252 SYSTEMATIC ARRANGEMENT. 



the express purpose of securing an increase of power 

 we perceive how admirably adapted these creature 

 are for a kind of motion which must often have ex 

 cited surprise by its extent and rapidity. 



The tibiae are thickly armed with spines, some < 

 which are merely processes of the crust, and other* 

 are implanted. Of the former there are two rows 

 one on each side, leaving a groove between them 

 and of the latter are those on the lower angles of th 

 tibiae. 



Of this family we shall figure, as examples, tw 

 British species, and a few remarkable foreign form 



ACRIDA VIRIDISSIMA. 



PLATE XIII. Fig. 1. 

 Gryllus viridissimus, Linn Donovans Brit. Ins. IV. PL 13 

 Locusta viridissima, Leach Conocephalus virid. Samouelle 

 Curtis' Brit. Ent. I. 82. 



ACRIDA has antennae as long as the body, setaceous, 

 the basal joint dilated, second short, third rather 

 longer ; maxillae with three small teeth at the tip, the 

 palpi having the terminal joint longest and truncate at 

 the extremity ; labrum orbicular, dilated at the base ; 

 mentum narrowed anteriorly ; the exterior lobes of 

 the ligula dilated and palpiform ; posterior tarsi with 

 the penultimate joint short and bilobed, the first hav- 

 ing a lobe on each side near the base. 



This genus contains all the British insects that can 

 be referred to the family of the Gryllidae. Although 

 they do not exceed a dozen, they are so diversified in 

 character that it is only by a pretty general definition 

 that they can be comprehended in the same generic 



