the Life History of Agriades thersites. 293 



line (flange) at front of segment, each oblique downwards 

 and backwards, hair points black, hairs numerous, not 

 conspicuously longer on flanges, under surface paler, 

 prothoracic plate deeply recessed, and so conspicuous, but 

 not by colour, honey-gland not conspicuous, but fans 

 indicated by a yellowish point. Head black, true legs 

 have some dark bands on plates, but have a larger green 

 area. 



PL XXVI. Figs. 9 and 10 show larvae that attained 

 this stage before hibernating. Fig. 11 one that reached 

 this stage after hibernating in 3rd instar. 



Sept. 22. The two larvae that had fed up in 4th instar 

 and seemed to be thinking of another moult, appear to 

 be in reality laying up for hibernation, these two were 

 from Lautaret eggs. Three other larvae from Bourg 

 d'Oisans eggs have also entered their 4th instar. 



Sept. 28th. The three last 4th instar larvae are ceasing 

 to feed, possibly for moult but more probably for hiberna- 

 tion, the two first are still quiescent ; it would thus appear 

 that the mass of larvae hibernate in 3rd instar, but that 

 some 5 per cent, or so do so in 4th instar. 



Amongst the last thersites eggs to hatch, a larva emerged 

 on Sept. 7. 



Hatched, Sept. 7. 



Moulted for the first time, Sept. 14. 

 Moulted for the second time, Sept. 22. 

 Moulted for the third time, Sept. 30. 



It then fed on and was found to be lethargic about Oct. 

 10. It was hoped it was going to moult for a fifth time, 

 but it turned out that it was taking up the attitude for 

 hibernation. 



The advance of certain larvae to the 4th instar before 

 hibernation led me to hope that some were going to com- 

 plete their transformations in the autumn ; this proved not 

 to be the case. 



It is worth noting that both Lautaret (7000 ft. single- 

 brooded) and Bourg d'Oisans (2600 ft. from second brood) 

 larvae passed on to 4th instar in autumn and hibernated 

 so. In putting them in refrigeration for the winter I did 

 not keep the two sets of larvae any longer separate, but 

 when brought out and fed up, there were no differences 

 observed to cause regret at this oversight. 



TRANS. ENT. SOC. LOND. 1914. — PART II. (OCT.) U 



