June, 191 1-] Barber: Resurrection of Thyanta. 109 



mens of this genus from various parts of the United States and I 

 have spent much time and studied several hundred specimens in the 

 endeavor to characterize the two confused species. But although 

 I can pick them out easily, from a difference in their general shape, 

 I have found it difficult to fix upon well marked constant structural 

 characters which will always serve to differentiate them. 



There is no doubt that the Thyanta cnstator Fahr. is a very plastic, 

 variable and widely distributed species while the other species which 

 has been confused with it, is more restricted in its distribution and 

 more constant in its characters. T. cnstator described by Fabricius 

 from Carolina (Syst. Rhyng., 164, 1803) occurs all over the United 

 States south of New York and becomes abundant in the South and 

 in the West, where it is subject to much more variation than our 

 eastern specimens. In the West, more rarely in the southeastern 

 United States, this species has the humeral angles frequently spinose 

 and varies much in color, ranging from green through testaceous to 

 rufescent as in the Lakehurst, N. J., specimens. The purple-red 

 pronotal band is subject to much variation, being absent entirely or 

 very conspicuous, with the humeral angles, costal margins of corium 

 and apex of scutellum frequently reddish. Furthermore, the western 

 specimens are inclined to be less hairy or setose. There is little doubt, 

 in my mind, that it is specimens of this species with the spinous 

 humeral angles which have been referred to by systematists in this 



Fig. I. Scutellum of Thyanta calccata and that of Th. cnstator. 



country as Thyanta perditor Fabr., which species I believe does not 

 occur within the limits of the United States either in the southeast 

 or southwest. 



After a careful comparison of specimens with the descriptions I 

 am convinced that the other species of Thyanta referred to as occur- 

 ring in the eastern United States and which has been so long sunk 

 in synonymy is T. calceata Say, the type of which is not in existence. 



