216 BULLETIN 14 5, UNITED STATES NATIONAL MUSEUM 



finely punctate, and rather densely clothed with long, very fine, erect 

 hairs ; prosternal lobe broad, strongly declivous, and feebly, broadly, 

 arcuately emarginate in front; posternal process moderately broad, 

 the sides parallel to behind the coxal cavities, then obliquely nar- 

 rowed to the apex, which is acute. Tibiae slender, and the anterior 

 and middle pairs armed with a short tooth on the inner margin at 

 apex. Posterior tarsi about as long as the tibiae, and the first joint 

 as long as the following three joints united. Tarsal claws dissimilar, 

 anterior and middle ones cleft near the tip, the teeth about equal 

 in length, and the inner tooth not turned inward; posterior claws 

 cleft near the middle, and the inner tooth much broader and shorter 

 than the outer one. 



Length, 5.5 mm.; width, 1.125 mm. 



Female. — Differs from the male in being usually more robust, front 

 of the head broader, uniformly reddish cupreous, and the lateral 

 margins more parallel ; sides of abdomen more broadly exposed 

 above; prosternum clothed with short, semierect hairs; tibiae with- 

 out a distinct tooth at apex, and the tarsal claws similar on all feet, 

 cleft near the middle, with the inner tooth shorter and broader than 

 the outer one. 



Redescribed from a male collected in Illinois which agrees very 

 closely with the original description. Since the type of this species 

 is lost, I am designating this specimen as the neotype, and depositing 

 it in the United States National Museum collection. 



Type localities. — Of politus, " Banks of the Mississippi River " ; 

 type lost. Of desertus, California (Junction of the Colorado and 

 Gila Rivers) ; type in Museum of Comparative Zoology. Of cupre- 

 olus, Kansas; type in Museum of Comparative Zoology. Of 

 plumb eus, Lake Superior ; type in Museum of Comparative Zoology. 

 Of canadensis, Canada ; type in Obenberger's Collection. 



Distribution. — This is the most widely distributed species of 

 Agrilus in North America, as specimens have been examined from 

 all parts of southern Canada from the Atlantic to the Pacific Ocean, 

 and from nearly all sections of the United States. It probably will 

 be found wherever willow occurs. 



Variations. — This seems to be the most variable North American 

 species of this genus, but it is just possible that when the habits of 

 these insects become better known these variations will represent 

 distinct phytophagic forms. The color varies from golden green to 

 bluish green, and through all shades of reddish cupreous to plumbeus; 

 the elytra are glabrous or sparsely, uniformly clothed with whitish 

 pubescence; the antennae usually have the outer joints wider than 

 long, but occasionally a specimen is found in which they are scarcely 

 wider than long; the head is usually without depressions, but some- 



