42 



Medial Basivenalia moderately reduced on all margins; narrow and long; rectangular but 

 narrowing proximally. Anterior and posterior margins concave. BMA narrow; completely 

 fused to BMP. Proximal and medial surfaces flat. Distal surface convex. Anterior margin 

 concave. Proximal arch broadly deltoid; planate; enlarged antero-proximally. Distal arch 

 distinct; very long; slender; convex. BMP junction with BMA discontinuous and very 

 broad; rectangular; very weakly separated from BMA by a shallow concavity; flat; distinct 

 from brace; separated from IBP and BCu. Postero-median, antero-distal and postero-distal 

 sections indistinguishable from each other. Distal margin strongly elevated above the 

 surrounding membrane. 



Cubital Basivenalia narrowly fused; slender and long. Postero-proximal margin of BCuA 

 fused with the antero-proximal margin of BCuP. Suture line present. BCuA very narrow 

 and long; convex; oriented postero-distad; strongly sclerotized; lies proximal of CuA. 

 BCuP very narrow and long; convex; oriented postero-distad; weakly sclerotized. Distal 

 embay ment narrow but deep. - Cubitus Anterior adjacent to. but discontinuous with, 

 BCuA. Junction separated by a concavity. Base strongly shifted distad. 



Basalare (Fig. 72) 



Head - HP lobe small; continuous with neck. Apex broadly rounded. Dorsal surface 

 elevated from neck; not polished. BScP lobe claviform; projects posteriad from neck. 

 Dorsal surface ovoid; weakly convex; polished; not elevated from neck. Ventral surface 

 polished. - Posterior Subcostal Basivenale broadly deltoid; polished. 



Discussion 



Monophyly of the Bolboceratidae is supported by the fact that all of the taxa in this family 

 share the following 12 apomorphic character states of the wing articulation and wing base: 



1. lAx: the ventral surface of the head has a prominent ridge, 



2. the dorsal surface of the head is very strongly oriented ventro-distad, 



3. the neck is extremely short, 



4. the distal embayment is secondarily extremely deep, but very narrow. 



5. posteriorly strengthened by a sclerotized plate; 



6. 2Ax: the anterior margin of the dorso-distal lobe is concave, 



7. the dorsal surface of this lobe is very strongly convex, 



8. the subalare tendon attachment point is very short, very broad, and apically shallowly 

 and narrowly concave; 



9. 3Ax: the posterior section of the head is enlarged dorsally to form an arm. which is 

 proximally continuous with the neck: 



10. 2BP: the postero-distal section of BMP is continuous with the BMP-CuA brace. 



11. the latter is very strongly convex, broad and oriented more strongly distad than 

 posteriad. 



12. the base of CuA is shifted distad. 



Bolboceratidae share six apomorphic character states of the wing articulation and wing 

 base with Passalidae. Diphyllostomatidae, Lucanidae. Glaphyridae, Trogidae and Pleoco- 

 midae (Browne & Scholtz 1995). Analysis of wing articulation and wing base characters 



