296 J. A. G. REHN 



center of differentiation, on the basis of present diversity, pre- 

 sumably was in the eastern and central United States. 



Another subfamily of the Blattodea, the Panchlorinae, aside 

 from the already mentioned Pycnoscelus, is represented in our terri- 

 tory by a single species of Panchlora, which may be autochthonous 

 with us in a circumscribed area. The genus is greatly diver- 

 sified in tropical America, and also has a few endemic species in 

 forested West Africa. The single species we have within our bound- 

 aries, P. cubensis, is broadly distributed to the southward, but 

 reaches its northern natural limit in the Brownsville area of southern 

 Texas. This insect is often brought in accidentally in bananas, 

 but cannot survive our usual winter conditions. The subfamily 

 Chorisoneurinae is a Neotropical assemblage made up of a large 

 number of species, although but a single genus and species, Choris- 

 oneura texensis, reaches our territory, where it ranges rather broadly 

 over the southeastern United States from North Carolina to eastern 

 and southern Texas in the Brownsville area. The genus, with us, is 

 clearly intrusive from the south, for our representative is the most 

 northern member, and the number of species represented regularly 

 increases as one goes southward in Mexico and Central America. 



The subfamily Attaphilinae, the members of which are ant 

 inquilines, is represented in our territory by the single genus Atta- 

 phila, of which the genotypic species is known only from central 

 Texas. This genus is represented by a number of other species in 

 South America, and a number of allied genera are found in the 

 Neotropical Region. It is evident that Attaphila, along with its 

 host Atta, has been derived from that great center. 



The subfamily Corydinae is represented in North America by a 

 single genus, Compsodes, the sole species of which in our territory is 

 known from the mountains of southern Arizona and from localities 

 in south and central Texas and Baja California. The genus, as well 

 as a number of related ones, is clearly Neotropical in origin. A 

 number of genera of this subfamily are inquilines with various 

 Hymenoptera, as well as with Isoptera. 



The morphologically very distinct subfamily Polyphaginae is 

 made up of genera that are largely desert forms, and that show 

 marked antigeny between their sexes. The greater number of the 

 genera, and the bulk of the species, are Palearctic, with others 

 arid Ethiopian. In Neogaea we have representatives of the sub- 



