the Life History of Gongylus gongyloides. 135 



but the main functions of this claw are for the seizure of 

 prey and for defence. The loss of a limb of either of the 

 hinder pairs is repaired at the next moult, but the newly- 

 developed limb is smaller and weaker than the original. 

 The more complex raptorial limbs are not reproduced, 

 although the tibial claw and the tarsus may be. Often a 

 joint or so of the tar^is is missing in the newly-formed 

 limb, but the terminal pair of tarsal claws is always 

 present. 



The Dcveloijmcnt of Sexual C'harcteteristies. 



Immediately after the nymph is hatched one notices no 

 distinction between the two sexes. They can be dis- 

 tinguished at this stage by microscopical examination of 

 the terminal ventral plate, the posterior margin of which 

 is deeply notched in the middle line in the female, but 

 straight and uninterrupted in the male. This character 

 persists throughout life. 



At the third ecdysis the antennoe in the male are 

 considerably longer than in the female, but in both sexes 

 they remain hair-like, and are curved into a rounded hook 

 at the free end, as in the adult female. 



At the ninth moult the male antennas become greatly 

 thickened for the basal three-quarters of their length, while 

 the remaining quarter is straight and finely tapering. The 

 bi-pectinate form is not assumed until the imago stage. 

 At the fifth moult the female is obviously larger than the 

 male, and this relative size is maintained for the rest of 

 life. About the same time the prothoracic disc of the male 

 assumes its characteristic shape, being smaller, narrower, 

 and more perfectly diamond-shaped than in the female. 



Cmn]3arison of the habits and mimetic characteristics oj 

 Gongylus with those of Idolum diabolicum. 



This large African species is most closely related to 

 Gongylus in its habits and conformation. For a description 

 of the insect the reader is referred to the article by Dr. D. 

 Sharp in Vol. X. of the Proceedings of the Cambridge 

 Philosophical Society, where a coloured sketch of the 

 ventral aspect of the insect is given ; this shows that the 

 floral simulation is effected by the petaloid colouring of 

 the inner asjDect of the greatly expanded coxae of the first 

 pair of legs, which is a brilliant purple ; and the coxse are 



