610 
DIPTERA. 
Fig. 268. 
the eyes, and the latter spotted, with yellowish white. The 
legs are ochro-yellow, except the shanks and feet of the 
first pair, which are black. Its 
body measures nearly three quar¬ 
ters of an inch in length. My 
Sphecomyia undata (Fig. 268) has 
the slender form of a Sphex or 
mud-wasp. It is of a light-brown 
color, darker on the back, and 
on the middle of the thi<Ths and 
shanks ; its head is conical, and bears the antennae on the 
tip of the cone; its wings are brown on the outer part, with 
a small transparent spot near the edge, and the inner part 
is transparent in two large wavy spaces. It is about five 
eighths of an inch long, and its wings expand one inch and 
a quarter, or more. It is possible that this singular fly may 
he the Pyrgota undata of Wiedemann. ® An insect closely 
tellum. Pleura with an elongated yellow spot. Scutdlum brassy green, metalles- 
cent. Poisers pale fenaiginous. Leffs yellowish fei'ruginons, fore tibia (excepting 
the knees) and tarsi black. Hind thighs unarmed. Wings tinged with gray and 
brown ; a pale stripe along the latter part of the cubital vein; another runs along 
the pobrachial area and reaches the posterior mai’gin. Abdomen yellow; first seg¬ 
ment black; the three following segments have more or less black at the incis¬ 
ures along the fore bordei*, and a black band, attenuated at both ends, and not 
reaching the lateral borders, in the middle; the band on the second segment is the 
broadest, and is sometimes connected with the black of the first segment; those of 
the third and fourth segments are interrupted in the middle. Venter yellow, with 
large black spots on the mitldle of the segments; sexual organs pale ferruginous. 
Female: shows the following differences: front yellow, with a black stripe ex¬ 
tending towards the black vertex. Beside the three pairs of spots already men¬ 
tioned on the thorax, there is a fourth pair in the middle of the disk, each of the 
spots communicating by the groove with the second lateral spot. The black bands 
on the segments of the abdomen are broader, and connect at the fore and hind 
borders with the black incisures; the fifth segment has a similar band. The wings 
are more tinged with ferruginous than with gray; the pale stripes less apparent. 
Base of thighs more or less blackish. 
I have before me two males from Illinois, collected by Mr. Kennicott, and one 
female from Maine, collected by Mr. Packard. 
This species is very much like the Em*opean M. vespiformis^ Linn.— Osten 
Sacken.] 
[8 Sphecomyia undata is the Pyrgota undata.^ Wied. S. valida is likewise a 
Pyrgota.^ but a new species. Myopa nigripennis.^ Gray, might belong to the same 
group, as the figure in Griffith’s Animal Kingdom seems to prove. — Osten Sacken.] 
