i7 



hatched larva. Spiracle number one is located between and outside 

 of the base of the second and third pairs of legs ; number two be- 

 tween the base of the second and third pairs of legs; number three 

 a little behind the base of the third pair of legs, and number four a 

 little behind the ventral spines in the caudal region. 



The length of the body in this instar varies from .26 to .30 mm.; 

 average length about .28 mm.; the greatest width from .121 to 

 .165 mm.; average greatest width about .16 mm. 



Second Instar. (Plate II, Figs. 6, 7 and 8; Plate III, Fig. 10.) 



In this stage the outline is more variable than in the first, vary- 

 ing from broadly oval to elliptical, usually with a slight inward curve 

 on each side of the thoracic region. The margin is finely crenulate, 

 but there is no well marked marginal rim as in the first instar. Im- 

 mediately after moulting, the body is flat and thin, but before the 

 next moult it becomes well rounded above. Three pairs of marginal 

 spines are present. The first pair is on the cephalic margin, one on 

 each side ; the second pair on the caudo-lateral region, one on each 

 side, and the third pair on the caudal margin. These probably rep- 

 resent spines numbers one, sixteen and eighteen respectively, of the 

 first instar. The third pair is a little more than one-tenth the length 

 of the body, the second pair is a little more than one-third the length 

 of the third pair, and the first pair is very minute, sometimes appar- 

 ently lacking. The first and second pairs usually become obscured 

 soon after the ecdysis by the lateral wax fringe, which, however, 

 never extends much beyond the basal half of the third pair. There 

 are three pairs of dorsal spines ; the first pair is on the cephalic 

 region, as in the previous instar ; the second pair is on the first ab- 

 dominal segment, one on each side ; and the third pair is near the 

 vasiform orifice, one on each side, opposite the operculum. Of these 

 spines, the second pair is invariably minute, as in the first instar, 

 but the first and third pairs, while very variable in different indi- 

 viduals, are developed to a much greater degree than in the preced- 

 ing instar, being sometimes as much as one-fourth longer than the 

 spines on the caudal margin, or they may be but one-fourth as long 

 as these spines. The variation in length of the two pairs of spines 

 is apparently independent ; in one specimen the first may be more 

 or less longer than the third pair, while in another the third may be 



