15 
the anterior wings, has by some authors been considered to represent 
the episternnm of the metathorax. As already indicated, it is inti- 
mately fused with the mesothorax, and its place here is still further 
shown by its relation to the anterior wings. The epimeron of the 
metathorax is comparatively small, and the episternnm is apparently 
wanting, unless the sclerite just above the metepimeron may be so 
considered. 
The leg includes a large coxal joint, 2-jointed trochanter, and the 
femur, tibia, and tarsus occurring in the order named. In two genera 
the legs are characteristically shaped — Croesus having the apex of the 
hind tibia' and the metatarsus broad and flattened, resembling the con- 
dition obtaining in social bees, and Holcocneme having these parts 
somewhat enlarged and the posterior tibiae distinctly grooved exteriorly. 
This last character is, however, present in other genera, though less 
distinctly. The tibial spurs, of which there are two at the apex of each 
tibia, do not vary sufficiently to be of much value in generic or specific 
descriptions. The forward one of the anterior pair of legs is much 
stronger than the others, and doubtless serves the role of an antennal 
scraper, as does the corresponding spur in other Ilymenoptera. 
The claws, while affording primarily generic characters, are of some 
value in the characterization of species. Three distinct tyx^es of claws 
are noted, viz, the first, in which the claw is 
more distinctly cleft, the two teeth, which 
have been termed rays throughout the de- 
scriptions, extending in a direction nearly 
parallel, the inner ray being commonly not 
much shorter than the outer (fig. 4, d, e, /); 
the second form of claw consists in the pro- 
jection of a minute tooth well within the 
apex of the claw and extending nearly at 
right angles to the claw (fig. 4, b y c) ; and the 
third, a simple claw, without branch or tooth 
(fig. 4, a). 
The abdomen is ovate or elliptical, less 
, , . . T , ., ,., Fig. 4. — Typos of claws: a, Gymno- 
commonly elongate, as in huura, and usually nye1mS caUfornicxts; &, Pachynema- 
more or less depressed. It presents in the tus extmswomis; c, Lyjaoncmatus 
/* -i • i t • ,* j l -n i ! erichsonii; d, Amauronematus luteo- 
female nine dorsal arcs, it the small terminal tergum; ' e / Fteronus corneUi; f% 
sclerite attached to the large overlapping p<mtania agttis (original), 
eighth arc is considered to be distinct. This last sclerite, the ninth, 
bears laterally within the margin at its base the two uivjomted append- 
ages known as cerci. The female has but six ventral arcs, the terminal 
ones being metamorphosed into the ovipositor and its basal supports. 1 
The male abdomen has seven prominent dorsal arcs, with a thin and 
frequently concealed termiual arc, and seven ventral arcs, the last 
(hypopygium) being very long, more or less curved upward at the tip, 
l For structure of this organ in Ilymenoptera, see Proc. Ent. Soc.Wash., vol. n, p. 201. 
