142 THE entomologist's recobd. 



where they give somewhat the effect of a black lead-pencil surface, 

 touched up Avith pen and ink. 



It would be interesting to know whether the other members of the 

 genus t'oliofi exhibit scale-characters analogous to those discussed 

 above. 



Explanation of plate iv. 

 Scales from Colias edusa (uniform enlargement). 



A. Fugitive yellow scales from the black border of the forewing of j Colias 

 ediisa. 



B. Black scale from black border of ? Colias edusa. 



C. Black scale from black border of c? Colias edusa. 



Larvae of Lasiocampa quercus and its vars. — callunae, Palm., 



viburni, Gn., meridionalls, Tutt, sicula, Staud., and of 



cross=pairings between these races. 



By AETHUR W. BACOT. 

 {Concluded from p. 117.) 



Many interesting facts were observed in the larval stage of the 

 various crosses. Among others, the larvae of the cross between ^ L. 

 var. meridionalis and ? L. var. callunae (Warburg's cross, see antea, 

 p. 114) fed up at an unprecedented rate. The pairing took place 

 in July, and the eggs hatched about one month later (about the normal 

 period), and the larvje, having outstripped all the other larvae either 

 from crosses or of pure stocks, including those of L. var. callunae, 

 which hatched nearly a month earlier, commenced to spin up during 

 the first week of November, giving a larval period of only three to 

 four months. I kept the pupre indoors, being uncertain whether the 

 constitution of the southern or northern race would be followed, but 

 no moths emerged during 1898, and it was not until midsummer of 

 the following year that I had the first and only emergence, a crippled 

 male. The pupte were kept out of doors during the greater part of 

 the winter of 1899-1900, and were still living in the spring of 1900, 

 but all died during the summer, after some 30 months in the pupal 

 stage. 



The great influence of the EngHsh strain in the four crosses of 

 which one parent was of this stock is very marked in the early larval 

 stages, and in all probability points to the English race being more 

 generalised than the Continental ones. LarvfB of three crosses — <? L. 

 var. meridionalis x 2 I>. var. callunae, g vihurni x ? quercfis 

 (English), and (? {viburni x meridionalis, white-haired larva) x 

 $ quercus (English) — in their first and second instars resembled the 

 larvfe of the female parent stock, while in the case of the cross be- 

 tween a ^ quercus (English) and $ lueridionalis (Cannes), the young 

 larvse resembled those of English race. 



I, Larvae of L. var, ^^BURNI x L. var. meridionalis. — The larvje 

 of the cross between L. var. viburni and L. var. meridionalis (the first 

 1896 cross, see antea, p. 114) divided into two moieties, one following 

 each parent, so that one part had red-brown and the other part white 

 urticating fur ; there were no intermediates. Of the second genera- 

 tion, only a few unfortunately reached adult age ; they resulted as 

 follows : — 



