*3 



.11 mm. Average'measurements of twenty eggs from several differ- 

 ent females gave : Length, .209 mm. ; greatest transverse diameter, 

 .0901 mm. 



First Instar. (Plate II, Figs. 3, 4 and 5. Plate III, Fig. 9.) 



In the first instar, the insect is oval in general form, the anterior 

 end being the more broadly rounded, the sides of the thoracic region 

 being approximately parallel and the abdomen narrowing posteriorly. 

 A longitudinal rounded dorsal ridge about one-third as wide as the 

 body, runs nearly the entire length. On each side of this ridge is a 

 flattened area considerably thicker than the narrow, thin rim which 

 surrounds the whole. The change in thickness of the body at the 

 inner edge of the thin marginal rim is quite abrupt. The dorsal 

 surface of the body also shows irregular elevations, depressions and 

 sutures, the latter more or less distinct, marking the thoracic and ab- 

 dominal divisions. Except in specimens mounted in balsam, these 

 divisions do not appear to cross the thin marginal rim. The body 

 as a whole is quite thin at first, but before the first moult takes 

 place it becomes well rounded above, the dorsal ridge disappearing 

 at the same time. From the under side of the thin marginal rim 

 many minute glistening granules may be seen, which appear to be 

 arranged in rows. The margin of the body is entire, except for the 

 attachment of the spines. Eighteen spines arise on or near the mar- 

 gin of the body on each side, and all except numbers two and sixteen, 

 counting from the anterior end, arise from the extreme margin. 

 Number two arises on the under side of the thin marginal rim a little 

 behind number one. Number sixteen arises just inside the margin 

 on the ventral side, a little nearer number seventeen than fifteen. 

 The distances between the base of numbers three and four and four 

 and five are about equal, and greater than between any other adja- 

 cent spines. Except numbers two, four and sixteen, the spines are 

 situated at nearly regular intervals. Numbers one, three and four 

 are horizontal and curved anteriorly ; number two is directed down- 

 ward and curves inwardly. The remaining spines are horizontal, 

 and excepting numbers sixteen and eighteen curve posteriorly. Num- 

 ber sixteen curves outward and downward, and number eighteen, in 

 respect to its mate, diverges at the base and converges outwardly, 

 the extreme tip being extremely slender and inconstant in position. 



