May 23, 1917 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



Vol. 30, pp. 79-82 



DESCRIPTIONS OF FOSSIL INSECTS. 



BY T. D. A. COCKERELL. 



The insects described below are of special interest, since the 

 first represents a family not before known fossil, the second a 

 family new to American strata, and the third an additional 

 species of a rare family represented previously in America by 

 only two species, though in Europe by five. 



Hymenoptera. 



Trigonalys pervetus, new species. 



Probable length about 6 mm., but only part of thorax, wings and mid- 

 dle and hind legs of one side, and abdomen (lacking apex), are preserved. 

 Thorax, abdomen and middle and hind legs black, the middle tibiae with 



the basal half reddish ; wings 

 dusky hyaline, nervures 

 dark, stigma small ; marginal 

 cell ordinary, pointed on 

 costa ; three submarginal 

 cells, first receiving first re- 

 current nervure a moderate 

 distance from its apex, third 

 receiving second recurrent 

 nervure beyond middle ; sec- 

 ond submarginal cell subtriangular, third short; basal nervure falling 

 short of transverse medial ; hind wing with discoidal cell contracted at 

 base, so that the cubital and discoidal nervures roughly form a cross ; 

 scutellum strongly bilobed, the lobes rounded; abdomen not hairy ; sur- 

 face of wing delicately hairy ; middle and hind femora short, angulate 

 beneath; tibige long and slender, each with two spurs; tarsi very long 

 and slender, the hind tarsi about 3 mm. ; mid tarsi with first joint about 

 as long as 2 to 4 together, the latter successively shorter, fifth joint nearly 

 as long as second. 



Burmese Amber (Miocene), received from Mr. R. C. J. Swinhoe. 



19— Proc. Biol. Soc. Wash., Vol. 30, 1917. (79) 



Sci* f tilum, 



Fig. 1. Trigonalys pervetus. 



