ABT. 9 



SCORPIONS OF WESTEEN UNITED STATES ^EWINQ 15 



graph, which was originally suggested by Essig. This scorpion is 

 from 5 to 6 cm. long, with a reduced postabdomen but a very large 

 vesicle. The pedipalps are stout and the fingers short and strongly 

 curved. These are black, while the remainder of the scorpion is a 



reddish brown. . 



The shiny-stinged scorpion has a wide distribution. Tocock 

 (1902) reports it from Virginia, Colorado, Utah, California, and 

 Guatemala. The first of these records, however, should be ques- 

 tioned. The species probably does not occur in a state of nature 

 in eastern United States. National Museum specimens are from 

 Utah and California. 



Genus UROCTONUS Thorell 



Vroctonus differs from Anuroctonus in the nature of the divisions 

 of the middle area of the pectines. This area is broken up into 

 over five pieces, the most of which are subequal. Only a smgle 

 species is reported from United States and northern Mexico. 



UROCTONUS MORDAX Thorell 



MORDANT SCORPION 



The mordant scorpion has large pedipalps and stout hands, while 

 the "tail" is somewhat reduced. The sting is but slightly curved, 

 except toward its tip. It is a dark-brown species, the carapace and 

 pedipalps being darker than the abdomen, and the abdomen in turn 

 is darker than the legs. 



V mordax is a Pacific coast species, being reported from Cali- 

 fornia and Oregon. Banks (1910) reports it from nine localities m 

 California, including one record from Santa Rosa Island. Borelli 

 (1909) reports it from Oregon. In the National Museum coUection 

 there are four lots of specimens, all from California. The habits 

 of the species have not been studied. 



Family BUTHIDAE 



The family Buthidae is at once distinguished from our other 

 American families of scorpions by the shape of the sternum. The 

 sternum is triangular, the sides being strongly convergent ante- 

 riorly. The membrane at the base of the last tarsal segment of most 

 of the legs has two unbranched spurs. The fixed arm of the chelic- 

 erae is without a ventral tooth. r n +1. 



The family Buthidae is the most widely distributed of all the 

 families of scorpions. It is the only family to be represented in 

 each of the six chief zoogeographical regions. Not only is it found 

 in all these regions, but from several to many species are found m 



