1890. J OF Tin: FAMILY BUTHID^. 127 



since this species is also the type of Leiurus it follows that Leinrus, 

 tlie subgenus, must give place to Androctotius. But europwus, the 

 type of Butlius, is recognized as synonymous with tunctunus, and 

 Buthus antedates ^«(/roc<onM* by 14 years: therefore Androcloniis 

 must be a synonym of Buthus. Prionurus can then be used to 

 include those powerful -tailed species of which australin is the type 

 -^that is, in the sense in which Ehrenberg presumably meant it to 

 be used, and in the sense in which Peters himself employed it. 



Si/nopsis of the Buthidse. 



a. The inferior border of the immovable digit of 



the chelicerre unarmed. 

 a'. The lateral -internal series of denticles on the 

 digits of the chelse composed of transversely 



set pairs of teeth Uroplectes, Peters. 



Type U. crnatun, Peters. 

 b^. The lateral-internal series of denticles on the 

 digits of the chelai composed of a row of 



teeth widely separated and set singly Lepreus, Thor. 



Type L. pilusus, Thor. 



b. The inferior border of the immovable digit of 



the cheliceraj armed with one tooth. 

 a'^. The intervals between the main teeth of the 

 lateral series on the digits of the cliela; not 

 occupied by smaller teeth. 

 a?. Ante-ocular portion of cephalothorax 

 horizontal, with lightly eiuarginate 

 anterior border. 

 aK With a spine or tubercle beneath the 

 aculeus ; fifth caudal segment not 

 coarsely punctured, and normally keeled 



beneath Isometkus (Ehrb.), Thordl. 



Type maculatus (De Geer). 

 6'. Without a spine or tubercle beneath 

 the aculeus ; fifth caudal segment not 

 keeled beneath and adorned with large 



punctures Isometroides, Keys. 



Type /. vcscus (Karsch). 

 b^. Ante-ocular portion of cephalothorax 

 sloped forwards, with its anterior margin 



convex; tail very powerful Butheolu.s, Simon. 



Type JB. thalassirms, Simon. 

 /;^. The intervals between the main teeth of the 

 lateral series on the digits of the chela; 

 occupied by a single row of smaller teeth ; 



the rest Tis m Isometrus Centrurus (Ehrb.), Peters. 



Type C. gracilis (Latr.), 



c. The inferior border of the immovable digit of 



the chelicera; armed with two teeth Burnrs, Leach. 



Type B. luropans (Linn.). 



<■'. Tergites with a single median longitudinal 



keel; cephalothorax witliout distinct keels. 



dr. All the pccthial teeth alike in both sexes ; 



tail moderate or powerful ; the segments 



moderately strongly keeled ; a distinct 



spine beneath the aculeus Subgenus Rnoi-TiuiRUS, Karsch. 



Type ff. (lentatiis, Karsch. 

 d'-. The basal pectinal tooth dilated in the 

 female ; tail moderate, not strongly keeled ; 



10* 



