410 bulletin: museum of comparative zoology. 



bb. Antennae filiform or somewhat clavate; labrum tripartite, 



entirely free. Geophilidae. 



aa. Mandibles with one dentate lamella and with several pectinate 



lamellae. Hi m antariidae. 



GEOPHILIDAE. 



This large family as represented in the southeastern states embraces 

 three subfamilies : — the Geophilinae, including the genera Polycricus, 

 Pachymerium, Arenophilus, gen. no v., and Geophilus; the Chileno- 

 philinae, including Watophilus, gen. nov. and Gnathomerium; and the 

 Linoteniinae, including the genera Linotenia and Agathothus. These 

 groups and genera, so far as affects the species here dealt with, may 

 be separated as follows. 



Key to subfamilies and genera. 



a. Median piece of labrum very large, armed with a fringe of teeth 

 or spines ; lateral pieces small, free edge smooth, unarmed. 



Linoteniinae. 



b. Claw of prehensors unarmed; conspicuously excavated at 



proximal end dorsally, constricted. Agathothus Bollman. 



bb. Claw of prehensors armed within with a single large tooth; 



not excavated proximally. Linotenia Koch. 



aa. Median piece of labrum relatively very small, the lateral pieces 



large and with the free edge armed with few to many spinescent 



processes. 



b. Second maxillae with a very strongly chitinized oblique, 



pleurosternal suture. Chilenophilinae. 



c. Middle piece of labrum completely separating the lateral; 



anal legs clawless, with seven articles beyond coxopleura. 



Watophilus, gen. nov. 



cc. Middle piece of labrum not separating the lateral; anal legs 



armed with claws, having six articles beyond the coxopleura. 



Gnathomerium Ribaut. 

 bb. Second maxillae without any such chitinous suture. 



Geophilinae. 

 c. Prehensorial feet mostly not extending beyond anterior margin 

 of head, the joints unarmed within or only obscurely so 

 (last ventral plate mostly wide to very wide). 



Geophilus Leach. 



