R. T. LEWIS ON A NEW SPECIES OP ALEURODE8. 91 



in a characteristic manner on a prolongation of the median line, 

 those at the anterior end being projected in two parallel plumes for 

 about the same distance as those behind. On either side of the 

 elevated dorsal ridge other series of excretory pores are found, and 

 from these the "wax is discharged in a nearly vertical direction in 

 parallel lines, farming an elegant double crest above the central 

 line. The whole appearance of the pupa in its complete condition 

 is thus exceedingly ornate, forming as beautiful an object under 

 the binocular microscope as can well be desired. 



The perfect insects, which I am now for the first time able to 

 describe, are very minute, the female not measuring more than 

 -j-Jo-ths" in length and the male being about £th less. In their 

 natural condition they are apparently a dull grey colour, with 

 wings of rather lighter shade, both body and wings being dusted 

 freely over with a waxy powder ; both sexes are furnished with 

 four wings, those of the female when expanded measuring about 

 -j^o" from tip to tip, and those of the male being slightly less. The 

 specimens sent to me were not quite in the condition which I could 

 have desired for successful mounting or examination, having been 

 caught in a paper bag, killed with tobacco smoke, and then sent 

 through the post in a small box, dry. On arrival, they were so 

 completely desiccated as to break to pieces with the least provoca- 

 tion, and though all attempts at relaxing them sufficiently to 

 display in good positions proved fruitless, I secured about sixty, 

 which, alter saturation in benzole, were mounted in balsam, and, 

 although all were of value for comparison, it is with difficulty that 

 I am able to exhibit a presentable slide this evening. When 

 mounted in this medium the insects became translucent and deep 

 yellow in colour, all trace of the waxy powder had disappeared in 

 the benzole, and the wings were perfectly transparent. The fore- 

 wing exhibits one median vein, with a single basal branch, the 

 hind-wing showing the median vein only with distinctness with a 

 1" power ; the margin of each wing appears to be minutely 

 beaded, and on examination with a power of about x 400 it is 

 seen that this is due to a number of small hemispherical elevations 

 "5 ~hnf a P ai % each bearing three or four extremely fine hairs. 



The eyes are compound, constricted — but not actually divided — 

 across the middle, and there is one small ocellus above and 

 immediately contiguous to each compound eye. The antennae are 



