Horn.] 448 [Sep. 19, 



The terminal ventral segment is longer than either of the two pre- 

 ceding and oval at tip. The dorsum of the abdomen has seven segments 

 only. 



Lacordaire (Genera VI, p. 12) mentions the occurrence of six ventral 

 segments in the specimen before him but failed to recognize the nature 

 of the terminal segment, and having probably only males before him 

 failed to recognize its sexual nature. The projection of the pygidium in 

 the manner indicated is by no means rare in its occurrence, and I have 

 seen it in Balaninus, Orchestes and many Cento rhynchidce but in a much 

 less marked degree than we see it in Ithycerus. The apparent reduction 

 of the number of the segments by the entire obliteration of a suture, 

 usually the first, has also been noticed. 



Ithycerus occurs from Canada to Texas. The southern specimens are 

 less densely pubescent in the spaces between the short lines of white 

 pubescence, so that the latter are more strongly marked by contrast. Its 

 habits have been, fully elucidated by Mr. C. V. Riley in the "Third An- 

 nual Report on the Noxious, Beneficial and other Insects of Missouri," 



1871, p. 57. 



Otidocephaltjs Chev. 



The peculiar Ant-like form of the species of this genus renders it easily 

 known. All our species except one, have the femora toothed and are 

 known as follows : 

 Femora toothed. 



Thorax cylindrical, not constricted at base. 

 Elytra densely clothed with white pubescence with four 



glabrous lines on each vittatus. 



Elytra moderately densely clothed, pubescence in tufts, 



surface faintly bronzed Ulkei. 



Thorax anteriorly broader and more convex, at base con- 

 stricted. 

 Femora very strongly toothed ; elytra with moderately 



coarse punctures myrmex. 



Femora with a small very acute tooth. 



Elytra striate, striae coarsely punctured ; thorax 



densely and coarsely punctured scrobicollis. 



Elytra with rows of moderately fine punctures. 

 Thorax sparsely punctured, elytra broadly oval, 



gibbous Chevrolatii. 



Thorax smooth, elytra oblong oval, moderately 



convex : . . . . lcevicollis. 



Femora not toothed and more slender. 



Thorax coarsely, deeply and evenly punctured, hairs 



white perforatus. 



O. vittatus n. sp. 



Form moderately elongate. Rostrum vertical, nearly cylindrical, slightly 

 broader towards the tip, moderately punctured, at apex sparsely, at base 



