THE ORTHID^E. 101 



(fig- 7 d), and pass this period of their existence near 

 or upon the surface of the ground ; while the pupa of 

 the third is entirely enclosed in a thick web, as in 

 Agarista (fig. 7 ., 9\ or cocoon, attached to vegeta- 

 bles. All the insects of this latter division fly during 

 the middle of the day ; it contains, however, insects so 

 very dissimilar in appearance, that we shall divide them 

 into the three subordinate groups. 1. The Sphingidce 

 Sw., or true hawk moths, which constitute a group equi- 

 valent to the Nymphalidffi; which they also represent. 

 Of these, the typical genus is the well-known death's 

 head (the Sphinx atropus Linn.) concerning which there 

 are so many tales of superstition and of terror. This 

 insect, which we have already said is the type of the 

 whole tribe, has been very properly detached from its 

 allies ; but the change has been attended with this dis- 

 advantage, that the family name has been left with the 

 others, which are not typical, and a new one proposed for 

 this, which is strictly and naturally so. The larva has an 

 ovate truncated head; and the horn at the end of the body 

 is lengthened, naked, and covered with tubercles : when 

 disturbed, it draws itself up in a threatening attitude (c); 

 and its whole appearance is then so formidable, that most 

 persons view it with fear. There are, nevertheless, many 

 deviations from this typical structure. In Smerinthus 

 (exemplified by our beautiful Poplar sphinx), the head 

 is pointed above, and almost triangular ; while in another 

 group the horn is nearly wanting. The pupa is terrestrial; 

 and presents a striking peculiarity in the proboscis being 

 detached, as it were, from the body, and protected by a 

 covering of its own (e). The perfect insect is generally 

 marked with transverse bands on each side the body ; and 

 the end of the abdomen is neither attenuated to a point, 

 nor tufted with hair, but is thick, and comparatively ob- 

 tuse. 



(97.) The ORTHIDJE, or spinning hawk moths, are 

 smaller and more beautiful than the last. The number 

 of species, and, consequently, of forms, is also much 

 H 3 



