AMERICAN PHILOSOPHICAL SOCIETY. 507 



flections ; thorax and elytra margined with yellowish, the latter 

 with an oblique subterminal line. 



Length one inch and three-tenths. 



Body impunctured, above black, with olivaceous green reflec- 

 tions, beneath piceous-black, suboval, very slightly broadest be- 

 hind and hardly narrowing before ; head large ; vertex with an 

 obscure rufous spot, a geminate, impressed, punctured spot near 

 the nasus, numerous superciliary [93] punctures; nasus and 

 labrum yellowish, the former with an abbreviated impressed line 

 each side before ; antennte and palpi rufous at base, piceous at 

 tip ; labium ventricose between the insertion of the palpi, rufous ; 

 labium and gula rufous; thorax margined each side with yellow- 

 ish, a longitudinal impressed line, a transverse, somewhat undu- 

 lated, submarginal line of impressed punctures each side before, 

 and a more abbreviated sparse one on each side behind; elytra 

 margined each side with yellowish, which becomes obsolete 

 behind, a yellowish, oblique subterminal line behind, three very 

 distinct series of punctures, with alternate series of minute remote 

 ones ; pectus pale rufous ; sternum black, hardly elevated before ; 

 postpectus piceous black ; feet piceous ; femora and basal joints 

 of the anterior pairs rufous ; venter piceous black, three obsolete, 

 lateral, piceous spots. 



Differs much from the preceding species, in being far more 

 robust before, and instead of the semideltoid termination of the 

 yellow margin, there is an oblique subterminal line, as in Z>. 

 marginatus, but it is very distinct from the latter species, by not 

 having the yellowish anterior and posterior thoracic margins. 



3. D. MEDIATUS. — Blackish, punctured, beneath black ; tho- 

 rax with a yellowish band and margin; elytra fasciate behind. 



Length about eleven-twentieths of an inch. 



Head rufous-yellow varied with dusky, base black ; front with 

 sometimes two oblique blackish spots; nasus paler; labrum 

 whitish, particularly on the anterior margin ; thorax black, a ^ 

 yellowish margin and abbreviated narrow band which is ab- 

 ruptly dilated backward near the lateral margin, where it be- 

 comes confluent with the basal margin ; scutel black, impunctured ; 

 elytra blackish-brown varied with yellowish, minute, irregular 

 lines, and as well as the thorax with numerous, minute punc- 

 1823.] 



