Casey — A Revision of the American Paederini. 23 



to the base, the basal part of the intermediate surface elevated above 

 the general level; basal joint of the antennae shorter than usual, being 

 scarcely one-half as long as the width of the head; prothorax slightly 

 broader near the base than at apex; elytra longer and wider than the 

 prothorax, parallel; abdomen as wide as the elytra, conically tapering 

 from the apex of the fourth segment; legs moderate, the tibiae strongly 

 spiuulose, the hind tarsi long and slender with the basal joint almost 

 as long as the next two combined and much longer than the fifth; in- 

 teguments smooth, polished and sculptureless above, except the basal 

 parts of the head and the abdomen, which are feebly micro-reticulate, 

 the head and pronotum rather finely, very sparsely puQCtate, the elytra 

 with widely separated even unimpressed series of extremely flue feeble 

 setigerous punctures. Brazil *A(lerobiam 



Neck distinctly and abruptly constricted across the dorsal surface; sculp- 

 ture strong and distinct, the punctures simple 5 



5 — Antennal joints not constricted at base, obconical, shorter and broader 

 toward tip; elytral suture strongly beaded. Body parallel, moder- 

 ately convex, moderate to large in size; head oblong, parallel, inflated 

 or narrowed behind the eyes which are well developed, finely faceted, 

 more or less prominent and anterior, the post-ocular foveolae well de- 

 veloped; neck broad, three-fifihs to three-fourths as wide as the head, 

 the basal angles of the latter only very rarely obliterated; mandibles 

 tridentate within, the two lower teeth on a broad common base and 

 equal in size, more developed on the left mandible; labrum edentate, 

 short, biobliquely truncate with a shallow rounded median sinus; basal 

 joint of the antennae relatively very moderate in length, not as long as 

 the next three combined; gular sutures fine, becoming very approxi- 

 mate behind the raiddle; lobes of the ligula rounded, coriaceous or 

 membranous, separate; mentum trapezoidal, large, feebly convex, coria- 

 ceous in apical half; prothorax rather small, oblong, always nar- 

 rower than the head; elytra greatly developed, always longer and wider 

 than the prothorax, usually elongate; abdomen seldom quite as wide as 

 the elytra, the sides parallel, the segments feebly impressed at base; 

 legs moderately long, slender, the hind tarsi elongate with the basal 

 joint usually distinctly shorter than the next two combined but about as 

 long as the fifth. Male with the subbasal ventral segments modified by 

 discal foveae or short transverse setose furrows, the third segment 

 lobed in the middle at apex, the lobe very variable. North and South 

 America Gastrolobinm 



Antennal joints not constricted or compressed at base, the el3tral suture 

 sti'ongly beaded. Body parallel or anteriorly attenuate, moderately 

 convex; head oblong, parallel, inflated or gradually narrowed behind 

 the eyes, sometimes notably small, the neck broad, three- fifths to three- 

 fourths as wide as the head, the ba'^al angles rounded to the neck or 

 obliterated; mandil)les bidentate within; eyes moderately large, an- 

 terior, more or less prominent, the facets fine and feebly convex; 

 labrum short, biobliquely truncate, edentate, with a small shallow 

 rounded median sinus; basal joint of the antennae elongate, as long as 

 the next three or four combined; post-ocular setigerous punctures well 

 developed; gular sutures fine and feeble, narrowly separated, most ap- 



