44 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



velvety luster on the anterior half, the latter half punctured ; the lower edges, at the 

 sides, paler— sometimes pale red, at others almost white. Elytra extending about half 

 over the abdomen (or not exceeding two-thirds), marked along their internal margins 

 with a light, reddish-brown ray ; external margin dusky ; a few dusky dots along the 

 internal margins. Wings not quite as long as the elytra ; transparent, pale yellowish 

 on the disk, tinged with red at the base (in recent specimens). Posterior thighs crossed 

 by two black bands, and black at the knees ; intermediate spaces pale yellow — often 

 almost white. Length of female, one inch and three-eighths; of the male, slightly 

 over an inch. 



This species is quite common here along the road-side and among low weeds and 

 grass. 



Immediately after this, in the same paper, follows a brief description 

 ot femur-rubrum^ showing that he then considered the two species as dis- 

 tinct. But there is evidently some mistake in his description ; although 

 it agrees in part with the characters of spretus^ part of the description 

 cannot possibly apply to that species. The original specimens were 

 destroyed soon after the paper alluded to was written, and Mr. Thomas 

 is unable at present to explain the error, and knows of no species in 

 Southern Illinois to which the description will apply throughout. It is 

 more than probable that there was some confusion of specimens at the 

 time the description was written. It is possible that one or more of the 

 three specimens '''a. h. cP (Walker's Cat. Dermap. Salt.) of the British 

 Museum are from the collection made by Mr. Thomas at that time. 



In the '^Practical Entomologist" (October, 1866), Mr. Walsh notices this 

 species somewhat at length under the name of Calopfenus sjjretus, quot- 

 ing Mr. TJhler as authority, but giv^es no further description than a com- 

 parison of the length of the wings with those of G. femur -ruhrum. 



In Mr. Scudder's •• Catalogue of the Orthoptera of North j^merica," 

 published in 1868, it is mentioned under the name Acridium spreUim 

 Uhler. 



No description of the species having been published previous to the 

 appearance of the '' Snyopsis of the Acrididse of North America," Mr. 

 Thomas described it as follows : 



Very much like C.femur-ruhrum, Burm., the principal difference being in the length 

 of the elytra and wiags, a notch at the tip of the last (^) ventral segment. Posterior 

 lobe of the pronotum slightly expanding; median somewhat distinct. Elytra and 

 wings pass the abdomen about one-third their length. The last (^ ) ventral segment, 

 which is turned up almost vertically, is somewhat tapering and is notched at the apex, 

 ■which distinguishes it from the femur-rubrum ; the notch is small, but is distinct. Pros- 

 ternal spine, robust, subcylindrical, transverse. Migratory. 



Color. — Scarcely distinct from the C. femur-rubrum. The occiput and disk of the pro- 

 notum generally reddish-brown ; the posterior lobe somewhat paler than the anterior 

 and middle. Spots as in femur-rubrum, arranged in a line along the middle of the ely- 

 tra ; these are a little larger and more abundant toward the apex. The head and tho- 

 rax are sometimes a very dark olive-brown, at others reddish-brown and even brown- 

 ish-yellow, the color deepening with age. The wings are pellucid, nerves dusky toward 

 the apex ; when flying high and against the sun their wings look like large snow-flakes. 



Dimensions. — $ Length (to tip of abdomen) 1 to 1.2 inches; elytra as long as the 

 body ; posterior femora, 0.55 inch ; posterior tibiae, 0.5 inch. $ Length, 0.85 to 1 inch ; 

 elytra, 0.9 to 1.05 inch. 



