174 THE COCKROACH. 



To see the stigmata, examine from the ventral surfaces, 

 stretching the abdomen slightly. The stigmata are at the apices, 

 of small backwardly projecting spout-like processes, which lie 

 just beneath the anterior angles of the several terga. 



C. The Appendages. 

 1. The head appendages are four pairs. 



a. The antennae are very long, slender, many-jointed, 



and freely movable filaments, inserted into a 

 pair of oval arthrodial membranes just in front 

 of and below the eyes. 



To see the next three pairs of appendages, fix the animal 

 down on its back by means of a pair of small pins passed through 

 the sides of its prothorax. Bend the ventral part of the head 

 forwards, and fix it in that position by means of crossed pins. 



Examine the appendages in situ, noting their positions. 



Remove the whole of the labium (sm to pg, fig. 39) without 

 injury to the structures beneath it. Mount it in glycerin. 



Similarly remove and mount the right first maxilla and 

 the right mandible. 



b. The mandibles are a pair of stout jaws, strongly 



toothed on their inner margins, and working 

 sideways. They lie immediately below the 

 gense, and articulate with the epicranium and 

 with the clypeus. 



c. The first maxillae are situated behind the mandibles. 



Each consists of the following parts : 



i. The protopodite consists of two segments, the 

 cardo or proximal piece, and the stipes or 

 distal piece. 



ii. The endopodite has two divisions, an inner and 

 an outer. The inner division, or lacinia, is a 

 hard blade pointed at the end, and provided 

 with stiff setae along its inner border. The 

 outer division, or galea, is softer and is elon- 



