284 II. C. FALL. 



fauna peculiar to the Carolinian area. It has occurred as for north 

 as Long Ishmd (Reutennuiller), and its western and southern limits 

 so far as recorded are Missouri and Georgia. According to Dr. 

 Hamilton it is common near Pittsl)urg on biennial oak. Dr. D. 

 M. Castle* records finding many specimens near Philadelphia on 

 beech and oak trees; the males appearing first, the females a week 

 or two later. He also states that specimens have been taken at 

 Lancaster, Pa., on flowers in mid-summer. The following localities 

 are represented in the material before me: Pennsylvania, New Jer- 

 sey, District of Columbia, Maryland, Kentucky, Tennessee and 

 Missouri. 



6. D. testacea Kby. 



Judging from the few specimens seen, this species is not a com- 

 mon one. It is exclusively northern in range, as the following 

 localities indicate : Vermont, Lake Superior, Winnipeg, Montana, 

 Nebraska. 



7. D. backii Kby. 



Nearly every genus of any complexity possesses one or more spe- 

 cies which serve as catch-alls for everything doubtful in their 

 vicinity. At present, about everything with brilliant elytra and 

 dark legs passes as backii, and in the material which has served as 

 the basis for these notes, no less than six species carry this label. 

 As a matter of fact there lies between backii on the one hand, and 

 crotchii and fulgida on the other, a debatable ground that is over- 

 run with a puzzling mixture of forn.'s that are neither typical 

 backii nor yet safely referable to either crotchii or fulgida. 



What I have considered the true backii occupies the territory 

 north of Lake Superior and thence west to the Rocky Mountains. 

 The color in mature specimens is always black or nearly so through- 

 out, except the elytra which are brilliant green or purplish, rarely 

 with golden or coppery reflections. The head is distinctly smaller 

 relative to the thorax, and the eyes a little less prominent than in 

 the corresponding sex of crotchii or fulgida; the elypeus is also 

 more broa,dly reflexed. Specimens from Colorada, Wyoming, East- 

 ern Washington and even Arizona and Southern California, while 

 differing in certain details are so nearly in accord with the typical 

 form that they must, for the present at least, be placed there. 



* Ent. Student, vol. ii, p. 5. 



