BY R. J. TILLVAHD. 285 



close students of the Order, and with a host of striking facts 

 now available to support them. As an example of the trend of 

 the most advanced opinion on the subject, we may cite Hand- 

 lirsch,* who not only makes out a strong case for their close 

 relationship with the Trichoptera, Lepidoptera, and Diptera, but 

 would even derive each of these three Orders separately from 

 the older Mecoptera ! This relationship is signalised by him in 

 the elevation of the group comprising these four Orders into a 

 Sub-Class, Panorpoidea. How^ far this is justified is a question 

 that I hope to go into in detail in a future paper. Very weighty 

 arguments would have to be brought forward in order to dis- 

 prove the extremely strong case set out by Handlirsch. In any 

 case, whether one accepts the Sub-Class Panorpoidea as valid or 

 not, the separation of the Scorpion-flies into a distinct Order 

 would seem at the present time to rest on absolutely unassailaV)le 

 foundations. 



The Order Mecoptera, though abundant enough in some parts 

 of the world in individuals, is yet a very small one in the number 

 of its genera and species. Esben- Petersen, in his synonymic 

 list published in 1915,t gives a total of three families, fifteen 

 genera, and one hundred and sixty- two species. As most of the 

 species are of moderate size, readily observed and easily caught, 

 it seems unlikely that the world contains more than two hundred 

 and fifty, or, at the most, three hundred, representatives of this 

 ancient Order. 



Comparatively scarce as they are now, yet the fossil record 

 would lead us to believe that these insects were more abundant 

 in past ages. Quite a number of fossil wings, of which the well- 

 known Orthophlehia may be cited as an example, are now con- 

 sidered to 1)6 Mecopterous. They are found chiefly in the Liassic 

 and Jurassic strata. Recently :j: I have described awing belong- 

 ing to this Order from the Triassic beds of Ipswich, Queensland, 



* "Die Fossilen Insekten," pp. 1252-1271. 



■\ "A Synonymic List of the Order Mecoptera." Entom. Meddelelser, 

 10 Bind, o Hefte, 1915, pp. 2 16-242. 



:J: Queensland (ieol. Survey, 1916. Publication No. 253, p.29 (il/esocAjQ- 



rista pi^oavita). 



22 



