672 BOSTON JOURNAL 



[From Boston Journal of Natural History, Vol. i. No. 3, pj). 210 — 305,} 



Descriptions of new North American HYMEKOPTERA, and Observations 

 on some already described. 



CommunicHteil Feb. 1835. 



FamUy TENTHREDINET^E. 



ACORDULECERA Say. 



Artificial character. — Antennae filiform, 6-jointed, short; radial 

 cellule one ; cubital cellules three, the second smallest. 



Natural character. — Antennae six-jointed ; first and second 

 joints subequal, the second larger ; third joint longest but equal 

 to the following ones in diameter ; remaining joints gradually 

 shorter; terminal joint not longer than the second: mandibles 

 arcuated, acute ; a prominent tooth on their middle : labrum 

 prominent and distinct : radial cellule rather large : cubital 

 cellules three ; first elongated, as long [210] again as the second: 

 carpus large : tibiae with one pair of spines at tip. 



Obs. The family of which this new genus is a member, was 

 divided by Leach into nine Stirpes, all of which have nine or 

 more joints in the antennae excepting the first, second, and fifth. 

 Of these, two genera only, have G-jointed antennae, viz., Zarca 

 and Perga Leach ; but both have clavate antennae and in many 

 respects are at variance with the characters of the present insect. 

 In a later work, the " Entomologische Monographieen," by Dr. 

 King, which that author has done me the favor to send me, are 

 the two new genera Pachylosticta and Syzygonia, both of which 

 have clavate antennae, and therefore, like the preceding, cannot 

 possibly include our insect. 



A. DORSALis. — Black ; hypostoma, a base of the tergum and 

 feet whitish. 



Inhabits Indiana. 



^ 9 Black, with minute whitish hairs ; uasus, labrum and 

 mouth white : mandibles rufous at tip : thorax with the anterior 

 segment, curving to the base of the wing, white ; line of the in- 

 sertion of the wings white : wings a little dusky ; nervures fus- 



[Vol. I. 



