84 NEOTROPICAL PSELAPHIDAE 



The head is almost semicircular from a dorsal point of view, with an 

 almost straight occiput, and a semicircularly produced front, the surface of 

 the head being medianly, broadly concave. Although the eyes are large, they 

 are wholly invisible from above, as a consequence of the expanded top of the 

 head. The extended front covers the mouth-parts, labrum, and base of antennae. 

 The antennae are inserted on the antero-lateral sides of the front, beneath the 

 expanded dorsal wall, instead of at the extreme end of an elongate rostrum 

 as in Rhinoscepsis, and these organs are relatively short, and the segments 

 progressively thicker apically, so that the club is not apparent, although the 

 distal segment is large, about three times the length of the tenth segment. 



Pronotum transverse, wider than head, with a strong bisinuate transverse 

 sulcus and a less developed longitudinal median sulcus. 



Elytra with three basal foveae on each elytron. 



Abdomen elongate-cylindrical, weakly margined; five tergites and six 

 sternites. Tarsi with two very unequal claws. 



Raffray (1908, p. 128) thinks that the species may be an inhabitant of 

 the nests of social insects, either ants or termites. 



longipennis Raffray. 1890. Brazil. Genotype. 



PHTEGNOMUS (Raffray, 1890) 

 Raffray (1890, 1904) 



This genus is also remarkable for the development of the head ; in fact it 

 may represent several genera and many undescribed species when it is more 

 fully understood. It is notable in that it is one of the very few genera of 

 pselaphids which are exclusively found in the nests of termites. 



Head always greatly dilated laterally, but not obscuring the eyes from a 

 dorsal viewpoint, and the front is always expanded to cover the mouthparts; 

 the eleven-segmented antennae are inserted under the sides of the front, and 

 not at the end of the expanded portion ; these organs have a conspicuous three- 

 segmented club. Vertex excavated. Eyes placed near the posterior margin of 

 the head. 



The front is variously formed; it may be expanded as an elongate tubercle, 

 with parallel sides and a truncate apex (naso) , or as a long median spur. 



Pronotum not greatly wider than head, transversely ovate, with the longi- 

 tudinal and transverse sulci more or less vestigial. 



Elytra with the base transversely carinated, and each elytron with two 

 foveoid depressions. 



Abdomen with a wide, strong margin; five visible tergites, with the first 

 tergite hidden beneath the elytral apices as usual, but appearing laterally, so 

 that six tergites may be counted; six sternites. 



inermis Wasmann. 1894. Venezuela, {con Eutermes meinerti Wasmann) 

 naso Wasmann. 1894. Venezuela, {con Eutermes meinerti Wasmann) 

 oberthuri Raffray. 1890. Brazil. Genotype. 



