NEW MALLOPHAGA. 463 



well developed, with distinct cardo, stipes, palpifer, 4- 

 segmented palpus, and both terminal lobes, the lacinia 

 sharply two-pointed, and the outer hoodlike galea fleshy; 

 labium (plate lxiv, fig. 1) with elongate elliptical sub- 

 mentum, men turn, 3-segmented palpi, and ligula showing 

 in each half both glossa and paraglossa. The Termite 

 species whose mouth-parts I figure to illustrate the gen- 

 eral character of the Termite mouth structures is Termop- 

 sis angusticollis, a large form common in California. 



The Perlidas, as the Termitidae, present the generalized 

 biting type. In the adult Perlids, to be sure, the mouth- 

 parts seem to be hardly functional, being reduced to a 

 semimembranous condition, with some correlated changes 

 in form. In the nymphs, however, the usual Orthopter- 

 ous form is shown. I have figured the mouth structures 

 of a nymph of Pcrla (plate lxiv, figs. 3 and 4). The 

 mandibles of the adult are very small and but slightly 

 chitinized. 



The Mouth-Parts of the Psocid^e. 



(Plate lxiv, figs. 5-1 1.) 



The mouth-parts of the Psocidae present a modified or 

 specialized type of biting mouth-parts. They have been 

 the subject of some study and some dispute, and perhaps 

 are not yet fully understood. An especially confusing 

 feature is the presence of the "forks," and characteris- 

 tic and little understood organs are the paired "lingual 

 glands" lying "within the tongue." The best paper on 

 the Psocid mouth-parts is one by Edward Burgess,* in 

 which special attention is given the forks and the lingual 

 glands. 



* Burgess, Edward. The Anatomy of the Head, and the Structure of the 

 Maxilla? in the Psocidre. Proc. Bost. Soc. Nat. Hist., 1878, vol. xix, p. 

 •291, pi. viii. 



