232 MANUAL OF NATUEAL HISTORY. 



24. Family. — Solitary-Bees (Andrenidse). Labium 



small or cordate ; jaws moderate, not form- 

 ing an elongated proboscis ; hind-legs gene- 

 rally clothed with hair ; trochanters and 

 femora in the females pollenigerous ; basal 

 joint of hind-tarsi not dilated into an angle. 

 Solitary. Males and females only. 



25. Family.— Social-Bees (Apidse). Labium long 



and filiform ; jaws extended into an elon- 

 gated proboscis usually folded up beneath 

 the head ; basal joint of hind-tarsi externally 

 dilated and angled ; the second joint arising 

 from the inner angle of the preceding joint. 

 Social. Males, females, and neuters. 



II. SUB-CLASS. — Suctorial-Insects (Haustellata). 



Mouth produced into a more or less elongated 

 proboscis. 



SCALY-WINGED INSECTS. 



The Lepidoptera have been arranged into those 

 that fly by day, or the Butterflies, those that come 

 forth at twilight, or the Hawk-moths, and those 

 that are nocturnal in their flight, as the Moths 

 properly so called. On account, however, of the 

 number of exceptional cases, we have followed 

 M. Boisduval, and thrown them into two divi- 

 sions, or those with clubbed and those with varied 

 antennae. As humble worms, toiling and spinning, 



