322 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



length, the third, slightly the thickest; iu the $ the second funiclar joint 

 is stout and slightly curved, the club joints being not more than 1 J times 

 as long as thick; the three middle joints outwardly subserrate, the last 

 couically pointed, much longer than the preceding; the legs are black, 

 the tip of anterior tibije and tarsi fuscous, while the wings are slightly 

 smoky. 



IIabitat. — San Francisco and. Alameda, Cal. 



Types in National Museum. 



Described from many specimens, reared by A. Koebele, January 10 

 and 23, 1883, and July 10 and December 17 and 19, 1885, from a Cecido- 

 myiid gall found on Baccharis pilularis. 



PLATYGASTBR Latreille. 

 Gen. Cms. et Ins., iv, p. 31 (1809) ; Furster Hym. Stu«l., n, p. 108 (1856). 



(Type P. riificormH Latr.) " 



Head transverse, rarely subquadrate, the vertex somewhat narrowed, 

 convex, the lateral ocelli usually far away from the eye margin but 

 still nearer to it than to the front ocellus. 



Antenna^ 10-jointed, the scape subclavate, the liagellum ending in a 

 6-jointed, filiform club, the second joint in the male a little swollen and 

 curved. 



Thorax ovat«, usually more elongated than in Polygnotus, the collar 

 usually distinct, the mesonotal furrows distinct, the scutellum convex, 

 unarmed, the metathorax short, carinated. 



Wings veinless, pubescent. 



Abdomen oblong oval or ovate, the petiole usually distinct, at least 

 as long as wide, or a little longer, striated, the second segment very 

 long, striate at base. 



Legs long, clavate; the tibiae slender, the tarsi very long, tlie hind 

 tarsi being much longer than their tibiae. 



The genera Platygaster and Isocyhns are exceedingly closely allied, 

 but the head in laocyhuH is more (juadrate and the lateral ocelli are 

 nearer to the front ocellus than to the margin of the eye. 



I am not fully satisfied that they should be kjpt separate, although, 

 so far, the position of the lateral ocelli seems sufficient to separate them. 



The head in Platygaster Herrickii Packard and the position of the 

 ocelli is, however, very similar to Isocybus. 



TABLK OF SPECIES. 



FEMALES. 



Coxas l>lack. 



Legs yellow or golden yellow, antennie yellow, the club fuscons. 



Vertex rugose, Avitli raised lines in the middle; face closely puuctulate, with 



some transverse lines on lower part. 



Pedicel very long; first funiclar joint a little longer than wide, the second very 



long, twice as long as the first ; dub 6-jointod, the joints, except the 



last, transverse ,,,,,.,, P. GARY JS Ashm. 



