S78 MODERN CLASSIFICATION OF INSECTS. 



The larvae of such species as have hitherto been observed form for 

 themselves a covering of excrements, w^hich they bear over their 

 backs by the assistance of an elongated forked appendage arising from 

 the extremity of the body, and bent forwards, reaching nearly to the 

 head (_/?<7. 46. 9. larva, with c, its covering, a, the place of the head, 

 and b, the feet, of the natural size, Jig. 46. lO. ditto seen from above, 

 and magnified). 



Reaumur has given a long and particular account of the habits of 

 one of the species of Cassida (C. viridis or equestris), (vol. ii. me- 

 moire 7. pi. 18.). The larva is broad and flattened, with the margins 

 of the segments furnished with long and setose spines, eight arising 

 from the prothorax, and four from each of the other thoracic seg- 

 ments, whilst only two arise from each of the abdominal segments ; 

 the legs are short ; the extremity of the body slightly recurved, with 

 the elongate fork arising rather above the anal aperture. By the as- 

 sistance of this instrument, the excrement is by degrees collected, so 

 as to form a parasol, which the insect has the power of elevating or 

 depressing, or, indeed, casting entirely off, at will. It feeds on thistles 

 and other plants, and is of an obscure green colour. The pupa 

 {Jig.^G. 11.) is also flat, with thin tooth-like serrated appendages 

 arising on each side of several of the abdominal segments; the pro- 

 thorax is also greatly dilated, entirely covering the head, and also 

 furnished with setose spines. On assuming the pupa state, the insect 

 loses the forks which sustained its parasol, although they may be ob- 

 served, with the other parts of the exuviae of the larva, still attached 

 near the extremity of the body. In about twelve or fifteen days, the 

 imago makes its appearance : it, as vvell as the pupa, is of a green 

 colour. My figures of the larva and pupa are from nature. 



These insects, from their singular habits and not uncommon occur- 

 rence, have attracted the attention of various naturalists. Goedart 

 first described the transformations of two species {Die Insecten, 

 No. 116 and 1 17.) ; discovering, with his usual proneness to the mar- 

 vellous, a human effigy, surmounted by an imperial crown, in the front 

 part of the body of the pupa. De Geer has also given the history of 

 Cassida maculata, in the fifth volume of his Bleinoircs, pi. 5. Mr. Kirby 

 has traced the transformations of the three following species : C. 

 murrsea (var. maculata), equestris (viridis lilig.), and vibex (liriophora 

 3Iarsh), in the third volume of the Linncvan Transactio7is. In the 

 first of these species, the excrement is arranged m fine branching 



