ICHNEUMON-FLIES OF AMERICA: 1. METOPIINAE 37 



carinae of third tergite present basally (indistinct in the species 

 T. teres) but absent beyond its middle (except in T. costatus, in which 

 these carinae are somewhat longer) ; fourth tergite without median or 

 sublateral longitudinal carinae except in some males of T. costatus. 

 This group contains eight known Nearctic species, an undeseribed 

 species in the Philippines, and another in Japan. Presumably some 

 of the described European species of the genus belong here also. 



1. Trieces masoni, new species 

 Figure 180,a 



Front wing 3.5 to 4.4 mm. long; face about 1.5 as wide as high^ 

 with small punctures that are separated by about 0.7 their diameter; 

 face and clypeus in profile weakly convex, with a distinct depression 

 setting off the clypeus; attachment of front tentorial arm outlined 

 as a brownish oval around clypeal fovea and a tail extending dorso- 

 mesad; eye apparently bare; flagellum of male with 29 segments, of 

 female with about 26 segments; metapleurum with coarse wrinkles 

 in its lower half that extend forward for about 0.8 its length, in its 

 upper half with finer irregular wrinkles interspersed with weak 

 punctures, this wrinkled area extending forward about 0.6 the length 

 of metapleurum; hairs on metapleurum numerous, arranged in a 

 broad subrectangular area in its upper hind part and in a small some- 

 what crescentic group in its upper front corner; propodeal spiracle short 

 elliptical, distinctly separated from pleural carina; front spur of 

 middle tibia about 0.60 as long as hind spur; second segment of middle 

 tarsus 2.3 as long as wide in male, about 1.6 as long as wide in female; 

 second abdominal tergite about 0.78 as long as wide in male, about 

 0.65 as long as wide in female, with rather close, subconfluent, oblique 

 punctures; sublateral longitudinal carina on third tergite rather 

 narrow, extending about 0.3 the length of the tergite. 



Black. Face except for a median dorsal area or a large median 

 area that is mostly subdorsal or widest dorsally, yellowish white, 

 the interantennal process always broadly bordered with yellowish 

 white; cheek in its front part or entirely, clypeus, and mouth parts, 

 yellowish white; tegula blackish brown, somewhat paler basally; first 

 trochanters apically, second trochanters entirely, and bases of femora 

 brown; tibial spurs pale brown; front leg beyond trochanters light 

 brown, the femur more or less infuscate basally; extreme apices of 

 middle and hind femora stramineous; middle tibia and tarsus light 

 brown, the basal 0.15 of the tibia faintly yellowish; hind tibia light 

 brown basally, blackish brown apically, the basal 0.15 faintly tinged 

 with yellowish; hind tarsus fuscous. 



Type: 9, Big Delta, Alaska, June 24, 1951, W. Pt. M. Mason 

 (Ottawa). 



Paratypes: c\ 29, same data as type (Ottawa). 



