TRÄGÅRDH, SPELEORCHESTES, A SALTATORIAL TROMBIDIIDE 9 



pair, which is the longest, is not half as long as the body 

 (resp. 4 and 9). They are placed remarkably far forwards, 

 almost in the anterior Vs of the body and not two and two 

 close together, as is usually the case, but are almost equi- 

 distant. The 1st and 4th pair are placed further from the 

 median line than the 2nd and 3rd one, so far indeed that 

 on lateral view they are inserted as far from the ventral as 

 the dorsal outline. 



Legs I — III 5-jointed, legs IV 6-jointed. 



Legs I; coxa very short, trochanter + femur (= 2nd joint) 

 three times as long as they are wide, genu half as long, tibia 

 half as long as genu, tarsus nearly as long as trochanter + 

 femur. 



Legs II and III of subequal length, shorter than legs I. 

 The relative length of the joints is the same as in legs I, 

 with one exception, that genu and tibia are of almost equal 

 length. 



Legs IV longer than legs I; coxse clubshaped and slightly 

 longer than trochanter and femur which are of equal length; 

 genu and tibia of equal length, as long as trochanter and 

 femur together; tarsus slightly longer. 



Where the coxa is articulated to the epimeron there is 

 a distinct fold of the cuticle. The epimera IV are enor- 

 mously devoloped, triangulär plates which all but meet in 

 the middle. Below the cuticle of the epimera we notice nu- 

 merous bundles of muscles, radiating from the place where 

 the coxse IV are articulated. 



One slender claw, curved like a hook. 



From the description of the legs, given above, 

 it is evident, that the ability of leaping is due to 

 the great development of the epimera of the 4th 

 pair of legs and their musculature. ^. ^ ^ 



But the concentrating of the legs far forward, of tarsus 

 the lateral position of legs I and IV and the hook- ^^\^2,f ^''^• 

 shaped claws are obviously also connected with this 

 mode of locomotion. 



Locality: In the nest of Formica rufa at Arilds läge, not 

 far from the shore. June 1907. 2 specimens. 



