66 



mentum in the head of the locust. The gula is usually a 

 well developed sclerite among beetles. The sutures separat- 

 ing it on either side from the contiguous portions of occiput 

 and epicranium (postgena) are called the gular sutures. 



Make a drawing of the ventral aspect of the head, show- 

 ing the skeletal parts described, and also what may be seen 

 of the mouth-parts in situ. 



THE APPENDAGES OF THE HEAD. 



Antennae. — T\\t antenncB are filiform, and ii-segmented ; 

 the third segment is the longest one. The proximal three 

 segments are glabrous, and the second and third bear each 

 two or three longish hairs near their distal end. The re- 

 maining eight segments are finely pubescent. In addition 

 each of these eight bears a few longer hairs at its distal end. 



Mouth-Parts. 



The mouth-parts are fitted for biting and are in general 

 similar to the mouth-parts of the locust. 



Labrum The labrum has been described already as a 



part of the skull. 



Mandibles. — The fnandibles are rather long, and taper 

 distad to a sharp, curving tooth. They bear on their sharp, 

 cutting, inner margin, near the base, a few, small, blunt 

 teeth, and their outer face presents a broad, shallow groove 

 or furrow called the mandibular scrobe. Make a drawing of a 

 mandible. 



Maxillae. — The maxillce differ especially from those of 

 the locust by the presence of an additional sclerite, the sub- 

 galea, by the side of the stipes, as if the stipes were divided 

 by a longitudinal suture. The cardo is large, and broadly 

 club-shaped ; the median portion of the maxilla is composed 

 of three sclerites, the stipes, palpifer and subgalea. These 



