1930 ] 
The Mecopteron Notiothauma reedi 
87 
trichia occur on the ventral surface of the basicostal 
structure labelled he in Fig. 4, and on the ventral surface 
of the humeral veinlet h of Fig. 4; and a row of macrotri- 
chia occurs on the ventral surface of the subcostal vein 
shown in Fig. 4. This row of macrotrichia may aid in hold- 
ing the wings in place in repose. 
Forbes, 1924 (Ent. News, 35, p. 232) in describing the 
nygmata of Holometabolous insects, states that in “Merope 
and apparently Notiothauma nygmata are absent,” but I 
find in the basal costal cell, for example, what appears to 
be the homologue of a nygma, similarly located to that 
of Panorpodes (see n of Fig. 7), and nygmata are thus 
apparently present in the fore wings of Notiothauma , 
although I have not examined Merope to determine if they 
are present in this insect also. 
The venation of the hind wings is quite easily homo- 
logized, but the tangle of cellules in the distal portion of 
the fore wings makes it extremely difficult to trace the 
course of the veins in this region of the fore wings, so that 
the course of the distal portions of such veins as the second, 
third and fourth branches of Media is merely suggested, 
although the basal portions of these veins are quite easily 
homologized. 
The fore wing has preserved a suggestion of a humeral 
lobe in the curved contour of the basal portion of the wing 
just anterior to the label h in Fig. 1 (which is a Proto- 
blattoid or Protorthopteroid feature) and the costal vein 
has become interrupted just basad of the humeral veinlet h 
of Fig. 1. The detached basal portion of the vein becomes 
broadened (to accommodate the large bristles bsc) and 
forms a structure homologous with the sclerite called the 
basicosta in the roach, Mantids, Trichoptera, Cicadas, etc. 
(Psyche, 34, p. 59, and Bull. Brooklyn Ent. Soc., 23, p. 
113). The occurrence of such a basicostal sclerite in 
Notiothauma indicates that its fore wing was derived from 
a Blattoid or Protoblattoid prototype rather than from a 
wing of the type occurring in the Archipterygotan insects 
(which have no such sclerite). I find a trace of the basi- 
costal sclerite even in the hind wing of such a highly spe- 
cialized insect as the monarch butterfly Danaus archippus 
(“Anosia plexippus”) in which the costal vein fades out 
