86 Cincinnati Society of Natural History. 



In the fifth stage, the maculated segmeuts are of a deep, smoky 

 hue, to the naked eye almost black, the macuhe also are of a darker 

 color, and the posterioi* line of a new one appears on the 2d segment, , 

 and a new ellipsoid one appears on the eleventh segment. Sixty hours 

 are spent in feeding, and twelve in moulting again, and at the timeotthe 

 moult the larva is 4.164 mm. long, or five times as long as it was at the 

 end of the first stage. The mine is now so irregular in outline that its 

 area can not be determined accurately, but the same or nearly the same 

 ratio evidently still prevails. The process of moulting is the same 

 as at the preceding moult, but the result is a creature of very different 

 form. "Ring by ring, and organ b}' organ is still withdrawn from the 

 corresponding parts of the old skin, but the new organs so withdrawn, 

 are now very different from the old, as ma}- be seen b^^ comparing figs. 

 1 and 3. (In the latter the labium and maxillae are seen protruded to 

 their full extent; they are capable of retraction so as to be no larger than 

 the other organs, as shown in fig 4.) In the 5th stage, the mandibles are 

 multidentate and formed for feeding. In the 6th they consist each of 

 onl}^ a single small tooth, and are placed so wide apart that the}' can 

 not be used for biting food. The maxilloe present a totall}' different 

 appearance (fig. 3 c, arid fig 2 c), as do also the labium and its palpi 

 fig, 3 a and y^ and fig. 2 a and h. Indeed no labial palpi have here- 

 tofore been observed. 



The spinneret (figs. 2 and 3/) appears now to be fully developed; 

 nevertheless, it still does not perform its functions. The mandibles and 

 maxillse, as stated, have changed greatly in form, and there are now 

 no organs of mastication, but none are needed, for the larva eats no 

 more. It has finished feeding in its fifth stage, and its sixth and 

 seventh stnges are stages of developmental growth. During the pre- 

 ceding stages the oil globules have been nearly all consumed at each 

 moult, but there has been a small residium left at each, and the quan- 

 tity of the residium has increased at each moult. After the fifth moult 

 the quantity is large, the larva in its sixth and seventh stages being 

 largely composed of them. The form of the body undergoes but little 

 change in tlie first five stages, only becoming a little thickened verti- 

 cally. It is still a " flat*' larva. In the fifth moult the larva thickens 

 still more vertically; and in the sixth stage, though still depressed, can 

 not be called flat. The feet are still as they were in the preceding 

 stages. The maculte and the smoky hue, however, have entirely dis- 

 appeared, and the larva is white, with an orange spot in each side of 

 the anterior margin of the first thoracic segment, produced by a collec- 

 tion of yellow oil globules. As the larva does not eat, of course 



