BY R. J. TILLVARt). 193 



33° for the hindwing. Hence we must conclude, from the com- 

 bined evidence of both Sc and Cuj, that No. 106a represents a 

 hiitd?vi)i(j, No. 120</. a foreiclny. 



Unfortunately, not quite enough of the main stem of >] is 

 preserved to enable us to say definitely with what vein it tends 

 to fuse basally. But, as the condition stated above in (2) is 

 universally present in Panorpid wings (even in the archaic 

 Merojje, which has been claimed, with good reason, to be a 

 Palaeozoic remnant), there is no reason to suppose that the same 

 rule did not hold for our fossil wings. Thus, in the restoration 

 of these wings given in Plate ix., I have correlated character (2) 

 with (1) and (3), so that fore- and hindwings are to be distin- 

 guished by three difi'erences, as in recent Mecoptera. 



The Structure and tlairiness of the Wimj-mertibrane. —In tlie 

 figures given of the two wings (Plate viii., figs. 4, 5:. and in their 

 restoration (Plate ix.), I have purposely omitted the finer struc- 

 ture of the wing-membrane, w^iich requires to be studied under 

 a higher power. The structure is not everywhere equally well 

 preserved in all parts of the wing; but a careful search soon 

 reveals a number of places at which, by careful use of oblique 

 light, the remarkable formation of the wing-mem biane can be 

 well studied and interpreted. Such a place is figured in Plate 

 ix., fig. 6, where I have drawn the structures seen upon and 

 above one of the smaller main veins. These may be described 

 as follows : — 



(1) Hairs upan the veius. — Following up any vein under a 

 moderate power, there will be found, at fairly regular intervals, 

 the typical circular-based tubercles which indicate the bases of 

 insertion of original sti^' hairs or bristles upon the veins. A 

 comparison with a cleared and mounted wing of Myrmeleoii 

 shows that these tubercles in Archipanorpa closely resemble those 

 of Myrmeleon in size and position; if anything, those of Archi- 

 panoi'pa are the larger in proportion to the size of the veins, 

 and of the wing as a whole. Thus we see that Archipanorpa 

 had hdiry veins, as in the Planipennia. Pecent Mecoptera also 

 possess these hairs, but they are not usually so large as in 

 Planipennia, and they are generally more abundant and closely 

 set. 



