144 ACADEMY OF NATURAL SCIENCES 



dense, a minute acute emargination each side near the tip : tho- 

 rax with dense profound and subequally distributed punctures : 

 scutel punctured, rounded at tip : elytra with dilated, shallow, 

 confluently and irregularly punctured grooves ; interstitial lines 

 narrower than the groove, elevated, convex : beneath subglabrous, 

 punctured. [245] 



Length nearly two-fifths of an inch. 



Mr. Nuttall obtained several species on the Missouri • it is also 

 found in the Atlantic States. It varies in color, being perhaps 

 generally light chesttiut-brown ; but it is sometimes dark chest- 

 nut, and I have a specimen that is nearly black. 



[Belongs to Serica of the division Camptorhina, and identical 

 with C. atricapiUa Kirby. — Leg.] 



6. M. SERICEA. — Dusky, iridescent; elytra concavely striated. 

 Inhabits the United States. 



M. sericea Knoch in Melsh. Catal, 



Body light reddish-brown, castaneous, dark-brown, or blackish, 

 strongly iridescent : clypeus densely punctured ; with sparse 

 hairs j edge very slightly reflected, anteriorly emarginate : thorax 

 with numerous small, nearly equal, and subequally distributed 

 punctures ; lateral edge not dilated in the middle : scutel longer 

 than wide, densely punctured each side nearly to the tip; a 

 longitudinal elevated line ; elytra concavely striated, striae con- 

 fluently punctured : anterior tibia bidentate. 



Length about seven-twentieths of an inch. 



This insect is beautifully iridescent, and by this character is 

 readily distinguishable from all other North American insects of 

 this genus that I have seen, with the exception of the M. iricolor 

 nob., which is much smaller, black, and hairy on the head and 

 thorax. 



It is an inhabitant of Pennsylvania, and we obtained specimens 

 near Council Blufi" on the Missouri river. 



[Also a Serica. — Lec] [246] 



7. M. IRICOLOR. — Blackish-brown, iridescent; with short 

 hair. 



Inhabits the United States. 

 M. micans Knoch in Melsh. Catal. 



Body blackish, distinctly iridescent: head hairy, punctured : 



[Vol. III. 



