TENTHREDO. INSECTS. 335 



I. Perforator not projecting beyond the anus. 



I. Labrum apparent ; internal side of the four posterior legs with sometimes a small 

 spine, (Perga.) 



Larvae with from ten to sixteen membranous feet. 



A. Antennae never having beyond sixteen joints, (nine or fewer in the greater part,) 

 always simple in the females ; forked, ciliated, or pectinated in the males. 



a. Antennae with from three to eight distinct joints, either terminated by a button, 

 or by a long cylindrical joint, sometimes ciliated or forked in the males. 



* Antennae with from five to eight joints terminated by a button. 

 Larvae with twenty-two feet 



Gen. CIMBEX, AMASIS, (Leach) ; PERGA. 



** Antennae with three distinct joints, the last an elongated club, or thicker than the 

 preceding, ciliated or forked in the males. 



Gen. SCHIZOCERUS, (antennae forked,) HYLOTOMA, PTILIA, (Lepeletier.) 



b. Antennas with from nine to fourteen joints, but nine in the greater number. 



* Antennae with nine joints. 



j- Antennas simple in both sexes. 



Gen. TENTHREDO, DOLERUS, NEMATUS, PRISTIPHORA. 

 t| Antennae branched in the males. 



Gen. CLADIUS. 

 ** Antennae with from ten to fourteen simple joints. 



Gen. ATHALIA. 



B. Antennae with at least sixteen joints, pectinated or fan-shaped in the males ; ser- 

 rated in the females. 



Gen. PTERYGOPHORUS, LOPHYRUS. 



2. Labrum concealed or slightly projecting ; internal side of the four posterior legs 

 with two or three spines. 



Antennae composed of a great number of joints ; head large or broad. 

 Gen. MEGALODONTES, (Tarpa;) PAMPHTLIUS, (Lyda.) 



II. Perforator of the females projecting beyond the anus. 



Larvae without membranous feet, living in the interior of vegetables. 

 Gen. XIELES, CEPHUS, XYPHYDRIA. 



Gen. TENTHREDO, Lin. Lat. 



Antennae simple in both sexes, of nine joints in the greater num- 

 ber, of ten to fourteen in others ; two radial and four cubital 

 cells, of which the second and third receive each a recurrent 

 nerve, and the fourth is bounded by the posterior margin of 

 the wing. 



T. tricincta, Lat. Body black ; antennae thickened towards the end, 

 with the last joint fulvous ; the upper lip, the posterior margin 

 of the first segment of the thorax, that of the first segment of the 

 abdomen, the fourth, fifth, and last yellow ; feet fulvous, with 

 black thighs ; upper wings with a brown tint along the sides. 6 

 lines long. Europe, on flowers. Nouv. Diet, xxxiii. 57. 



TRIBE II. UUOCERATA. 



Maxillary palpi with two or five joints, and the labial three ; 

 mandibles short and thick ; labium entire ; antennae vibra- 

 tile ; head almost globular. 



