COLORATION IN POLISTES. 39 



The Texanus-Rubiginosus Type. 



By this name we designate a number of large, handsome forms which 

 pass into one another by innumerable transitions. The prevailing color 

 varies from a light golden red to a deep red-brown. Some of the species 

 are nearly uniform in coloring, while others are conspicuously orna- 

 mented with yellow, and yellow and black. The ornamentation of the 

 abdomen and face is of the same general nature as that already described, 

 but the thorax displays several new characters. I have succeeded in 

 securing only one colony of riibiginosus from Florida, but the series is 

 well represented in all the general collections I have studied, and 

 through the kindness of Messrs. Melander and Brues I am in posses- 

 sion of a large number collected at Austin, Tex. 



CONSIDERATION OF VARIATIONS AT RANDOM. 



P. texanus is the lightest member of the series. It has a reddish-yellow 

 color, varied with yellow in the borders and the metameric spots ; 

 metathorax with two or four variable yellow stripes, post-scutellum all 

 yellow or more or less obscured by yellowish red, lower side in general 

 less yellow except in the male, where it has the yellow pattern character- 

 istic for the male of variatus. The size and uniformity of the yellow 

 areas varies greatly, as does also the depth of the yellowish red coloring. 

 Occasionally black appears in the anterior part of the anterior abdominal 

 segments. P. riibiginosus represents the uniform red-brown extremes of 

 the series. It is the most commonly known member of the group and 

 was first described by Lepeletier as being entirely clear reddish yellow. 

 But in the various collections studied the name has been made to include 

 specimens prevailingly uniform in their coloring, the tone ranging from 

 very light to very dark reddish brown. Yellow occasionally persists in 

 the anterior segments of the abdomen, and black appears to a varying 

 degree in the thorax and the anterior portion of the abdominal segments. 

 The various patterns which the red and brown may assume in the meso- 

 metathorax are illustrated in Plate II, figs. 30, 31, and 32, and their 

 relations will be made clear by the study of the ontogenesis of the color 

 pattern. 



Between these two species as extremes occur three species, bellicosus, 

 pcrplcxics, and generosus, which in the order named form a series with 

 increasing melanic tendency ; bellicosus has its markings somewhat more 

 obscure than texajiiis and a somewhat deeper general coloring. Ac- 

 cording to Cresson, who had 7 specimens, it is "smaller, less robust, 

 and darker in coloration than texanus, to which it is closely allied." 

 The ornamentation of the abdomen is different. The yellow margins 



