210 MESOZOIC INSKCTS OF QUEENSLAND, V., 



off at an angle exceeding 45°, and all are approximately parallel 

 to one another. Thus, a little thought will show us that the 

 condition of these veinlets shown in the fossil is definite proof 

 that the wide costal area existing at the base does not continue 

 further distad, and that the more distal portion is of the narrower 

 Prohemerobiid type. 



Further evidence in the same direction is afforded by the 

 existence in the Ipswich Trias of the Prohemerobiid Protopsy- 

 chopsis venosa Tillyard, described by me in No. 1 of this series 

 (3, p. 178). This fossil is only represented by the apical portion 

 of the wing, which is of true Prohemerobiid type, with narrow 

 costal area. It is not possible, owing lo obvious differences of 

 size, that Protopsychopsis and Archepsychops represent apical and 

 basal portions of the wing of the same species; but it is extremely 

 probable that they are parts of the wings of two closely allied 

 insects, and very unlikely that they represented two distinct 

 families. Indeed, if we were to restore Archepsychops on the 

 supposition that its apical portion resembled that of Protopsy- 

 chopsis, we should obtain a Prohemerobiid wing in its entirety, 

 and there would be no clashing of characters anywhere. 



Turning now to the relationship of Archepsychops to the recent 

 Megapsyc/iops, we see at once that there is not a single character 

 present in the former which is incompatible with its being con- 

 sidered as the direct ancestor of the latter. When we consider 

 how unique Meyapsychops is in its venation, we must see that 

 this is a very remarkable thing. If we add to this, that the 

 differences in size of the two insects, and in the strength and 

 closeness of their veins, are practically negligible, and that 

 Meyapsychops at the present day is only known to inhabit an 

 isolated mountain-top situated some thirty miles from the Ipswich 

 Fossil Beds, we see how strong a case there is for considering 

 the fossil Archepsychops to be the direct ancestor of the recent 

 Meyapsychoj)s. If this be accepted, then it has also been demon- 

 strated that the Psychopsidie, as a family, are the direct de- 

 scendants of the older Prohemerobiidce; the changes required to 

 evolve the one from the other, through the immense period of 

 geological time beginning with the Upper Trias, being really 



