ACARINA FROM THE JUAN FERNANDEZ ISLANDS 567 
i 
been able to ascertain that the articulation of its legs is typical and that the 
claws are sessil. 
But, on the other hand, the maxille of Platerem@us are built essentially 
on the same plan as those of Veoliodes, as I have pointed out above. 
The structure of the legs is, however, so unique in Plateremeus that the 
raising of it to the type of a family is certainly justified. This family is as 
yet rather isolated but is related to the NMeoldide. 
Plateremzidz nov. fam. 
Diagnosis: Hysterosoma flat, covered by 4 concentrical skins (I 
larval, 3 nymphal exuviz). Body and legs covered by a thick layer 
of secretion. Terminal ends of femur, genu and tibia narrow, arti- 
culating in sockets of resp. genu, tibia and tarsus. Claws three, on 
top of small peduncle. 
Typical genus: Platereme@us (BERL.) TRAGARDH. 
4. Plateremeus vestitus n. sp. — Figs. 20—31. 
Length 880, width 600 m. Length of propodosoma 250 »., width 250 p.. 
Length of hysterosoma 625 w. 
Colour bright red-brown. Texture beautifully areolated through minute, 
circular depressions (fig. 22). The cover of secretion is thick (fig. 24) and of 
a spongy texture; it seems to be composed of perpendicular cylindrical pieces 
of waxy matter packed densely together; the surface is irregularly reticulated. 
Propodosoma (fig. 20) as long as it is wide at the base, rounded at the 
top. There are no lamellz nor any true ridges but half-way between coxa I 
and the top the surface slopes abruptly downwards; in front of this the cir-_ 
cular depressions are much smaller than further backwards. The posterior part 
behind the acetabula I is also depressed so that the median third of the propodo- 
soma forms a very broad transversal ridge. At the postero-lateral angles of 
this ridge, at the foot of the slope there is a sharp tooth directed obliquely 
backwards and outwards which is opposed to a similar tooth which points in 
the opposite direction (fig. 25). This structure vividly recalls the teeth found 
in Odontocepheus on both sides of the suture between propodo- and hysterosoma. 
Presumably in both instances they add to the rigidity of the cuticle. The 
interlamellar hairs are placed on a level with the pseudostigmata and close to 
them and are very short but stout and almost perpendicular. I have not 
been able to find any interlamellar hairs but marginally, near the top of the 
rostrum there is a pair of rather short hairs curved inwards, which may either 
be homologuous to these hairs, in which case the rostral hairs have dis- 
appeared, or are true rostral hairs. 
The pseudostigma (fig. 25) is of a rather peculiar shape; from a 
narrow circular base it widens to twice is basal diameter and is bent obliquely 
downwards, outwards and forwards; the posterolateral angle is flattened to a 
blade and the anteromedian angle has the same shape, but is smaller. The 
