1922.) 47 



1 (2) A distinct pattern of white spots or bands of hair on the abdomen 



these being placed along the apical margins of the segments. 

 .... Group I. 



2 (1) Spots or bands situated at the base of the segments or wanting. 



3 (4) Thorax not metallic, except slightly so in prasiniis Sm., which has the 



pvopodeum black, not metallic, and the apical dorsal segment of 

 the c? blood-red. .... Group II. 



4 (oj Thorax including the propodeum distinctly metaUic ; the apical dorsal 



segment of the c? not blood-red. 



.... Group III. 



The extensive second group may be tabulated as follows : — 

 Group II, 



1 (2) A very large .species, expanse of wings often 17 mm. or more, the 



hind tibiae clear testaceous. 



(Mandibles, labrum, and often the apex of the clypeus also black ; 

 abdomen with tomentose bands, the 5th vential segment conspicu- 

 ously emarginate, 6th with a deep longitudinal impression) 

 .... xanlhoi?us K. 



2 (1) Hind tibiae black or black and flavous. 



3 (4) Apex of clypeus, labrum, mandibles, and the antennae both above and 



beneath black, the abdomen beneath bare or only with short hairs. 

 (Antennae long and slender ; propodeum coarsely rugose above 

 and also on its posterior face ; abdomen elongate, subcylindrical, 

 polished, tlie punctures for the most part sparse and with distinct 

 tomentose spots in fresh specimens, the 4tli and 5th ventral seg- 

 ments widely emarginite) .... laevigatvs K. 



4 (3) Apex of clypeus in most species, and often the labrum and mandibles, 



yellow or yellow marked, antennae oi'ten red or fulvous beneath. 

 When all are black the abdomen has long hairs on the 2nd ventral 

 segment, easily seen in lateral aspect. 



5 (6) Ilind tibiae and the tarsi (except sometimes the claw-joint) black. 



A large species, generally 15 mm. or more in expanse, with distinct 

 tomentose abdominal spots, the 1st and 2nd segments densely, 

 nearly evenly punctured except at the apex. Wings infuscate or 

 smoky. 



(Anterior area of the propodeum closely rugose, and viewed from 

 in front, its hind margin is raised in the middle ; the lateral areas not 

 margined behind) nitidus Panz. {Q-notatus K.). 



6 (5) iSpecies which have both the hind tibiae and tarsi black are either 



small, or, if large, either the tirst abdominal segment is very re- 

 motely punctured or the wings are clear* hyaline. 



7 (8) Seventh abdominal segment wholly red both on its upper and its 



reflexed surfaces. 



(Head and thorax often distinctly metallic ; mesonotum finely, 

 densely punctured ; anterior area of the propodeum densely and 



* This character will at once distinguish the rare black-legged variety of leucozonius on the 

 most casual inspection. 



