284 



MEMOIES OF THE QUEENSLAND MUSEUM. 



10. 

 11. 

 12. 

 13. 

 14. 

 15. 



16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 

 23. 



Pronotiim strongly emarginate in middle above 



Pronotuni not emarginate 



Tibiae entirely red 



Tibiae not red 



Legs mainly black, not red or yello\ 



Legs red 



Wings strongly dusky . . 



Wings clear hyaline 



Face with golden hair . . 



Face without golden hair 



(Males) Abdomen red . . 



Abdomen pallid, with a broad median black band 



Abdomen black, or with hind margins of segments red 



Very small, about 4 mm. long ; upper margin of pronotum reddened 



Much larger ; upper margin of pronotum not reddened 



Mesonotum dark-blue . . 



Mesonotum black 



First abdominal segment black, with hind margin red 



First abdominal segment red 



Mesonotum red . . 



Mesonotum black 



Pronotum strongly emarginate in middle above 



Pronotum not emarginate 



Tibiae entirely red 



Tibiae not red 



Legs bright ferruginous 



Legs yellow 



Front with silvery hair 



Front with golden hair 



Z. mfipes Rohwer is omitted, as it is a Sericophorus. 



11. 

 12. 



emarginatmn n. sp. 



nigrum n. sp.- 



argyreum n. sp. 



13. 



fuscipenne n. sp. 



14. 



crassicorne Ckll. 



iridipenne Turner. 



16. 



flavofasciatum Turner. 



19. 



pusillum n. sp. 



17. 



erythrosoma Turner. 



18. 



ornatuni n. sp. 



splendidum n. sp. 



rufonigrmn Turner. 



20. 



21. 



22. 



emarginatum n. sp. 



nigrum n. sp. 



crassicorne Ckll. 



23. 



affine n. sp. 



doddl Turner. 



The material of this genus in the Queensland Museum shows uniformity 

 in most structural characters. Where these are very close, as between Z. emargi- 

 natum and Z. nigrum or Z. erythrosoma and Z. splendidum, there are well marked 

 colour differences by which the forms may be easily separated. Colour characters 

 seem constant and may be used with more confidence in this genus than in some 

 others of the Crabronidse. 



In most of the species where both sexes are known, the females possess two 

 pairs of teeth on the apical margin of the clypeus, while they are absent in the males. 

 Several species of which but one sex is known are in agreement and may be included 

 eventually in the above group. A few species, however, show a different arrange- 

 ment. Z. f.avofasciatum has one pair in each sex ; Z. argyreum has one pair in the 

 female ; Z. dipteroides is said to be without teeth in the females. In a few male» 

 there is a slight angulation on the clypeal margin, but this is not considered to be 

 within the meaning of the term " tooth." 



