I. TRÄGÅRDH, METAMORPHOSIS AND BIOLOGY OF ORCHESTES. 13 



as long as the are wide at the base. They are more pointed 

 at the top than in O. quercus; and at the top there are 

 narrow oval areas, exactly as in O. quercus, where there are 

 no cutioular teeth, and a fine träns verse cuticular fold runs 

 across. The lOth segment, the pygidium, is verv small and 

 conical, as long as it is wide at the base. 



2. The pupa. 



The pupa is of a white colour. It has some character- 

 istic hairs and bristles, as the pupse of the other two species. 



On the rostrum there are 3 pairs of small brown-coloured, 

 perpendicular bristles, arranged in two longitudinal rows in 

 the basal -/s and almost equidistant; but there is no 4th 

 pair, as in O. populi. 



Fig. 4. Top of abdomen, pupa of O. fagi, ventral view. X 75. 



At the top of the vertex there are two pairs in a trans- 

 verse row, close together; of these the median pair is inser- 

 ted on low, brown-coloured tubercles and curved down- 

 wards; the other pair is only V^ as large as the median one. 

 On the dorsal side of the prothorax, near the anterior margin, 

 there is another pair, whioh however, is not very conspicuous. 



The abdomen (Textfig. 5). Topographically, on dorsal 

 view, only 8 segments are distinguishable, the terminal one 

 of which projeots in a narrow appendage, bipartite at the 

 top and provided with a pair of dark coloured bristles. 

 But, as in O. populi we notice, on closer examination, on 

 the ventral side, the small 9th and lOth segments telescoped 

 in the 8th ; on the dorsal side they both bear a pair of small 

 lateral processi. 



