Nov., 1902.] Passalus Cornulus. 309 



there is a spindle-shaped area where the veins are separate. The 

 proximal portion of this vein is connected by a transverse chitin- 

 ized bar with the next vein, and from this point is continued as 

 a strongly chitinized bar to the end of which the articular mem- 

 brane lying in front of the wing is attached. 



The subcosta (14) lies just posterior to the costa and is 

 closely fused to it except at the point mentioned above and also 

 at the proximal end where after fusing with the transverse bar 

 connecting it with the costa it projects toward the median line and 

 articulates with a large movable sclerite. The fused costa and 

 subcosta can be traced as far as a transverse articulation of the 

 outer third of the wing. 



The radius (15) is a large vein lying posterior to the sub- 

 costa and extending from the base of the wing to the transverse 

 articulation. At its proximal end it is interrupted by an oval 

 membranous area over which it extends as a narrow bar, and be- 

 yond this enlarges and fuses with the enlarged end of the sub- 

 costa. It also sends posteriorly a small process which articulates 

 with one of the free sclerites. Distally beyond the tranverse articu- 

 lation of the wing these veins are continued as a broad slightly 

 chitinized area. Just posterior to this broad area wdiich forms 

 the anterior margin of the outer third of the wing is a short vein 

 extending from the articulation of the wing. It is the posterior 

 division of the radius. 



The next three veins arise together from an irregular plate 

 formed by the fused and enlarged ends of the veins. The plate 

 articulates with the movable sclerite by a well defined process ex- 

 tending between two non-chitinized areas. The media ( 16.) is the 

 most anterior and the largest of the three. At its base it is in 

 contact on its anterior border with the radius. Distally it separates 

 from the radius and at the transverse articulation turns poster- 

 iorly and reaches the margin of the wing. There is a second short 

 vein lying anterior to the distal end of the medius and reaching 

 from the transverse articulation to the tip of the wing. This is 

 media No. i, the main vein beyond the articulation being media 

 Xo. 2. Posterior to the main branch of the media and within 

 the transverse articulation is a small vein which is probably media 

 No. 3. It does not come quite into contact with the media but 

 arises near it. 



The cubitus (17) is the second of this group and arises pos- 

 terior to the medius and is in contact with it for some distance 

 after which it turns by a gentle curve to the anal margin of the 

 wing. It forms a large triangle in which the third division of the 

 media lies. 



The third (18) and most posterior vein arising from this plate 

 is the first division of the anal vein. It is not in contact with the 



