564 The University Science Bulletin. 



The jemale genitalia in the first and second instars (pi. LXII, 

 figs. 1 and 2) are very difficult to distinguish from those of the male. 

 There are two pairs of valves present, but since they are practically 

 of the same color and texture and one pair is placed upon the other, 

 they appear as a single pair and therefore resemble the male. The 

 first pair are small, rounded at the tip and project from the eighth 

 sternite as a caudal extension of the latter. Thus it is clearly evi- 

 dent that they arise from the eighth sternite, whereas in the male 

 the posterior margin of the eighth sternite can be seen to lie on 

 top of the first pair of pockets. This pair of pockets develops into 

 the ventral valves of the adult ovipositor. The second pair of 

 pockets, which produce the dorsal valves of the ovipositor, project 

 from above the first pair and are twice as long as the first pair. 

 Together they occupy about one-half the length of the ninth 

 sternite. 



In the third instar the ventral pockets have increased both in 

 width and length. Here they are more easily seen to be attached to 

 the eighth sternite. The dorsal pockets have become greatly en- 

 larged. They are entirely separated from the ventral pockets, 

 occupying about the center of the ninth sternite. The lateral 

 pockets are present in the third instar for the first time. They lie 

 laterad of the dorsal pockets, are somewhat narrower, although 

 much longer, and curve slightly mesad. They develop into the 

 lateral valves of the adult. 



In the fourth instar the ventral plates are greatly enlarged, so that 

 their apices reach the base of the dorsal valves. The dorsal valves 

 are larger than in the preceding instars, but are still the smallest of 

 the three pairs. The lateral pockets, which are the largest pair of 

 pockets, have their apices projecting much farther caudad than the 

 dorsal valves and their bases reaching cephalad almost to the eighth 

 sternum. 



In the fifth instar the pockets are very prominent. The ventral 

 pockets are broad at the base, extending the entire width of the 

 sternum and taper gradually to narrowly rounded apices. The dorsal 

 valves are somewhat the shape of the ventral and are entirely covered 

 by the latter. Their bases, however, do not reach to the eighth 

 sternum. The lateral pockets are fingerlike structures with their 

 bases partly covered by the ventral valves and are still slightly 

 longer than either of the other two pairs. The genital area is very 

 prominent and has been pushed cephalad until it occupies all the 

 eighth sternum, and even extends into the seventh, where the indica- 



