4 Memoirs on the Coleoptera 



much reflexed at the sides and with rounded basal angles. [Type 

 Feronia hypoUthus Say] _• • . • .Platynidius 



Elytra opaque to shining; pro thorax long, subcordiform, feebly to 

 strongly reflexed at the sides and with sharp to blunt right basal 

 angles; fades often as in Anophthalmtis or AntUcus. [Type R. 

 larvalis Lee] Rhadine 



Elytra opaque or alutaceous, finely striate, with flat intervals; prothorax 

 not elongate, strongly and widely reflexed at the sides, with rounded 

 or obtuse basal angles and large concave basal impressions; elytral 

 striee fine. [Type Platynus chihicahuce Bates] *Hemiplatynus 



4 — Head with a single superciliary puncture; posterior thoracic marginal 

 puncture wanting; prothorax relatively narrow, parallel, with almost 

 strarght sides. [Type A. recticollis nov.] *Anacolpodes 



Head with the usual two superciliary punctures; prothorax never so 

 rectilinearly parallel 5 



5 — -Prothorax trapezoidal, widest at or near the base, the sides reflexed, 

 very broadly so toward base; elytra rather inflated; antennae long 

 and very slender, the third and fourth joints exactly equal. [Type 

 Colpodes ceneicauda Bates] *Trapezodera 



Prothorax quadrate, nearly as in Calathus, with the sides broadly reflexed 

 basally, the basal angles obtusely blunt or rounded; antennae nearly 

 as in the preceding. [Type Anchomenus sulcatus Dej.].. .Tanystola 



Prothorax rather inflated at or before the middle, narrowed toward base 

 and apex 6 



6 — Posterior thoracic angles sharp or at any rate more or less distinctly 

 defined; prothorax more or less cordiform; hind body evidently 

 inflated, always very much wider than the anterior parts; legs and 

 antenna more or less long and slender. [Type An. sinuatus Dej.]. 



Anchomenus 



Posterior thoracic angles broadly rounded, rarely becoming evident 

 though blunt or very obtuse 7 



7 — Posterior thoracic marginal puncture wanting; prothorax long, 

 broadly and strongly reflexed at the sides; subbasal foveae large, 

 concave and smooth. [Type M. panamense nov.] . . . *Macragonum 



Posterior puncture distinct as usual 8 



8 — Prothorax about as long as wide; body small to very small in size; 

 hind body more or less inflated, oval, always much wider than the 

 prothorax 9 



Prothorax transverse lo 



9 — Prothorax circularly subquadrate, more or less convex, very finely 

 reflexed at the sides, the basal foveae small, sharply defined, smooth 

 and punctiform; body convex, with thick and- highly polished 

 integuments. [Type Feronia punctiformis Say] Circinalia 



Prothorax subcordate, the basal impressions large and concave, not 

 definitely prolonged anteriorly, the sides extremely finely reflexed 

 or beaded; body rather less convex. [Type Feronia nutans Say]. 



Micragonum 



Prothorax nearly flat, widest before the middle as a rule, very finely 



reflexed at the sides, the basal impressions very feeble and in- 



