ART. 15'. KKVISION OF SUBFAMILY PLATYGASTEKINAE FOUTS. 109 



Ashmead's redescription of yalli'pes^^ is based on specimens conspe- 

 cific with the paratype of Isocyhus canadensis Provancher (see p. 11) . 

 They disagree with the description quoted above in such a remark- 

 ably way that I can not see how Ashmead could have made the mis- 

 take in identification which he did. 



IX. Genus PIESTOPLEURA Foerster. 



Piestopleura Foerster, Hym. Stud., Heft 2, 1856, p. 144, no. 4 (Monobasic). 

 Genotype. — Platygaster cafillus Walker (by original designation). 



Catillus Foerster, Hym. Stud., Heft 2, 1856, pp. 107, 111 (Monobasic). — Geno- 

 type. — Platygaster catillus Walker (by original designation). 



This genus, which has not as yet been correctly recognized outside of 

 Europe, differs from Leptacis only in having the scutellum more 

 strongly compressed. wSince compression to a certain degree is com- 

 mon in many species of Leptacis the character is not so very distinc- 

 tive. Still it seems best to retain the genus until intermediate forms, 

 if there are any, are found. 



Ashmead's species maculipes^^ is a Leptacis species. It has the 

 thorax and head only slightly compressed. 



X. Genus SACTOGASTER Foerster. 



iSaciooosfer Foerster, Hym. Stud., Heft 2, 1856, pp. 108 and llo. Two species 

 Genotype. — Epimeces ventralis Westwood. 



Head traverse, the vertex subacute to rounded, the occiput mar- 

 gined; ocelli 3, disposed in a triangle, the lateral ones about their width 

 from the eye margin; antennae 10-jointed in both sexes, in the female 

 terminating in a 4-jointed club, in the male the first flagellar joint 

 very closely joined to the second, causing the flagellum to appear 7- 

 jointed; pedicel obconic, as long as first two flagellar joints; first four 

 joints of flagellum cylindrical, the first joint half as long as second, the 

 third a little shorter than first, fourth slightly larger in diameter 

 than any of preceding, triangular; thorax ovoid, convex above, not 

 compressed laterally, the notauli indicated basally on the mesonotum ; 

 scutellum convex, transverse, armed with a thorn at apex, bifoveated 

 at base, covered •wath silvery pubescence; propodeum short, with a 

 median divided carina, it and the metapleura covered with silvery or 

 hoary pubescence; front wings veinless, with short cilia; legs clavate, 

 tibial spurs 1, 1, 1; basal joint of hind tarsi more than twice as long 

 as second. 



Some explanation is needed in regard to this diagnosis. The 

 characteristics of the female are well known and are correctly de- 

 scribed above, but those of the male are less well known in several 

 instances doubtful. This is due to the fact that the females are 

 very readily recognized while the males are so easily confused with 

 forms in closely related genera that authors have chosen to omit 



'8BuU. 45, U. S. Nat. Mus., 1893, p. 328. i»BuU. 45, U. S. Nat. Mils., 1892 'p. 265. 



