136 SIREX MELANOCERUS. 



Rarer than 8. gig as. 



Continental distribution : General. 



2. SlREX JUVENCUS. 



Ichneumon juvencus, Lin., S. N., i, 560, 3. 

 Sirex juvencus, Lin., F. Sv., 396 ; Thorns., Hym. Sc., i, 327 

 juvencus, var. 2, King, Mon., 38, pi. iv, f. 3 ; Htg., Blattw., 

 327. 



Violet-bluish-black; legs testaceous, except coxae and trochanters. 

 Wings yellowish-hyaline. The antennae pale or testaceous at the base. 



The <$ has the abdomen yellow, except at base ; the legs testaceous, 

 except the coxee, trochanters and posterior tibiae and tarsi. 



Length 1017 lines. 



Rare. 



Continental distribution : General. 



3. SlREX MELANOCERUS* 



Sirex noctilio, Fab., E. S., ii, 130, 22 ? 



juvencus (excl. var. 2), Klug, Mon., 36, pi. iii, f. 6 ; pi. iv, 



fs. 1, 2, 81 ; Htg., Blattw., 384. 



melanocerus, Thorns., Hym, Sc., i, 328. 



Similar to juvencus, but the body has a more dis- 

 tinctly "violaceous tint ; the antennas are black, with- 

 out any trace of blue or violet, or testaceous at the 

 base. The central suture on vertex is deeper, that 

 in breast narrower, the abdominal spine is longer and 

 narrower; the terebra projects more than its length 

 beyond the apex of spine, while in juvencus it does not 

 do so ; the patellse are more distinct ; the wings want, 

 as a rule, a yellowish tinge, and the costa and stigma 

 (especially the latter) are darker. 



The (J has the apex of abdomen bluish. 



On all these points, however, I find so many inter- 

 mediate variations that I can hardly look upon 

 iuvencus and melanocerus as really distinct. 



