PACKARD.] THE LOCUST EAST OF THE PLAINS. 637 



great difference of opiuion in regard to this form. Mr. Eiley was the first 

 to describe it fully, and I quote his description : 



Calopteniis atlaiiis, n. sp. — Len}j;th to tip of abdomen, 0.70-0.85 inch; to tip of closed 

 wiugs, 0.92-1.05 inches. At once distinguisbed from femiir-ntbntm by the notched char- 

 acter of the aual-abdomitial, joint in the male, ai>d by the shorter, less tapering cerci ; 

 also by the greater relative length of wiugs, which extend, on an average, nearly one- 

 third their length beyond the tip of the abdomen in the dried specimens ; also by the 

 larger and more distinct spots on the vrings — iu all which characters it much more 

 closely resembles spretus than femiir-ritbrtivi. From spretus, again, it is at once distin- 

 guished by the smaller size, the more distinct separation of the dark mark running 

 from the eyes on the prothorax and of the pale line from base of wings to hind thigh; 

 also by the anal Joint in the ^ tapering more suddenly; and by the two lobes forming 

 the notch being less marked. From both species it is distinguished not only by its 

 smaller size, but by the deeper, more livid color of the dark parts, and the paler yellow 

 of the light parts — the colors thus more strongly contrasting. 



6 (? 's, 7 5 's from New Hampshire. Just as the typical fenmr-rnirmn is at once distin- 

 guished from the typical sjjretushj the characters indicated, so athinis, though structur- 

 ally uearer to 82)re1us, is distinguished from it at a glance by its much smaller size and 

 darker, more marbled coloring. The contrast is all the greater iu the living specimens, 

 and I have seen no specimens oi -spretus that at all approach it in these respects. 



Whether this is the femur-rubrum, as defined by De Geer or by Harris, it is almost 

 impossible to decide, though Harris's figure of femur-rubrum better represents it than 

 the true femur-rubrum as subsequently defined by Thomas, and as found in Illinois and 

 Missouri. 



I have collected this grasshopper in Central Maine, and at Amherst, 

 Mass., where it is not uncommon, and could be easily confounded with 

 the eastern red-legged locust, {C. femur -rehrum). It is also common in 

 Essex County, Massachusetts, and has been since 1864, as seen by speci- 

 mens in the museum of the Peabody Academy of Science at Salem. 

 Mr. S. H. Scudder has also specimens from New Hampshire, and it is 

 not improbable that it is a widely-distributed form, with a range ap- 

 proximating to that given on the map. I am inclined to regard it as by 

 no means a distinct species, but as an eastern variety of G. spretus, re- 

 placing that species on the Atlantic coast and in the Mississippi Valley. 

 In this region it will probably never become injurious. Mr. Tliomas 

 regards it as a variety of C. femur-rubrum rather than C. spretus. In 

 speaking of Caloptenus femur-rubrum, he remarks as follows:* "A few 

 specimens taken in Iowa. These belong to the typical form, but they 

 and all others obtained within the last two or three years appear to me 

 to be slenderer and more like Riley's atlanis than iu former years. That 

 this species has been undergoing some modification in the Mississippi 

 Valley within the last three or four years I think must be admitted. Al- 

 though Riley's atlanis is certainly but a variety of femur-rubrum, yet it 

 can be separated from the latter at a glance, and when the specimens 

 are fresh without opening the wings or examining the posterior ab- 

 dominal segments." 



It should be borne in mind that the western spretus dififers from the 

 femur-ruhrum in the much longer wings and its larger size. The legs 

 are the same in both, while spretus is paler, with shades of dull yellow 

 and red. The legs are of the same length in both, and the spines (ovi- 

 positor) in the end of the body are the same in the two species. These 

 differences I find constant after careful examination of twelve speci- 

 mens of each species, and of many others more superficially studied. 

 The male of spretus differs decidedly from that of femur-rubrum in the 

 characters already pointed out, namely, in the narrow, prominent, deeply- 

 notched tip of the abdomen, as well as the short fork iu the complete 

 tergal piece of the abdomen. On the other hand the end of the body of 

 the male of femurrubrum is rouuded, full, and entire, and not thickened, 

 yet I have observed in one or two of the specimens of the male femur- 



* Proceedings of the Davenport Academy of Natural Sciences, 1870, p. 2G0. 



