376 THE CANADIAN ENTOMOLOGIST. 



xylol-balsam (i slide), i 9 head in xylol-balsam (i slide). Co-type No. 

 I2,igg, United States National Museum, Washington, D. C; i c?, i $ 

 tag-mounted. 



Species Formerly Referred to Arthrolytus. 



1. Arthrolytus clisiocampce (Fitch). 



This species was described as C/eofiyt/ms disiocatupcehy Fitch (1856), 

 Riley (187 1) thought the species to be more properly a Se?neotelliis : 

 about twenty years later, Ashmead (1894) referred it to Arthrolytus, and 

 subsequently in Howard, in 1897 J Fiske (1903) decided it to be synonymic 

 with Dibrachys bouchea?ius (Ratzburg). Still later, however, he again 

 refers to it as Arthrolytus clisiocampce (Fitch) (Mason, 1906). I have 

 examined specimens of this insect in the Mason collection, determined by 

 Ashmead and labelled variously Dibrachys clisiocampce. (Fitch), Arthroly. 

 ius clisiocampce (Fitch), and there can be no doubt but that they are 

 identical and belong to Dibrachys. The species is Dibrachys bouchea?ius 

 (Ratzburg) of authors. 



2. Arthrolytus pimplce (Ashmead). 



Ashmead, 1894, p. 339. 



De Dalla Torre, 1898, p. 155. 



An examination of the description of this species, together with notes 

 furnished me by Mr. J. C. Crawford, of the National Museum, Washing- 

 ton, D. C , taken from the types, shows that it belongs properly to 

 Dibrachys Foerster. The antennae are inserted distinctly below (ventrad 

 of) the middle of the face, from the direct cephalic aspect, the face not 

 being produced ventrad. This character is easily seen upon comparison 

 of the two genera. The species pifuplce, however, has the antennal 

 pedicel longer than the proximal funicle joint, not true with Dibrachys^ 

 but the sum of its characters, so far as I know them, shows its affinities 

 to the latter genus. 



3. Arthrolytus i?ico??grue?is Masi., 1907. 



This species has 3- and 4-dentate mandibles ; it is therefore not 

 Arthrolytus, as at present understood. 



Table of the Species. 

 The following diagnosis is based mostly on the literature. I have 

 been unable to select structural characters as a basis for separation of the 

 species, and have not much reliance on colorational differences in these 

 metallic Pieromalinae. For the present, therefore, the species, as they now 

 stand, are indexed in the following table, which should be used with caution. 



