Casey — A Revision of the American Paederini. 207 



very slightly longer than wide and but little narrower than the head, 

 parallel and straight at the sides from the obtuse and slightly rounded 

 angles at apical fifth to the rather broadly rounded basal angles, the 

 longitudinal impression at each side of the median line in basal third 

 distinct; elytra somewhat longer than wide, about a third wider and 

 one-fourth longer than the prothorax; gular sutures rather widely 

 separated, the under surface of the head broadly and feebly convex, 

 shining, finely, rather sparsely punctulate. Male secondary characters as 

 in arizonae. Length 2.4 mm.; width 0.4 mm. Iowa to Lake Superior. 



notsingulus n. sp. 



12 — Form slender and parallel, the elytra being but little wider than the head ; 



abdomen piceous, gradually paler at tip; surface noticeably shining, the 

 minute punctules only moderately close-set throughout; head well 

 developed, as wide as long, parallel or subparallel at the sides, the eyes 

 moderately large, convex and prominent, the base distinctly sinuato- 

 truncate, the angles moderately rounded; antennae rather short; pro- 

 thorax but little longer than wide, obviously although not greatly 

 narrower than the head, the sides distinctly converging and straight 

 from the obtuse but scarcely at all rounded angles near apical fifth, to 

 the feebly rounded basal angles, the median line slightly and obtusely 

 elevated very near the base; elytra relatively small, slightly longer 

 than wide, not quite a fourth wider and about one-fifth longer than the 

 prothorax, the sides just visibly diverging from the basal angles; 

 gular sutures widely separated, the under surface of the head sparsely 

 punctulate and shining though feebly reticulate. Broadly angulate 

 notch of the sixth male ventral much shallower than in the preceding 

 species but of the same form. Length 2.1-2.4 mm.; width 0.3-0.35 



mm. Texas (Austin). [= bicolor Csy.] versicolor Csy. 



Form less slender and not parallel, the elytra much wider than the head, 

 pale dusky -testaceous throughout, the prothorax rather brighter rufous ; 

 surface somewhat strongly shining; head well developed, as wide as 

 long, the eyes rather large, prominent; antennae slender, but little 

 shorter than the head and prothorax, pale in color; prothorax relatively 

 small, notably elongate, much narrower than the head, the sides very 

 slightly converging and not quite straight from the obtuse and rather 

 broadly rounded angles near apical fourth, to the less obtuse but 

 rounded basal angles, the median line prominent only very near the 

 base ; elytra unusually developed, a fourth longer than wide, about 

 two-fifths wider and a third longer than the prothorax; gular sutures 

 moderately separated, rather deeper than usual, the under surface of 

 the head rather closely and strongly punctulate. Male unknown. Length 

 2.3 mm. ; width 0.45 mm. New York (Hudson Valley). 



hndsonicns n. sp. 



13 — Species of the Atlantic coast regions „ . 14 



Species of the Sonoran region 17 



14 — Head but little longer than wide, body only moderately slender 15 



Head elongate ; body extremely slender 16 



15 — Body parallel, alutaceous in lustre, the abdomen black or blackish, 



feebly paler toward tip, the head and elytra blackish-piceous, the pro- 

 thorax dusky testaceous, the legs and antennae pale throughout; head 



