[March 
86 Psyche 
Mecopteron as Noliothauma (with its many cellules) from 
Protoblattoid ancestors. 
In both the fore and hind wings of Notiothauma, there is 
a postero-basal lobe, or jugalula, labelled a in Figs. 1 and 2, 
which is called the alula in Coleoptera, etc., but the term 
alula was long ago used by Osten-Sacken, 1896 (Berlin Ent. 
Zeit., 41, p. 285) to designate an entirely different struc- 
ture, namely the anal lobe of the Dipterous wing (i. e., the 
lobe distal to the calypteres) ; and it is preferable to refer 
to the jugalular lobe as the jugalula, since it is homologous 
with the jugalula of the roach. Esben-Petersen, 1921 (Me- 
coptera in Coll. Zool. Selys Longchamps) calls these jugal- 
ulse the “clavi” in Notiothauma, but the clavus is an en- 
tirely different region, homologous with the anal region 
presently to be described, and there is no excuse for apply- 
ing the term clavus to any structure other than the region 
homologous with the clavus of the Hemiptera. The juga- 
lula a is bordered by a fringe of hairs labelled af in Figs. 1 
and 2, and when the jugalula a of the fore wing (Fig. 1) 
is folded forward under the fore wing, it engages the bris- 
tles labelled bsc in Fig. 2 of the hind wing, thus serving as 
a primitive type of jugum. In my specimens, the jugalula 
was folded forward, and it was very difficult to make out 
its structure in the mounted wings. 
The basicostal bristles bcs of Figs. 1 and 2, are borne on 
a thickened, antero-basal, marginal structure in both 
wings; and these bristles in the hind wing are apparently 
the forerunners of the frenulum of higher insects, although 
they can hardly be called a frenulum on the fore wing. 
These bristles are unusually stout and long, and belong to 
the type of bristle which may be called dinotrichia, or 
powerful bristles, such as those occurring on the veins, etc., 
at the base of the fore wings (Fig. 7) or on the thorax, etc., 
Macrotrichia occur on the costal margin of the wings in 
the neighborhood of the humeral veinlet h of Figs. 1 and 
2, and gradually become smaller toward the middle of the 
wing, (they are not drawn in this region of the wing in 
Figs. 1 and 2). The “dinotrichia” occurring on some of the 
veins in the basal region of the fore wing are shown in 
Fig. 7, and the sockets or pits, which are left when such 
bristles are broken off, are shown in the figure. Macro- 
