ART. 15«. REVISION OF SUBFAMILY PLATYGASTERINAE FOUTS. 11 



(Latreille) Walker is not Latreille's species and has been synonym- 

 ized with Platygaster grandis Nees by Dalla Torre/ In the National 

 Museum there is one specimen from Europe labeled "Essex, England, 

 Isocyhus grandis Nees." I do not know who labeled the specimen 

 but it agrees pretty well with Nees' description.^ Compared with 

 specimens of canadensis (Provancher) I can find few differences, none 

 fundamental, the most important of which are the slightly coarser 

 sculpture of the mesonotum and the darker color of the antennae. 



Only one species is known from North America. The two others 

 included in this genus by Ashmead ® do not agree with the diagnosis 

 given above and are placed elsewhere. Platygaster pallipes Say is 

 retained as a doubtful species in Platygaster. Isocyhus longiventris 

 Ashmead is redescribed in the same genus. 



1. ISOCYBUS CANADENSIS (Provancher). 



Platygaster canadensis Provancher, Addit. Fauna Ent. Can. Hym., p. 181. 

 Monocrita canadensis (Provancher) Ashmead, Can. Ent., vol. 19, 1887, p. 126. — 



. Cresson, Syn. N. Amer. Hym., 1887, p. 249. 

 Isocybus canadensis (Provancher) Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 



329.— Brues, Bull. 22, Conn. Geol. Nat. Hist. Survey, 1916 (1917), p. 541. 

 Isocybus nigriclavus Ashmead, Bull. 45, U. S. Nat. Mus., 1893, p. 328. 

 Isocybus pallipes (Say) Ashmead, Can. Ent., vol. 19, 1887, p. 132. — Cresson, 



Syn. N. Amer. Hym., 1886, p. 250.— Ashmead, Bull. 45, U. S. Nat. Mub., 



1893, p. 328. (Misidentification of Say's species, see p. 109.) 

 Isocybus pallipes (Say) Brues, Bull. 22, Conn. Geol. Nat. Hist. Survey, 1916 



(1917), p. 541. 



Female. — Length 4 mm. Head two-thirds as wide as long, as wide 

 as the thorax, very full behind the eyes, the cheeks being highly con- 

 vex and much wider than the eyes; occiput and vertex shagreened, 

 the former emarginated, sometimes punctate rugose; frons rugose, 

 finely set with twisted raised lines, reticulated; cheeks sometimes 

 with a sculpture similar to that found on the frons, frequently sha- 

 greened, without raised lines; antennal projection depressed down 

 the middle, notched anteriorly ; scape slender, long and curved, extend- 

 ing above the dorsal surface of the head; pedicel as long as joint four, 

 shorter and wider than three which is three times as long as wide at 

 apex; joints five to nine wider than four, a little longer than wide, 

 cylindrical; ten as long as three, subacute apically, the upper side 

 curved near the apex; thorax nearly twice as long as wide, more or 

 less flattened above, higher than wide; pronotum roughened and 

 strongly punctate above on the sides; mesonotum usually mostly 

 polished, sometimes mostly sculptured like the frons; notauli deep, 



<Cat. Hym., vol. 5, 1898, p. 469. 



» Hym. Affin. Monogr., vol. 2, 1834, p. 30a 



'Bull. 45, U. S. Nat. Mus., 1893, pp. 3-7-33 



