THE SHORT- WINGED SCAVENGEE BEETLES. 



409 



Division E. 



In this division the punctures of elytra are all separate and 

 distinct one from another. The species are rather small and, except 

 the first two, highly polished. 



KEY TO SPECIES OF DIVISION E. 



a. Pubescence very coarse and distinct, brownish-yellow on the abdomen ; 

 punctures crowded, the interspaces not polished. 



b. Longitudinal grooves between the eyes distinct; form slender. 



789. STYGICUS. 



hh. Longitudinal grooves absent, the surface between the eyes flat; form 

 more robust. 790. egenus. 



a a. Pubescence very fine and indistinct, very seldom yellow ; punctures 

 rather sparse, their interspaces polished. 



c. Transverse carinas of abdomen with four cusps. 



d. Thorax with an impression along some part of the median line. 

 e. Thorax elongate, slender; punctures separated by at least their 

 own diameters; length 3-4 mm. vinnulis. 

 ee. Thorax shorter, robust; punctures very close, never separated 

 by more than one-third their own width; third joint of an- 

 tennae much longer than fourth ; length 3.2-3.4 mm. 



CANALICULATUS. 



dd. Thorax without an impression along the median line. 



/. First joint of hind tarsi twice as long as second; length 3 mm. 



791. ARGUS. 



ff. First joint scarcely one-half longer than second; antennal joints 

 four and five equal in length, abruptly shorter than third: 

 length 2.3 mm. minor. 

 cc. Transverse carinae of abdomen without cusps ; thorax not impressed. 

 g. Very small, not over 2.2 mm. 



h. Elytra much longer than wide, sparsely punctured, highly pol- 

 ished. 792. juvencus. 

 Till. Elytra nearly quadrate, very densely punctured. pauperculus. 

 gg. Larger, not less than 2.8 mm. ; antennal joints three to six decreas- 

 ing in length. 793. morio. 



789 (2383). Stenus stygicus Say. Trans. Ainer. Phil. Soc, IV. 1834. 458: 

 ibid. II, 574. 



Rather slender. Black, feebly shining ; rather thickly clothed with long, 

 coarse, prostrate grayish-yellow hairs; legs and antenme piceous, tarsi 

 slightly paler. Head rather small, not twice as wide as long; surface be- 

 tween the eyes nearly flat, densely and coarsely punctate. Antennae slightly 

 longer than width of head, the third joint a little longer than fourth. 

 Thorax subcylindrical. widest in front of middle, one-fourth longer than 

 wide ; coarsely, closely and evenly punctured. Elytra at base slightly wider 

 than head, suture one-fifth longer than thorax, punctured like the latter. 

 Abdomen at base narrower than elytra, very feebly tapering to apex, finely 

 and sparsely punctate, the transverse carinae with four cusps. Length 3- 

 3.7 mm. 



