380 
Psyche 
[December 
forms such as Xiphydria (Fig. 1) the parapsidal furrows 
extend from the transcutal suture of the mesoscutum to the 
anterior margin of the mesonotum. In forms like Para- 
ponera (Fig. 5) they extend only halfway to the anterior 
margin of the mesonotum. Other gradations may be noted 
by simply examining other forms which always exhibit the 
tendency of the furrows to be lost in the anterior region and 
to be retained in the posterior region of the mesonotum. 
This would seem to indicate that the parapsidal furrows ex- 
tend forward from the posterior region of the mesonotum 
or from the transcutal suture of the mesoscutum a varying 
distance in different forms. Another feature of the parap- 
sidal furrows is that they usually extend forward parallel 
to each other (Figs. 4 and 5) or they diverge (Figs. 1 and 
2) and rarely, if ever, have their terminal points at a posi- 
tion which is convergent from the assumed starting point 
at the transcutal suture. In the form of Polistes (Fig. 3) 
figured in this paper the parapsidal furrows appear to con- 
verge though their terminal points are at a position which 
is divergent from the points of intersection of the parap- 
sidal furrows and the transcutal suture. The distinctive 
characteristics of notauli are to some degree the converse 
of the characteristics of parapsidal furrows. In forms like 
Paraponera (Fig. 5) and Xiphydria (Fig. 1) they converge 
backward from the anterior margin of the mesonotum, and 
fuse to form a median line. In forms like Ampidex they 
extend backward in a course closely approximating parallel 
lines but do not reach to the transcutal suture of the meso- 
scutum. In forms such as Myopopone (Fig. 4) they extend 
but a short distance backward and in Polistes (Fig. 3) they 
are absent. From the above facts the following generaliza- 
tions may be made: notauli apparently extend backward 
from the anterior margin of the mesonotum a varying dis- 
tance and at a varying angle of convergence, occasionally 
approximating parallel lines in their course but rarely, if 
ever, diverging from their assumed starting points at the 
anterior margin of the mesonotum. 
Occasionally in some forms such as Xiphydria (Fig. 1) 
a median line {me of Fig. 1) is present extending longitudi- 
nally along the central region of the mesoscutum. The pres- 
