ACARINA FROM THE JUAN FERNANDEZ ISLANDS 569 



is far forward in the anterior half and the other shields cover one another in 

 such a way, that their anterior margins are close together, almost equidistant. 



Mouth parts (fig. 23). The hypostome is very large, almost twice as 

 wide as it is long (13:7) with broadly rounded posterior margin and tapering 

 forwards from the posterolateral angles. It has the same reticulated texture 

 as the dorsal side except at the margin. The hypostomal hairs are rather 

 short, straight and pointed and inserted as far from the median line as their 

 own length and close to the anterior margin. 



The maxillae have a very peculiar shape; their basal portion is shaped 

 as an irregular shield with reticulated surface and carries two pair of hairs, one 

 straight near the anteromedian angle, the other is curved inwards and inserted 

 in the postero-lateral angle. As I have pointed out (p. 560), the same structure is 

 found in the genus Neoliodes, but, as far as I know, in no other Oribatei. Its 

 presence in these genera possibly indicates a relationship between them. 



The mandibles (fig. 27) have no very characteristic features; the lower 

 jaw has two strong terminal teeth and one similar tooth half-way between the 

 top and the base, the upper jaw has one tooth op- 

 posite the terminal teeth of the lower jaw and further 

 back three rather blunt teeth. 



The palpi have the basal joint very short, 

 ringshaped, the 2nd joint is the longest and has 

 ventrally near the middle two long tactile hairs; 3rd 

 and 4th joint of equal size, the former with one long 

 hair dorsally, the latter with two hairs, one dorsal, 

 one exterior, 5th joint of uniform width in the prox- 

 imal ^/4, then suddenly tapering from the dorsal side; 

 on this slope there are the usual three hyalin, short ^. 



Plff. 22, Pl(lt€'K61fl(ZilS UCStltuS 



and straight hyalin bristles, forming a comb, and a ' n. sp. Dorsal shield. 

 little further back dorsally a curved bristle on a low 



projection; ventrally and subterminally a pointed hair curved forwards and 

 further backwards dorsally and exteriorly two slender tactile hairs. 



Ventral side (fig. 21) with almost the same reticulated texture as the 

 dorsal side. Epimera I and II well demarcated, the former with three pairs of 

 small, equidistant hairs near the anterior margin, the latter with only one pair 

 in the median angle. Epimera III with only faint traces of their posterior mar- 

 gin in the lateral half, with three pairs of small hairs. The posterior margin 

 of epimera IV may be indicated by two faint, semicircular ridges on a level 

 between the genital and anal plates. 



Genital aperture rectangular, almost twice as long as it is wide, with 7 

 pairs of small marginal hairs along the median edges of the genital plates. 

 Anal aperture large, almost rectangular and nearly continuous with genital 

 aperture, with two pairs of small marginal hairs near the middle of the median 

 edges of the anal plates. 



Legs (figs. 28 — 30). The legs are, as already pointed out (p. 556), quite 

 unique through the structure of the articulation. As a rule, whenever there is 

 a condylus developed which turns in a socket, the condylus is furnished by 

 proximal end of the distal joint while the socket is furnished by the distal end 



