378 
Psyche 
[December 
rior margin of the mesonotum and converging more or less 
in their course. It is these furrows that have been erro- 
neously identified by some workers as parapsidal furrows 
for years; likewise, the lateral regions delimited by them 
and the true parapsidal furrows have been erroneously 
identified as parapsides. Since the correct term which should 
be applied to these furrows is little known, it may be of 
interest to review briefly the terms that have been applied 
to them, and, also to indicate the term which should have 
priority over the others as determined by its commonly 
accepted and correct usage in the literature. 
Morphologically these furrows which extend backward 
from the anterior margin of the mesonotum a varying dis- 
tance and at a varying angle of convergence have been con- 
sidered to form the lateral limits of the prescutum when 
they converged sufficiently to fuse into a single median line. 
They have been correctly referred to as “prescutal sutures” 
by Crampton, 1926. In such cases as Paraponera (Fig. 5) 
they clearly limit the prescutum, but in many forms like 
Ampulex (Fig. 2) they open out and approximate parallel 
lines. It is obvious in such cases that the prescutum is not 
clearly delimited and that it fuses with the scutum to form 
the general region prescutum plus scutum. 1 Although, as 
just stated, the failure of these furrows to converge and 
fuse makes it impossible to determine the posterior lateral 
limits of the prescutum; their presence, if even of short 
length extending backward from the anterior margin of 
the mesonotum, indicates at once the lateral limits of the 
prescutum in the anterior region. In some forms such as 
Polistes these furrows are absent (Fig. 5) and in a similar 
case it has been assumed by a recent worker that the pre- 
scutum extends laterally to the parapsidal furrows. An 
examination of the immature pupal stages of Polistes re- 
veals the presence of these prescutal sutures which gradu- 
ally disappear as the chitin hardens before attaining the 
adult condition. In at least one species of Polistes 
1 The writer is cognizant of the fact that when the furrows con- 
verge and fuse, Snodgrass, 1926, does not consider the region delim- 
ited by them as the prescutum but as a part of the scutum. The writer 
does not on the basis of the evidence presented accept this view. 
