NORTH AMERICAN COLEOPTERA. 31 



2. — Anterior supplemeutary carina of prothorax long, extendinji from the apex 



to the middle, the posterior carina entirely wanting peetiiiatiis. 



Anterior supplementary carina short, not reaching the middle of thorax 3. 



3. — Posterior supplementary carina very short. 



Outer carina of juxta-sutural sulcus entire ; middle of disc of thorax im- 

 pressed aiidax. 



Outer carina of juxta-sutural sulcus much abbreviated posteriorly ; disc of 



thorax not impressed illiperfectus. 



Posterior carina extending at least to the middle of thorax, sometimes lon- 

 ger 4. 



4. — Metathoracic episterna very narrow in front, broader posteriorly 5. 



Metathoracic episterna broad and parallel 7. 



5. — Pronotuni without ante-sciitellar carina, the median line impressed poste- 

 riorly snb!«iiiiiatus. 



Pronotum with distinct ante-scutellar carina, without median impressed 



line 6. 



6. — Pronotum narrowed in front, the sides distinctly sinuate oblittl!^. 



Pronotum with parallel sides, or even slightly wider in front. 



triaiii;;iilai*i»$. 

 7. — Disc of thorax impressed, posterior supplementary carina very nearly entire. 



iiiipresisticolliis. 

 8. — Prosternum obtuse at tip, outer carina of the juxta-sutural sulcus entire. 



Boiivonloiri. 

 Presternum prolonged and acute at tip, outer carina of juxta-sutural groove 



obliterated posteriorly Iiuineralis. 



M. peetiuatus Lee. — Piceous, moderately shining, form elongate, slightly 

 narrower posteriorly, stirface sparsely clothed with a very short cinereous pubes- 

 cence ; antennse piceous, two-thirds % , or one-half the length of body 9 > pecti- 

 nate from the third joint %, , or acutely serrate J ; head coarsely and rather 

 closely punctate, a distinct longitudinal impression between the eyes, the occiput 

 carinate, supra-antennal ridges distinct ; clypeus very narrow at base ; prothorax 

 wider than long, sides parallel, rounded in front, disc moderately convex, mod- 

 erately coarsely, but not densely punctured, a slight ante-scutellar carina with 

 a slight depression each side, hind angles finely carinate ; anterior supplementary 

 carina of the thorax long, reaching the middle of the thorax, posterior carina 

 extremely short, almo.st entirely absent; juxta-sutural sulcus slightly wider pos- 

 teriorly, the outer carina entire extending to the hind angles of the thorax ; 

 elytra as wide at base as the thorax, slightly narrowed posteriorly, disc vaguely 

 striate, densely and more coarsely ptinctured than the thorax; prosternum 

 coarsely punctured, propleurse more coarsely punctured ; metasternum and ab- 

 domen at sides coarsely closely punctate, at middle and apex more finely and 

 sparsely ; metasternal episterna slightly wider posteriorly ; legs brownish, tibi» 

 and tarsi paler; fourth joint of tarsi dilated and lobed beneath, claws simple, 

 hind coxal plates distinctly narrower externally. Length .18 -.20 inch; 4.5- 

 5 mm. 



This species is known by the pectinate male antennae, the long an- 

 terior supplementary carina and the almost total obliteration of the 

 posterior. The latter character has been passed in silence by Bon- 

 vouloir, who states, by mistake, that the metasternal side pieces are 

 parallel. 



