8 ARKIV FÖR ZOOLOGI. BAND 6. N:0 2. 



cal, about twice as long as it is wide and truncated at the 

 top ; it has three fine terminal hairs, which are a little longer 

 than the joint, and one similar exteriorly near the base. 



The lingua (Fig. 2 1) is rather blunt and as long as the 

 median appendages. 



The abdomen (Figs. 5 & 6) is, as above stated, separated 

 from the cephalothorax by a distinct, rather deep furrow. 

 It is anteriorly truncated, posteriorly rounded, narrows to- 

 wards coxse IV, and widens from thence gradually towards 

 the middle of the distance between coxse IV and the poste- 

 rior margin, where it attains its greatest width. 



The dorsal side is far less convex than the ventral one. 

 It shows two distinct träns verse furrows in the anterior half, 

 one on a level with coxae IV, the other further backwards, 

 twice as far from the anterior margin of the abdomen as 

 the first one. The former furrow is deeper and extends down 

 the sides to near coxae IV; the latter is clearly visible only 

 on the dorsal side. 



;^^;u..^ The hairs are of a peculiar shape, densly plu- 



^P mose and the plumulse increase gradually in length 



^ towards the top, where the exteriör rows are the 



Il longest, and in consequence the hairs seem to be 



M truncated. In the two anterior Vs of the ab- 



|F' domen the hairs are scarce and arranged in 2 — 4 



longitudinal row^s, but in the posterior Vs ^^^ 



behind the anal aperture on the ventral side 



f ^^ ^ w?^^ there are numerous hairs all standing out perpen- 



men. ^^V^- dicularly. 



It seems very likely that this feature, viz. the 

 extraordinary accumulation of hairs at the posterior end of 

 the body, is in some way connected with the ability of lea- 

 ping; possibly it serves the mite as a mean of defence against 

 getting hurt when dashing against the walls of the ants' 

 nests, as it is liable to do when leaping in the subterranean 

 galleries. 



The ventral side is as above stated more convex than the 

 dorsal one. 



The genital aperture is large as in Alichus, with 3 pairs 

 of suckers; the anal aperture is small and placed close to the 

 posterior margin. 



The legs (Fig. 5) are slender but short, and even the 4th 



