132 
Psyche 
[September 
means coarsely so; punctures of areae superoexternae and dentiparae 
often strongly defined, but generally discrete with highly polished 
intervals. The white markings, which are constant in location, vary 
only slightly in extent. 
affinities: The female holotype will run directly to the couplet 
containing M. brevicinctor (Say) and M. saevus (Cresson) in 
Heinrich’s key (Heinrich 1962) to the eastern Nearctic species of 
the subgenus V ulgichneumon Heinrich. 
From M. saevus (Cresson) it differs in the frontal orbits which 
are only white for a short distance above; in the flagellar annulus 
on segments 7 to 12 rather than 6 to 14 or 15; in lacking all white 
maculation on the collare, apex of pronotal ridge, and scutellum; by 
reason of the 31 segmented flagellum [38 or 39 segments in saevus 
(Cresson)] ; in the area superomedia which is distinctly longer than 
wide, and in its smaller size ± 8.5 mm. as compared to 11-13 mm. 
The female of M. heleiobatos displays also many points of distinc- 
tion from that of M. brevicinctor (Say). As to color, there is the 
white line on the frontal orbit above, the black scutellum and black 
hind trochanters as compared to the black frontal orbits, wholly 
white scutellum, and white hind trochanter of brevicinctor (Say). 
Furthermore heleiobatos has a white macula on gastral tergites 6 and 
7, brevicinctor (Say) only on 7. The lateral carinae of the scutellum, 
which in brevicinctor (Say) are only present at the extreme base, 
extend in heleiobatos almost half the length of the scutellum. The 
mesopleuron (and thoracic pleura in general) is much more shining 
and sparsely punctate than in brevicinctor (Say), where the surface 
is dull, closely punctured and extensively wrinkled, not only below 
but also above beneath the subalaum. The hind coxa is without a 
distinct scopa, whereas brevicinctor (Say) has a comparatively weak 
but easily visible and clearly delimited scopa. The surface of the 
areasuperomedia is smooth and polished with obscure wrinkles, while 
in brevicinctor (Say) it is completely reticulo-rugose. Likewise the 
areaesuperoexternae and dentiparae are more shining and less closely 
punctured in heleiobatos. Finally, in the females of brevicinctor 
(Say) examined, the area between the gastrocoeli has much less 
tendency to longitudinal striation than in the present species. 
The male may at once be distinguished from all eastern Nearctic 
species of Melanichneumon Thomson with mostly black abdomen by 
three characters in combination: no white flagellar annulus, black 
legs, prominent white marks on gastral tergites 6 and 7. 
From the male of saevus (Cresson) this species is moreover dis- 
tinct in its completely white clypeus and face, 32 to 34 segmented 
