NORTH AMERICAN BUPRESTID BEETLES 59 



Variations. — Length, 4-6.5 millimeters; width, 0.85-1.5 milli- 

 meters. The pronotum and underside of the body are sometimes 

 rather strongly cupreous, the sides of the pronotum occasionally are 

 more feebly rounded anteriorly, being nearly parallel to each other, 

 and the median depressions are more or less A^ariable in size. The 

 anterior margin of the prosternal lobe shows considerable variation ; 

 in some examples it is subtruncate, whereas in others it is distinctly 

 emarginate. 



Hosts. — This species has been reared by Knull (1922) from the 

 sapwood of dead box elder or ash-leaved maple ( Acer negundo Lin- 

 naeus) and red maple {Acer rubrum Linnaeus). 



17. AGRILUS ALBOCOMUS, new species 



Male. — Form resembling arcuatus, rather strongly shining, and 

 feebly flattened above; head dark blue in front, becoming greenish 

 on the occiput ; pronotum green, with a feeble bronzy tinge on disk ; 

 elytra piceous ; beneath black, with a distinct bluish or greenish tinge, 

 and more shining than above. 



Head with the front wide, feebly convex, slightly wider at top 

 than bottom, the lateral margins feebly, obliquely expanded from 

 bottom to top, and with a narrow, longitudinal groove extending 

 from occiput to middle of front; surface coarsely but not deeply, 

 irregularly rugose, sparsely, finely punctate between the rugae, and 

 clothed with a few, very short, inconspicuous hairs ; epistoma slightly 

 transverse between the antennae, not elevated, and broadly but not 

 deeply, arcuately emarginate in front; antennae extending nearly 

 to base of pronotum, serrate from the fourth joint, and the outer 

 joints slightly longer than wide; eyes moderately large, elongate, 

 and equally rounded beneath and above. 



Pronotum one-half wider than long, about equal in width at base 

 and apex, and widest near middle; sides arcuately rounded from 

 apical angles to base, slightly more strongly posteriorly ; when viewed 

 from the side the marginal carina is distinct and feebly sinuate, the 

 submarginal carina straight and more or less indistinct, and the two 

 carinae widely separated anteriorly ; anterior margin feebly sinuate, 

 and the median lobe broadty, vaguely rounded; base rather acutely 

 emarginate at middle of each elytron, the median lobe broadly 

 rounded, and subtruncate or feebly emarginate in front of scutellum ; 

 disk moderately convex, broadly concave along base, the concavity 

 extending along lateral margins, but becoming narrower toward 

 apical angles, a broad, shallow, median depression near anterior 

 margin, and with sharply defined, straight, prehumeral carinae : 

 surface coarsely, vaguely, irregularly rugose, finely, sparsely punctate 

 between the rugae, and sparsely clothed with a few short, incon- 

 2305—28 5 



