144 
the abdomen, as well as the tail, have been examined 
with the magnifying-glass but without result. The 
sternite, in which the first pair of spiracles is situated, 
and considerable parts of the upper side of the 4th 
and 5th joints of the legs have been cut off and 
examined with the microscope to find, if possible, similar 
small fissures, which hereafter are shown in several 
other orders; not one fissure, however, has been found. 
No better result was gained from the dissection of the 
sternites and the mandibles of Centrurus biaculeatus Luc. 
The expansion of the fissures for the apex of the 
nerve is always situated at the one end; except in the 
organ lving at the basis of the 4th joint all the fissures 
are almost parallel with the longitudinal direction of 
the joints of the legs, or placed in an oblique direction 
in proportion to them, and the expansion is always at 
the proximal end. 
2. Androctonus australis L. 
Ambulatory limbs. 
2d joint. On the anterior side close above the 
apophysis one fissure of middle length, and at a small 
distance from it a small group of 3 tiny fissures. 
Nothing on the posterior side. 
3d joint. On the posterior side close behind the 
apex above the apophysis 4 fissures, partly of middle 
length, partly shorter, and more or less removed from 
each other. 
4th joint. Nothing at the basis. On the posterior 
side close to the apex above the apophysis one single 
long fissure, and below this one 3 extremely short 
fissures. 
5th joint. Apically on the upper side one very 
long fissure and semicircularly behind it 4 short longi- 
tudinal fissures. On the posterior side near the apical 
