10 NEW YORK STATE MUSEUM 



p u n c t i c o 1 1 i s and m o e s t a have about the same range, being 

 found in Canada, in the eastern states and also in the ^liddle West. 

 The t}'pical p o p u 1 n e a is found only on the Pacific coast, t u 1 a r i 

 occurs in the same localities and also in Colorado and Arizona. 

 Con color is found in Arizona and Colorado. The variety u n i - 

 color has the same general range as m o e s t a . H o r n i i is 

 confined to the western coast from Los Angeles Cal. to British 

 Columbia. 



Specific relationships. Before attempting to group the species 

 according to their natural affinities, a few remarks on their specific 

 characters may be of interest. The antennae of most species are 

 unicolorous. In some, o b 1 i q u a , m u t i c a , h o r n i i, p o p u 1 - 

 nea, moesta, tulari and c o n c o 1 o r and its variet}-, they 

 are more or less annulated with gray, (brown and black in 

 obliqua), and two of these species have the first joint enlarged. 

 The length of the antennae also varies in the dift'erent species, being 

 ver}- short in m u t i c a . 



The shape of the last segment of the female abdomen presents an 

 excellent character for the separation of some species. The pygidium 

 of some is broad witli the apex blunt and in others it is long. The 

 tip may be more or less divided into two lobes, the upper surface 

 may be either marked by a median depression or may be convex as 

 in m u t i c a . 



The angle formed by the sides varies in different species. The 

 front claws of the anterior and middle tarsi of the males are 

 armed with either a blunt process or tooth, which is lacking on 

 the front pair inpuncticollis, wanting on all claws in p o p u 1 - 

 nea, moesta, tulari and c o n c o 1 o r and present on both 

 claws of each pair of legs in lateralis. This process is subject 

 to variation as to size and form in individuals of the same species, 

 and it has been used as a specific character as little as possible. The 

 shape of the thorax, whether cylindric or narrowed in front, 

 affords a good character. The form of the apex of the elytra is of 

 value in determining species, as they may be rounded, obliquely 

 narrowed, armed with a spine or truncate. The shape of the head 



