315 
Notes on the Uropodinas. By A. ID. Michael. 
the dorsum, which forms such a characteristic feature of the species, is 
formed of thinner chitin than the remainder of the notogaster ; while 
in the elevated parts at the side the chitin is extremely thick and 
dense. It will also be seen that the curved transverse markings which 
cross the depression are not mere outer thickenings or differences of 
colour, hut are actual foldings inwards of the dorsal shield itself, and 
project on the inner surface of the tergum ; the two sides of the fold 
have coalesced so as to form one ridge ; hut these ridges are not all 
quite similar, some are deeper and larger than others ; the more shallow 
ridges usually have quite sharply pointed ends, whereas the deeper 
ones, where the folding of the ends has not been effected in the same 
manner, mostly swell out, forming slightly bulbous terminations. It 
may also be roughly said that almost all the numerous irregularities 
and sculpturings of the dorsal surface are produced partly or entirely 
by out-pushings or in-pushings of the chitinous cuticle, not by mere 
thickenings. 
The mandibles, fig. 3, are scarcely of the type most usual in the 
Uropodinae, they are somewhat shorter and thicker, and the chelate 
portion is more powerful. They contain a very good example of what 
is not very unusual among Acarina, viz. that the tendon by which the 
muscle communicates with the movable chitinous part which it works 
is not attached directly to the movable part, but is attached to a small 
loose chitinous piece ( c ) from the opposite end of which another short 
tendon runs to the working part ; this chitinous piece probably serves 
to some extent as a fulcrum, and enables a slight change in the direc- 
tion of the line of force to be obtained. 
The hypostome (maxillary lip), fig. 4, is characterized by the 
extreme fringing with long hairs of the paired lateral parts (gal) which 
Megnin calls the “ galeae ” ; they stand out like great brushes of hair 
in a very unusual manner. The long rod or spine, which Berlese calls 
the “ style ” ( st ) is also much developed for one of the Uropodinae. 
The palpi (fig. 5) are very short, thick, and conical ; the basal 
joints being much larger than is usual in the sub-family. 
Oral tube . There is a rather remarkable median pair of serrated 
spines articulated to the under-side of this organ ; one of them is drawn 
(.tig. 6). 
The Alimentary Canal. 
It will be seen on comparing fig. 7 with the drawing of the 
alimentary canal of Uropoda Krameri (fig. 8 of the plate illustrating 
my paper published in this Journal in 1889) that there are considerable 
differences between them, although of course the general principle is 
the same. The present species much more resembles the short descrip- 
tion given (without a special figure) by Winkler of what he calls 
TJropoda obscura (Koch).* 
* Winkler does not figure or describe bis species; there is a little uncertainty as 
to what it was, as he possibly followed Oanestrini and Berlese in their nomenclature, 
which, in this case, I do not think correct. See the synonymy of TJrojpoda ovalis 
Koch, at p. 303 of this paper. 
