128 PSYCHE [December 
length, a third the length of 2; segments 4, 5, 6 and 7 subequal, slightly shorter than 
3; segment 8 conic, shorter; abdomen flatly convex dorsad, about as long on the 
head and thorax combined. Male.— Abdomen nearly as in the female, stout, as 
long as the combined lengths of the head and thorax; segments 2, 3 and 4 subequal, 
and 5, 6 and 7 subequal, slightly shorter, the 7th somewhat shorter than 6, and seg- 
ment 8 still smaller, conic. Highly convex above and flatly so ventrad; sometimes 
larger in proportion to the body than in the female. 
Both sexes vary considerably in size as shown by the measurements given, so 
that size is not always indicative of sex. A number of males and a few females have 
been seen which were not much larger than some Mymaridae, not easily noticed with 
the naked eye, though distinct when once seen. 
Types:— Type No. 12,318, U.S. National Museum,’ Washington, D. C. Co- 
types, — 2 2’sin the Nason Collection (Illinois State Laboratory of Natural History, 
Urbana, Illinois), Algonquin, Illinois, May 11, July 3, 1895. Homotypes — Acces- 
sion No. 40239, Illinois State Laboratory of Natural History, Urbana, 12 <’’s, 
126 2’s, tagmounted, and 2 o’’s, 2 2’s in collection U. 5. National Museum, Wash- 
ington, D. C., also tagmounted. 
Described from the following series of 640 specimens, nearly all of which were 
reared from various muscid puparia in the insectary of the Office of the State Entomol- 
ogist of linois, at Urbana, Ilinois, during 1908, and now in the collections of the 
Illinois State Laboratory of Natural History; unless otherwise stated the specimens 
are mounted on tags. All of the host material was collected in the immediate vicinity 
of Urbana or its twin town, Champaign, Illinois, Champaign County: 
(1.) Four females reared September 9th and two females September 11th, 
in a cage containing decomposed chicken viscera obtained from the city garbage 
grounds on August 22nd and infested with the maggots of the following Diptera — 
Chrysomyia macellaria (Fabricius), Sep. 7th, Calliphora erythrocephala (Meigen), 
Sep. 11th, and Sarcophaga species “‘k’’? (Sep. 22nd); one of the females observed 
ovipositing into a puparium of the Chrysomyia on the 9th of September; Accession 
Nos. 39912 (3 2’s xylol-balsam, 1 2 head, 1 slide) and 39921 (2 2’s); the latter is- 
sued in company with asingle female of Pachycrepoideus dubius Ashmead MS. (2.) 
1 female captured at large in insectary around fly breeding-cages, September 12th; 
Accession No. 39925 (1 2). (3.) 7 females captured in the insectary same date 
“119, tagmounted, from the Nason collection, Algonquin, Illinois, labelled 6.18.95-114 and 4495. 
There are also 2 other tagmounted females from the same collection, designated as cotypes and respectively 
labelled6.24.95-114 and 4593; and 6.2.95-114 and 4644. Thesejlabel numbers were made by Dr. Nason.” 
2Species nova; designated thus for convenience. The Diptera mentioned throughout were deter- 
mined by C. A. Hart. 
3 This species is described in the second paper of this series. 
