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individuals, though always longer than the other dorsal spines. In 

 one specimen examined these were observed to be about one-third 

 longer than the vasiform orifice, representing about the maximum 

 length. 



Eight abdominal segments are evident from above, except on 

 the extreme sides ; that which appears to represent the ninth seg- 

 ment is much modified by the vasiform orifice being much narrowed 

 posteriorly and somewhat flask-shaped in outline. This portion of 

 the dorsum is much more clearly defined than in previous instars. 

 The vasiform orifice (Plate III, Fig. 13) is similar in form to that of 

 the previous instar. The chitinous ridges which bound it laterally 

 appear to meet posteriorly, with a rounded chitinous thickening at 

 the point of union. The operculum is nearly hemi-elliptical in out- 

 line (having the form of an ellipse cut through its shortest axis), 

 reaching from the base of the orifice to a little over one-half of the 

 distance toward the apex. The lingula has one large apical lobe 

 and three pairs of smaller side lobes, and is densely covered with 

 longitudinal rows (about twenty-five) of minute setae. From each 

 side of the apical lobe below arises a spine, which curves slightly up- 

 ward and extends caudad beyond the apex of the orifice, its length 

 being somewhat variable in different individuals, but never more than 

 one-third the greatest width of the vasiform orifice. A second pair, 

 less than one-fifth as long as these, arise, one on each side, between 

 the first and second side lobes. In one instance a side view of a 

 pupa case was obtained with the operculum and lingula extending 

 almost perpendicularly to the dorsum of the case, and the ventral 

 surface of the operculum and the ventral surface of the lingula 

 showed minute setae about the size of those present on the dorsal 

 surface of the lingula. The anterior pair of side lobes of the lingula 

 is frequently hidden by the operculum. A shallow but well marked 

 furrow extends caudad from the apex of the orifice to the margin of 

 the body, where a short cottony tuft of wax almost invariably occurs 

 in full grown pupae. 



The vertical wax fringe is probably homologous to the lateral 

 fringe of the previous instars, and consists of narrow ribbons of wax 

 fused together laterally, which arise from the so-called marginal wax 

 tubes. Above the points determined by C. W. Woodworth* as the 



* Canadian Entomologist, vol. xxxiii, p. 173. 



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