6Y JOHN L. FROGGATT. 661 



contract, and often curve the l>()dy. The maggots are then 

 placed in 35% alcohol, and, after about 14 hours, they are trans- 

 ferred to 75,/ alcohol, in which they can be preserved. Asa 

 general rule, the maggots are left perfectly white by this prepara- 

 tion, excepting occasionally when they have been feeding on 

 niaterial rich in blood. When ready for preparation as micro- 

 scopic specimens, the body of the maggot is slit along the median 

 basal line, and boiled in 10% KOH until only the integument 

 remains. This is then put through the usual process for such 

 preparations, and mounted in Canada Balsam. All measure- 

 ments are in fractions of a millimetre. 



The bibliography on the spiracles of dipterous larvye is, so far 

 as I have been enabled to trace it, very scanty. Figures of the 

 spiracles of different species have been given on a number of 

 occasions; but when a description is given, it is brief and with- 

 out detail. 



Nielsen(l) figures the spiracles of certain species of Tahanidie^ 

 but goes no further. 



Froggatt(2) figures the spiracle of a dipterous larva found 

 parasitic in locusts at Minimbah Station, near Singleton, N.S.W. 

 A curious feature in this species was an elongated, cone-shaped 

 tail fitting over the anal portion of the abdomen. This was 

 doubtless to protect the spiracles, and prevent the maggot from 

 being smothered when the legs and wings were folded. The 

 perfect tiy was never bred out, so that it could not be identified. 



GurneyO) figures the spiracles of three species of fruit-Hies, 

 and states that the identification of the different species can be 

 thus determined, but gives no description. 



Banks(4) gives a slightly more extended account of the spiracles 

 of the different species he deals with, but gives very little detail. 

 He refers to what I am calling the space in the band of the anal 

 spiracular plate, as a "button"'; in which I do not agree with 

 him. He does not say how the spiracles were examined. 



As extreme forms of spiracles, the following may be given. 

 Eristalis tenax, " The Common Drone-Fly," an introduced species 

 common in gardens, is the parent of curious rat-tailed larvae 

 which can live not only in putrid but even in salt water. The 



