124 MK. R. I. rocoCK ON THE SCORPIONS [l\Iar. IS, 



Subgenus Parabuthus, nov. 



Frionurus, Elirenberg (in part) ; Karsch (in part). 



Tyjie, P. liosoma (Ehrb.), Symb. Phys. no. 10, })1. ii. ^'^. (i. 



Hab. Ethiopian Region. 



Ehrenberg included in his group Prionurus a species named liosoma 

 which departs sufficiently widely from the type P. fimestus to be 

 worthy of special recognition. Dr. Karsch was the first to point 

 out this fact ; but in attempting to establish a separate genus of 

 which liosoma was to be the type, this author appears to me to have 

 fallen into error in two particulars. In the first place, since Thorell 

 had restricted Androcionus to those Scorpions which were termed 

 Prionurus by Ehrenberg — a jiroceeding justifiable on the grounds 

 that no type had been named for Androctonus and that a genus 

 must supersede its subgenus — it is clear that the type of Prionuj-us, 

 iiamely futiestus, is also the type of Androctonus and that Prionurus 

 must, in that case, be regarded as a synonym of Androcionus. But 

 Dr. Karsch, wishing to preserve the term Frionurus, selected as the 

 type Ehrenberg's species /zoso?rta, on the understanding that liosoma 

 is generically, or at all events subgenerically, distinct from funestus. 

 But, as stated above, it seems to me to be absolutely essential to 

 select as the tyjie of a genus the species which is the first referred 

 to it by the author— unless any other be specially mentioned by him 

 as typical — and never to transfer this generic term from this species 

 and its allies to anotlier, which differs from the type in generic 

 characters, although this other was referred originally to the same 

 genus. Consequently I hold t\i^.t fuiiestus is the type of Prionurus, 

 and that the transference of the name to liosoma can only lead to 

 confusion. 



I have therefore found it necessary to create a new subgeneric 

 name for liosoma and its allies, since the group appears to me to be 

 a ])erfectly natural one, agreeing both in important characters and in 

 geographical distribution. 



But the group as characterized by Dr. Karsch cannot stand, 

 inasmuch as it was based upon a character — the presence of a median 

 lateral keel on the fourth caudal segment — which may or may not 

 e.\ist within the limits of a single species, and is valueless for generic 

 distinction. Moreover, as thus defined the genus is quite an un- 

 natural group, inasmuch as it includes forms, such as e. g. liosoma and 

 pclopponensis {ffibOosus), wliich are widely separated from each other, 

 and in addition coiiijjletely severs pelopponensis from its nearest 

 allies — europceus, leptocheles, &c. 



The subgenus may be characterized thus : — 



On the digits of the chelae the external series of teeth are formed 

 by the enlargement and partial assumption of a lateral position of 

 the two posterior teeth of the median rows ; the internal series by 

 the enlargement and separation of the anterior tooth of each median 

 row. The cephalothorax is not costate, and the tergites are 

 lurnished with only a median keel. The tail is powerful and strongly 

 keeled, but there is a marked tendency to obliteration on tlie part of 



