Casey — A Revision of the American Paederini. 123 
2— Head widest near the base, the sides diverging posteriorly from the 
eyes. Body very large in size, polished, black, the elytra bright rufous, 
with a black scutellar cloud, the abdomen toward tip, legs and antennae 
pale ferruginous; head large, rather wider than long, very coarsely 
and sparsely punctate, the sides broadly arcuate; angles rather nar- 
rowly rounded, the base broadly arcuato-truncate; eyes moderate; an- 
tennae long and slender, filiform, not at all incrassate distally, longer 
than the head and prothorax, the medial joints more than twice as long 
as wide and much longer than the subapical; prothorax only very 
slightly longer than wide and somewhat wider than the head, strongly 
obtrapezoidal, the sides straight; punctures rather coarse, very sparse, 
irregular, excepting a single close-set series at each side of the broad 
median smooth line; elytra quadrate, parallel, very slightly wider and 
longer than the prothorax, the punctures rather fine and arranged in 
uneven series; abdomen narrower than the elytra, shining. Male with 
the surface of the fifth and sixth ventrals wholly unmodified, the apex 
of the former with a broad and very shallow cuspidiform emargina- 
tion, the latter with a large triangular apical notch but little wider than 
deep, one-half as wide as the apex, with its anterior angle slightly 
blunt; female unknown. Length 10.4 mm.; width 1.4 mm. Arizona 
(Williams),— Mr. Wickham.......c..00 cee ceceeeeeesCONtUriO D. Sp. 
Head parallel at the SideS.... .cccccccccccccccscceccccsscccecccecs esses O 
3 — Head and prothorax black or blackish, always darker than the elytra. 4 
Head black, the prothorax rufous and concolorous with the elytra....... 7 
Head and prothorax rufous and concolorous with the elytra.............10 
£+— Abdomen not rufous at tip ices ion veiescc side leatssces ccasevivcsceoens: O 
Abdomen distinctly rufous at tp... 6 sccesccee Seca decenceceseccecccd sees 6 
5 — Body polished, black, the prothorax slightly picescent, the elytra dark 
though clear rufous, with a feeble piceous scutellar cloud; legs and 
antennae ferruginous; head subquadrate, as long as wide, the sides 
straight, the angles rounded for a short distance to the neck, which is 
three-fourths as wide as the head, the punctures coarse, uneven in size 
as usual and very sparse; antennae a little longer than the head and 
prothorax, moderately slender, feebly incrassate distally, the medial 
joints barely twice as long as wide and shorter than the subapical; pro- 
thorax oblong, only slightly longer than wide, slightly wider than the 
head, the sides straight and only just visibly converging throughout, 
the punctures moderately coarse, very sparse and irregularly distrib- 
uted, the median smooth line bounded by a narrow closer aggregation 
of punctures, not regularly serial; elytra quadrate or slightly elongate, 
parallel, slightly longer than the prothorax and about a fourth wider, 
the punctures only moderately coarse but strong, arranged in regular 
and feebly impressed series; abdomen slightly narrower than the elytra. 
Male withthe fifth ventral gradually, very feebly sinuate at the middle of 
the apex, the adjoining surface glabrous and shining but not impressed, 
the sixth with a broad shallow, gradually formed, broadly rounded 
sinus, about two-fifths as wide as the apex and six or seven times as 
wide as deep, the surface with a large median patch of dense and 
slightly stouter black hairs; female with the sixth ventral abruptly 
