138 INSECTA. 



the first joint of the posterior tarsus very large and compressed 

 in the form of a square or triangular face. 



Subgenus Bombus, Lat. 



Corselet much larger than the head ; posterior legs spiny. 



Subgenus Apis proper. 



Head and corselet equal in width ; posterior legs without 

 spines ; first articulation of the tarsus squared. 



ORDER VIL LEPIDOPTERA. 



Four membranous wings covered with little coloured scales ; 

 mouth forming a rolled proboscis, produced by an elongation 

 of the jaws, upon the sides of which are found the rudiments 

 of mandibles and downy palpi. Metamorphosis complete; 

 larvae called caterpillars — of which some feed upon leaves, 

 others, less common, gnaw the ligneous part of trees, soften- 

 ing it with a saliva which they disgorge ; some live at the 

 expense of woollen stuffs and furs. The nymphs are almost 

 always motionless, and generally spin a cocoon to effect the 

 metamorphosis. 



FAMILY I. DIURNA. 



Wings vertical during repose ; antennas terminated, in ge- 

 neral, by a small round club, at other times tapering at the 

 end and reflexed into a hook; caterpillars almost always 

 provided with sixteen feet; chrysalis hardly ever enclosed 

 in a cocoon, but suspended in the air by the posterior extre- 

 mity of the body. 



Genus Papilio. Butterfly. 

 Subgenus Papilio proper. 



The six feet adapted to walking ; inferior palpi very short, 

 hardly reaching the hood. 



Subgenus Parnassius. 



Six feet adapted to walking; inferior palpi elevated beyond 

 the hood and with three joints. 



