400 U. S. NATIONAL MUSEUM BULLETIN 216 



This species occurs in Arizona and Colorado, where it has been 

 reared from semidesert conifers. 



II. AMOENA GROUP 



Face with sparse hairs laterally and somewhat denser hairs medially; 

 lateral portion of prepectal carina moderately strong; first tergite 1.15 

 to 2.5 as long as wide; second through sixth tergites mat, the mat 

 sculpturing transverse, giving a transversely aciculate appearance, 

 especially in females; third tergite with rather short hairs of rather 

 irregular density, on the average their sockets separated by about 

 1.5 (in males) or 3.0 (in females) length of the hairs; second through 

 fourth sterna of male with three separate longitudinal sclerites (a 

 median wider sclerite and two narrower lateral ones) ; apical mem- 

 branous area of female second through fourth sterna extending forward 

 between paired sternites or about 0.35 length of the sternites; apical 

 margin of male subgenital plate convex, subtruncate, or with a broad 

 weak median notch. 



There is a strong tendency in this species group and in the 

 persuasoria group for the coloration to vary with size. Larger speci- 

 mens tend to have the white markings more extensive than normal 

 and smaller specimens to have not only the white markings reduced 

 in size but the fulvous of the legs replaced by fuscous. These same 

 correlations of color with size occur in a great many Hymenoptera, 

 but in such species as Rhyssa lineolata the unusually extensive 

 white markings of larger females is so striking that the specimens 

 appear to belong to a separate species. 



The general coloration is black with white markings distributed 

 about as described for R. persuasoria, but all species of the present 

 group differ from persuasoria in tending to have a white vertical bar 

 or splotch in the hind part of the mesepisternum, this bar or splotch 

 often broken into two spots, one near the middle coxa and one more 

 dorsad. These two spots may be of about equal size or the more 

 dorsad one larger and more persistent. In persuasoria the mesepi- 

 sternum has a large white spot next to the middle coxa, and other 

 white areas which may be present are smaller and less persistent. 

 In both groups of species there is constantly a white spot on the 

 sub tegular ridge. An additional difference between this group and 

 persuasoria is that in persuasoria the seventh tergite of the female 

 has two large spots on each side (a long one in front and a shorter one 

 behind), which are sometimes more or less fused. In the amoena 

 group there is a long broad band in this position, which is of even 

 width or weakly lobed (figs. 317, c-f). The individual species of 

 the amoena group differ in color pattern as described below. Color 



