288 



THE PANORPOID COMPLEX, 1. 



it would certainly conduce to clearness, if the adjective jncial 

 were to be employed only in connection with the forewing. As 

 authors who have written upon the Lepidoptera have generally 

 alluded to this part of the hindwing as the shoulder or humerus 

 (a somewhat too general term), there can be little objection in 

 replacing it by the term here proposed. 



(4) The bristles projecting from this area towards the forewing 

 may be called the fremihwi. This term is already in general use 

 in the Lepidoptera, and should now be adopted for ihe homo- 

 logous structures in other Orders, 



p The relationships of these 



four parts to one another, in 

 an ideal archaic coupling-ap- 

 paratus, may be seen from 

 Text-fig. 1, it being under- 

 stood that, owing to the 

 slightly higher level of the 

 Text-fig. 1 . * forewing, the frenulum passes 



beneath the jugal lobe, but the jugal bristles lie above the costa 

 of the hindwing. 



We may now profitabl}^ study the formation of the coupling- 

 apparatus in the wings of the diiierent Orders comprising the 

 Panorpoid Complex. From this discussion, we are compelled to 

 omit the Protomecoptera (in which the bases of the wings have 

 so far not been discovered in the fossils known), and the Aphani- 

 ptera, in which the wings have been lost. 



Order MECOPTERA. (Text-figs. 2-4). 

 This is the only Order extant in which all four parts of the 

 ideal coupling-apparatus can still be recognised. In Text-fig. 2, 

 I have figured the coupling-apparatus from the wings of two 

 very archaic families, found only in Austi-alia. In the family 

 Choristidce (Text-fig. 2a), there is a slightly projecting, but quite 



* Ideal archaic wing-conpling apparatus at bases of wings: //•, frenulum; 

 Fw, forewing; ///, humeral lobe; Hm, hindwing; jh, jugal bristles; ,//, jugal 

 jobe. (Jugal bristles rest above costa of hindwing, but frenular bristles 

 pass beneath jugal lobe of forewing), 



