18 PEOCEEDIISrGS OF THE NATIOI^TAL MUSEUM vol. 73 



CENTRUROIDES MARGARITATUS (Gervais) 



G. muTgaritatus is similar in general appearances to G. nigrescens^ 

 but has one less row of teeth in the middle series on the fingers, and 

 the basal segments of the postabdomen and the legs are lighter in 

 color than the body. Male specimens measure as much as 10 cm. 

 in length. 



This is a widely distributed species occurring in America from the 

 southern United States to Brazil and Chile and, according to Pocock, 

 is found in West Africa. Comstock (1912) reports it from Florida. 

 Pocock (1902) states that there are specimens in the British Museum 

 from California. Banks (1910) does not include it in his list of 

 California scorpions. Specimens from the United States are wanting 

 in the National Museum. According to Baerg (1925) this species is 

 the one most commonly met in the Panama Canal Zone. 



Baerg (1925) experimented with this species, inducing it to sting 

 white mice and himself. The effect on the mice was not serious, and 

 the bitten area showed no inflammation or other effect. When the 

 scorpion stung Doctor Baerg there was a severe pain at first and the 

 affected area was reddish. No permanent effects were produced. 

 Baerg reports the experiences of two scientists who were stung by 

 this species. In these cases there was considerable swelling pro- 

 duced and in one case some lameness in the tongue. 



CENTRUROIDES EXILICAUDATA (Wood) 

 SLENDER-TAILED CENTRUROIDES 



This scorpion not only has a slender tail, or postabdomen, but also 

 slender appendages. The fingers of the hand are very slender, being 

 about one and a half times as long as the hand proper. In the male 

 the postabdomen is almost twice as long as the abdomen. There is 

 no vestige of a tooth or tubercle under the sting. The absence of this 

 tooth alone distinguishes this species from all other United States 

 species of its genus. A male specimen in the National Museum 

 collection measures 5.1 cm. in length. 



This species was orginally described from Lower California, the 

 type specimens being in the National Museum. Also in the Na- 

 tional Museum there are a number of specimens from Lower Cali- 

 fornia, most of them coming from Cape San Lucas, but there are 

 two specimens coming from San Diego, Calif. 



According to Jackson (1910) the stings of this species may prove 

 fatal to man. In fact he attributes many deaths to it in the State 

 of Durango, Mexico. It is possible in this connection, however, 

 that the species involved was not C. exilicaudata^ as I do not find it 

 in a large collection of scorpions taken in Durango by Baerg. 



