XIH. & XIV.) 



[Keceived March 15, 1890.] 



In 1876, when Ur. Tliorell revised the classification of the Scor- 

 pions, he divided tlie Buthidre, or Androctonoid(e, as he called them, 

 into two subfamilies — the Androctonini for those genera possessing 

 two inferior teeth on the immovable digit of the chelicerse, and the 

 Centrurini for those with one tooth in this position, or none. It is 

 needless here to enter upon the reasons wliich liave led me to the 

 conclusion that this division into subfamilies did not, at the time it 

 was proposed, represent accurately the state of our knowledge of the 

 affiniiies of the genera composing them ; for doubtless, at the pre- 

 sent mom.ent, in view of the number of new forms that have been 

 brought to light since 1876, Dr. Tliorell wouki be the first to abandon 

 his classification. It will be sufificieut here to state that an examina- 

 tion of the rich material of Buthidce contained in the British Museum 

 has convinced me that the members of this family are too closely 

 related to allow of its subdivision into groups of greater value than 

 is usually accorded to genera. 



Again, with regard to the foundation of genera, I find that it is 

 impossible to follow Dr. Thorell in the reliance that he placed upon 

 the form of the tail. The genera, however, based upon the armature 

 of the digits of the chelse appear to me to deserve recognition ; but 

 since the form of the tail varies with sex so enormously in many 

 genera, I have decided not to retain Phassus, Ithopalurus, and Ba- 

 bi/cuj'us, which were based upon a character merely, to my mind, of 

 specific importance. 



And, lastly, in accordance with what appears to me to be the best 

 working system of nomenclature, I have thought it advisable, at the 

 risk of some slight and, let us hope, temporary inconvenience, to alter 

 the names of two of Dr. Thorell's genera and to substitute a new 

 term for one of the genera proposed by Dr. Karsch. In each case 

 reasons are given for the change. 



In the accompany ing synopsis the genera have been classed under 

 three headings. The first heading, containing Uroplectes and Lepreiis, 

 is unquestionably a natural group : the same may be said of the second 

 — if a possible exception be made of the remarkable form Biitheoius ; 

 but I am very doubtful if the third section, namely Buthus, can 

 rightly be considered as such. Undoubtedly all the forms con- 

 tained under it agree in possessing the two inferior teeth on the 

 immovable digit of the chelicerse, but there appears to be no reason 

 why such a character should not have arisen independently in two 

 instances, and thus fail to be a sign of athnity between them, And, 



