88 Cincinnati Society of Natural History. 



first do not appear to be difFerent in form from those of the larva. Tn 

 fact, it looks like only the larva in an eighth stage; bnt it is in fact the 

 pupa. It differs onl}' in form from the preceding larval stage by being 

 more cylindrical, slightly constricted behind the thorax, the mandibles 

 are reduced greatly in size; the maxillae are mere small fleshy lobes, 

 similar to the labial palpi, but a little larger; and the labrum and labi- 

 um are also small and membraneous. The antennae at first scarcelj' 

 diflTer from those of the preceding stage. There are no ventral feet, 

 and the thoracic feet are merely fleshy, mamillar3' bulbs; and minute 

 sacks, the rudiments of the wings, may be observed on each side of the 

 thorax. Still the creature looks much more like a larva than it does 

 like the pupa into which it will soon grow. It does not remain long in 

 this condition. The head and its appendages, the antennae and trophi, 

 are slowly retracted ; the eye spots are drawn together (those of each 

 side) under the head, and form the eye of the future imago, and when 

 the head is fully retracted thej^ will be found as far back as the middle 

 of the first thoracic segment of the old skin. The antennae and parts 

 of the trophi grow rapidly. At first they show no sign of articulations. 

 The maxillae grow into two fieshy appendages stretched side by side in 

 front of the head; and the labial palpi appear beside but beneath them, 

 and smaller. The antennae grow more rapidly, turn upon themselves, 

 and finally their vermiform convolutions fill each side of the head of the 

 larval skin. The head at this stage is represented at fig. 4, and if we 

 remove it from the larval skin, and extend the antennae and trophi in 

 front, it will appear as in fig. 5. Whilst these changes have been pro- 

 gressing, the cephalotheca, or head shield of the pupa, has also made its 

 appearance, at first as a white, thickened spot on top of the head, 

 growing then into a triangular form, and gradually extending its apex 

 in front over the entire head. The articulations of the anteuure be- 

 come gradually more distinct, and when these and the trophi have at- 

 tained their full growth, the antennae are graduall}'' uncoiled, and to- 

 gether with the trophi are laid beneath the body, as we find them in the 

 pupa. Wliilst these changes have been progressing, the muscles and 

 other organs of the thorax and abdomen grow rapidly, and the constric- 

 tion between the thorax and abdomen becomes deeper, and the wings 

 also have grown from the minute sacks which I have mentioned into 

 their appropriate size and position in the pupa. 



The pupa is now fully formed, though it is soft and wiiite, and is 

 still contained within the larval skin. It, however, hardens and darkens 

 rapidly, but even after escaping from the larval skin is still pale and 

 tender. The cephalotheca is produced as a curved acute point in front, 



