ART. 16 NORTH AMERICAN ICHNEUMON-FLIES CUSHMAN 31 



of metapleurum more or less distinctly obliquely striate, propodeum 

 reticulate-rugose, striately so in middle posteriorly, apophyses thick, 

 subtuberculate, apical carina otherwise entirely lacking, spiracles 

 small oval; areolet somewhat shorter than high; nervulus antef ur- 

 eal ; postnervulus broken above middle ; nervellus distinctly inclivous, 

 broken far below middle; legs slender, front tibia subinflated. Ab- 

 domen broadly fusiform, finely opaque coriaceous, first tergite pol- 

 ished, petiole broad, depressed, second tergite densely finely punc- 

 tate ; sheath less than half as long as abdomen, ovipositor stout, com- 

 pressed, apex subsagittate. 



Black with very profuse white markings as follows: Head (ex- 

 cept occiput, a median band on vertex and frons, apices of mandibles 

 and clypeus, and sometimes the clypeal suture) ; antennal annulus 

 centering on flagellar joint 7; propleura below; broad humeral mar- 

 gins and collar of pronotum ; two lines on mesoscutum ; scutellum and 

 its basal carinae ; postscutellum ; tegulae ; mesopleurum and sternum 

 excejDt along sutures and impressions; both upper and lower divi- 

 sions of metapleurum ; a broad band on each side of propodeum from 

 basal carina to apex and enclosing the apophyses; base and apex of 

 first tergite and broad apices of others ; wings hyaline ; legs testaceous, 

 front coxae and trochanters, middle coxae, dorsal spot on hind coxa, 

 and hind tarsus except blackish apical joint whitish. 



Male. — More slender than female, subpolished, the sculpture much 

 weaker throughout ; temples broader and more strongly convex ; api- 

 cal carina more or less distinct throughout and without apophyses; 

 abdomen very narrowly fusiform. 



Clypeus entirely white ; antennae without annulus ; hind coxa white 

 with a black stripe above; trochanter largely black; tibia fuscous 

 with a paler dorsal streak, which sometimes encircles the tibia; tar- 

 sus black at extreme base and apex, otherwise white; apex of third 

 and entire fourth tergite reddish. 



The normal host for this species is apparently the egg-sacs of 

 spiders, many of the specimens examined having been reared from 

 the egg-sacs of Drassidae; but there are two specimens said to have 

 been reared from lepidoptera, one from Laspeyresla fiiolesta Busck 

 and one from a case-bearer on smartweed. 



The type of orhus was from Indiana; that of diligens from Illi- 

 nois; and that of amMiIicornis from Mississippi. The other speci- 

 mens studied are as follows : Four females and two males, including 

 the neotype of orhus and the homotype of diligent., Twining, Md., 

 April, 1898, ex-egg-sacs of {P7'ostheswia)=Z€lotes sp., A. Busck; 

 two females and one male from the same or a similar host, without 

 locality label but reared by Theodore Pergande probably from near 

 Washington ; one female. Glen Echo, Md., July, 1923, R. M. Fouts ; 



