98 
Mr. A. 8. Packard on the Hymenoptera. 
the thoraco-abdominal ring, or propodeum (c), with its oblong 
spiracle (),- essentially differmg from those on the abdomen. 
At this point the body contracts; but the head and thorax toge- 
ther are yet, as still more in the previous stage, much smaller 
than in the pupa, and there is still a continuous curve from the 
tip of the abdomen to the head. g, antenna; h, lingua and 
maxille and palpi; 2, fore legs; j, middle legs; k, mesoscutum ; 
1, mesoscutellum; m, metascutellum; 7, spiracle of the propodeum. 
Fig. 3. Bombus fervidus. The third stage of the semipupa. The head 
and thorax together now nearly equal in size the abdomen; the 
propodeum (c) has become entirely transferred to the thorax. 
The head has become greatly enlarged; the wings are very un- 
equal, the hinder pair are much smaller, and overlam by the 
anterior pair; the three terminal pairs of abdominal rings, so 
large in fig. 2, have been absorbed, and partially enclosed in the 
cavity of the abdomen; and there has been a further differentia- 
tion of the ring into the sternite (d), pleurite (e), and tergite (f). 
a, eye; h, lingua; 0, ovipositor, two outer rhabdites expused to 
view. The abdominal spiracles in figs. 2 and 3 are repre- 
sented by a row of dots. In the pupa (fig. 4) they are concealed 
by the tergites. 
