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Show 124 MR. R. I. POCOCK ON THE SCORPIONS [Mar. 18, Subgenus PARABUTHUS, nov. Prionurus, Ehrenberg (in part) ; Karsch (in part). Type, P. liosoma (Ehrb.), Symb. Phys. no. 10, pi. ii. fig. 6. Hab. Ethiopian Region. Ehrenberg included in his group Prionurus a species named liosoma which departs sufficiently widely from the type P. funestus 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 Androctonus to those Scorpions which were termed Prionurus by Ehrenberg-a proceeding 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 Prionurus, namely funestus, is also the type of Androctonus and that Prionurus must, in that case, be regarded as a synonym of Androctonus. But Dr. Karsch, wishing to preserve the term Prionurus, selected as the type Ehrenberg's species liosoma, on the understanding that liosoma is generically, or at all events subgenerically, distinct from funestus. But, as stated above, if seems to me to be absolutely essential to select as the type 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 another, which differs from the type in generic characters, although this other was referred originally to the same genus. Consequently I hold that funestus 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 perfectly 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 exist within the limits of a single species, and is valueless for generic distinction. Moreover, as thus defined the genus is quite au unnatural group, inasmuch as it includes forms, such as e. g. liosoma and pelopponensis (gibbosus), which are widely separated from each other, and in addition completely 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 furnished with only a median keel. The tail is powerful and strongly keeled, but there is a marked tendency to obliteration on the part of |