Plate XVII. 



(To be bound facing Plate XVII.) 

 Larval hairs and spiracle of Bithys quercOs. 



Fig. 1. — Hairs of fullgrown larva x 100. 



The hairs show the characteristic floral form of base seen in the larval hairs 

 of many Theclids. The margin of the apparent petals are attached to skin ; 

 the hair represents the stalk, so that the apparent flower is inverted, the resemblance 

 being none the less striking. The dark rays that divide the base are probably 

 manifestations of the same developmental tendencies that form the rays of the 

 stellate bases of the larval hairs of Lycsenines. The spiculation of the hairs and 

 fine reticulation of the skin are shown very distinctly (though greatly lost in 

 reproduction). 



Fig. 2. — Spiracle of 4th abdominal segment of larva in last instar x 200. 



This shows the curious way in which, in some Theclid larvae (very pronounced 

 in that of B. querciis), the lenticles are, in the later larval stages, embedded in the 

 actual chitinous margins of the spiracles ; in this species they have rounded 

 margins, but the same dotted membrane filling up the lumen as in ordinary 

 lenticles. Separate lenticles are also well-shown with the lateral processes that 

 these nearly all have ; occasionally a lenticle has a margin like the bases of the 

 hairs, but narrowed and small, one such is seen opposite the middle of spiracle on 

 right margin of figure ; these show the close relationship of hairs and lenticles, 

 and suggest that the processes of lenticles are traces of the radiating lines of hair- 

 bases. The fine skin-netting is well shown ; also some hairs (better, however, 

 seen in fig. 1). 



