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MANUAL OF ZOOLOGY. 



pairs) of soft fleshy legs, which are borne by the segments of 

 the abdomen, and are known as "pro-legs." Each is usually 

 furnished with a crown of several rows of small horny hooks, 

 and they are never attached to the 4th, 5th, loth, and nth seg- 

 ments behind the head (t.e, to the ist 2d, 7th, or 8th abdomi- 

 nal segments). 



In the Diurnal Lepidoptera, or Butterflies proper (fig. 189), 



the antennas are knobbed 

 (hence the name of Rho- 

 palocera often given to 

 the group) ; the wings are 

 usually held erect when 

 the insect is in a state 

 of repose ; the larvae 

 have six thoracic legs, 

 and ten pro-legs ; and the 

 pupae are always naked, 

 attached by the poste- 

 rior extremity, or head 

 downwards, and usually 

 angular. 



In the Crepuscular Lep- 

 idoptera, including those 

 forms which are active 



Fig. 189. Large White Cabbage Butterfly (Pieris during the twilight, the 

 brassier), a Larva or caterpillar; b Pupa or , r v 



chrysalis ; c imago or perfect insect. antennae are f usif orm, or 



grow gradually thicker 



from the base to the apex ; the wings are horizontal or a little 

 inclined when the insect is at rest ; the posterior wings generally 

 have their front margins furnished with a rigid spine (" retin- 

 aculum ") which is received into a hook on the under surface 

 of the anterior wings ; and the pupae are never angular. 



The Nocturnal Lepidoptera have the antennae setaceous, or 

 diminishing gradually from the base to the apex, often serrated 

 or pectinated (fig. 190); the wings in repose are horizontal or 

 deflexed, and the hind-wings are often furnished with a " retin- 

 aculum," as in the preceding section; the pupae are mostly 

 smooth, sometimes spiny, and often enclosed in a cocoon. 



The two groups of the Crepuscular and Nocturnal Lepidoptera 

 are often included in a single division, under the name of 

 Heterocera. It is to be remembered that many members of the 

 Nocturnal division of the order, though they would ordinarily 

 be called Moths, are active during the day, and in this respect 

 resemble the true Butterflies. 



ORDER XL HYMENOPTERA. Wings four, membranous, with 



