CHAP. XII.] 
THE AZORES. 
245 
found in any of the other Atlantic islands, showing that they 
have been introduced directly from Europe by causes which 
have acted more powerfully here than farther south. Besides 
these there are thirty-six species not found in Europe, of which 
nineteen are natives of Madeira or the Canaries, three are 
American, and fourteen are altogether peculiar to the Azores. 
These latter are mostly allied to species found in Europe or in 
the other Atlantic islands, while one is allied to an American 
species, and two are so distinct as to constitute new genera. 
The following list of these peculiar species will be interesting : — 
CAIIABID2E. 
Anchomenus aptinoides Allied to a species from the Canaries. 
Bernbidium hesperus Allied to the European B. latum. 
Dytiscidas. 
Agabus godmanni Allied to the European A. dispar. 
COLYDII DAS. 
Tarphius u'ollastoni A genus almost peculiar to the Atlantic islands. 
ELATERIDiE. 
Heteroderes azoricus Allied to a Brazilian species. 
Elastrus dolosus Belongs to a peculiar Madagascar genus I 
Melyridas. 
Attains miniaticollis Allied to a Canarian species. 
Rhyncophora. 
Pldceophagus variabilis Allied to European and Atlantic species. 
Acalles droned A Mediterranean and Atlantic genus. 
Laparocerus azoricus Allied to Madeiran species. 
Asynonyckus godmanni ....A peculiar genus, allied to Brachyderes, of the 
south of Europe. 
Neocnemis occidental is A peculiar genus, allied to the European genus 
Strophosomus. 
Heteromera. 
Helops azoricus Allied to H. vulcanus of Madeira. 
Staphylinid^e. 
Xenomma melanocephala . . .Allied to X. filiforme from the Canaries. 
This greater amount of speciality in the beetles than in the 
birds may be due to two causes. In the first place many of 
these small insects have no doubt survived the glacial epoch, 
and may, in that case, represent very ancient forms which have 
