COLORATION IN POLISTES. 53 



GEOGRAPHICAL DISTRIBUTION OF TYPES OF COLOR MARKING. 



Distribution in the United States. 



the types. 



The species represented in the United States are so numerous and 

 varied in their minute details and the characterizations so difhcult to 

 follow that for the purposes of this description the various species will 

 be grouped under a number of heads according to affinities determined 

 in the study of individual variation. For the detailed description of 

 the species the reader is referred to the systematic treatment of the 

 genus given at the close of this paper. Each group is named from its 

 best known and most widely distributed representative, wherever this 

 could be determined. The grouping is as follows : 



1. Annularis : 



annularis, canadensis, comanchus, navajoe, apachus, carnifex. 



2. Aurifer : 



aurifer, anaheintensis , variatus. 



3. Pallipes : 



pallipes, metrica, neslor, fuscaius , fuscatus exilis,fuscatus instabilis. 



4. Carolittus : 



carolinus, americana, criniius, crinitus lineatis. 



5. Rubiginosus : 



rubiginosus, perplexus, generosus, bellicosus, texanus,Jlavus. 



The a7inularis group runs parallel in its general coloration with the 

 pallipes and aurifer groups. It is separated from them mainly by 

 differences in size, although in this matter the smaller representatives 

 of canadensis easily pass into the large representatives of pallipes. 

 Moreover, the larger members of the annularis group tend to be less 

 conspicuously colored than in general do the pallipes and aurifer <gxo^x■^s. 

 The conspicuous yellow or yellow and brown spots are uniformly 

 absent, and the borders if broad are not so bright a j^ellow. The 

 group, then, is characterized by great size and dull brown or brown 

 and black coloring ; yellow is present in the borders, but restricted or 

 often slightly suffused by the darker pigment. Thus in ca7iadensis all 

 the borders may be lacking or extremely narrow, while in an?iularis 

 the border of the first abdominal segment alone persists as a more or 

 less conspicuous ring. In the remaining members of the group the 

 borders are broad, but suffused and darkened by the cuticular pigment. 



The aurifer group is intermediate in size and coloring. It is black 

 or dull brown, with conspicuous yellow borders and metameric spots, 

 which blend to form large areas, especially in the more xanthic mem- 

 bers of the species atirifer and anaheimeyisis . The metathorax is 



