OF WASHINGTON. 281 



The genus belongs in the subfamily Microgasterinag, in the 

 family Braconidae, and Ruthe has recorded that his species was 

 captured by Prof. Schenck with Formica rufa. He was of the 

 opinion it was parasitic on this ant. 



Ruthe briefly characterized the genus as follows : 



Maxillary palpi 2-jointed, labial palpi unjointed. Antennae 14-jointed, 

 the scape abbreviated. Eyes smooth (bare). Occiput flat, the vertex 

 narrowed. Front wings with 3 inconstant cubital cells, the radius eva 

 nescent towards apex. Abdomen depressed ; ovipositor hidden. 



Soon after my return from Germany, in 1890, among some 

 chalcidids taken by Mr. E. A. Schwarz at Washington in 1889, 

 I discovered a curious little 9 microgasterine with a long abdo 

 men, short, i3~jointed antennae and a peculiar wing venation 

 which I was unable to place in any known genus and to which I 

 gave the MS. name Par amir ax schwarzi, placing it away in my 

 cabinet for future study. 



Some months ago a $ of this peculiar braconid, with i4-jointed 

 antennas, was received from Mr. Carl F. Baker, taken at Fort 

 Collins, Colorado, and only a few nights ago I finished studying 

 it and the one taken by Mr. Schwarz and arrived at the conclu 

 sion that my MS. genus Par amir ax would not hold, since it 

 was identical with Elasmosoma Ruthe, the difference in the num 

 ber of joints in the first species not being sufficient to justify the 

 erection of a new genus. 



It is very remarkable that, the very next morning after reach 

 ing this conclusion, Mr. Pergande sent word from his office, if I 

 had time to spare, he would like to see me. 



Judge of my surprise, therefore, when he brought out two 

 specimens of a third species of this rare genus, mounted on a 

 single pin with an ant, two myrmecophilous beetles, and a myr 

 mecophilous cricket and asked me what it was. 



Having just finished studying my own specimens, I replied at 

 once, "Why, that is a species of the rare genus Elasmosoma 

 Ruthe. Where did you take it? " 



Mr. Pergande then told me that the day before, which was a 

 holiday, he went out collecting myrmecophilous insects and that 

 while inspecting the nest of Camponotus melleus Say, which 

 was under a large stone, he was pestered with some little flies 

 which were quite numerous and kept flying into his eyes and ever 

 and anon alighting among the ants, during his examination of the 

 nest. At first he paid no attention to them, mistaking them for 

 small oscinids ; but they were so persistent in alighting among 

 the ants that finally his curiosity was aroused and he determined 

 to find out what they were. Wetting the tip of his finger 

 with his mouth, he captured two, placing them in a vial with the 



