XIl] 



COCKROACH 



235 



ground on which the creature moves and now waving aloft as if 



testing the air. 



The mouth is on the lower edge of the head and is covered in 



front by a small movable flap called the labrum or upper lip. 



At the sides it is protected by the first and the second pairs of 



appendages, and behind by the fused third pair which form a plate 



called the labium, which completes the boundaries of the mouth 



behind (Fig. 98, C). 



If the first pair of mouth-appendages or mandibles be removed 

 from the head and examined through a lens, each is 

 seen to be a single-jointed stout jaw with a toothed 

 inner edge which bites against the corresponding part 



of its fellow. It is characteristic of the mandibles of all Antennata 



Mouth 

 appendages. 



A B C 



FIG. 98. Mouth-appendages of Stylopyga. Magnified. 



A. Mandible. B. 1st maxilla. 1. Cardo. 2. Stipes. 3. Lacinia. 



4. Galea. 5. Palp. C. Eight and left 2nd maxillae fused to form 



the labium. 1. Submentum. 2. Meutum. 3. Ligula, corresponding 



to the lacinia. 4. Paraglossa, corresponding to the galea. 5. Palp. 



to have no palp or remnant of the distal joints of the limb, such as 

 is almost universally present in Crustacea. 



Behind the mandibles and like them situated on each side of 

 the mouth, are the first maxillae. Each consists of a number of 

 joints and each joint has a special name. Like the typical 

 gnathite of other Arthropods we may regard them as consisting 

 of a limb-like appendage with out-growths from the basal joints 

 biting against corresponding processes gnathobases of the 

 fellow appendage. There are two of these gnathobases, the hard 

 pointed lacinia and an outer portion, the softer gale a (4, Fig. 98, B). 

 The lowest joints termed the car do and the stipes form an 



