DERMA PTERA AND ORTHOPTERA 255 



United States there are two distinctive endemic members of the 

 genus. It is possible that Doru reached North America in two 

 separate invasions, the eadier of which established the line that 

 developed the endemic southeastern species D. aculeatiim and davisi, 

 and the later of which brought in the widely spread D. lineare, 

 which is now known from within our territory only from areas of 

 Texas, southern New Mexico and Arizona, and California. A 

 single species undoubtedly referable to Doru was described from New 

 South Wales in 1891. With an intimate knowledge of the hiding 

 places that Doru selects, I suggest that a restudy of the unique 

 type will probably show it is inseparable from the widely spread 

 Neotropical D. linear e, and also that it was introduced from Rio de 

 Janeiro, when in 1789 various specimens of Opimtia, the nest-egg 

 of the Australian "prickly pear" scourge, were brought in to supply 

 food for the similarly introduced cochineal insect. 



One of the really puzzling anomalies in the relationship and dis- 

 tribution of the Dermaptera found in America north of Panama is 

 the occurrence in areas of south-central Mexico of one species (vara) 

 of the genus AnechiLrella, the sole representative known from the 

 New World of the otherw^ise widely distributed subfamily Anechuri- 

 nae, members of which elsewhere occur from western Europe and the 

 Madeira Islands to India, China, Japan, Formosa, and Borneo, but 

 not from continental Africa. 



No genera of the Dermaptera are peculiar to North America. The 

 areal distribution of the genera of Dermaptera shows clearly that the 

 largest number of generally recognized generic entities occurs ex- 

 clusively in the Oriental Region, this closely followed in numbers by 

 the similarly restricted Neotropical, with the I ndo- Malayan and 

 Ethiopian (with its Malagasy subregion) following. The exclusively 

 Palearctic genera (12) are equaled in number by those which are 

 pantropical, with the Australian, Melanesian, and Pacific, broadly 

 paleotropical, and cosmopolitan following in regularly reducing 

 representations. 



No member of the North American dermapterous fauna, except 

 those of cosmopolitan distribution, and these usually limited to such 

 special environments as sea beaches or river banks, appears to have 

 been derived from the Palearctic Re-ion. All other elements have 

 clearly come from the Neotropical Region. Several genera of this 

 source have apparently been established sufficiently long in the east- 



