18 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



BBB. Wings violaceoixs; antenna black, apex yellow; abdomen 



more or less black or entirely red, apex always red; legs 



exce(tt tlie posterior tibia:" and tarsi yellow or more or less 



black. crcssoni Norton 



AAA. Abdomen entirely reddish or brownish yellow. 



B. Thorax red or brownish ; antennie, legs, and abdomen yellow- 

 ish red; wings jadlow. S califondcHS Norton 



BB. Thorax, head, base of antennae, and more or less of legs, black ; 

 wings violaceous. 5 and variety of 9 cressoni Norton 



BBB. Thorax except tiietauotum black; apex of abdomen dusky. 

 (See S taxodii.) 



Urocerus fi<iricoriiis Fabrieius 

 (Figs. 8 and 26) 



1781 Sirex flavicornis FH]n-k\ufi. 9. Spec, insec. : v. 1 : p. 418. 



1835 Sirex bizonatus Stephens, 9. Illus. Brit. ent. ; v. 7 : p. 114; pi. 



36, f. 2. 

 <1841 Urocerus abdomhialis Harris, S- Rep. ins. Mass. inj. to veg. ; p. 



392. 

 1874 Sircx latifasciatiis Westwood, S. Thes. ent. oxon. ; p. 114; pi. 21, 



f. 2. 

 1893 Urocrru.t riparius MacGillivray, $ . Washington Tenthred. and 



Uroeeridre. < Can. ent. ; v. 25 : p. 244. 



This liandsome insect is our commonest species of Urocerus 

 There is no doubt tliat tlie male described by Harris as ahdom- 

 iualis is in part the male of this species, and also probably in 

 jiart of albicanris. In a series of over fifty males I find five 

 that possess but a single spur on the apex of the posterior 

 tibiae, a character that would place them in the subfamily 

 Tremicinae according to Ashmead's classification. 



Kirby says that hizoiiattwi differs in the lighter color of the 

 hind legs and the color of the abdomen, but specimens of flavi- 

 cornis show this same variation. 



The North American pdvicoriiis is very closely related to the 

 European gigas. The difference may be expressed by the fol- 

 lowing table: 



