PLATE iv 



Figure 1. The first maxilla of the cockroach, x 20 

 Figure 2. The mandible of the cockroach, x 20 

 Figure 3. The second maxillae of the cockroach, pgl., 

 paraglossae. x 20. These three figures from Miall 

 and Denny. 



Figure 4. The mouth parts of Haematopotapluv ialis, as displayed 

 by cutting off the upper and anterior part of the head 

 capsule. The blade of the maxilla is omitted on the 

 left side, and the palps are not drawn. The intracranial 

 tunnel of the left side is shown, broken from its 

 attachment to the anterior wall of the head, gy., 

 ginglymus, the joint of the mandible, l.r., a strong 

 flattened rod of chitin, which supports the intracranial 

 tunnel at its base, and compensates for the laxity of 

 the wall in the gular region, g.r., where the chitin is 

 replaced by membrane. The presence of this strong 

 bar is easily recognized in dissection, r., the ridge on 

 which the cardo rests, cu., the cornu of the mandible, 

 to which the strong adductor muscle is attached, oc.r., 

 a ridge of thick chitin surrounding the occipital 

 foramen, x 65. 



