HYMENOPTERA 891 



The Cuckoo- wasps, p. 951 Family Chrysidid^ 



The Anthoboscids. p. 952 Family ANTHOBOSCiDyE 



The Sapygids. p. 952 Family Sapygid^ 



The Thynnids. p. 952 Family Thynnid^ 



The Tiphiids. p. 953 Family Tiphiid^ 



The Velvet-ants. p. 953 Family Mutillid^ 



The Scoliids. p. 954 Family Scoliid/E 



The Ants. p. 954 Family Formicid^ 



The BethyHds. p. 965 Family Bethylid^ 



The Rhopalosomids. p. 965 Family Rhopalosomid/E 



The Typical Wasps or Diploptera. p. 965 Family Vespid^ 



Superfamily Sphecoidea. The Sphecoid-wasp and the Bees. 



I. The vSphecoid-Wasps. 



The AmpuHcids. p. 978 Family Ampulicid^ 



The Dryinids. p. 978 Family Dryinid^ 



The Typical Sphecoid- wasps, p. 979 Family Sphecid^ 



II. The Bees. p. 989 



The Bifid-tongued Bees. p. 993 Family PROSopiDyE 



The Andrenids. p. 995 Family Andrenid/E 



The Leaf-cutter Bees and their Allies, p. 999 Family Megachilid^ 



The Bumblebees, p. looi Family Bombid^ 



The Honey-bees. p. 1005 Family Apid^ 



KEY TO THE SUBORDERS OF HYMENOPTERA 



A. Base of abdomen not slender but broadly joined to the thorax by a more or 

 less immovable joint; subanal vein of the fore wing present (except in the 

 genus Acordulecera) ; wings always present, p. 894. Suborder Chalastogastra 



AA. Base of the abdomen constricted to a slender pedicel and joined to the 

 thorax (alitrunk) by a narrow movable joint; subanal vein of the fore wings 

 absent; wings often absent, p. 907 Suborder Clistogastra 



KEY TO THE FAMILIES OF CHALASTOGASTRA 

 By Dr. H. K. Townes 



A. Front tibia with two apical spurs; body usually rather short and broad. 



B. Third antennal segment very long, about as long as or longer than all of the 



following segments together; fore wing usually with vein Ro. p. 896. Xyelid^ 



BB. Third segment of antenna not remarkably long or the antenna consisting 



of three segments only; fore wing without vein R2. 



C. Subcostal vein present and distinct; antenna with thirteen or more 



segments, filiform, p. 897 Pamphiliid^ 



CC. Subcostal vein absent or present as a trace; antenna either with less 

 than thirteen segments or pectinate or serrate. 

 D. Antenna ending in a knob; abdomen with the lateral margin sharp. 



p. 902 ClMBICID^ 



DD. Antenna not ending in a knob, filiform, somewhat enlarged toward 

 the tip, or of other form; abdomen with the lateral margin rounded. 

 E. Antenna with three, six, or thirteen or more segments, p. 904. Argid^ 

 EE. Antenna with seven to twelve segments, p. 902 . TENTHREDiNiDiE 

 AA. Front tibia with one apical spur; body usually more elongate. 



B. Antenna attached under a ridge just above the mouth, apparently arising 



from the mouth, p. 905 Oryssid^ 



BB. Antenna attached normally, near the middle of the face. 



C. Abdomen terminating in a hard spike-like or triangular point (in females, 



above the ovipositor), p. 898 SiRlciDiE 



CC. Abdomen not terminating in a hard point. 



D. Pronotum rectangular, saddle-shaped, with lateral and dorsal surfaces; 



abdomen compressed, p. 900 Cephid^e 



DD. Pronotum a narrow collar extending around the front of the thorax, 

 presenting a lateral and cephalic but no dorsal surfaces ; abdomen cylin- 

 drical, p. 899 XiPHVDRIIDiE 



