THE CANADIAN ENTOMOLOGIST, 15 



On Ocf. 27 the nests failed to produce any Trigonalys, but I captured 

 one $ at rest on the leaves of an apple tree much frequented by wasps 

 and growing about 100 yards away from the nests. 



Total specimens, 23 (^ and 4 ? . 



After the last-named date the weather became cold and wet, and no 

 more Trigonalys appeared ; so after waiting a day or two, I dug up the 

 nests, but was not able to detect any signs of the parasites. It will be 

 noticed that the flies were not commonly taken in the afternoons, and in 

 all cases (except the solitary specimen on the apple tree) they were at rest 

 on the grass and weeds within a ievf feet of the entrance to the wasps' 



nest. 



The type of T. canadensis, as may be seen by reference to the 

 paper above cited, was taken at Victoria (75 miles south of this place) 

 from what was supposed to be the nest of the same species of Vespa 

 {V, occidentaiis) vfhich. had built a suspended nest on the under side of a 

 veranda roof. 



As the $ o( T. canadensis differs from the $ in several details, I 

 have asked Mr. Harrington to kindly append a description of the former 

 sex to the present note. My 4 pairs of T. canadensis have been dis- 

 posed of as follows : i to Dr. Fletcher, i to Mr. Harrington, i to the 

 Entomological Society, and one reserved for my own collection. The 

 remaining $ specimens will be gladly given to any hymenopterists who 

 may care to ask for them. 



ADDENDUM BY W. H. HARRINGTON, F. R. S. C, OTTAWA. 



In accordance with the wish expressed by my esteemed friend in the 

 foregoing most valuable note on the occurrence of these rare and interest- 

 ing insects, I have prepared, from the three pairs submitted for inspection, 

 a description of the male, for in the original description (as is evident) 

 the word male should read female. 



Trigonalys canadensis, Hargtn. — Male. This sex differs in general 

 appearance from the female, chiefly in the larger and broader abdomen, 

 which makes it look much more robust. The following differences are 

 noted: Antennre 19-jointed, with the pedicel rufous, and terminal joints 

 sub-serrate, very much like those of the antennas oi a. S Vespa, but much 

 slenderer. Mandibles more prominent, with the teeth rufous. The yellow 

 markings of thorax are more conspicuous, and are as follows : Angle of pro- 

 thorax ; spot at each humeral angle of mesonotum, two lunate spots on 

 scutellum, and a smaller spot on each side between scutellum and base of 



