22 PROCEEDINGS OP THE NATIONAL MUSEUM vol. 7S 



CENTKUROIDES CHIARAVIGLI Borelli 



Borelli (1915) described as new a species taken at Dinamita, State 

 of Durango, Mexico. According to his description it is a pale yellow- 

 ish species, with a triangular brown spot on the anterior part of the 

 cephalothorax. The cephalothorax is densely and finely granular. 

 The teeth in the pectinal comb of the male are 28 to 29; in that of 

 female, 26 to 27. Length of male is given as 7 cm.; of female, 5.3 

 cm. Numerous examples of males, females, and young were obtained. 



Borelli 's description of this species is very suggestive of C. sufusus 

 Pocock. That the males should exceed the females by 1.7 cm. in 

 length is somewhat unusual. Pocock gives lengths of sujfusus as 

 follows : Male, 6.2 cm. ; female, 4.6 cm. The ratio of Pocock's meas- 

 urements are, however, similar to those of Borelli. I can find noth- 

 ing in Baerg's collection of scorpions to correlate with this species 

 except sufusus, which agrees in many respects. 



Genus TITYUS Koch 



In Tityus the first tarsal segment of leg IV is without distal spur. 

 The fingers are provided with overlapping oblique rows of teeth but 

 there are no supernumerary flanldng rows. 



This is an American genus. It is best represented in the Tropics 

 but extends from California and Florida to Argentina. Only two 

 United States species are known. They may be separated as follows : 



KEY TO UNITED STATES SPECIES OF TITYUS 



A*. Sting with large ventral tooth near base ; total length about 8 cm. Found in 

 Florida T. floridanus Banks. 



A'. Sting without a ventral tooth ; total length about 5 cm. Found in Cali- 

 fornia T. tenuimanus Banks. 



TITYUS TENUIMANUS Banks 

 CALIFORNIA TITYUS 



Our knowledge of this species is limited to the original description 

 of it which was published in 1910. It is described as a yellowish- 

 brown scorpion, 2 inches in length, with a weakly keeled hand and 

 long fingers. It difi^ers markedly from the Florida species, in the 

 absence of the tooth below the sting and in its much smaller size. 

 The only record for it is from Buena Vista Lake, Calif. 



Genus ISOMETRUS Hemprich and Ehrenberg 



Isometnis is similar to Tityus^ but the rows of teeth on the fingers 

 of the chelae do not overlap. There are no supernumerary rows of 

 flanking teeth. 



The genus is represented in both the Old and New Worlds. 



