OF THE FAKM AND GAEDBK. 109 



with a bluish shade along the back, which shade disap- 

 pears however when the insect has fasted for a few hours. 

 It carries its excrement in irregular broad masses, often 

 branching as in the species next to be described. The 

 pupa (fig. 75, i), is also of a uniform green color, with a 

 conspicuous black ring around the base of the first ab- 

 dominal pair of spiracles. Before changing to pupa, 

 and previous to each moult, this larva is in the habit of 

 removing the excrement from its fork. 



THE BLACK-LEGGED TOETOISE-BEETLE. 

 (Cassida nigripes, Oliv.) 



This species, which is likewise found on the Sweet- 

 potato, is a little the largest of those we have mentioned. 



Fig. 76. — BLACK-LEGGED _. „„ 



TOKTOISE BEETLE. Flg.YY. — BLACK-LEGGED TOKTOISE-BEETLE. 



u, Larva of natural size ; b. Magnified. 



The beetle (fig. 76) has the power, when alive, of putting 

 on a golden hue, but is not so brilliant as G. aurichalcea, 

 from which species it is at once distinguished by its larger 

 size, and by its black legs and three large conspicuous 

 black spots on each wing-cover. The larva (fig. 77, b), is 

 of a pale straw-color, with the spines, which are long, tip- 

 ped with black; and besides a dusky shade along each side 

 of the back, it has two dusky spots immediately beneath 

 the head, and below these last, two larger crescent marks 

 of the same color. The excrement is spread in a charac- 



