Tenthredo. HYMENOPTERA. 1 75 



The abdomen throughout of equal fize a and 

 clofely joined to the thorax. 



Three (lemmata. 



The remaining Tenthredines which, according 

 to Geoffroy, have filiform antennae, that author 

 has divided into three families -, the firft com- 

 pofed of fuch as have nine ; the fecond of fuch 

 as have eleven, and the third of fuch as have 

 thirteen articulations in their antennas. The 

 fame author obferves, that the under wings, 

 like wife, of the Tenthredo ■, are fhorter than the 

 upper ones ; that the abdomen is clofely united 

 to the thorax, not joined to it by a petiolum, or 

 little ftalk, as in the Cynips, nor becoming 

 fmaller from its extremity towards its bafe, fo as 

 to form a kind of petiolum, as in the Ichneumon; 

 and that the antennse differ from thofe of the laft- 

 mentioned genus in the form of their articula- 

 tions, thefe in the Tenthredo are long, and 

 rather rough, which makes their antennae appear 

 as if compofed of fo many knots ; thofe of the 

 Ichneumon, on the contrary, are fo very fliort 

 as fcarce to be perceptible, and exceedingly 

 fmooth, fo that, if not attentively examined, the 

 antennas would appear to be inarticulated, or 

 like a briftle. 



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