NEMATUS ABDOMINALIS. 153 



The males have the abdomen somewhat keeled on 

 the back, and have, at the apex, a pair of shallow 

 furrows. The genital organs are broader than usual, 

 and project considerably. 



The larvse are flat, usually green, the skin beset 

 with tubercles, and the head marked on the vertex 

 with two black marks. They feed on the flat surface 

 of the leaf, especially of the alder. The eggs are laid 

 in the twigs or young branches. 



The very long ovipositor is a character very dis- 

 tinctive of this group, as is also the yellowish stigma, 

 black at the base. 



Synopsis of the Species. 



1 (2) Head and thorax entirely black ; wings deeply infuscated. 



Abdominalis. 



2 (1) Head and thorax for the greater part luteous. 



3 (6) Mesonotum entirely luteous. 



4 (5) Abdomen broad, not narrowed from the middle; the dorsum 



entirely luteous ; mouth and tibiae luteous. Ruficapillus. 



5 (4) Abdomen distinctly narrowed from the middle; the dorsum 



marked with black ; mouth and tibiae white. Acuminatus. 



6 (3) Mesonotum marked with black. 



7 (8) Head without black on vertex ; abdomen with black transverse 



lines on back. Caledonicus. 



8 (7) Head marked with black; abdomen entirely luteous. 



9 (10) Head without black on the vertex; clypeus incised; third 



cubital cellule much longer than broad. Bilineatus. 



10 (9) Head black (mouth excepted) ; clypeus transverse ; third 



cubital cellule not much longer than broad. Antennatus. 



72. NEMATUS ABDOMINALIS. 



Vol. I, PL VI, fig. 9, Lar. ; Vol. II, PI. XXIII, fig. 7, 

 Saw. ; PI. XXVII, fig. 7, Trophi of Larva. 



Tenthredo abdominalis, Panz., F. G., 64, 3 (1799) ; Latr., H. N., 



xiii, 131; Fall., Acta Holm., 

 1808, 115, 54. 



Nematus abdominalis, Dbm., Consp., 66 ; Zett, I. L., 352, 50 ; 



Br. and Zad., Schr. Ges. 

 Konig., xvi, 48, pi. i, f . 5 ; 

 Andre, Species, i, 179; Cat., 

 24,* 186. 



fuscipennis, Lep., Mon., 68, 204 ; F. Fr., 70, 24 ; Ste., 



111., vii, 31. 



fumipennis, Ste., 111., vii, 35. 



