﻿126 SEVENTH ANNUAL HEPORT 



DESCRIPTIVE. 



The large amount of material above referred to has enabled me to make very thor- 

 ough comparisons between the two species. The genus Coloptenus to which the spe- 

 cies belongs, is distinguished principally by the stoutness of the spine-liive tubercle on 

 the fore-breast between the front legs, and by the tip of the abdomen in the male being 

 much swollen. Mr. Cyrus Thomas, in his admirable work on the " Acridid^e of N. A." 

 has published good descriptions of the known N. A. species, and I will transfer what 

 he has said of the two in question— adding only some subsidiarj' remarks in brackets, 

 and at the close : 



Coloptenus Fe.mur-rpbrum, Burra. Handb. Ent., IF. 63S. 

 Syn. Acrldium femur-rubrwn, Deg. Ins.. Ill, PI. 42, YVx- 5. p. 498. 



femornle, Oliv.. Encyl. Meth., 121 Ins. VI, 228. 

 Gryllus (Locusta) erythropus, Gmel., Linn. Syst. Nat. I, IV, 208(5. 



" Grizzled with dirty olive and brown ; a black spot extending from the eyes along 

 the sides of the thorax; [but never onto the third lobe] ; an oblique yellow line on each 

 side of the body beneath the wings ; a row of duskj\ brown spots along the middle of 

 the wing-covers; and the hindmost shanks and feet blood-red, with black spines. The 

 wings are transparent, with a very pale greenish-yellow tint next to the body, and are 

 netted with brown lines. The hindmost thighs have two large spots on the upper side, 

 and the extremity black [more correctly three such spots, or including theextremeone 

 at tip, four : Harris seems to have overlooked the basal one] ; but are red below, and 

 yellow on the inside. The appendages at the tip of the body in the male are of a long 

 triangular form. Length from [to tip of abdomen] 0.75 to 1 inch ; expansion of wings 

 1.25 to 1.75 inches." As this species, which is so common, varies considerabl}% I have 

 concluded to give Dr. Harris's description without change, adding the following : Ver- 

 tex but slightly depressed, with a minute angular expansion in front of the eyes ; front,il 

 costa usually but slightly sulcate ; sides parallel. Eyes large and rather prominent. 

 Elytra and wings generally a little [usually extending about 1-6 their length beyond 

 the abdomen] longer than the abdomen. The cerci of the male ratlier broad and flat 

 [longer and narrower towards tip than in spretus] ; apex of last ventral segment entire 

 and truncate. The yellow stripes on the side extend from the base of the wing to the 

 insertion of the posterior femora. The ground color varies with localities and age, and 

 most of the specimens Irom one or two sections appear to have unspotted elytra ; some- 

 times a retldish-brown tint prevails ; at others a dark-olive ; at others a dark purplish- 

 brown ; yet the markings generally remain the same. 



Localities. — Maine, Massachusetts, Connecticut, New York, Pennsylvania, Mary- 

 land, Tennessee, Illinois, Minnesota, Ohio, Nebraska, Missouri, Kansas, Colorado, 

 Wvommg, Vancouver's Island (?), west coast of America (?)— [Thomas, ^crirftc^ce of N. 

 A. (1873), pp. 103-4. 



In addition to what Mr. Thomas states of the variation in color, it may be added 

 that the dark marks on the hind thighs are in exceptional specimens wholly wanting, 

 -and in others so confluent that the whole of the upper part is brown-black. In order 

 to show how variable (within certain limits, however,) is the relative length of wing, I 

 will add measurements of over eighty specimens, all taken in St. Louis county. As 

 the length of the abdomen is an uncertain criterion, varying according as this last is 

 distended with eggs or contracted from one cause and another, I have made these 

 measurements from the juncture of the hind thighs and shanks. The specimens were 

 killed in the cyanide bottle, and while yet fresh and supple laid flat on a scale divided 

 into hundredths of an inch. The furthermost hind leg was then stretched until the 

 suture between shank and thigh was just visible above the inner border of the front 

 wings. Careful measurements were then taken, first of the whole body, second of the 

 extent of wing beyond the base of shank, third of extent of abdomen beyond the 

 the same. It will be understood that as the abdomen shrinks slightly in drying, and 

 the wings do not, the figures in the fourth column in all these tables are somewhat 

 lower than if taken from dry specimens. The tables showing these measurements 

 •will prove interesting when compared with that further on, giving similar measure- 



