292 AMERICAN PACHYBRACHYS (cOLEOPTERA) 



collectors will be stimulated and the ends aimed at be more 

 speedily attained by placing before them the results so far as 

 reached. 



The present investigation has been spread over some six or 

 eight years and has been prosecuted more or less continually 

 during the last three or four. There have been, however, during 

 this time many longer or shorter interruptions of active work, 

 and because of this, a certain irregularity, or lack of uniformity of 

 treatment may be noticeable to the critical reader, but it is 

 hoped that the usefulness of the work has not suffered in conse- 

 quence. 



Owing to the great difficulty experienced in identifying many 

 of the species of Suffrian and Jacoby from the descriptions, and 

 inability to obtain authentic examples for study, it is not un- 

 Hkely that a few of the forms here described as new may prove 

 to be identical with, or merely variations of, certain Mexican 

 species; it is, however, thought best to risk this small amount of 

 synonymy in the interest of completeness of treatment of the 

 material at hand. After making all possible assignments, there 

 remains of course the inevitable residue of unplaceable speci- 

 mens. There are some fifty or sixty of these — less than one per 

 cent of the total number studied — nearly all of them females, and 

 many unique. Among them are unquestionably a number of 

 undescribed species, but we must await further examples, espe- 

 cially males, before they can be properly characterized. 



According to Bowditch, eburifer Suffr. occurs at Brownsville, 

 Texas, and he has doubtfully recognized rubronotatus Jac. from 

 Iowa and Illinois. The doubt in the latter case I believe to be 

 well founded, and as ehurifer was described from South America 

 there is more than a chance that there is some mistake in the 

 identification; at all events, I have not sufficient information to 

 permit my including either of these doubtful things in my tables. 



.4 cknoivledgments 



As usual I have found my entomological friends and corre- 

 spondents generous in contri))uting material for study, and it is a 

 pleasure to here acknowledge this assistance. No less than 

 seven thousand specimens have been examined, among them 

 almost the entire material of the National Museum Collection, 



