LEPIDOPTERA HETEROCERA 
FAM. MICROPTERYGID/E 
by E. MEYRICK 
WITH I COLOURED PLATE 
General Characters. — Head more or less rough-haired; ocelli present. Maxillary palpi 
developed, usually folded. Posterior tibi with four spurs. Forewings with an oblique membranous 
dorsal process (jugum) near base, forming with the dorsal margin a notch or sinus which receives the 
costa of hindwings. Hindwings without frenulum, rc present, with ten or more veins, neuration 
essentially almost or quite identical with that of forewings. 
This family and the Hejialidae constitute together the most primitive group of the Lefidoftera 
( Micropterygina), distinguished from all others by the possession of the jugum for interlocking the wings 
in flight, and by the existence of additional veins in the hindwings which make the neuration practically 
identical with that of the forewings. The two families agree also in having the forewings and hindwings 
more than usually remote at their base, in a tendency to a rather peculiar semi-oval form of wing, with 
the termen and dorsum forming a nearly uniform curve, and in type of markings of forewings, which 
is an irregular marbling or reticulation, tending to form transverse fascie. The Microfterygidae differ 
from the Hefialidae in the possession of maxillary palpi and tibial spurs, absent in the Hefialidae ; they 
are also of much smaller size, this being no doubt primarily due to the difference in larval habits. 
The possession of additional veins, which could not have originated by modification of existing 
characters and are therefore primitive, proves the Microfterygina to be earlier than any other group of 
the Lepidoptera, and on similar considerations the Microfterygidae are earlier in origin than the Hefialidae. 
Further, the more complex (and therefore earlier) genera of Micropterygidae (as Sabatinca) present in 
their scheme of neuration and other essential characters a close resemblance to certain forms of 
Tvichoplera (especially the genus Zyacophila), whilst no other insects of any Order at all nearly approach 
this type, and this may be taken as conclusive evidence that the Micropterygidae originated from the 
Tvichoptera (which taken as a whole is a more primitive group with originally much more complicated 
neuration). and are therefore the ancestral group from which the whole of the Lepidoptera have been 
