TRÄGARDH, SPELEORCHESTES, A SALTATORIAL TROMBIDIIDE ,^ 



ranean habits, by its inconspiciious size, as the largest spe- 

 cies attains a length of only 348 u and by the fact that 

 sys tema tio researches of the microarthropods of ants' and ter- 

 mites' nests have only in the last years begun to be carried out. 



The ability of jumping which the genus enjoies is in 

 itself very remarkable, but becomes still more interesting 

 Avhen we consider, that both species are subterraneous, and 

 one of them probably termitophilous, the other certainly 

 myrmecophilous. Another feature is also very remarkable, 

 when combined with the subterraneous life viz, the great 

 development of the lenses of the eyes. 



As to the systematic position of the genus it is, as far 

 as it is at the present time possible to ascertain, most closely 

 related to the genera Alichus and Monalichus, as is also 

 Nanorchestes. The relationship will be further discussed at 

 the end of this paper. 



Speleorchestes formieorum nov. sp. 



(Textfigs. 1—8). 



Length 348 ii. Length of rostrum and cephalothorax 

 80 n, of abdomen 268 u. 



Colour light red, with a lighter median longitudinal band. 

 Under the cuticle of the abdomen there is a layer of small 

 crystals, which render the specimens very obscure, when 

 mounted, and probably are composed by uretic acid, as 

 Berlese ^ States to be the case with Monalichus arhoriger. 

 The crystals resemble also those I have found under the 

 cuticle of Monalichus sp. from Natal. The cuticle is finely 

 striated. The body is elongate, more than twice as long as 

 it is wide; the greatest width is half way between coxae IV 

 and the hind margin. 



The cephalothorax (Fig. 1) is narrow, only half as wide 

 as the abdomen and shorter than it is wide. It is sepa- 

 rated from the abdomen by a distinct, straight and transverse 

 furrow. 



The sides widen a little behind the eyes, but narrow 

 again towards the posterior margin. The anterior margin is 

 slightly concave near the sides, but rises in the middle to a short 

 rounded projection which has a distinct transverse line at 



'- Acari nuovi. Redia. vol. 2. fasc. 1. 1904. 



