Species of Opisthophthalmus. 135 



developed lamellae on each mandible, while among the numerous 

 specimens of crassimanus, which I have grouped together as var. fi, 

 1-3 lamellae are often present ; so, for example, in 22 specimens 

 from Eooibank lamellae were present at least on one mandible in 15 

 and absent in 7, while in 21 specimens from Hournoed they were 

 present in 12 and absent in 9. In glabrifrons the lamellae were 

 found in the specimens from Mashunaland, but were absent in all 

 specimens from the Transvaal. In granicauda 1-2, and in kar- 

 rooensis and carinatus 3-6 lamellae were present in all the specimens 

 in the Museum. I have also found the organ in all the remaining 

 species of the genus with the exception of laticauda (which, being 

 dry, I have not examined). As I have not, however, examined all 

 the specimens in the collection I cannot state whether the organ is 

 invariably present in these latter. 



The fact that these lamellae may be constantly absent from all 

 specimens of some species from one locality and yet appear in some 

 of the specimens of the same species from another locality tends 

 to show that no specific value can be attached to the presence or 

 absence of this organ. Of course there may be, and probably are, 

 species in which the organ is constantly present and others in which 

 it is constantly absent, and in such cases it may be of some service, 

 e.g., in a synopsis. 



Habits. Nearly all the species of this genus construct deep 

 burrows in the earth, in which they remain during the day. These 

 burrows are all formed after the same plan. They enter the ground 

 generally at an incline not exceeding half a right angle, proceed for 

 about 6-10 inches in the same plane in a straight or winding 

 direction, and then suddenly dip down and descend, often with much 

 winding, to nearly a foot below the surface. These burrows may 

 always be easily recognised by their depth in conjunction with the 

 shape of the entrance, which resembles in outline the space 

 between the eyelids of an open human eye. 



Two species, karrooensis and pallidipcs, do not appear to con- 

 struct deep burrows at all, but live in shallow excavations under 

 stones. Both these scorpions are remarkable for the long and 

 slender hands of the adult male. I do not know the habits of the 

 allied species with similar hands, viz., peringueyi, gigas, and 

 longicauda. 



Distribution. The genus Opistlioplitlialmus is very characteristic 

 of the Cape Fauna. All the species whose localities are known, with 

 the exception of two, have been recorded from the Cape Colony, in 

 which there appears to be scarcely a part not inhabited by some 



