1915] North American Pachygasterine Sili7 
Dorsum of mesonotum and scutellum distinctly punctured; between the 
groups of silvery hairs on mesonotum, and on the scutellum also, are 
numerous, less conspicuous, silvery hairs; shape of scutellum when 
viewed from the side as in Figure 8. Abdomen short and broad, disc of 
segments punctured as mesonotum. Legs rather stout, surfaces with 
very short hairs. Fork of third vein slightly sloping towards apex of 
wing, distance from apex of fork to apex of third less than one-third the 
distance from apex of stigma to apex of fork. 
Length, 3.5 mm. 
Type locality, Algonquin, Ill. (W. A. Nason). 
A specimen, without locality data, from the Loew collection 
and placed with the type Pachygaster pulcher, has the antennz 
considerably larger, the third joint very much deeper than 
long, the arista slender, with very short pubescence, the silvery 
pile arranged in irregular narrow stripes instead of punctiform 
groups; no noticeable silvery pile on abdomen. I am rather 
inclined to the opinion that this specimen is the female of a 
distinct species, but because of uncertainty as to the locality 
from which it was obtained and a disinclination to dissect 
a specimen which does not belong to me, I am forced to leave 
the matter in doubt, even as to sex. 
Dr. Kertesz has described the genus Vzttiger* from Peru. 
This genus closely resembles punctifer in the arrangement of the 
thoracic pilosity, antennal structure, and venation. The 
principal differences between the two genera lie in the position 
of the antenne, which in Vzttzger are inserted below the middle 
of the head, in profile, while in Eupachygaster they are at the 
middle; in the form of the scutellum; and in the form of the fore 
legs, which in Vzttiger are distinctly stronger than the other 
pairs and have the tarsi flattened, whereas in Poe eee, 
the legs are all of equal strength. 
Themiite history of the: present, species, is unknown, >. 
tarsalis has been reared from larve found on Pinus in Scotland, 
and on Populus in England. Lundbeck has recorded the 
same species from apple and oak, while Verrall indicates that 
Dr. Sharp reared it from Fagus. The pupal case is figured by 
Verrall,j Figure 11 in present paper being a reproduction 
of that by Verrall. 
*Ann. Nat. Mus. Hung., Vol. 7, 1909, p. 395. 
{British Flies, Vol. V, Stratiomyide, Fig. 100, p. 75. 
