296 StODlKS tX ACStKALIAN MECOPTERA, 1., 



Archaic Characters. 



] . Method of folding the ivings. The high roof-like manner of 

 folding the wings is probably the original manner for the 

 ancestor of all the Panorpoid and Neuropterous (s.str.) groups. 

 It is still retained in the Megaloptera, most of the Planipennia, 

 in many Trichoptera, and in some ancient Lepidoptera, e.g., the 

 Hepiahd(P. 



'1. The presence of a ivmg -coupling apparatus, with frenulum 

 ivell developed. J. have already shown that most Planipennia 

 possess this coupling-arrangement for the wings. As is well 

 known, the majority of Lepidoptera also possess a well-de- 

 veloped frenulum. Now the same structure turns up in the 

 Mecoptera ! Although not before recorded for this Order, its 

 presence in Nannochorista led me to examine carefully the other 

 representatives of the Mecoptera in my collection. In the 

 Choristiiue, I find a definite jugal process present on the hind- 

 wing, with a distinct frenulum of two bristles. On the fore- 

 wing, instead of the single strong jugal bristle of N annocho7nsta , 

 there is a l)unch or pencil of stiif bristles of smaller relative size. 

 A small frenulum is present at the extreme base of the hind wing 

 in Pa7iorpa, also in llarpobtttaciis. 



Two important conclusions follow from this : — 



a That the equality and independence in flight of fore- 

 and hind wings in recent Mecoptera, such as Bitfacus, is not 

 primitive^ as Handlirsch supposed, but a secondary development 

 from an original condition in which the wings acted together in 

 flight, the connection being made by means of the frenulum and 

 jugal lobe. 



6. That the frenulum is an archaic structure which was 

 present in the ancestral form of the Panorpoid Orders, and con- 

 sequently the main stem of the Lepidoptera must be the Frenatce^ 

 with the Jugata) as an archaic side-bi'anch ivith specialised wing- 

 connection. I shall have more to say upon this in a future 

 paper, when dealing with the origin of the Lepidoptera. 



3. The probable aquatic or semi-aquatic life-history. — Much 

 evidence can be brought forward to show that the ancestors of 



