ART. 9 SCORPIO Jn^S of western UNITED STATES EWING 7 



ocelli on each side of the cephalothorax. This family is rather 

 closely related to the family Chactidae, but differs from it in having 

 more than two ocelli on each side of the cephalothorax. 



The family is best represented in North and Central America, but 

 also occurs in the northern part of the Old AVorld and in South 

 America. Dr. de Mello Campos (1924) does not mention it in his 

 synopsis of the Brazilian scorpions. The four genera found in the 

 United States may be separated as follows : 



KEY TO THE GENEEA OF TAEJOVIDAE OCCUEKING IN THE DNITED STATES 



A\ Middle area of peetines broken up into more than eight small pieces, the 

 most of which are subcircular ; first four segments of postabdomeu with- 

 out single ventral keel. 

 B\ Movable finger of chelicera with a spinelike tooth on the lower surface. 



Large hairy scorpions Hadrurus Thorell. 



Bl Movable finger of chelicera without ventral tooth Vaejovis Koch. 



A^ Middle area of peetines more or less indistinctly broken up into seven or 

 less pieces. 

 B\ Divisions of middle area of peetines unequal and few in number ; sting 



sometimes bulbous near base— Anuroctonus Pocock. 



B". Most of the divisions of the middle area of peetines subequal and num- 

 bering over five; sting normal Uroctonus Thorell. 



Genus HADRURUS Thorell 



In Radi-ui'us the middle area of the peetines is broken up into more 

 than eight small pieces, those toward the distal end being very small 

 and subcircular. The first four segments of the postabdomen, or 

 Cauda, are without the single median keel. The movable finger of 

 the chelicera has a spinelike tooth on its lower surface. 



This genus includes only a few North American species. One 

 species and a variety occurs in the southwestern part of the United 

 States and another species in Mexico. These may be separated by 

 means of the following key : 



KEY TO THE NOETII AMERICAN FORMS OF HADRURU.S 



A\ Length over 70 mm.; body reddish brown; appendages and postabdomen 

 \ very hairy ; number of teeth in peetines 34 to 40. 



B\ Frontal space of carapace finely granular; hand and brachium finely 

 and closely granular ; movable finger longer than carapace. 



H. hirsutus Wood. 



Bl Frontal space of carapace sparsely studded with large round granules; 



hand and brachium smooth except on crests; movable finger shorter 



than carapace H. aztecus Pocock. 



A'. Length not over 60 mm. ; body olive gray ; appendages and postabdomen less 

 hairy ; number of teeth in peetines 25 to 32. 



H. hirsutus var. arizonensis, new variety. 



