EXTERNAL CHARACTERS. 



163 



2. 



e. The eyes are large black reniform elevations, one 



on each side of the head. They are compound, 

 each having very numerous hexagonal facets. 



f. The fenestrae are a pair of small white oval patches 



to the inner sides of the bases of the antennae. 



The neck is short and slender : its cuticular covering 



is soft and white, with the exception of seven 



thickened patches or sclerites which are hard and 



brown. Of these sclerites two are slender trans- 



FiG. 36. — Periplaneta Americana. The head, front view, (o. h, h.) 



A, antenna. CL, clypeus. E, eye. P, epicranium. F, feneatia. 

 Gr, galea. GB, gena. L, laoinia. LP, labial palp. JjE, labriim. MIT, 

 mandible (the left mandible has been removed). MP, maxillary palp. M 2, 

 second maxilla. 



Fig. 37.— Periplaneta Americana. The head from behind, (c. h. h.) 



E, BP, Q-. L, LP, MM", and MP, as in tbe preceding figure. 



Ccardo. LG,liguIa. M, mentum. W, nerve-connective. O, oesophagus. 

 PQ-, paragloasa. S, stipes. SD, salivary ducts. SM, submentum. TR, cer- 

 vical tracheae. 



verse bars on the ventral surface ; a third is median 

 and dorsal, and almost divided into two longitudi- 

 nally ; the remaining four are much larger, and 

 form two pairs at the sides of the neck. 

 8. The thorax consists of three segments. 



a. The prothorax is the first and longest segment of 



m2 



