1930 ] 
The Mecopteron Notiothauma reedi 
97 
apically (see figure by Tillyard, 1926, Proc. Linn. Soc. 
N. S. W., 51, p. 278). In the American Journal of Science, 
11, p. 138, Tillyard, 1926, proposes that the fossil Mecop- 
teron, which he calls “Protomerope,” is ancestral to Merope 
and probably also to Notiothauma, but the shape of the 
wing of “Protomerope” is different from that of Notio- 
thauma, the anals are not as primitive as those of Notio- 
thauma, the first branch of Cu (i. e., Cui) is not forked as 
in Notiothauma (which is a very primitive feature in 
Notiothauma) ; and many other features prevent our de- 
riving Notiothauma from “Protomerope,” which is more 
specialized in these respects than Notiothauma is. Under 
these conditions all that can be said of the hypothetical 
“Protonotiothaumidse” ancestral to the Notiothaumidse and 
Meropidse, is that they were Protomecoptera, in which sub- 
order the superfamily Meropoidea, including the Meropidse 
and Notiothaumidse, belongs. 
The family Choristidse (superfamily Choristoidea) , which 
occupies a position at the base of the suborder Eumecop- 
tera, may be descended from the fossil Permopanorpidse, 
but the Choristidse themselves, are so primitive in many 
respects, that they probably arose from forms more primi- 
tive than the Permopanorpidse, and of a type almost as 
primitive as the ancestors of the Notiothaumidae. 
The Nannochoristidse (superfamily Nannochoristoidea) 
possibly descended from the fossil Mesochoristidse. There 
are several features, however, which suggest that the 
Nannochoristidse and Panorpodidse ( Panorpodes ) may have 
descended from ancestors resembling those of the fossil 
Mesopanorpidse, and the shortened head in Nannochorista 
and Panorpodes may be a feature of some phylogenetic 
significance. 
The Panorpidse (superfamily Panorpoidea) were proba- 
bly descended from the fossil Orthophlebiidse. The Boreidse 
(superfamily Boreoidea) were apparently descended from 
ancestors like the Panorpidse. The Boreidse, however, have 
an entirely different type of terminal abdominal structures 
(in both males and females) from those of the Panorpidse, 
and the Boreidse have become so extremely specialized that 
they might be placed in a distinct suborder, the Neomecop- 
tera, distinct from the Eumecoptera, mentioned above. 
