L4 



arch terminus (Fig. 17). Posteriorly BMA is fused with BMP. This fusion may be 

 incomplete (Figs. 13a, 18) or complete (Fig. 13b). Distally BMA is primitively continuous 

 with MA. 



BMP is a rectangular sclerite, which narrows proximally and broadens distally (Fig. 13a). 

 It is composed of a postero-proximal section, which lies posterior of BMA, and a distal 

 section, which lies distal to BMA. The distal margin is continuous with MP and gives rise 

 to one, or rarely two, tube-like braces, depending on the taxon concerned. These braces 

 extend from BMP and fuse with either the base of BCuA or with CuA. They are termed 

 the BMP-BCuA brace (Figs.3b, 13a, 19) and the BMP-CuA brace (Fig. 13b) respectively. 

 Browne ( 1 99 lb:223) incorrectly termed these braces the bmal+bmpl-BCuA brace and the 

 bmal+bmpl-CuA brace having erroneously concluded that BMA also shared in the 

 formation of the brace with BMP. BCuA is either adjacent to or fused with BCuP (Figs. 3b, 

 13b). The fusion can be deep and broad or secondarily reduced as a distal concavity, 

 termed the distal embayment (Fig. 13b). 



Basalare (BAS). 



The basalare is composed of a head, neck, and tail. It is not strictly part of the dorsal 

 wing articulation but it serves an important function in the depression and elevation of 

 the wing. 



The head is clavate and bi-lobed, and articulates with HP and BScP. The proximal lobe 

 articulates with the eyelet formed by HP ventrally and is termed the HP lobe (Fig. 14). 

 When the wing is closed, the distal lobe fits in an eyelet between the postero-ventral 

 margin of HP and the antero-ventral margin of BScA. When the wing is extended the 

 distal lobe articulates with BScP and is termed the BScP lobe (Fig. 14). 



Anteriorly the neck separates the two lobes and posteriorly it extends ventrad as a long 

 tube-like structure which terminates at the tail. The tail is embedded in the proximal margin 

 of the tergum, anterior of the posterior wing process (see Fig. 72 in Kukalovä-Peck & 

 Lawrence 1993:245). It is broad and scaphoid. 



Additional Structures. 



The subcostal and radial proxalaria (PRSc + PRR) are fused together (Fig. 2b). Their 

 proximal margins are fused to the tergum while their distal margins are stiffly hinged to 

 the proximal margin of lAx. 



The cubital, anal and jugal proxalaria (PRCu, PRA, PRJ) are also fused to the tergum 

 (Fig. 2b). PRCu medially extends distad as a projection termed the medial extension. It 

 can be of variable length and is associated with the proximal margin of the detached AXCu 

 fragment of 3Ax. 



PRA and PRJ are fused together and the antero-distal margin articulates weakly with the 

 proximal margin of the 3Ax tail (Fig. 2b). The ventral side of the postero-distal margin is 

 stiffly connected to 2 Ax by a very strong strip of membrane. Ventrally it is connected to 

 the subalare which is attached to the M79 muscle. Posteriorly the subalare is connected 

 to the the lateral process of the epimeron by the short M70 muscle. 



