ODONATA. 81 



beginning to grow out from the mesothorax and meta- 

 thorax, so that the larva is changing to a pupa. The 

 pupal dragon-fly (PL III., Fig. 37, p. 73, pupa of one 

 species of Libellula) is active, but is unlike the adult 

 insect, owing to the watery medium in which it lives. 

 The body, like that of the larva, is broad and flattened 

 on the lower side. The head (Fig. 37, A) PL III., 

 Fig. 2)'^, front view of the same ; PL III., Fig. 39, side 

 view) is not freely movable as compared with that of 

 the adult, as its motion backward is limited by the 

 prothorax ; and if one attempts to turn it, not half a 

 revolution can be made without meeting strong resist- 

 ance. The prothorax (PL III., Fig. 37, //) is still 

 large, distinct, and ring-like. The mesothorax (Fig. 

 37, /^") and metathorax (Fig. 37, ^'") are less closely 

 consoHdated than in the mature fly. The prominent 

 toothed ridges on the abdomen of the imago are in- 

 dicated in the pupa (not represented in Fig. 37, but 

 distinctly seen in Fig. 42, which is a dorsal view of 

 the pupal skin of Libellula tn??iaciilafa 9 , and also in 

 Fig. 43, a side view of the male of the same species). 

 The channel is entirely wanting. The compound eyes 

 (PL III., Figs. 7,^, 39, 40, ey) are prominent ; but in- 

 stead of meeting on the top of the head, they are 

 widely separated, as in the larva, reminding one of 

 the eyes of the Agrionidse. There are two minute 

 oceUi. The antennae (Figs. :^,^, 39, 40, at) are small, 

 as in the adult. The most conspicuous appendage of 

 the head is the mask (wx"), which is the second pair 

 of maxillae modified for seizing food. In Fig. 40 this 

 mask is thrown out, while in Figs, t^^, 39, it is folded 

 over the mouth, entirely concealing the formidable 



