INJURIOUS INSECTS. 259 



honey-yellow, their pedicels with a strong notch in the middle of 

 their anterior sides. 



The' ABDOMEN throughout is of an orange color, more inclining to 

 red than to yellow. Its broadest part scarcely equals the thorax in 

 diameter. Tt is of an ovate form, attenuated towards its tip, whence 

 the two valvular sheaths of the ovipositor are often seen more or less 

 cxserted, and sometimes the apex of the ovipositor itself projecting 

 between them like a fine slender thread. According to Mr. Curtis, 

 by a slight pressure on the abdomen of the living insect, the ovi- 

 positor ( Plate 5, fig./) can be made to protrude, and may then 

 be drawn out to nearly thrice the length of the body. 



The WINGS are hyaline and colorless, appearing like thin plates 

 of glass or mica, but reflecting the tints of the rainbow, particularly 

 the violet, when viewed in certain directions. Their margins are 

 densely ciliated with longish hairs, and their surface is covered with 

 minute pubescence. The mediastinal or submarginal nerve is but 

 shghtly distant from the costal (marginal), and becomes confluent 

 with it rather forward of the middle of llie exterior margin. From 

 its middle, it sends a small connecting nerve backward to the post- 

 costal. The postcostal, which is the most conspicuous nervure of 

 the wing, runs direct, or with but an insensible curve, to the tip of 

 the wing. The medial is straight, and attains the inner margin at 

 about three-fourths of the distance from the base to the apex of the 

 wing. The anal runs nearly parallel with the inner margin, and, with 

 a very sudden curve from its direct course, joins the margin near 

 its middle. It gives off an obscure branch at its angle, which curves 

 Dutwards and backwards, joining the medial, or rather, seeming 

 if the wing be moved so as to give a slightly different incidence 

 ;o the light) to be continued onward, parallel with and contiguous 

 the medial nerve, till it attains the margin of the wing. The me- 

 iial and anal nerves are very slender, and are often invisible, ex- 

 cept in a particular reflection of the light. The former, especially, 

 ;an seldom be distinctly traced, except towards its termination. 

 These details of the ncuration of the wing apply equally well to all 

 he species of Cecidomyia that have fallen under my observation, 

 lave only that they are more distinstly traced in the others, parlicu- 

 arly the larger species. At rest (Plate 5, fig. 6), the wings are laid 

 ine upon the other, reposing horizontally upon the back of the 

 .bdomen, and reaching about a fourth of their length beyond it. 



VOL. II. — NO. II. L 



