Aculeate Hymenoptera in the Oxford 3hisciim. 379 



of the basal abdominal segment angulated posteriorly 

 and bears transverse yellow bands on the 1-4 abdominal 

 segments. 



Odyneiuis decoratus, sp. nov. 



W. Australia : Towranna Plains between Yule River 

 and Sherlock River : Jan. to May, 1898 (B. Clement). 



(^. Lemon yellow, the mandibles, the ba^r^es of the antennae, the 

 apex of the scape, the flagelkun, a large square mark on the vertex 

 surrounding the ocelli and reaching the upper margin of the eyes 

 on each side, a square mark on the collar, the mesonotum, scutelluni 

 and postscutellum, an oblong mark on the 2nd abdominal seg- 

 ment, the base of the 4th and 5th narrowly and the apical two 

 segments black, a spot at the base of the mandibles, two minute 

 spots on the vertex at the upper angles of the eyes, a square mark 

 at the base of the mesonotum, a transverse mark on the scutellum 

 divided medially by a fine black line and the middle of the post- 

 scutellum yellow. Head, thorax and abdomen punctured rugose 

 and covered with a minute, short, silky pubescence ; clypeus pyri- 

 form truncate at apex ; prothorax vertically truncate in front, almost 

 concave, the pronotum margined anteriorly ; mesonotum slightly 

 convex, scutellum and i^ostscutellum not prominent, median seg- 

 ment rounded at the sides, the apex slightly concave. Wings hyaline 

 brown along the costal margin, nervures brown, tegulae yellow 

 with a faint brown spot in the middle. Abdomen massive, sessile, 

 longer tlian the head and thorax united, the apical margin of the 

 2nd segment crenulate, 



5 . Similar to the ^ but in the two specimens before me the 

 ground-colour is reddish (in one specimen certainly, and in the 

 other probably darkened by cyanide). It differs in being larger 

 and more strongly built than the ^ and has the apical two 

 abdominal segments reddish brown, not black : the shape and 

 character of the black markings however are very similar. 



Length ^ 10 mm. ; 9 11*5 mm. (to apex of second abdominal 

 segment). Exp. ^ 23 mm. ; ^ 27 mm. 



Described from a single example of each sex. 

 Belongs to Saussure's subgenus Lioiiotus. 



I have preferred to give a full description of the $ 

 rather than of the $ because, as noted above, I consider 

 the ground-colour of the two female specimens I have 

 before me altered by cyanide. 



