ACRYDIUM. 



GENERIC CHARACTERS. 



Thorax elongated behind, often longer than 

 the abdomen ; elytra very small ; pectus with a 

 cavity for the reception of the inferior part of 

 the head ; tarsi three-jointed, destitute of pul- 

 villi; antennae thirteen or fourteen jointed, not 

 half the length of the body ; oviduct not exsert- 

 ed ; posterior feet formed for leaping. 



OBSERVATIONS. 



This genus was established by Fabricius under 

 the name which, with Thunberg, I have adopt- 

 ed. Linne included the species in his genus 

 Gryllus. Lamarck distinguished them by the 

 name of Acheta, and Latreille by that of Te- 

 trix. The species are nearly all small, and 

 several are common. They may be very readily 

 distinguished from " grasshoppers" of other ge- 

 nera, by the remarkable elongation of the thorax, 

 which is continued backward so as to cover the 

 abdomen wholly or in great part. 



plate v. 



