6 PEOCEEDIIirGS OF THE NATIONAL MUSEUM vol.73 



two large specimens from Durango, Mexico, and six smaller ones 

 (including some that are evidently immature) from Atotonilco, 

 Mexico. 



It would be of much importance to experiment with this species to 

 see if it could be implicated in any way in the serious cases of scor- 

 pion stinging reported from Durango, Mexico. 



Family CHACTIDAE 



The family Chactidae differs from our other American scorpion 

 families in having only two ocelli on each side of the carapace. The 

 sternum has straight, but slightly converging sides and an outwardly 

 angulate anterior margin. It is as long as, or longer than broad. 



The family has a wide distribution in the world but is wanting 

 in the Ethiopian and Australian regions. Kraepelin (1905) lists 

 four genera and 29 species for the Neotropical Region, all of which 

 are characteristic of this region. In the United States but a single 

 genus and species is found. \ 



Genus BROTEAS Koch 



In the genus Broteas the latest tarsal segment bears two rows of 

 short spines on the under surface. Segments I-IV of the postab- 

 domen are keeled below and the stigmata are slitlike. Only one 

 species occurs in the United States. 



BROTEAS ALLENI (Wood) 

 ALLEN'S SCORPION 



This is a small dark-brown species. The hands are slightly keeled 

 and swollen ; the fingers are very short, being but little over one-half 

 as long as the hand. The small, slender tail has the vesicular seg- 

 ment depressed; the sting broadens out proximally into the vesicle. 

 A National Museum specimen measures 3 cm. in length. 



This species occurs, as far as known, only in the extreme south- 

 western part of North America. The type was taken at Cape San 

 Lucas, Lower California. There are two specimens in the National 

 Museum collection, both from Fort Tejon, Calif, These two records 

 are the only ones known to the writer, hence it is assumed that the. 

 species is rare. Its habits are unknown. 



Family VAEJOVIDAE 



Members of the family Vaejovidae have the sternum subpentag- 

 onal, the sides being subparallel. There are two spurs on the mem- 

 brane at the base of the last tarsal segment, and from three to five 



