152 AMERICAN HYMENOPTERA. 



has led to considerable confusion with E. arctice Ashm. Dr. 

 Ashmead gave with the original description of arctics a num- 

 ber of characters which he thought separated niacrurus and 

 arctics, but a good series of both shows that many of these 

 are not constant. I have before me a series of macrurus 

 showing a complete gradation from a condition where the 

 wings are entirely fulvous to one where they are completely 

 hyaline. In this gradation the fulvous tinge seems to be 

 most permanent at the base of the wing, the clearing begin- 

 ning at the apex and working towards the body. The num- 

 ber of frenal hooks varies from 7 to 15 and even with the 

 same individual. The type of arctics has 9 frenal hooks on 

 one side and 11 on the other, and similar variation is com- 

 mon. Too much weight has been laid upon the number of 

 frenal hooks, which, as is thus shown, varies widely. Varia- 

 tion in the form of the anterior transverse metathoracic 

 carina has already been noted in the description. Two char- 

 acters are, however, apparently quite constant and contrast- 

 ing in macrurus and arctics ; in the former the outer half of 

 the third discoidal cell is markedly widened and the disco- 

 cubital vein therefore somewhat sinuous ; in the latter this 

 cell is of nearly equal width throughout and the discocubital 

 vein is evenly arcuate, its outer half — along the third dis- 

 coidel cell, nearly parallel with the subdiscoidal nervure. In 

 arctics the radial vein is narrowed at the base and thickened 

 beyond, while in macrurus it is evidently thickened to the 

 stigma. I have seen no specimens of arctics with this char- 

 acteristic venation which showed any trace of fulvous in the 

 wings. Some writers have included the smaller specimens 

 — which I place in macrurus — with hyaline wings, in arctics, 

 but they have characteristic macrurus venation and the 

 other characters are not constant, as is shown by a series of 

 these specimens. If these are not included in macrurus, 

 arctics Ashm. can not be considered more than a weak sub- 

 species. This question can not be settled absolutely until 

 breeding experiments have been made, but for the present 

 it seems wise to retain arctics in a restricted sense. There 

 is little doubt that Ophion glabratus Say is a synonym of 

 macrurus, but since Say's type is lost this can not be abso- 



