Caves, mines, and animal burrows are somewhat similar habitats that provide many species of cockroaches with shelter and frequently with food. The microclimates of these cockroach habitats have not been described in detail in the papers cited, but it seems rather obvious that natural caves, man-made caves (mines), and burrows offer relatively stable temperatures and humidities and protection from adverse climatic conditions. Although such cavernicolous animals as birds and bats periodically leave caves to search for food, cockroaches find the accumulated guano and animal and plant detritus an entirely adequate dietary (Chopard, 1938). Cockroaches in mines presumably subsist on the food and feces dropped by man and mine animals (e.g., pit ponies). Food stored in their nests by burrowing animals is undoubtedly utilized by the associated cockroaches. Cavernicolous cockroaches show varying degrees of dependence on and adaptation to these specialized habitats. Some of the common domiciliary species (_Blatta orientalis_, _Blattella germanica_, and _Periplaneta americana_) may have accompanied man into caves and remained there after he left (Chopard, 1929a, 1936, 1938). Other species, from the paucity of records noting their occurrence in caves, are undoubtedly accidental inhabitants that may never become established. Besides these, however, many other species of cockroaches have established large breeding colonies in caves. Although some of the latter species show very pronounced morphological adaptations to a cave life, many others resemble their noncavernicolous relatives. The possible origin of cavernicolous Orthoptera has been discussed by Chopard (1938). Cavernicolous cockroaches have been segregated into four groups according to their ability to adapt to their environment and the degree of their specialized evolution (Chopard, 1936, 1938): (1) =Trogloxenes=: Cockroaches that occur in caves in a sporadic fashion (the domiciliary cockroaches and accidentals such as _Ectobius_ and _Heterogamodes_). (2) =Troglophiles=: Cockroaches found habitually in caves (_Symploce_, _Periplaneta cavernicola_). (3) =Guanobies=: Cockroaches that live in the guano of cavernicolous vertebrates (_Gyna_, _Acanthogyna_, _Dyscologamia_, _Pycnoscelus_). (4) =Troglobies=: Cockroaches that apparently cannot live outside of caves and which show very marked adaptive characters (_Alluaudellina_, _Nocticola_, _Spelaeoblatta_, _Typhloblatta_). For complete discussions of these groups including descriptions of the adaptive characters shown by certain genera, the original sources should be consulted.