4 INTRODUCTIOX. 



placed between the eyes and the antenna^ and the middle one on 

 the frontal ridge. The frontal ridfje is the central part of the 

 face. It is generally raised, and bounded by a carina on each 

 side. These carinse often curve outwards above each eye, and 

 below the anteunse they may either run parallel as far as the 

 extremity of the lower part of the face (the chipexis) or they may 

 become obsolete below the level of the antennae, or may diverge, 

 leaving a more or less triangular space. The middle of the frontal 

 ridge is often more or less thickly punctured, and is often deeply 

 grooved; sometimes, however, it is Battened throughout, with the 

 carinae scarcely marked. Under each eye there is frequently 

 another straight or oblique canna, the lateral carina. 



[On each side, above the antennal socket and between the eye- 

 and the fastigium, there is a space, generally more or less tri- 

 angular, called the tempera, lateral fovece ov foveola;.^ 



Fis. 3. 



-Moutb parts oi Locust a : (A) labrum ; (B) mandible ; (C) maxilla ; 

 (D) labiimi : a, galea, b, lacinia, d, paraglossa. 



The mandibles are strong, pointed or bifid at the extremity, 

 occasionally with a tooth, or several teeth, on the inner edge. 

 [The maaillcv have a fleshy galea, which more or less wraps 

 round the lacinia ; this latter is curved and bifid, or may have 

 three teeth at the apex. The j)rtZ/9i are of moderate length, with 

 five joints. The labium, which in the MANTiDyi5 is extremel}'^ 

 primitive and shows the maxilla-like structure most distinctlv, 

 is much modified in the AcRiniiDiE, the paraglosm' being greatl"}^ 

 developed and the lirjula much reduced. The intermediate form 

 is seen in Agroecia, one of the Phasgonurid.i;. The lahicd pcdpi 

 are simple, and three-jointed. The labnim is leathery in texture 

 and to a considerable extent shuts in the mouth parts.] 



