J. H. MERRILL 141 



In 1864, Cresson described Rhyssa alhomaculata. He separated 

 this species from R. persuasoria on the grounds that the former 

 had a white band on its antennae, a slight difference in color 

 markings and a small petiolated areolet, but as specimens occur 

 with white banded antennae and areolets similar to those with 

 black antennae and vice versa, and as there is a great range in 

 both thoracic and abdominal markings which do not adhere 

 always to the antennal or areolet differences, it would seem that 

 R. alhomaculata is really R. persuasoria. R. skinneri Viereck 

 is described from one specimen, mainly upon structural characters, 

 with some difference in color markings, but in R. persuasoria 

 there is a marked variability in structural as well as in color 

 markings. The clypeus may range from pointed to truncate, 

 the face may be medially elevated and smooth or striated or 

 the whole face may be elevated. There is considerable variation 

 ' in the puncturing and rugulose characters of the thorax. The 

 notum of the propodeum may or may not have a medial-longi- 

 tudinal depression. As for the differences in color it would 

 seem that no dependence could be placed upon them, and that 

 Rhyssa skinneri will probably prove to be a synonym. Rhyssa 

 ala&kensis was described by Ashmead from one specimen. The 

 description of this species will apply equally well to Rhyssa 

 persuasoria and it will probably prove to belong to the latter 

 species. 



Table to Species of Rhyssa 



1 . Face elevation longitudinally rugulose skinneri Viereck 



2. Face elevation not longitudinally rugulose persuasoria Linnaeus 



Rhyssa skinneri Viereck 



Rhyssa skinneri Viereck, Trans. Am. Ent. Soc, xxix, 1903, p. 87, 9. 



Type. — In collection of Acad, of Nat. Sci. Phila., from Beulah, 

 New Mexico, Aug. 17, 1901, (H. Skinner). 



"Face rugulose; mesonotum almost uniformly transversely striate, the 

 striae not apparently gibbose. Raised line separating metanotum and pleura 

 poorly defined, being obsolete below the spiracles. Length, 23 mm., face 

 somewhat elevated medially, the elevation rather longitudinally rugulose, 

 sides and anterior margins of the face, polished and moderately sparsely jjunc- 

 tured. Clypeus highly pohshed, distinctly produced to a point medially, and 

 with a row of deep punctures. Cheeks polished, almost impunctate. Dor- 

 sulum transversely striate, the striae delicate but well defined posteriorly. 



TRANS. AM. EXT. SOC, XLI. 



