ENTOMOLOGICAL SOCIETY OF ONTARIO. 43 



cannot be lured by the calls of a different species. If such be the case then the peculiar 

 sounds and calls must be produced by harps differing a little in structure, perhaps in the 

 number of oblique veins or in the tenseness of these veins, that is whether undulating or 



straight. 



The classification of the species is somewhat difficult. Several entomologists prefer 

 to place all our native members in one species while some would make three or four. This 

 question will remain in dispute till the life history of the genus has been thoroughly 

 worked out and experiments have been made upon interbreeding. 



Charles A. Hart of Champaign, Illinois, in an article in the Entomological News 

 "Vol. 3, 1892, page 33 divides the (Ecanthi by means of black markings on the first two 

 segments of the antennae. These markings are very distinct and appear to be quite con- 

 stant, and should they be discovered to be of functional importance are of great value as 

 they are discernible by the naked eyp, and easily outlined with the aid of an ordinary 

 lens. In Niveus (Fig. 31, 1,) the markings are two black circular spots, one on under- 

 side of first and second segments. 



In Angustipennis, (Fig. 31, 2,) the markings are a curved black line on first segment 

 and a black oval spot on second. 



In Nigricornis, (Fig. 31,3 and 4) on the first segment there are a black longitudinal 

 Sine, and a black spot exterior to it with similar markings on second segment. In some 

 cases the markings are confluent at the upper part of the first segment. 



Figure 31, 5 shows the venation peculiar to the harp of Niveus. The number of 

 oblique veins varies from three to five, only the first two meeting the vena dividens. 

 These undulate considerably and meet vena dividens at an acute angle. Oblique veins 

 three, four and five extend parallel to one and two, but end in a second longitudinal vein (d.) 



The venation of Angustipennis, (Fig. 31, 6) is remarkably like that "of Niveus but 

 there is a difference in oblique vein two. In Niveus it seems to extend from the vena 

 plicata to vena dividens, but in Angustipennis it ends at the longitudinal vein (d) which 

 is continued down to vena dividens. 



The venation of Nigricornis (Walker) is decidedly variable, yet a study of the varia- 

 tions as in figure 31, 7-13 reveals a type which embraces all the forms. By far the largest 

 number have the venation as shown in figure. By a reference to figure 31, 7-13 it will be 

 seen that an additional cross vein has been developed between the .oblique veins one and 

 two, and which is marked (e) on figures. The migration of veins has been somewhat 

 remarkable ; in some cases a straightening has taken place so as to make one vein out of 

 two as in figure 31, 11, where cross vein (<?) and (x) portion of oblique vein two have been 

 waited into one line. In some cases (e) and (x) have become more inclined to each other 

 as in figure 31, 10, while in other cases the oblique veins (1) and (2) have converged and 

 united with the disappearance of veins (e) and (*) as in figure 31, 12. In figure 31, 8, 

 ie) and (x) have begun to straighten; in figure 31, 9 oblique vein two has straightened 

 itself. Usually there are only three oblique veins but occasionally a fourth is found aa 

 in figure 31, S, 6 and 11. 



Keys for the Determination op the Species of GScanthus. 



/. Males. 



A. Wing covers with a cross vein between the oblique veins 1 and 2 of harpa 

 — nigricornis. 



A A. Wing covers without a cross vein between the oblique veins 1 and 2 of harpa, 

 B. Second oblique vein extending to vena dividens — niveus. 



BB. Second oblique vein terminating at longitudinal vein between VV. plicata 

 and dividens — angustipennis. 



