chamberlin: geophiloidea of the southeastern states. 411 



cc. Prehensorial feet much exposed from above, extending well 

 beyond anterior margin of head, the joints distinctly denticu- 

 late within; (last ventral plate either wide or narrow). 

 d. Last ventral plate very wide; coxopleural pores aggregated 

 and opening into two large pits on each side adjacent to or 

 covered by edge of last ventral plate; anal legs clawless, 

 composed of seven articles beyond coxopleura. 



Arenophilus, gen. nov. 



dd. Last ventral plate narrow; pores of coxopleura not 



aggregated and opening into pits; anal legs with six joints 



beyond coxopleura (with or without claw). 



e. Ventral pores in four areas, two on anterior portion of 



plate and two on posterior; (anal legs in ours clawless). 



Polycricus Humbert and Saussure. 



ee. Ventral pores not in four areas in this way; anal legs 



with claws. Pachymerium Koch. 



GEOPHILINAE. 



Geophilus Leach. 



Trans. Linn. soc. London, 1814, 11, p. 384. 



The species recognized as occurring in the southeastern states may 

 be separated by means of the following key. 



Key to species, 



a. Frontal plate discrete, 

 b. Prebasal plate exposed. 



c. Coxopleurae of last pediferous segment with two large pits 



which are covered by the last ventral plate. G. rubens Say. 



cc. Coxopleurae of last segment with from five or six to many 



small pores. G. mordax Meinert. 



bb. Prebasal plate not exposed. 



Pairs of legs — sixty-one or close thereto. 



G. legiferens Chamberlin. 

 aa. Frontal plate not discrete, 

 b. Prebasal plate not exposed. 



c. Last ventral plate wide. G. huronicus Meinert. 



cc. Last ventral plate narrow. G. varians McNeill. 



