150 INSECTS INJURIOUS TO VEGETATION. 



LinnsBus), and Tetrix (of Latreille). These three genera may 

 be distinguished from each other by the following characters. 



1. Acrydium. The thorax {prothorax of Kirby) and the 

 wing-covers of ordinary dimensions; a projecting spine in the 

 middle of the breast; and a little projecting cushion between 

 the nails of all the feet. 



2. Locusta. The thorax, and usually the wing-covers also, 

 of ordinary dimensions; no projecting spine in the middle of 

 the breast; cushions between the nails of the feet. 



3. Tetrix. The thorax {prothorax) greatly prolonged, ta- 

 pering to a point behind, and covering the whole of the back 

 to the extremity of the abdomen; wing-covers exceedingly 

 minute, consisting only of a little scale on each side of the 

 body; fore part of the breast forming a projection, like a cravat 

 or stock, to receive the lower part of the head ; no spine in the 

 middle of the breast; no cushions between the nails. 



I. ACRYDIUM. Spine -breasted Locusts. 

 This word, which is nearly the same as one of the Greek 

 names of a locust, has been variously applied by different 

 entomologists. I have followed Latreille and Serville in con- 

 fining it to those locusts which have a projecting spine or 

 tubercle in the middle of the fore part of the breast between 

 the fore legs. To this genus belong the following native 

 species. 



1. Acrydium alutaceum. Leather-colored locust. 



Dirty brownish yellow; a paler yellow stripe on the top of 

 the head and thorax; a slightly elevated longitudinal line on 

 the top of the thorax; wing-covers semitransparent, with 

 irregular brownish spots ; wings transparent, uncolored, netted 

 with dirty yellow; abdomen with transverse rows of minute 

 blackish dots; hindmost thighs whitish within and w^ithout, 

 the white portion bounded by a row of minute distant black 

 dots, and crossed, herring-bone fashion, by numerous brown 

 lines; hindmost shanks reddish, with yellowish white spines, 

 which are tipped with black. Length, to the end of the abdo- 

 men, 1| inch ; the wing-covers expand over 3 inches. 



