=Polyphaga aegyptiaca= _Turkmen S.S.R._--Nymphs and adult females were often found in burrows of the sand mouse, _Rhombomys opimus_ (Vlasov, 1933). =Polyphaga indica= _Turkmen S.S.R._--This species prefers sandy soils where it can be found in burrows of _Spermophilopsis leptodactylus_ and _Pallasiomys meridionalis pennicilliger_ Heptner (Vlasov and Miram, 1937). =Polyphaga saussurei= _Tadzhikistan._--Found in burrows of turtles and rodents (Zmeev, 1936). _Turkmen S.S.R._--Nymphs and adult females are common in burrows of _Rhombomys opimus_ and in burrows of _Testudo horsfieldi_. Its principal habitat is rodent burrows in loess dust, where it is not infrequently found in the food stores of the host (Vlasov and Miram, 1937). =Pycnoscelus surinamensis= _Texas._--In the nests of wood rats, _Neotoma_ sp. (Hebard, 1917). DESERT HABITATS There is relatively little ecological information about cockroaches that live in deserts, even though certain species, notably _Polyphaga aegyptiaca_, have long been known to inhabit arid zones. In fact, so little is known about the ecology of arid-zone insects in general that it is more a subject for research than for review (Pradhan, 1957). In their account of the cockroaches of Northern Kenya and Jubaland, Kevan and Chopard (1954) describe in some detail the vegetational areas of this arid desert or semidesert country, which averages only about 10 inches of rain per year. The other sources that are cited below contain very little more biological information than the abstracted material that is given under each species. Nearly all the Polyphaginae are said to be marked xerophiles whose distribution coincides with that of the deserts (Bei-Bienko, 1950). With the exception of _Arenivaga floridana_, the species of Polyphaginae in the United States all occur in the Southwest, where they are (with a few exceptions) the only cockroaches that inhabit the desert regions proper (Hebard, 1917). The Polyphaginae reach their greatest diversity in the deserts of Northern Africa and Anterior and South-Central Asia (Bei-Bienko, 1950). Some of the desert-inhabiting species have also been found under nondesert conditions. This only further exemplifies the plasticity of cockroaches in adapting to different environments.