GKYLLIDJS. 563 



abdominal ring and are very long. In the male the long anal 

 hairy stylets are retained, while the parts representing the ovi- 

 positor are aborted. The shrilling of the male is a sexual call, 

 made by raising the fore wings and rubbing them on the hind 

 wings. The noise is due to the peculiar structure of the fore 

 wings, the middle portion of which forms, by its transparent 

 elastic surface, on which there are but few veinlets, a resonant 

 drum, increasing the volume of sound emitted by the rubbing 

 of the file on the upper surface of the hind pair of wings. 

 This file is the modified internal vein, the surface of which is 

 greatly thickened, rounded and covered closely with fine teeth. 

 In the females the wings are not thus modified, and they are 

 silent. They have been known to lay 300 eggs, glued together 

 in a common mass. In July the larvae appear, and by the last 

 of August the grass is alive with fully grown crickets, their 

 loud chirruping resounding through the warm days and nights 

 of autumn. The species are generally dull black or brownish, 

 and in the tropics attain to a large size. 



In the genus Tridactylus the males have the anterior tibiae 

 three-fingered, i. e., the tibia has a lateral hooked appendage 

 to which the tarsus is attached, while a long hooked projec- 

 tion takes the place of the feet. The species are minute, 

 the largest known, T. apicalis Say, being one-fifth of an inch 

 long. It is found in the Southern States, while Tridactylus 

 terminalis Uhler is found northward. The Mole-cricket, Gryl- 

 lotalpa, so-called from the enlarged fossorial fore feet, lives in 

 wet, swampy soil, by ponds and streams, where it raises ridges 

 while constructing .its subterranean galleries in search of 

 insects. Its fore legs are adapted like those of the mole 

 for digging, and are remarkably short and stout, much flat- 

 tened and armed with solid tooth-like projections. Their eggs, 

 from 300 to 400 in number, are laid ii> the spring in tough 

 sacks, in galleries. Very rare northward, they are more com 

 mon in the Middle and Southern States. 



Gryllotalpa borealis Burmeister is found in New England, 

 burrowing in moist earth near ponds. The Southern species is 

 Gryllotalpa longipennis Scudder, and in the West Indies an- 

 other species ravages the Sugar-cane. The genus Gryllus in- 

 cludes the common crickets. The European House-cricket, 



