72 MEMOIRS ON THE COLEOPTERA 



Group II (er r aliens) . 

 Subgenus Plectralidus nov. 



The habitus in this group is altogether isolated in the genus, 

 the body being very elongate and rather large though extremely 

 variable in size intraspecifically and the coloration varies from a 

 peculiarly pallid tint to deep black; the external dentition of the 

 elytral apices, which in the female sometimes becomes conspicuously 

 spiniform, is a remarkable and distinctive character of the group. 

 We apparently have six species as follows: 



Basal angles of the prothorax obtuse and narrowly rounded or never 

 sharply marked 2 



Basal angles sharply marked, not blunt and generally subprominent; 

 outer prominence at the elytral apices very obtuse, never spiniform 

 even in the female 5 



2 Outer angle of the elytral apices spiculiform, the spicule minute (d 71 ) 

 or long and spiniform (9) 3 



Outer angle distinct but never spiculiform, obtuse (cf ) or right (9 ). - .4 



3 Form rather narrow, very elongate, moderately convex, shining 

 throughout (cf ) or with the elytra duller (9 ), piceo-rufous in color, 

 the elytra nearly black; under surface, legs, antennae and trophi 

 rufous; head rather large, three-fourths as wide as the prothorax, 

 with prominent eyes, the frontal foveae very small, lying in large, 

 feeble and very vague impressions; antennae extending fully to the 

 thoracic base; prothorax only about a fourth or fifth wider than long, 

 the transverse, strongly margined base as wide as the broadly 

 sinuate apex, the sides broadly and feebly arcuate, becoming gradu- 

 ally slightly convergent basally, the obtuse angles evidently rounded 

 though distinct; surface smooth, the side margins rather strongly 

 re flexed, the gutter coarse and deep, punctulate, much expanded into 

 the flattened and sparsely punctured latero-basal regions, the foveae 

 rather large, feebly and somewhat vaguely impressed, punctulate; 

 median stria fine; elytra long, three-fourths longer than wide (c?) 

 and nearly so (9 ), obtuse at tip, the striae deeply impressed, with 

 shining convex intervals and the sides feebly arcuate (o 71 ), or with 

 the striae feebler, the intervals flatter and the sides more arcuate 

 (9), two-fifths to one-half wider than the prothorax; first four 

 joints of the hind tarsi gradually diminishing in length, the first 

 as long as the fifth. Length (d 71 9) 11.7-16.0 mm.; width 3.7-5.8 

 mm. Rhode Island to Indiana. Eleven examples. . erraticus Say 



Form nearly as in the preceding but notably stouter, larger in size, less 

 shining and paler in color, the elytra brown, dull in both sexes; 

 head nearly similar but with less prominent eyes; prothorax much 

 more transverse, more than two-fifths wider than long, otherwise 

 nearly similar, except that the flattened surface toward the obtuse 

 and rounded hind angles is much less distinctly punctured; elytra 

 nearly similar but broader and still more rounded at the sides, less 



