THE NORTH AMERICAN ICHNEmiON-FLIES OF THE TRIBES LYCORINI, POLYSPHINCTINI, AND THERONIINI. By R. A. CusHMAN, Of the Bureau of Entomology, United States Department of Agriculture. INTRODUCTION. This paper consists of revisions of the North American species of three of the tribes of the subfamily Ichneiimoninae, the Lycorini, Polysphinctini, and Theroniini as defined by Cushman and Rohwer/ and is a contribution to a revision of the entire subfamily as represented in the North America fauna. The drawings of the entire insects and many of the detail drawings are by Miss Mary Carmody, formerly of the Bureau of Entomology, United States Department of Agriculture. Tribe LYCOEINI Cushman and Rohwer. This tribe includes the genera Lycorina Holmgren and Toxo-pJiorides Cresson as well as a new genus described below. The two described genera have always been referred to the (Pim-plini) Ichneumonini. The tribe is distinct from all the other tribes of the Ichneumoninae in the peculiar structure of the tergites. In this it superficially resembles the Glyptini, but is distinct from that tribe in having the first tergite apically similar in structure to the others and, in the female, in the form of the ovipositor and hypopygidium. These differences are of such nature that it is very doubtful if these two tribes have any real affinity. In the lanceolate ovipositor and pectinate claws the Lycorini are allied to the Phytodietini, but are readily separated by abdominal, propodeal, and other characters. With the latter tribe the Lycorini seems to have more in common than with any of the other tribes of the subfamily, but that the affinities between the two are very close seems rather doubtful. The species so far as is known, are parasitic on the larvae of micro-lepidoptera. Description. — Body stout; head in front view strongly transverse; eyes large, parallel within and usually slightly emarginate opposite > Proc. U. S. Nat. Mus., vol. 57, 1920, p. 379-396. Proceedings U. S. National Museum. Vol. 58— No. 2326. 7