430 DESCRIPTION OF A MITE 
founded, resembles Trachynotus pyriformis (Kramer) 
more closely than it does any other recorded species. It 
is, however, decidedly different, and is characterised by 
the squareness of its abdomen, the thickness and rough- 
ness of its chitinous dermal skeleton, and especially by 
the powerful chitinous ridges or wing-like expansions 
on the lateral surface between the second and third pair 
of legs. 
Length, ¢ and ?, about ‘95 millim. 
Breadth a aan 15 Mae 
The abdomen is almost square, but somewhat longer 
than broad, and slightly narrowed at its junction with 
the cephalothorax, from which it is not plainly dis- 
tinguished. The extreme edge is a strong chitinous 
ridge bordered with a thick fringe of short, stout, 
curved hairs, as in 7: pyriformis. The dorsal surface 
of the cephalothorax is also narrowed towards the front, 
and has a curved anterior margin bent down so as to 
protect the mouth, as in that species ; it bears a few of 
the same kind of hairs as the abdomen, and _ has a chiti- 
nous thickening at each side. The abdomen rises almost 
perpendicularly from the marginal ridge. There is a 
central depression occupying the posterior half, or rather 
more than half of the abdomen ; and at the bottom of 
this depression are transverse ridges, the hinder ones 
nearly straight, and the anterior ones bent in the mid- 
dle, the central point being forward ; at the sides of, but 
not in, this depression, are two chitinous blocks which 
seem to form a starting-point for the ridges. Anterior 
to this depression the central portion of the creature, 7.¢. 
its longitudinal dorsal axis, is higher in level than in 
parts nearer the margin, and forms an irregular triangle 
of rough chitine. A broad chitinous plate or ridge pro- 
jects on each side above the second leg, and between 
that and the third, evidently for their protection ; it is 
probably flexible at the will of the creature, as in the 
genus Oribates. 
