226 L^*5vember, 



In the Qryllidce and Locustina (Von Siebold, Erichson's Archiv 

 before quoted) we can find a similar auditory organ, often pre- 

 senting four equally efficient " tympana." The fore tibiae in both 

 sexes are usually thickened above, and present on either side a 

 cavity more or less developed, "with an ovate or linear opening, closed 

 inwardly by a milky- white {Oryllidce), or silvery and glassy mem- 

 branes, semi-chitinous, or a chitinous piece on the disc {Locustina). 

 Between the pro- and meso-thorax is found a funnel-shaped opening, 

 which proceeds towards the median line, and making a bend, traverses 

 the fore leg, dilating vesicularly within the membranes of the tibiae, 

 and thus supplying the function of an Eustachian tube. The nerve 

 which represents the acoustic, according to Siebold, proceeds from the 

 first thoracic ganglion, and immediately above the vesicle swells into a 

 flat ganglion, the inferior extremity of which in the form of a band 

 is inserted into the sides of the vesicle. This auditory organ was 

 first described by Von Siebold ; its function was surmised by Goureau 

 and Miiller. The male Locusta {Phasgonura) viridissima, when it per- 

 forms, extends its fore legs (as it struck me), in order to adjust these 

 cavities and receive the music of its rivals. The organ of hearing in 

 Grylhis Ideroqlypliicns (Miiller, Zur vergleich. Physiol, des Gesichts- 

 sinnes, p. 439), and in GryUotalpa (?) resembles that of the Acridiidcs, 

 and is similarly situate. 



Guildford : IQth June, 1877- 



A SINGULAE HABIT OF HILARA. 

 BY BARON C. R. OSTEN-SACKEX. 



During a short stay at G-urnigel, the well-known watering-place 

 near Berne (August 20-27 of this year), I had occasion to observe a 

 fact which, as far as I know, is so unique in entomology, that I do 

 not hesitate to give it immediate publicity. 



Walking about in the woods, at the back of the hotel, between 9 

 and 10 a.m., I noticed in the sunbeams, penetrating through the dense 

 shadow of the fir trees, small swarms of flies, performing that rapid 

 flight in zig-zag, backwards and forwards, which is commonly observed 

 among Muscid(jB, especially males, in similar situations. What at- 

 tracted my attention to them, was the uncommonly brilliant white or 

 silvery reflection which they gave in crossing the sunbeam. I caught 

 one of them with my forceps, and was astonished to find a much 

 smaller fly than I had expected, and witRout anything silvery about 



