Fussorial Ilymcnoptcra of North America. 10!) 



outside in a yellow streak ; flagcllum black, first joint polished, re- 

 maining ones dull black. Surface of the head minutely punctured. 

 Prothorax narrow, high and convex, mesial notch deep ; lateral sur- 

 faces obscurely channelled, sides rounded not angular, black. 



Surface of thorax minutely puncto-striated. Mesoscutum with 

 mesial and subiuesial lines very distinct; parapsidal grooves slightly 

 marked. Surface entirely black except the yellow lateral tubercles. 

 Scutellum and meta-scutellum black, minutely puncto-striated, the 

 latter especially so. Propodeuiu with an obscure sublunate enclosure, 

 with a basal row of small fossae from whence diverge cuvilinear 

 minute strife ; hinder portion rather smaller than usual, with minute 

 ridges converging towards insertion of abdomen, bounded above 

 by a ridge which distinctly separates the two regions of the noturn; 

 mesial furrow well marked expanding on the posterior region. Coxae 

 and femora black, tibiae black with a yellow stripe externally; which 

 on the hind tibiae is dilated towards end of joint. Tarsi ferruginous, 

 three middle joints lighter than the rest, basal and unguinal joints 

 dark brown. Tegulae and nervures rufous, wings slightly clouded. 



Abdomen broadly ovate flattened above, beneath convex, nearly as 

 long as the head and thorax together, surface shiney smooth, with four 

 pairs of short, broad, ovate, non-sinuate fasciae; basal pair on second 

 ring twice as large as the succeeding ones, and placed on the sides, 

 not contiguous above; tip acutely mucronate, deeply channelled above, 

 narrow at base, hardly one-third as wide as long. Beneath black, 

 edges of rings slightly paler. 



Length of body, .28 ; head and thorax, .16; abdomen, .12 inch. 



Colorado Territory, (Coll. Ent. Soc. Phil.). 



Smaller than the allied species C. montanus and C. atricfps, and can 

 be easily known by its black thorax and the sculpturing of the propo- 

 deum ; its anterior portion being divided by the mesial furrow into 

 two quite regular quadrants, and bounded below by the ridge, while this 

 region is much longer than usual, and the posterior vertical portion 

 much smaller than commonly observed. Its black thorax, the very 

 distinct ridges on the anterior portion of the scutum, the entirely black 

 femora, unusual style of coloration of the tarsi and black scape ringed 

 with yellow at the tip, and the unusually cubical head when compared 

 with C. obscurus and aurifrons will easily distinguish it. 



The group of which C. septentrionalis and C. cephalotes of Europe are 

 types, differs trom the foregoing species in some remarkable characters. 

 '1 he head is a third shorter, and longer by a third, being unusually 



