GENERA OF THE TENTHREDINIDES. 69 



cubital cellules receive each a recurrent nervure. The basal nervure is 

 straight, and runs parallel with the first recurrent ; it is always received 

 in the costal cellule before the first cubital nervure, with which it 

 never unites. Lanceolate cellule more or less subcontracted, or more 

 usually with a straight, and more rarely an oblique cross nervure. The 

 hind wings with two median cellules ; the cubital and recurrent nervures 

 -are widely separated. 



The larvae have twenty-two legs. They are cylin- 

 drical, generally of uniform colour, or greenish above, 

 and pale at the sides ; or, more rarely, they may be 

 ornamented with dots on the sides or along the back. 

 Many change colour before pupating, which they do in 

 the earth, in a cocoon or in a cell formed of earth. 

 They are principally attached to herbaceous plants, 

 comparatively few feeding on trees. As a rule they 

 rest rolled up in a spiral, and when alarmed eject a 

 brownish or blackish liquid from the mouth. 



The most constant marks of distinction between this 

 tribe and the Sehiii<1i-i"(l?s consist in the position of 

 the basal nervure, in the spurs being always as long 

 as half of the metatarsus, and in the more strongly- 

 toothed mandibles. 



The species of this sub-tribe are common in the 

 Palsearctic and Nearctic regions, rarer in the Oriental, 

 and would seem to be absent from Central and South 

 America, as well as from the Australian region. 



Synopsis of Genera. 



A. Coxae small. 



a. Antennae long, filiform, rarely fusiform. 



1. The third joint of antennas considerably longer than the 



fourth ; posterior wings with two median cellules in 

 both sexes ; blotch distinct. Tenthredo. 



2. The third and fourth antennal joints sub-equal; blotch 



indistinct ; posterior wing with the transverse cubital 

 and recurrent nervures at edge of wing in $ . Antennae 

 long, filiform. 



Lanceolate cellule with a straight nervure. Two median 

 cells in both sexes. Accessory nervure in posterior 

 wing shortly appendiculated. Tenthredopsis. 



Posterior wing with no median cellule in $ t two in 9. 

 Lanceolate cellule contracted. Syn&rema. 



b. Antennae short, thickened. Accessory nervure at apex in 



posterior wing slightly appendiculated. Eyes converging ; 

 labrum rounded at apex. Allantus. 



