200 long's second expedition. 



as the abdomen, but mucli shorter than .the hemelytra ; sides of 

 the thorax posterior to the horns blackish-brown, with an arcuated 

 spot or line behind the horns, and a band near the tip, whitish ; 

 hemelytra and wings blackish-brown ; beneath blackish ; rostrum, 

 knees, tibia, and tarsi, whitish. 



Length three-tenths of an inch. 



This is an inhabitant of Pennsylvania, and also of the North- 

 west Territory. It is closely allied to Centrotus huhalus Fabr. 

 and is infested by Leptus hispidus, nob. 



2. M. TRILINEATA. — Brownish-rufous ; thorax elevated on the 

 middle, with three longitudinal, one oblique, and one transverse 

 line, whitish. 



Inhabits North-west Territory. 



Body with rather large dense punctures ; head pale greenish- 

 yellow, obsoletely irrorate with brown points ; thorax before 

 rounded, unarmed ; a dilated pale greenish vitta from the head, 

 is divided by the rounded elevation near the middle of the back, 

 and passes down on each side in an oblique white line, which 

 terminates at the inferior edge behind the middle ; a narrow line 

 on each side passes from the head and terminates at the emargi- 

 nation of the origin of the hemelytra ; a white band near the 

 tip margined with fuscous ; dorsal foliaceous elevation taking its 

 rise behind the line of the origin of the hemelytra, its edge very 

 obtusely curved, and gradually disappearing behind at the white 

 band, its sides in the middle are abruptly compressed ; tip acute, 

 not attenuated ; hemelytra with a punctured scale at base, which 

 is adjusted in the emargination of the thoracic edge; coriaceous 

 exterior margin less than one-fourth the length of the hemelytra, 

 and punctured ; beneath yellowish-green. 



Length three-tenths of an inch. [301] 



3. M. CONCAVA. — Fuscous with elevated lines on the thorax, 

 and an oblique white band behind. 



Inhabits North-west Territory. 



Body with dilated punctures; head inequal, varied with 

 whitish and fuscous ; tip a little more prominent in the middle ; 

 thorax unarmed, rounded before, with a carina originating at the 

 head and continued to the tip; elevated lines like nervures, 

 which are reticulate on the anterior part and near the back, but 



