314 MEMOIRS ON THE COLEOPTERA 



Tricena a valid genus, related to Amara in much the same way that 

 Triplectrus is to Anisodactylus . The trifid anterior tibial spur at 

 least is a purely non-sexual feature, which can be said of but very 

 few of the taxonomic characters serving for generic definition in the 

 Amarinae. The lateral series of ocellate elytral punctures is always 

 more or less interrupted medially. 



The species in my collection may be known as follows: 



Elytra \vith a subscutellar ocellate puncture 2 



Elytra completely devoid of the ocellate puncture; antennae black, with 



three basal joints and base of the fourth testaceous 7 



2 Antennae with the first four joints pale testaceous, the fourth often 

 feebly infumate, however, except basally. Body oblong-suboval, 

 strongly convex, polished throughout in both sexes, aeneous to viridi- 

 aeneous above, black beneath; legs bright rufous, the tarsi infuscate; 

 head but little more than half as wide as the prothorax, with large 

 and moderately prominent eyes, the antennae slender, piceous ex- 

 cept basally; prothorax widest at base, two-fifths wider than long, 

 the sides feebly arcuate, more rounded apically; apex scarcely two- 

 thirds as wide as the base, sinuate, with well defined and narrowly 

 blunt angles; anterior impression obsolete, the posterior often dis- 

 tinct; inner fovea with a few fine punctures, large, broadly impressed, 

 the incised part distinct, the outer obsolete; posterior puncture 

 nearer base than side; elytra not quite one-half longer than wide, 

 equal in width to the prothorax, the sides gradually arcuate and con- 

 verging behind the middle; striae rather fine but deep, impunctate, 

 the lateral fine and superficial, the scutellar moderate; intervals con- 

 vex, except laterally: anterior tarsi of the male rather feebly dilated. 

 Length (d 71 9 ) 5.6-6.9 mm.; width 2.2-2.8 mm. Lake Superior to 

 Rhode Island, District of Columbia and Virginia (Norfolk). Abun- 

 dant pallipes Kirby 



Antennae blackish, the three basal joints and base of the fourth testa- 

 ceous 3 



3 Femora very pale testaceous 4 



Femora black or piceous-black 6 



4 Legs rufous, the tibiae feebly infumate distally, the tarsi black; pro- 

 thorax just visibly wider at about the middle than at base. Body 

 oblong-elongate, moderately convex, polished, the elytra somewhat 

 alutaceous in the female; under surface black, the epipleura rufes- 

 cent; metasternum and side-pieces virtually impunctate; head nearly 

 three-fifths as wide as the prothorax, with large and moderately 

 prominent eyes; antennae (9) rather thick, extending fully to the 

 thoracic base; prothorax two-fifths wider than long, the sides arcu- 

 ate throughout, more so and slightly converging apically; apex three- 

 fourths as wide as the base, very moderately sinuate, with rounded 

 angles; basal angles right, sharp, the puncture small and at the tip; 

 base broadly sinuate laterally; impressions obsolete; foveal region 

 not evidently punctate, the inner fovea large, broadly impressed, 



