ART. 9 SCORPIONS OF WESTERN UNITED STATES EWING 13 



VAEJOVIS SPINIGERUS (Wood) 

 STRIPED-TAILED SCORPION 



This species (pi. 2, fig. 4) is easily recognized from the others occur- 

 ring in the region where it is found by its large size and the presence 

 of four longitudinal dark stripes on the under side of the " tail," or 

 postabdomen. It varies in length from about 5 to 8 cm. and is rather 

 stout-bodied and is exceeded in size in the Southwest only by Hadru- 

 rus hirsutus (Wood) (pi. 1, fig. 1), a hairy species of a different 

 genus. 



Its home is the desert region of the Southwest where it has been 

 reported from Texas to California. The type specimens were taken 

 in Texas. This species must range far into northern Mexico, but 

 it is not represented in the Baerg collection from the State of 

 Durango. 



It is found particularly in rocky waste places where there is some 

 moisture. However, during the spring of 1927 the writer took two 

 adults under a large rock at a street corner in the center of the town 

 of Tempe, Ariz. It is the most common scorpion in the Papago 

 Saguaro National Monument, in the Salt River Valley, Ariz. At 

 Yuma, Ariz., a persistent search for it by the writer failed in locating 

 specimens. However, on May 4, 1927, E. E. Russell, of the Bureau 

 of Entomology, took three specimens here along the reclamation 

 levee and railroad track. A few years ago the writer determined a 

 number of specimens of this species from southern New Mexico, for 

 Dr. W. J. Baerg. 



Baerg (1924) allowed this species to sting him and reported the 

 results as follows: 



" The sensation was very much like that of a pin prick, and the 

 resulting pain, which was very slight, lasted scarcely half an hour. 

 There was no white area around the punctures and not the slightest 

 swelling or inflammation." 



VAEJOVIS FLAVUS Marx 



This yellowish species is probably our most slender representative 

 of the genus. The pedipalps are particularly weak and slender and 

 the hands smooth and without keels. The fourth and fifth segments 

 of the postabdomen are scarcely as stout as those in front of them. 



The species occurs in the arid Southwest, but is rarely encountered. 

 Two specimens are in the National Museum, one from Albuquerque, 

 N. Mex., and one from " Fort Yuma," Ariz. Records from Mexico 

 appear to be wanting. The species doubtless occurs in that country 

 near the United States border. 



