8 ARKIV FÖR ZOOLOGI. BAND 7. N:0 12. 



About the function of this peculiar organ there seems, 

 to judge from its structure, to be but little doubt. Evidently 

 it acts as a sucker or haustorium. 



The thin cuticle of the shields adheres closely to the 

 surface of the Ehombocephalus ; by contraction of the musc- 

 les a vacuum is attained, by means of which the high ridge 

 is pressed close to the smooth cuticle of the höst. As bund- 

 les of muscles run also to the marginal shield, this is very 

 likely also capable of being moved and acts in connection 

 with the suckers. 



In the female, drawn in fig. 10, the muscles are extended, 

 or only partly contracted, and consequently the blotch is 

 expanded. 



The peritremata are narrow, straight and run outside the 

 coxse from a level between coxse II and IV to a level with 

 the anterior side of coxse I; the stigmata are small. 



On the ventral surface of the body there are 4 pairs of 

 comparatively long hairs, placed along the posterior margin 

 of the metapodial shields. 



The legs are placed closely together in the anterior half of 

 the body; they are, with the exception of coxse and trochan- 

 teres slender, for instance much more slender than in Neome- 

 gistus and Paramegistus and, contrary to all other Antennopho- 

 rince, the first pair of legs are provided with ambulacres. 



The legs have a conspicuous feature in common, viz. 

 the presence of 5 to 6 stout hairs, pointing outwards, on the 

 trochanter. 



Legs I (Fig. 5 & 6) are the only ones which for the greater 

 part of their length are visible on dorsal view (Fig. 1); they 

 seem to act as tentacles, being stretched forth obliquely for- 

 ward and sideways, the narrow, neck-shaped basal portion 

 of the femur fitting in to the sinuosity, where the marginal 

 shield narrows abruptly; but they are also of locomotorial 

 use, as they are provided with ambulacres. 



Coxa (Fig. 5) on lateral view (when dissected) sub- 

 triangular, very short dorsally, whereas the ventral side is 

 more than 4 times as long and convex, with a median 

 transversal, bifurcated and acutely pointed ridge; trochanter 

 tapering forward to half its basal width and bent slightly 

 upwards in the middle; the ventral side with a ridge similar 

 to that of the coxa; femur (fig. 6) with distinctly demarcated 

 basifemur, a little in front of which it is constricted and bent 



