JOURNAL OF ENTOMOLOGY AND ZOOLOGY 49 
with the spiracle and with a large sac opposite and the arrange- 
ment of the smaller sacs is as shown in Fig. 1, C. 
Along each side is a large tube-like trachea which is con- 
nected with six spiracles as shown in Fig. 1, B, and also in 
eNrkes, Ay 1B} 
In the ventral part of the abdominal region there are also 
variations. In some there are five pairs of air sacs, not so wide 
and more elongated than the smaller sacs of the dorsal region, 
and uniformly arranged. These are connected with each other 
and with the trachea which runs along the side, being attached 
to the outside of the tube at the point where the branches go to 
the spiracles. Some of these air sacs are attached to the one 
posterior by smaller tubes as shown in Fig. 2, A. The branches 
at the caudal end of the long tracheal tube pass in to the 
internal organs. 
Fig. 3 shows a variation from the uniform arrangement al- 
though in this specimen there are also the five main air saes on 
each side but with different connections. It was difficult on 
account of the stiff exo-skeleton to open the insect and lay back 
the body wall without disturbing the natural arrangement of 
the trachee. At first I thought the air sacs as shown in Fig. 
3 were drawn out of position but since examining other speci- 
mens I have concluded that it is a variation. 
In this account there is no description given of numerous 
small branches from the large air sacs which go to various 
parts of the abdominal region. 
(Contribution from the Zoological Laboratory of Pomona College.) 
