152 Psyche [August 
the naked eye, the species resembles some of the smaller species of Spa- 
langia and more closely, Pachycrepoideus dubius Ashmead, but the bodies 
of the latter are noticeably shorter and more compact, the antennz shorter 
and stouter. 
Described from the following 324 specimens, all, with the excep- 
tion of 50, now in the collection of the Illinois State Laboratory of 
Natural History and all reared from various house fly puparia, and 
those of two other Diptera, during the investigations of 1908 in the 
insectary of the office of the State Entomologist of Illinois at 
Urbana. Unless otherwise stated all of the specimens are mounted 
on tags. 
(1) Eleven males of the parasite emerged singly on October 17, 
from 11 puparia of Musca domestica Linneus which had been ex- 
posed in the insectary September 20 and 30; accession No. 40,251 
11 °’s. (2) On October 24 from the same lot of isolated puparia, 
there were removed 34 ©’s, 83 *’s; accession No. 40,250, 32 °%’s, 
81 *’s (2 3's, 2 ¥’s — Cotype No. 12,240, U. S. N. M.). (3) 6 *’s 
from the same lot April 25, 1909; accession No. 41,082, 6 °’s. (4) 
2 3's, 2 %’s, part of 7 3’s, 3 *’s reared October 2 from Musca 
puparia (see 11), parents of the next two numbers; accession Nos. 
40,248, 1 ¢, 1 *, and 40,246,1 9,1 °. (5) 4 9’s, 19 *’s reared 
October 20 and November 7 from single Musca puparia in confine- 
ment, progeny of the single pair of accession No. 40,248 (see pre- 
ceding) ; accession Nos. 40,249, 3 %’s, 10 °’s and 40,269, 1 7, 9 ®’s 
(6) 1%, 14 *’s reared October 20 to November 7 from 15 Musca 
puparia in confinement, progeny of the single pair of accession No. 
40,246 (see 4); accession Nos. 40,247, 1 9,7 °’s and 40,268, 7 °’s. 
(7) 3 °’s reared September 26 from three Musca domestica puparia 
formed from maggots in horse manure and exposed to parasitism in 
the insectary September 8 to 11; accession No. 40,144, 3 9’s. (8) 
4 °’s reared from four of the same host Jot, September 27; accession 
No. 40,146, 4 %’s. (9) 2 9’s reared from two of the same host lot 
September 28; accession No. 40,150, 2 °’s. (10) 2.9’s, 7 *’s 
reared from nine of the same host lot September 30; accession No. 
40,153, 2 2’s, 7 *’s. (11) 2 parthenogenetic females, reared from 
two puparia of lot 4 in preceding, parents of the following; acces- 
sion Nos. 40,298 and 41,000, 2 °’s. (12) 2 °’s reared October 24 
from two puparia of Phormia regina (Meigen), parthenogenetic 
