MR. LUBBOCK ON THE THYSANURA. 591 
simple hairs and scales. Antennae very long, four-jointed, the two terminal 
ments ringed. Eyes seven in number on each side. 
- ■» * 
6. Lepidocyrtits, Bourlet {Cyphoderns, Nicolet). Abdominal segments unequal, with 
simple hairs and scales. Antennae long, four-jointed. Eyes eight in number on 
each side. * 
7. Podura. Abdominal segments subequal; hairs simple, no scales. Antenna? four- 
jointed, shorter than the head. Eyes eight in number on each side. Saltatory 
. appendage of moderate length. 
8. Achorutes, Templeton. Abdominal segments subequal. Antenna? short, four-jointed. 
Eyes eight in number on each side. Saltatory appendage quite short. 
These two latter genera, or subgenera, differ only in the form and size of the caudal 
appendage, a point, however, of special importance in this group of animals. Templeton, 
indeed, calls the fork "obsolete;" but it is present, though small. We thus pass 
naturally to the IApuridce, in which it is altogether absent. This small family contain- 
as yet only two genera, IApura (Burmeister), in which the mouth is composed of the 
same parts as those in the preceding genera, and Anoura (Gervais), in which the mandi- 
bles and maxillae disappear. 
Orchesella. 
Orchesella eilicornis, Temp. My specimens were not so green as those of Templeton, 
and in the colouring of the antennae they agreed more closely with his figure than 
with his description. The two small basal segments and the small fourth segment 
were black ; the third had the basal half brown, the apical white ; the fifth, on t he 
contrary, was palest at the base ; the two terminal segments were pale, but not 
greenish. Body black, more or less weakened by greenish brown ; the mesot borax 
has two pale oval spaces converging in front, and leaving a triangular central space, 
and the margins dark ; the metathorax and first abdominal segment have al 
each side a pale band, which are, as it were, continuations of those on the mesot borax. 
Posterior half of second abdominal segment white, with a greenish tinge. Third 
abdominal segment very dark, especially in front, and with a lunate greenish patch 
at the centre of the posterior margin. Fourth abdominal segment with a white 
lateral spot at the posterior margin. Legs annulated with light and dark brown. 
The abdominal hairs are, in Templeton's figure, curved backwards; in my specimens 
they stood out straight. 
Length \ t h of an inch . 
Common throughout the year, under logs of wood. 
Orchesella fastuosa, Nicolet. M. Nicolet's description of this species is as follows : 
M Corps cylindrique ; moitie" superieure du second article des antennes, quatrieme 
segment du corps et deux bouquets de poils a l'extremite" posterieure du sixieme 
d'un blanc tres-pur. Les deux segmens thoraciques brims, avex quatre t aches ob- 
liques et une ligne mSdiane d'un beau jaune claif au premier, et d'un jaune fence" 
VOL. XXIII. 
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