ART. 15«. REVISION OF SUBFAMILY PLATYGASTERINAE FOUTS. 51 



This beautiful species is easily recognized, the color of the wings 

 and the shape and sculpture of the abdomen being characteristic. 



19. PLATYGASTER HYALINIPENNIS (Ashmead). 



Isorhombus hyalimpennis Ashmead, Can. Ent., vol. 19,1887, p. 129, female. — 

 Cresson, Syn. of Hym., 1887, p. 249.— Ashmead, Bull. 45, U. S. Nat. Mus., 

 1893, p. 276, pi. 12, fig. 2, male. 



Female. — Length 1 .50 mm. Head transverse, twice as wide as long, 

 a little wider than the thorax, rather full behind the eyes; head mostly 

 shagreened; frons finely shagreened, moderately striate just above the 

 insertion of the antennae; vertex separated from the occiput by a 

 blunt ridge; antennae long and slender, the ilagellum gradually 

 increasing in thickness toward tip: last three joints somewhat thicker 

 than the others, black; joints eight and nine transverse; ten longer 

 than wide, blunt apically; thoracic ratio; length 25 (0.555 mm.), 

 width 17, height 19; mesonotum subconvex, shagreened, shining, no- 

 tauli distinct to the middle of the mesonotum, strongly diverging 

 anteriorly; median lobe narrowed apically, rounded, nearly touching 

 the scutellum; scutellum convex, shagreened, with high margins later- 

 ally, sparsely pubescent on the sides ; dorsal plate of the scutellum 

 turned upward slightly at apex, forming a small tubercle: the length 

 of the abdomen is to the length of the thorax as 30 is to 25; abdomen 

 spatulate, alm^ost two-thirds as wide as long, sharply pointed apically, 

 more strongly pubescent on the first tergite and the second at base, 

 laterally and ventrally; second tergite about as wide as long, without 

 sculpture (except on the inner sides of the short basal foveae, where 

 it is striate) ; segments three to six united a little less than half as 

 long as the second, polished and shining; last segment triangular, 

 broadly transverse, acute at apex ; abdomen widest at the apex of the 

 second segment, the sides anterior and posterior to this point straight, 

 forming a continuous line; first segment half as wide as the second at 

 apex ; legs rather long and slender, the hind femora reaching to the apex 

 of the second abdominal tergite; wings hyaline, without cilia, reaching 

 far past the apex of the abdomen. 



Type locality. — Jacksonville, Florida. 



Tyve.--Csit. No. 25435, U.S.N.M. 



Thetype and paratype were studied in drawing up the descrip- 

 tion. A female paratype in Ashmead's type series belongs to a dif- 

 ferent species (in Leptacis) as yet undescribed. The male described 

 by Ashmead (1893) is a different and new species belonging to the 

 genus Platygaster but is in poor condition for description. 



This species represents another extreme in the genus Platygaster. 

 The antennal color pattern is unique and the tubercular scutellum, 

 while not unique, is certainly very extraordinary. 



