In the preparation of the present paper I have been greatly indebted 

 to my friend Mr. John D. Sherman, Jr. for the privilege of unrestricted 

 study of his very rich collection, and for the loan and gift of speci- 

 mens. Mr. J. B. Wallis of Winnipeg has assisted materially with 

 good series of the numerous species taken by him in various parts 

 of Manitoba and British Columbia. To Mr. C. A. Frost, Chas. Liebeck 

 and Chas. Dury, I am indebted for material contributed with equally 

 good will if in lesser numbers, to all of whom I wish to express 

 sincere appreciation. I have, of course, carefully examined the types 

 in the Museum of Comparative Zoology at Cambridge, which thanks to 

 the courtesy of Dr. Henshaw and Mr. Banks have been freely available 

 for study; while Dr. Lutz and Mr. Mutchler have kindly granted 

 similar privileges with the Roberts collection in the American Museum 

 of Natural History. To Mr. Arrow of the British Museum I owe 

 especial thanks for his kindness in sending to me for examination 

 one of Kirby's original specimens of A. phaeopterus, and typical 

 examples of several of Sharp's species, as well as notes made at my 

 suggestion on other species which could not be sent out from the 

 museum. The types of all new species herein described, unless other- 

 wise indicated remain in my own collection, which contains all the 

 species here recognized. 



Table of Species 



1 . Prothorax narrower at base than near the middle, and much narrower 

 than the base of the elytra, the sides strongly discontinuous with those 



of the latter 2 



Prothorax not narrower at base than at middle, the sides commonly 

 more or less nearly continuous with those of the elytra 3 



2. Prothorax cordate, the sides distinctly sinuate posteriorly, head more 



or le^s rufous in front and behind (Montana to New Mexico.) cordatus 



Prothorax not cordate, less narrowed at base, the sides posteriorly 

 not or only just perceptibly sinuate; head entirely black. (Vancouver; 

 Washington.) rectus 



3. Antennae with the outer joints dilated and compressed in the male .40 



Antennae nearly filiform, alike in the sexes 4 



4. Prosternal process broad and flat, rather widely margined at sides 

 basally, the surface somewhat rugose; basal two joints only of pro- 

 tarsus clothed beneath with glandular hairs, mesotasi apparently de- 

 void of such hairs; sides of prothorax feebly sinuate at the front 

 angles in the female; species small (6^4 nim.), black, densely finely 



subgranosely reticulate and opaque spinipes 



Prosternal process broad, smooth and flatly convex, the apex acute but 



not finely acuminate, joints 1-3 of the four anterior tarsi of the male 

 clothed with glandular hairs as in all the species that follow ; species 

 strongly shining, deep black (often brownish black in planitus}, elytra 



