﻿170 SEVENTH ANNUAL REPORT 



notched character of the anal abdominal joint in the male and by the sliorter, less 

 tapering- cerci ; also by the greater relative length of wings which extend, on an aver- 

 age, nearly one-third their length beyond the tip of the abdomen in the dried speci- 

 mens ; also by the larg-er and more distinct spots on the wings — in all which characters 

 it much more closely resembles spretus than fcmur-rubrum. From spretus,&gii\xi, it is 

 at once distinguished by the smaller size, the more distinct separation of the dark mark 

 running from the eyes on the prothoraxand 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 c?'s, 7 5's from New Hampshire. Just as the typical femur-ruhrum is at once 

 distinguished from the typical spretus by the characters indicated ; so Atlanis, though 

 structurally nearer to spretus, is distinguished from it at a glance by its much smaller 

 size and darker, more marbled coloring. The contrast is all the greater in the living- 

 specimens, and I have seen no specimens of spretus that at all approach it in these 

 respects. 



Whether this is the femur-ruhrum as defined by DeGeer or by Harris, it is 

 almost impossible to decide, though Harris's figure of feynur-imhrum better represents 

 it than the true jemur-ruhrum., as subsequently defined by Thomas, and as found in. 

 Illinois and Missouri. 



It has always been a question among orthopterists, as to whether 

 spretus should really be considered specifically distinct from femur-^ 

 ruhriun^ and Mr. Uhler has himself expressed to me his doubts as to 

 the two being distinct. This indecision, which I myself very freely 

 shared, may be attributed principally to the fact that the species just 

 described {Atlanis) has very generally been mistaken for femxir- 

 rubrum^ and that the accounts of this latter rising into the air in 

 swarms have in reality had reference to the former species. The only 

 reference to this longer-winged species, in the East, that I am ac- 

 quainted with, is that by Dr. A. S. Packard, jr., whose reference to the- 

 occurrence of spretus in Maine and Massachusetts, as exhibited by 

 specimens in the museum of the Peabody Academy of Science,* 

 doubtless applies to Atlanis. 



Whether these three insects, as here defined, are really distinct 

 species, or only races of one and the same, is a question that each in- 

 dividual entomologist will decide for himself, according to his idea of 

 what constitutes a species. As ordinary distinctions go, however^ 

 there can be no doubt as to their specific distinctness, notwithstand- 

 ing my own conviction that they merge into each other through ex- 

 ceptional intermediate individuals. That they will cross with each 

 other and produce fertile progeny, I have little doubt, and that femur- 

 ruhrum mixes more or less with the other two, is probable ; yet spre- 

 tus and Atlanis can never thus cross, l"or they are effectually sepa- 



* Am. Naturalist, Ylll, p. 502. Since the above was written, Dr. Tackard has submitted * 

 rather poor and discolored specimen to me, and it is, as I inferred, what I here call Atlanis. 



