INSECT VARIETY. 163 



Vawlois Alps, stridulates in the sun, when walking over the 

 grass, emitting a music intermediate in measure and timbre 

 between that of a little Decticus and the Great Green Leaf- 

 cricket — " Zie, zie, z\e." On approach the male intimates 

 alarm, and softens his tone, hardly moving the elytra ; and 

 when closing them he emits a sharp sound. The long- 

 winged Xypulium fascum, Fab., as he stridulates ascends 

 and descends the reed-stems which he frequents, moving 

 the elongate antennae with a slow oscillatory movement. His 

 music consists in an indefinite series of notes shorter than those 

 of the Great Green Leaf-cricket, run together, and so feeble as to 

 be audible only to an observer close at hand. The teeth of the 

 shrill-vein number about thirty, and are scarcely "08 Mm. broad. 

 Some leaf-crickets produce a stridulatory sound during flight, 

 for we find it stated, in Harris's " Insects of New England," of 

 Phylloptera oblongifolia, which obtains the perfect state 

 in September and October, that it frequents trees, and when it 

 flies makes a whizzing noise somewhat like that of a weaver's 

 shuttle. The notes of the male, though grating, are compara- 

 tively feeble. The anal fields of the elytra in the males of 

 Odontiira and Xyp Indium Vitis Graber notices are identical as to 

 venation; while in Odotiticra Fischeri and albovitfata the mirror 

 is small and rough, and the shrill-vein simply bowed instead of 

 S-shajied, denoting here a low state of development in these 

 organs. The same authority states that the mirror in the leaf- 

 crickets is formed from the space enclosed by four intersecting 

 veinlets, these he terms the vena specularis anterior, posterior, 

 interna, and externa. He considers certain tubercles on the 

 dorsal surface of the second and third abdominal segments in 

 the genera Gryllacris and Bienacrida postulate stridulation. 



The file and mirror are sometimes noticed in fossil species. 

 Dr. Scudder discovered a lima in his Xenoneura antiquorum, from 

 the Devonian of Lancaster, New Brunswick ; I have myself 

 detected it in Corydalis {?) Brogn'iarti, from the Carboniferous 

 of Coalbrookdale, Shropshire — a wing fragment figured in many 

 geological text-books, that is closely allied by wing venation 

 with the Gryllacrl, Heer, from Saarbrucken mines ; and also 

 with Lithomantis carbonarim , Woodward, from Scottish coal- 

 fields. These gigantic winged insects of Sigillaria and Calamites- 

 T. 9, 



