ICHNEUMONID^. 293 



area rather large, subquad rate; wings uniformly jiale fusco-hyaline,with a strong 

 purple reflection; tibire with a whitish annulus at base, nearly obsolete on the 

 posterior i^air ; abdomen long, basal segment bilineated and aciculate, the ba- 

 sal fovese of the second segment deep, neither transverse or oblique. Length 9 

 lines. 



Hab. — Illinois, (Dr. Lewis). One % specimen. 



I. saucius. — I cannot agree with Mr. Walsh (1. c.) in considering ater identi- 

 cal with this sjiecies. The two agree well in the antennoB and in the sculpture 

 of the metathorax ; but the head of saucius is unusually large in proportion to 

 the size of the insect, the wings dark, the abdomen long, narrow, convex above, 

 smooth and shining; while ater has a smaller head, the wings clear, the abdo- 

 men shorter, subdepressed and less shining, by reason of the surface being more 

 closely jiunctured. The general appearance of the two species is totally differ- 

 ent, and they are undoubtedly distinct. 



I. excultus. — 9 • Black, shining, abdomen with a rather strong blue reflec- 

 tion; head slightly narrowed beneath, immaculate; antennse rather stout, as 

 long a» head and thorax, black, with a broad whitish annulus about the middle, 

 third joint longer than fourth, which with the fifth is long and subequal; tho- 

 rax sliining, very finely punctured, immaculate; scutellum polished, impunc- 

 tured, slightly convex; metathorax rugulose, the elevated lines tolerably well 

 defined, the central area quadrate; wings uniformly jiale fuliginous, nervures 

 and stigma black; legs black, anterior pair pale in front; abdomen elongate, 

 immaculate, with a more or less obvious blue tinge ; first segment longitudinal- 

 ly aciculate, second densely punctured, aciculate on the basal middle, third 

 delicately punctured, the punctures becoming obsolete at tip, remaining seg- 

 ments smooth, polished and impunctnred. Length 6^ — 7 lines. 



Hab. — New Jersey, (Cresson). Three 9 specimens. 



I. apertus. — 9- Black; head and thorax thinly clothed with a very short, 

 fine, pale pubescence; head large, broad, not narrowed beneath, deeply punc- 

 tured ui^per half of anterior and posterior orbits narrowly white; antennre 

 moderately slender, longer than head and thorax, black, with a more or less 

 broad white annulus a little beyond the middle; thorax shining, a spot before 

 the anterior wing and another beneath, white, these are sometimes obsolete or 

 wanting ; scutellum flat, sometimes with a white spot at tip ; metathorax dense- 

 ly punctured, disk nearly smooth and shining, central area subquadrate, not 

 well defined; wings vary from hyaline to dusky; legs black, the anterior pair 

 pale in front; abdomen elongate, often tinged with blue; first segment gradu- 

 ally dilated at tijj, which is convex and closely punctured; second and third 

 segments closely punctured, a.\ncBA segments smooth, shining and almost with- 

 out punctures. Length 5J — 7 lines. 



Hab. — Connecticut, New York, Illinois. Twelve J specimens. Closely allied 

 to excultus and ater. From the former it is at once distinguished by the third 

 to sixth joints of the antennfe being oblong and subequal, and by the basal seg- 

 ment of the abdomen being punctured and not aciculate; and from ater by the 

 much longer autenn£B and its longer basal joints. 



I. acerbus. — %. Slender, black, shining, closely and finely punctured; head, 

 thorax and legs clothed with a very short, yellowish-sericeous pile; head small, 

 narrowed beneath, eyes large; a more or less distinct yellowish line on each 

 side of the face, wanting in two specimens; antennae long, slender, subserrate, 



