18G 
OBTHOPTERA. 
I. Antennae 14-jointed; eyes very prominent, with a 'project- 
ing ridge between them, formed by a horizontal extension of the 
flat top of the head ; thorax prolonged beyond the extremity of 
the body. 
1. Tetrix ornata. Ornamented Grouse-locust. 
Dark ash-colored ; a large white patch between four black 
spots on the top of the thorax ; a white spot on the top of the 
hind thighs ; thorax nearly or quite as long as the wings. 
Length Lj- to fa inch to the apex of the thorax. 
This species varies in wanting the white spot on the top of 
the thorax sometimes. It was first described by Mr. Say, 
under the name of Acrydium ornatum.* 
2. Tetrix dorsalis. Red-spotted Grouse-locust. 
Rusty black, with oclire-yellow spots on the sides and legs, 
and a large rusty-red spot on the top of the thorax ; wings 
extending beyond the apex of the thorax. Length 4 inch. 
3. Tetrix quadi-imaculata. Four-spotted Grouse-locust. 
Ash-colored or dark gray above, variegated with black; 
four velvet-black spots on the top of the thorax; wings 
projecting beyond the extremity of the thorax. Length from 
Ar to of an inch. 
This is a shorter and thicker species than the ornamented 
grouse-locust. It is not uncommon in pastures from the first 
of May to the first of June. 
4. Tetrix bilincata. Two-lined Grouse-locust. 
Ash-colored ; thorax paler, with a narrow angular whitish 
line, on each side, extending from the head beyond the mid- 
dle ; the angular portion including a long blackish patch on 
each side ; wings, in the male, rather shorter than the tho- 
rax, in the female longer. Length from to more than fa 
inch. 
* American Entomology, Vol. I. Plate 5. 
