285 [Packard. 



it has now become still smaller, and its tergal portion instead of being 

 nearly horizontal, is now much inclined downwards posteriorly. 



The abdomen, though still larger, approaches much nearer the form 

 of the pupal abdomen than before, and the segments are flatter. The 

 second ring has become much contracted, as it is destined to become 

 the "pedicel" or "1st abdominal segment" of descriptive entomology. 

 There is now a differentiation of the elements of the ring. Thus the ter- 

 gites (notum, Fig. 3,/,) are clearly distinguished from the pleurites 

 (Fig. 3, e, flanks.) and urites (L. Duthiers, Fig. 3, f/, ventral side). 

 The spiracles are situated on the upper edge of the pleurites, opening 

 out just under the edge of the tergite. As we go back towards the tip 

 of the abdomen, the tergites, as well as the urites, decrease in width, 

 while the pleural region or pleurites increase in size. It is the pleural 

 portion however which is afterwards to become absorbed, by which 

 the dorsal and ventral portions of the abdomen approximate more 

 intimately, and overlap each other, thus making the tip acute, as in the 

 pupa (Fig. 4), and especially the perfect bee. 



During this time the ovipositor, owing to the diminished size, by 

 absorption, of the parts supporting it, has become gradually more and 

 more retracted, while the entire tip of the abdomen is more acute 

 and incurved. 



THE PUPA STATE. 



In this stage (Fig. 4,) the whole body is shorter, and there is a 

 decided transfer of the bulk of the body towards the head. The head 

 has increased in size, the thorax is one-third larger, while the greatly 

 shortened abdomen is a third shorter than in the preceding stage. 

 At this period the longitudinal axis of the body is less curved than 

 before. The meso-scutellum is now placed just in the middle of the 

 body, when before it was situated at the anterior third. This change 

 also carries the wings far back to the middle of the body, from their 

 previous situation very near the head, and on the anterior third of 

 the body. The limbs are greatly enlarged ; the tarsi of the hind pair 

 now reach near the tip of the abdomen, where before they were simply 

 folded upon the thorax, not reaching to, or resting upon the abdomen. 



Great changes have occurred in the appendages of the head. The 

 clypeus, labrum and mandibles are now exposed to view. The anten- 

 nae have become straightened and greatly elongated, and a corres- 

 ponding change has occurred in the maxilla3 and labium with its 

 palpi, which now reach to the middle of the abdomen, wliile the 

 lingua extends as far as the seventh abdominal segment. This stage, 

 therefore, is characterized by important modifications in the size and 

 position of the extremities and appendages of the head, thorax and 

 abdomen. In the thorax the changes are not especially remarkable. 



