436 MR. LUBBOCK ON THE THYSANURA. 
a foil, or rather perhaps a drop of dew, except that the form is more elliptic. The ter- 
minal portion of the organ has no hairs ; it has a broad knife-like shape, and is -009" 
in length by -0025" in breadth. On its inner margin it has a row of minute teeth ; 
the outer edge is smooth. At the base of the spring are two peculiar, thickened parts of 
the skin (PL XLV. fig. 13). They are constant in form and position : the shaded part 
seems to be rather thicker than the rest ; but the whole structure is transparent, and 
more refractive than the skin round it. They do not serve as attachments to muscles, 
and I am at a loss to understand what their function can be. On each side of the anus 
are two great scimitar-shaped organs (PL XLV. fig. 14), which are no doubt gigantic 
and specially modified hairs. They appear, indeed, to agree with the ordinary ones in 
their constitution and mode of attachment. They are about -008" in length, and -001" 
in breadth. The apical half of the inner margin, and a small part of the outer edge, 
are roughened by irregular teeth, which, however, are so unsymmetrical as rather to 
suggest the idea of the border being fretted by use. The two scimitars did not even 
agree in the extent to which they were thus affected. 
Papirius, Lbk. 
The characters of this genus have been given above. 
Papiritjs 
Body globular, with scattered hairs ; abdomen without 
tering angle. Colour dull purple. Eyes not situated in a black patch. Ends of 
spring pale. Antennae four-jointed ; terminal segment short, with about ten distinct 
whorls of hairs, but without actual joints. Claw with two distinct teeth on the 
lower margin. 
Length -05". 
PL XLVI. fig. 25, represents a form of Gregarina frequently found in this species. 
This species occurred, with the preceding, under logs of wood. It appeared, however, 
somewhat later in the autumn ; at least, I found the first specimen towards the end of 
October. It was common through November, but died out again towards the end of the 
year, reappearing in May. 
The structure of the antennae at once distinguishes this species from all those described 
by M. Nicolet. In this respect it approaches more nearly to the Smynthurus viridis of 
Templeton, from which, however, its colouring is entirely different ; and Mr. Templeton 
does not, unfortunately, give any anatomical details. 
The legs are longer than in the preceding species ; the animal is altogether more lively, 
not indeed so fond of walking as the following species, but more so than S. Buskii, which 
does not very often move except by leaps. 
The antennae are much longer than in the preceding species, the increase being in the 
two middle segments. The whole organ has a length of -055", with the comparatively 
&**" ""» » i0ii 5 
small thickness of -002". The basal segment is -005" in length ; the second '0225 
the third is a little longer than the second, and especially towards its apical end, w 
hich 
slightly swollen, and resembles a knobby stick. The terminal segment is about 
the basal, and is somewhat conical. The whole organ is covered with scattered hairs 
which are particularly numerous on the distal half of the third and on the apical segments 
