39° CALIFORNIA ACADEMY OF SCIENCES. 



ly bluish, densely punctate and opaque. Length .48-. 66 

 inch.; 12— 16.5 mm. 



This species has a much broader thorax than gracilis, 

 and a little more closely punctate. 



Occurs in the Lake Superior region and eastward to 

 Maine. 



Ditylus quadricollis Lee. Ann. Lye. N. Y., v, p. 157. 



Ditylus vestitus Lee, Pacif. R. R. Rep., p. 52. 



Form robust, black, rarely with a slight violaceous 

 tinge. Head coarsely and closely punctate. Thorax 

 subquadrate, base not narrower than apex, sides in front 

 feebly arcuate, disc slightly irregular, surface densely 

 punctate and opaque, the pubescence more distinct than 

 in either of the preceding species. Elytra densely punc- 

 tate and opaque, finely quadri-costulate. Abdomen dense- 

 ly, finely punctulate. Length .48-. 75 inch.; 12-19 mm - 



In this species the pubescence is normally black, but 

 specimens occur with fulvous pubescence (vestitus) over 

 the entire surface. One specimen in my cabinet has ful- 

 vous pubescence at the sides of the elytra only. 



Occurs in northern California, Oregon, Washington, 

 Vancouver, and western Nevada. 



The other species formerly included in Ditylus have 

 been removed to Copidita. 



Nacerdes Schmidt. 



Form slender. Antennae twelve-jointed in male, eleven 

 in female. Mandibles bifid at tip. Last joint of maxil- 

 lary palpi elongate-triangular. Anterior tibiae with one 

 terminal spur. Tarsi with penultimate joint alone spongy- 

 pubescent beneath. Claws simple. 



Nacerdes and Xanthochroa are very closely related, 

 and are separated by the deeper emargination of the eyes 

 in the latter. The character is not a strong one, and may 



