EEVISION OF STREPSIPTERA PIERCE. 117 



segments greatly surpassing ninth ventral and bearing a spine on the 

 outer apical angle. Tenth ventral elongate subtriangular, equal in 

 length to about four segments, apically cleft, with a long stylet on 

 each apical point. 



The genus contains but two typical species: 



1. vesparum Rossi (1790), parasitic on Polistes gallicus; Italy. 



2. jurinei Saunders (1872) , parasitic on Polistes gallicus; Switzerland. 

 The two species may be identical, but by description are separated 



as follows: 



1. Maxillae with joints unequal, the first short , rounded, ttecondeloiig&te .vesparum Rossi. 

 Maxillae with joints subequal, the last subulate jurinei Saunders. 



i. XENOS VESPARUM Rossi (1790). 



Ichneumon vesparum Rossi, 1793. 



Xenos vesparum Siebold, 1843. — Pierce, 190S. 



Xenos rossii Kirby, 1813. — Saunders, 1872. — Nassonow, 1892 c, e. 



Host. — Polistes gallicus Linnaeus; Europe (Italy) ( fig. 2, nos. 15, 

 16, 17; pi. 5, fig. 4; pi. 7, figs. 4, 8, 13). 



The original description by Saunders was essentially as follows: 



Male. — Black, fuliginous. Head small. Eyes strongly prominent, 

 spherical, composite. Maxillss short, rounded, with palpus elongate, 

 compressed. Antennas short, hardly longer than head, third joint 

 branched, the branch equalling the elongate fourth, both of which 

 are defiexed, compressed, somewhat ensiform. Pro thorax and meso- 

 thorax cylindrical, neck like ; metathorax broader, convex, posteriorly 

 greatly elongate. Abdomen almost cylindrical. Femora and tibias 

 posteriorly depressed and short. Tarsi fuscous, beneath white. 

 Wings white, as long as the abdomen." 



Kirby (1813) has made a humorous statement. He asks pardon 

 for "altering the trivial names" given by Rossi and Peck to these 

 species as they would lead to confusion, and because " a species should 

 not be named from a habitat which is common to several or to a 

 genus." Now it happens that Kirby described Stylops melittse, which 

 name is as general as vesparum or vespse. The writer replaces ves- 

 parum, as according to his interpretation it is a legitimate name. He 

 permits vespse to become a synonym of Schistosiphon peckii Kirby, 

 because it was merely a manuscript name (Stiles, 1905, p. 45). 



a Malc. — Totus ater, fuliginosus. Caput parvum. Oculi valde prominuli, sphaerici, 

 manifeste compositi. Palpi duo filiformes longiusculi, articulis duobus inaequalibus, 

 primo brevi, rotundo, altero elongato, compresso. Antennas breves, vix capite lon- 

 giores, dupliei ramo instructs, ramis aequalibus, deflexis, compressis, quasi ensiform- 

 ibus. Thorax lobo antico in collum veluti protractus, et singulariter utrinque ad 

 basin appendiculatus, membranula, seu pedunculo instar halterum porrecto, coch- 

 leariformi (elytris); in medio latior, convexus, inaequalis, posticeque admodum elon- 

 gatus. Abdomen fere cylindricum, neque petiolatum neque aculeatum. Femora 

 tibiaeque postice depressse et breviores. Tarsi (articulis) quatuor, fusci, subtus albidi. 

 Alae albae, longitudine abdominis (Saunders, 1872). 

 84359— Bull. 66—09 9 



