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VII. A Preliminary Revision of the Labiduridae, a family 
of the Dermaptera. By Malcolm Burr, D.Sc., 
F.L.S., F.B.S. 
[Read February 2nd, 1910.] 
Plates XLVI, XLVII. 
The family Lahiduridae was erected by me in a recent 
paper (1909^) as one of the five families into which I 
divide the order Dermaptera. It is well characterised by 
the peculiar form of the pygidium; this organ is i*epre- 
sented by a flap of the dorsal sclerite of the last abdominal 
segment, which is bent downwards between the branches of 
the forceps, so as to present a more or less vertical sur¬ 
face. The passage from the dorsal surface to the posterior 
is marked by an angular fold which is usually sharp and 
distinct; only in the curious Chilian genus Gonolahina, 
Verhoeff, is the passage gradual and the line of division not 
marked. 
We may add that the antennae have generally numerous 
segments; the first few after the basal one being as a rule 
short. 
In the paper referred to above, the group is sub-divided 
into six sub-families; this I now propose to raise to nine. 
The Echinosomatinae are separated from the Pyragrinae, the 
Parisolabinae from the Brachylabwae, and a new sub-family, 
the Palicinae has been since added, with a single species. 
The arrangement of these sub-families is as follows ;— 
1. Corpus valde deplanatum.1. Paiucinae. 
1.1. Corpus baud valde deplanatum. 
2. Mesosternum valde angnstatum . . 2. Allostethixae. 
2.2. Mesosternum hand angnstatum. 
3. Prosternum valde angustatum . 3. Esvhalmexinak. 
3.3. Prosternum baud angustatum. 
4. Metasternum postice sinuatum. 
5. Prosternum antice rotun- 
datum.4. Echinosomatinae. 
5.5. Prosternum antice acum¬ 
inatum .5. Pyragrinae. 
TRANS. ENT. SOC. LOND. 1910. —PART III. (NOV.) M 
