COLORATION IN POI^ISTES. 



63 



Mississippi Valley from the Gulf of Mexico. A third minor trend is 

 along the Pacific, coast. He also states it to be his opinion that this 

 same course of migration has been taken by various other species of 

 Coleoptera and Ivcpidoptera. 



Fig. 26.— Correlation between pigmentation of second abdominial segment and clypeus of females 

 in collection from Gotha, Fla. Classes o and i, fig. 24, are combined to form Class i, 

 Classes 5 and 6 are combined to form Class 5, and distribution of material in these 

 five classes is represented by the continuous line. With respect to markings of the 

 clypeus material falls into the following classes : 



1. Red-brown with prominent yellow border. 



2. Red-brown, yellow persisting occasionally at tip. 



3. Red-brown, with black spot on dot. 



4. Black or red-brown in about equal amounts. 



5. Entirely black. 



Distribution of material represented by dotted line. 

 Fig. 27.— Showing correlation between melanism of second abdominal segment and remaining 

 segments for collection from Cold Spring Harbor, New York. (See figs. 24 and 25.) 



Distribution in Europe. 



In Europe some entomologists recognize four species of Polistes — 

 i. e., bighcmis, pidior, gallicus, and diadema ; others recognize only the 

 two latter. D. Sichel, whose premature death prevented the publica- 

 tion of detailed observations on this group, proposed (20) to reduce 



