13 



Dorsal view (Figs. 3, 10-11, 17): HP distally is continuous with PC and C and folds posteri- 

 orly along its whole length (Figs. 3b, 10-11). The membranous gap between HP and BScA 

 + ScA can be of varying width (compare Fig. 10 with Fig. 11). 



BScA is usually deltoid and separated into a proximal section and a distal section (Figs. 10- 

 11). The postero-proximal and posterior margins of BScA articulate with the lAx head 

 via deep grooves and convexities mediated by tough membranous strips (Fig. 3). Two 

 convexities separated by a narrow groove are located proximally and a very deep concavity 

 extends along the posterior margin of BScA. 



The ScA bulge lies distal to BScA and is partially separated from the latter by a concavity 

 of varying width and depth (compare Fig. 3b with Fig. 11). Posteriorly, the ScA bulge is 

 adjacent to, and may be fused with, the anterior margin of BR. In some taxa a small 

 convexity, an extension of the postero-proximal margin of the ScA bulge, overlaps the 

 antero-distal margin of BR. This is termed the ScA-BRP brace (found only in Geotrupidae). 



BRP is an arch-shaped structure curving anteriorly (Figs. 3, 10, 13). The proximal and 

 distal sections are termed the proximal arch and distal arch (Fig. 13). Medially BRP forms 

 a membranous embayment (Fig. 13). If the embayment is wider anteriorly than posteriorly, 

 then BRP is termed closed (Fig. 13b). If not then BRP is termed open (Fig. 13a). The 

 proximal arch is usually secondarily divided into a large main arch and a small, proximal 

 sub-arch termed brp (Fig. 13a). The posterior margins of both brp and the proximal arch 

 articulate with FR (Fig. 3). Anteriorly, brp gives rise to a long extension which fuses with 

 the posterior margin of BScA, forming part of the concavity which articulates with FSc2 

 (Fig. 3b). This extension is termed the brp projection (Fig. 13a). Distally, the distal arch 

 gives rise to, and is fused with, RP (Figs. 3b, 13). 



Anterior view (Fig. 12): HP is a slender structure which is usually clavate proximally and 

 slender apically. The apex is continuous with PC and C (Fig. 3b). The proximal section of 

 HP folds dorsally and ventrally. 



Ventral view (Fig. 15): HP forms an eyelet which surrounds the small, proximal section of 

 the basalare (see Fig. 72 in Kukalovä-Peck & Lawrence 1993:245). This junction is 

 strengthened by a short section of tough membrane. 



BScP (Fig. 15) is a polished, smooth, usually deltoid structure which articulates with the 

 distal section of the basalare when the wing is extended. No membrane mediates this 

 junction. Distally BScP is continuous with ScP. 



Second Basal Plate (2BP). 



The second basal plate is a large central plate composed of the anterior and posterior 

 medial basivenale, the anterior and posterior cubital basivenale and the base of the cubitus 

 anterior vein (BMA + BMP + BCuA + BCuP + CuA) (Figs.3b, 13). 2BP is articulated to 

 MED and 3Ax (Fig.3). 



BMA has a similar shape to BR, an arch-shaped structure curving posteriorly (Fig. 13a). 

 It too is separated into a proximal arch and a distal arch (Fig. 13b). The posterior margins 

 of the BRP arches meet, but do not fuse with, the anterior margins of the BMA arches 

 (Fig. 13b). The BMA proximal arch is often extended ventrad below the BRP proximal 



