1877.1 219 



covered with fiue furrows, which he compares to the files o£ certain 

 stridulating Coleoptera of tlie genera Necrophoruti, Geotrupes, and Ce- 

 rctmhtfji;, and these he concludes produce the sound when rubbed over 

 the haustellum, which is also furrowed transversely. He adds, the 

 moth will only cease squeaking when these are entirely eradicated. 

 The note of the female is deeper, and its lima coarser, than that of the 

 male. He also finds the lima on the palpi of other Spliiiigina : — 

 Sphinx convolvuH, ligustri, pinastri, SmerintJms tilice, Deilephila eu- 

 pliorhice, and Choerocampa Elpenor, but poorly developed, and capable of 

 px'oducing only slight sounds. 



It has been also submitted to my notice (by the Editors) that 

 Linnanis differed slightly from Reaumur in opinion, regarding the man- 

 ner in which Alropos produces the squeak, for he does not say it 

 passes the haustellum over the palpi, but, " Stridet allidendo paJpos nd 

 linguam'' (Syst. JN'at. ed. xii, p. 800, 17GG — 68), and this is the notion 

 I imagine Dr. Landois would endorse. Without hazarding further 

 conjecture on this crucial point, I merely add that, in "good squeakers " 

 I have invariably found a portion of the hair at the outer edge of the 

 basal joint of the palpi worn, and that the sound of the file may, in 

 some slight measure, be re-produced after the death of the insect, by 

 a gentle friction. 



Thus it would seem Acherontia Afropos is really a stridulator, and 

 yet there remain some phenomena in connexion with this stridulation 

 that need explanation. For instance, w^hen the species of this genus 

 squeak, the two large air-vesicles at the anterior j)art of the abdomen 

 generally inflate by an unusual spasmodic compression of the posterior 

 segments beneath, and a yellow fan or fasicle of hairs, rising perpen- 

 dicularly from a fold at either side, emits a pungent scent of jessamine, 

 and expands to a stellate form, which gave rise to the theories of Lorey, 

 "Wagner, and Nordmann, lately resuscitated, to account for the stridula- 

 tion of Acherontia Satanas (" Ceylon," by Sir Emerson Tennent, vol. 

 i, p. 264, London, 1860). The former appearance seems also to have 

 led Wagner to conceive air was then forced into the cleft haustellum, 

 which has a double row of orifices at its extremity like the holes of a 

 flute, a circumstance one would think of actual occurrence secondary 

 to the stridor. But the fan itself, well described by Nordmann, may be 

 shown, on the other hand, to be entirely unconnected with the "squeak " 

 — a secondary sexual character it would seem, as I find the little wave 

 moth Acidaliu remutata carries it expanded during copulation. It also 

 exists on the abdomen (base or anus), or on the 2nd pair of tibiae in 

 various genera of Noctuina {Leucania, Xylophasia, Mamestra, Fhlogo- 



