364 PROCEEDINGS OF THE IS^ATIONAL MUSEUM vol.83 



region is additional and more conclusive evidence of the previous 

 existence of tropical conditions, for all the members of this genus 

 are distinctly tropical and of delicate structure and sluggish habits, 

 which combine to restrict their distribution and make migration a 

 slow process dependent on the constant protection of a moist humus 

 layer, such as usually is found in tropical forests. Because of the 

 persistence of such types as Siphonopliora^ it is evident that in small 

 areas in south Texas satisfactory environmental conditions for 

 humus animals have been maintained with unbroken continuity 

 since the disappearance of the forests, and through the period of 

 changing vegetation, to the present day. 



Genus SIPHONACME Cook and Loomis 



SIPHONACME LYTTONI Cook and Loomis 



In addition to the type locality, which is near the highest point of 

 the road^ between Miami and Superior, Ariz,, the species has since 

 been collected by me at Prescott and in Cave Creek Canyon of the 

 Chiricahua Mountains, Ariz. 



Genus ANDROGNATHUS Cope 



ANDROGNATHUS CORTICARIUS Cope 



Previously reported from Virginia and Tennessee. Specimens 

 have been collected at Quincy, Fla., by Dr. O. F. Cook, thus consid- 

 erably extending the range to the south and indicating that the 

 species will probably be found in several States from which it has 

 never been reported. 



Genus GOSODESMUS Charaberlin 



GOSODESMUS CLAREMONTUS Chambcrlin 



As the names implies, the type locality of this species is Clare- 

 mont, Calif. Additional specimens have been collected by Dr. O. 

 F. Cook in the following California localities: "South of Pesca- 

 dero"; Santa Cruz Mountains, between Santa Cruz and Holy City; 

 Santa Monica. 



The male gonopods are shown in figure 32, c. 



Genus BRACHYCYBE Wood 



This is probably the most interesting genus of the order in the 

 United States because of its wide distribution, its species being found 

 on the Pacific coast as well as on the Atlantic seaboard, whereas the 

 other genera are monospecific, except Siphona&me and /Sij)honophora, 

 and their species restricted to one side of the continent or the other. 



