Vol. 1.] Woodwortli.—Wing Veins of Insects. 33 



connected by a feeble cross vein with the fifth, and by a 

 stronger enlarged one with the seventh. This appears to bear 

 the same relation to the posterior condyloid cavity that the 

 vein between the second and third does to the anterior. There 

 may be some connection between the base of this sixth vein 

 and the green tuberosity, or with the black corrugations 

 beneath it, but this is certainly not very evident. 



The seventh vein ends at the base in a tracheoid structure ■ 

 that bends ventrad near the posterior end of the L-shaped 

 portion of the posterior wing-root, and then proceeds dorsad 

 and across the body to meet the corresponding structure from 

 the opposite wing, forming the posterior lioundary of the 

 X-shaped portion of the notum. 



The parts of the body that come in contact with the wings 

 are a little more difficult to compare in the two segments, but 

 in most features associated with the wings there will be no 

 difficulty in recognizing the homologies. 



The closest attachment between the body and wing is where 

 the tissue about the suture between the side pieces is extended 

 upward into a process, which is reinforced by a triangular 

 sclerite bearing articular apophyses (Fig. 11, aa). These scle- 

 rites are evidently chitinizations of the articular membrane 

 above the two pleurites. Their processes are strengthened by 

 a system of rod-like, cuticular thickenings, as shown in Fig. 

 11, B. The lower lamina of the wing is continuous, as a soft 

 flexible membrane, with the ends of these pleural processes. 



Dorsally the posterior wing-root (Fig. 12) is opposite the 

 X-shaped portion of the notum, which is evidently composed 

 of the scutellum and postscutellum, the hard parts of which 

 meet only at the middle and diverge laterally. with a rather 

 delicate membrane between. The postscutellum is for the 

 most part tubular; and it is tracheate and directly continuous, 

 as already described, with the end of the seventh vein. The 

 ends of the scutellum project rather deeply into the body and 

 approach closely to the deeper portion of the end of the hinge 

 piece lying between the anterior wing-root and the scutum. As 

 seen from within (Fig. 11, B) the end of the scutellum is found 

 to be continuous with the longitudinal support of the muscle 

 disk to which the elevator muscle is attached. The scutum 

 has a broad, rather smooth surface, which in the vicinity of 

 the wing dips deeply into the body and there expands into 

 muscle disk. 

 3— V 



