62 MONOGRAPHIA 



GENUS I. PHILOPTERUS. (Nitzsch.) 



Burmeister, Stephens. Pediculus, Linn. Fabr. Ricinus, DeGeer, Latreille. 

 Nirmus, Hermann, Olfers, Leach, Samouelle. 



GENERIC CHARACTER. 



HEAD depressed, scale-like, horizontal. 



MANDIBLES somewhat angular, terminating in two strong 

 teeth. 



LABRUM dilated at the base, loose, expansible, inflated, 

 and in some species changeable in appearance, margin 

 free, slightly notched. 



LABIUM small, margin notched, so that when the mouth is 

 closed an aperture is left. 



LABIAL PALPI small and two jointed. 



ANTENNAE five jointed, inserted into the lateral margin of 

 the head, the third joint in the males of some species 

 somewhat branched or curved backwards upon the first, 

 so as to act like a claw or pair of forceps. 



EYES on the lateral margin of the head behind the an- 

 tennae, slightly convex, sometimes inconspicuous or ab- 

 sent. 



THORAX of two segments, the prothorax narrower than the 

 head. 



LEGS formed for climbing ; tarsus two jointed, curved ; 

 ungues two, parallel, and contiguous, not capable of 

 spreading, and having the appearance of being single, 

 which folding upon two short spines at the base of the 

 tibia, forms an efficient claw. 



