30 C. SASAKI. 



assume by farther develüpinent a shape somewhat like that of a too, 

 and, at the same time, they became separated from ench other by a 

 space between them. Also on each side near the posterior margin of 

 the anterior region there arise two tiny tubular processes ( iV. T, /?'^. 

 10 h), which later form the balancer or halter. The three pairs of 

 legs (-/''/. \\ ßg. 11 a) are somewhat increased in length, but tlie 

 bases of the last two pairs are still covered by the lamellar sac-like 

 wings ( PL F, 10 h ). 



On the eighth or ninth day, a large median process is developed 

 from the space between the two top-shaped tubercles in front. This 

 forms the head. Between it and the succeeding portion, a transverse 

 constriction appears, marking out the regions of the head {PL VI, ßg. 

 1 a) and thorax {PI. VI, ßg. 1 h). The head assumes a triangular form 

 being composed of three large lobes — one median ( PL VI, ßg. le) 

 and two lateral ( PL VI, ßg. If ). On the dorsal median portion be- 

 tween these lateral processes, appear three tiny processes (PL VI, 

 ßg. Ig) lying close together, which are the first appearance of the 

 simple eyes. On each side of the base of the mouth-parts ( lU. VI, 

 ßg. 2 a) on the under side of the head arises a small process (7''/. VI, 

 ßg. 2 h), which subsequently forms the marginal ridges of the cavity 

 in which the mouth-parts are inserted. The top-shaped bodies (PL 

 VI, ßg. 1 h ), which were situated on the front edge of the anterior 

 region in the last stage, alter their positions as the head is developed, 

 and are at the junction of the head and thorax. On the ventral side of 

 the thorax, the first pair of legs which were previously close to each 

 other are now separated by a small space, which become occupied by 

 the mouth-parts or proboscis ( .7 V. VI, ßg. 2 a). The membranous 

 flap or alula ( PL VI, ßg. I c) is also formed just below tlie balancer. 



On the 12th day, the pupa (PL VI, ßg. 3 and 4) is colored light 

 yellowish brown, and the three regions of its body attain their 



