THE GROUSE-LOCUSTS. 187 



5. Tetrix sordida. Sordid Grouse-locust. 



Yellowish ash-colored ; thorax with minute elevated black 

 points ; wings, in both sexes, rather longer than the thorax. 

 Length from /$ inch to nearly inch. 



I have taken this species both in May and September, and 

 have received a specimen from Dr. D. S. C. H. Smith, of 

 Sutton, Massachusetts. 



II. Antennce 22-jointed; eyes hardly prominent, top of the 

 head not horizontal between them, but curving towards the front, 

 with a very slightly projecting ridge; wings smaller than in 

 those of the preceding group. 



6. Tetrix lateralis. Black-sided Grouse-locust. 



Pale brown ; sides of the body blackish ; thorax yellowish 

 clay-colored, shorter than the wings, but longer than the 

 body ; wing-covers with a small white spot at the tips ; male 

 with the face and the edges of the lateral margins of the tho- 

 rax yellow. Length from ^ to -& of an inch. 



This species was first described by Mr. Say under the 

 name of Acrydium laterals.* I have taken it from the mid- 

 dle of April to the middle of May. It varies in being darker 

 above sometimes. 



7. Tetrix parvipennis. (Fig. 82.) Small-winged Grouse-locust. 



Dark brown ; sides blackish ; thorax clay-colored or pale 

 brown, about as long as the body ; wing-covers 

 with a small white spot at the tips ; wings much Fi e- 82 - 

 shorter than the thorax ; male with the face and 

 the edges of the lateral margins of the thorax 

 yellow. Length from $ to more than 2 9 o- inch. 19 



This species is much shorter and thicker than 

 the Tetrix lateralis. I have taken it in April 

 and May, in the perfect state, and have found 

 the pupae near the end of July. 



* American Entomology, Vol. I. Plate 5. 



[ 19 Color and style of marking is of very little value in separating the species 

 of Tetrix, and the species described by Dr. Harris are probably all referable to the 

 two species of Say. UHLER.] 



