STATES OF INSECTS. 141 



throcephala L.) a . Two of the prolegs are anal, and the 

 rest intermediate, and none are furnished with claws; 

 This circumstance, in conjunction with the greater num- 

 ber of prolegs, except in the case of Lyda, will always 

 serve as a mark to distinguish these fausses chenilles, as 

 the French call the larvae of saw-flies, from true caterpil- 

 lars. The dorsal prolegs of a species of Cynips described 

 by Reaumur have been before noticed. 



Coleoptera. — The larva? of insects of this order are so 

 little known or attended to, that no very accurate gene- 

 ralization of them in this respect is practicable. Many of 

 them, in addition to their six horny legs, have a proleg 

 at the anus ; which in many cases appears to be the last 

 segment of the abdomen, forming an obtuse angle with 

 the remainder of it, so as to support that part of the body, 

 and prevent it from trailing; and in some instances, as 

 in Chrysomela Popidi, a common beetle, secreting a slimy 

 matter to fix itself 5 . In the larvae of Staphylinidce this 

 proleg is very long and cylindrical j in that of Cicin- 

 dela it is shorter, and in shape a truncated cone rather 

 compressed ; it is very short, also, in those of the Silphce 

 that I have seen. In the wire-worm (Elater Segetum) it 

 is a minute retractile tubercle, placed in a nearly semi- 

 circular space, shut in by the last dorsal segment, which 

 becomes also ventral at the anus. This space is in fact 



a De Geer ii. t. xhf. 15, 16. Bergman has added to these four 

 classes of the larva? of saw-flies, a fifth ; the insects belonging to 

 which, he affirms, though they have sixteen prolegs, are without the 

 anal pair. Ibid. 931. But as neither De Geer nor Reaumur ever met 

 with one of this description, it is probable he was mistaken. Reaumur 

 thought he had seen one with eighteen prolegs upon Erysimum alli- 

 aria (v. 91), but he does not speak positively. 



b De Geer v. 288. 



