318 Annals Entomological Society of America [Vol. VIII, 
Neopachygaster Austen. 
As indicated in the introductory remarks to this paper, 
Neopachygaster was erected for the reception of a single species, 
orbitalis Wahlberg (as meromelena Perris), a species which 
is very closely related to maculicornis Hine, considered con- 
generic with it by the present writer. It is not difficult to 
separate the genus from Pachygaster in the male sex, as the eyes 
in the latter are contiguous.above, but the females are very 
much alike, both having the eyes separated, and more obscure 
characters must be used to separate this sex. Austen has used the 
form of the posterior orbits as the character for the separation 
of the females, stating that in Pachygaster these are produced 
in the form of a ‘‘prominent ridge,’’ while in Neopachygaster 
they are not. It is apparent from the figures given by Verrall 
that what Austen referred to, unless he was using minutissimus 
for comparison, was the distinct production of the posterior 
orbits on their lower half, which is almost indistinguishable 
in Neopachygaster. A character which very probably holds 
good and is of considerable value also, though not mentioned 
by Austen, is the shape of the head, which in Pachygaster atra 
Meigen is elongate, the eye being longer than high, while in 
Neopachygaster orbitalis 1t is short, the eye being distinctly 
higher than long. Unfortunately, it is not possible to use 
this character here unless one is prepared to erect a new genus 
for pulcher Loew, as this species has the eyes of the male con- 
tiguous above and the head higher than long, i. e., intermediate 
between Pachygaster and Neopachygaster. For a discussion 
of this point see under Pachygaster. It is not clear whether 
in orbitalis the dark mark on the antenne is of the same nature 
as in maculicornis—glossy and possibly of a sensory nature— 
though Austen’s description leads me to infer that it is. If 
this supposition is correct the presence of this mark or organ 
on the antenne might be used as a character for the separation 
of the genera in both sexes. 
Neopachygaster maculicornis Hine.* 
Male—Glossy black. Head black, eyes in life with a purple tinge; 
antennze yellow, a conspicuous glossy dark brown spot on inner surface 
of third (complex) joint; depressions above antennz and the lateral 
*Ohio Naturalist, Vol. 2, 1902, p. 228 (Pachygaster). 
