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,
BioStor
