132 lliilli'liii (Ir la Sncirir E II ImiKiI (nj i ij II r il'Eiji/pti 



in the adnlt stage, the aiitcniial tccth arise within a 

 hiineUale sheatli which under the microscope shows 

 transverse striae very regularly disposed. 



8. The teeth arise hy a differentiation of the 

 epidermis from the antennal joints of the larva which 

 are considerably dilated and look like lamellae joined 

 along their edges but which are really composed of 

 shortened and flattened rings. Tlie dividing line be- 

 tween the antennal teeth and the stalk which carries 

 them only appears very late ; it is only a few days 

 before the last moult and after trt^itmcJit \\ ith caustic 

 potash that it can be observed. 



9. The lamellae of which the sheath is com- 

 posed are at first, as it lias just been stated, joined to 

 one another. It is only after the last moult, when the 

 cuticular sheath has been slu'd, that the lamellae 

 separate and can rightly be called teeth. 



N.B. — An id(Milical meliiod of growth niay be 

 ()bs(M\(Ml in Ihc magnificent bipodinaled antviuiao 

 of the male of the great Empusa of Ceylon, Congyius 

 (jongyloidcs, L. 



10. At the beginning of the larval period the 

 antennae of both sexes of Emjjusa are approximately 

 the same length. It is only when the striated sheath 

 begins to appear tliat a difference in favour of the 

 male becomes obvious. At the same time the basal 

 portion of the male antenna becomes considerably 

 tlîicker than that of the female so that it is quite easy 

 to se|)arate the sc\es by this character alone. 



