Liihiduridae, a family of the Dcrmaidera. 189 
very gently arcuate. The only sexual dilference in the 
forceps is that in the female the branches are somewhat 
closer together at the base than in the male. 
The pauci-segmentate antennae may perhaps be looked 
upon as another primitive feature, as also the spindle- 
shaped body. In many or all of the species there is a pair 
of curved impressions on the frons between the eyes; can 
these be vestiges of ocelli ? These organs are unknown in 
earwigs. 
The total absence of organs of flight is probably to be 
explained rather by degeneration than by non-develop¬ 
ment, since one African form, Arlex sjoestedti, Borg., 
possesses signs of rudimentary elytra on the mesonotum 
analagous to the same rudiments in Karschiella, which is, 
moreover, also a primitive type, its larva probably having 
segmented caudal setae instead of forceps, as in its near 
ally Borniansia, and the not distantly related Diplatys. 
The legs in the Brachylahinae are very simple, and show 
neither keels on the femora nor specialisation in the seg¬ 
ments of the tarsi. The second segment is decidedly 
longer than in most other earwigs. I can detect no trace 
of pulvillus between the claws, nor are the claws different 
from those of other earwigs. The Brachylahinae all have a 
strong family likeness and cannot be confused with any 
other group. 
Apart from the various features enumerated above, the 
last dorsal segment has the posterior margin emarginate 
or concave, and the two lobes are pointed and slightly 
produced over the forceps. All known species are deep 
dull black in colour, and probably are clothed in life with 
a long velvety pubescence, which is generally worn off in 
cabinet specimens. 
They appear to be rare insects, but are widely distributed 
throughout the tropical regions, occurring in Java, Burmah, 
India, Ceylon, Madagascar, Africa, Guatemala, Brazil, Peru, 
etc. This wide distribution of so well-marked a type of 
earwig is probably also an archaic feature. 
Verhoeflf was the first to draw attention to the great 
size of the eyes in certain Brachylahinae : in his paper on 
“ Neue ungefluegelte Eudermapteren-Gattungen” (SB. Ges. 
Naturfr. Fr. 1901, p. 10) he makes a special point of this 
feature in distinguishing his family Isolahidac. 'I'he words 
he uses are: “ Augen sehr gross, hoechstens um ^ ihres 
Durchmessers von Hinterhaupte entfernt.” 
