ON SOME RACES OF LASIOCAMPA QUERCCS. 315 



(3) L. (ineridionalis x viburni) ^ X L. (ineridionalis X vihurni) J 

 ( = 6<y X 6 ? ).— Two batches secured by Mr. Bacofc (I. July 28th, 1897, 

 and August 3rd, 1897). The larvte like either pure race, except 

 that the ribnrni-\\V.e ones often have more long white hairs than L. 

 viburni, especially on the sides and in a mediodorsal ridge, or on the 

 last few segments. My 30 larvte had nearly all pupated by April 

 20th, 1898, and produced (between June 7th, 1898, and August 21st, 

 1898) 11 (? s and 8 5 s. The insects were much like nos. 6 and 7 but 

 a little smaller. They were fertile as I proved by crossing two of the 

 moths on Angust 4th, 1898. The larvjT; hatched August 26th, 1898, 

 but were not kept. They were (6 x 6) x (6 X 6) that is the third 

 generation of L. vicridionalisx viburni. I refrain from writing the 

 pedigree in full. 



(4) Turning now to the derivations of the brown-haired cross no. 

 7. — L. (ineridionalis x vibitrni)^ X L. meridionalis 2 ( = 1 3' x2?). — 

 Two batches of ova obtained by Mr. Bacot (B. July 19th, 1891, 

 and N. August 7th, 1897). From these larvse he reared no imagines, 

 but out of some five pupre which I obtained from larvae which he gave 

 me, I reared one ? on June 10th, 1898. It is an undersized and 

 rather malformed specimen with the markings rather indistinct. 

 Larvfe like pure ?;/('r^//o»«//s or viburni, or somewhat intermediate, with 

 the short dorsal hairs (which are white in meridionalis) reddish-white 

 or yellowish. 



(5) L. (ineridionalis x viburni) ^ x viburni 2 ( = 1 3 X3?).— Two 

 broods by Mr. Bacot (G. July 25th, 1897, and S. August 12th, 1897), 

 the first only gave larvfB. No imagines seem to have been reared. 



(6) L. (uieridionalisX vihurni) $ X L.(iurridionalisX viburni) ? ( = 7 

 <y x6 $ ). — Ova August 3rd, 1897, lot M, by Mr. Bacot, who reared 

 one male. The larva) I had were white-haired like meridionalis. 



(7) L. (meridionalis xviburni) 3' X L. (ineridionalis x viburni) 2 

 ( = 7 (J x7?).— Ova (P), August 9th, 1897, of Mr. Bacot produced 

 larvfB, no imagines reared. 



This completes the cross-breeds of ineridionalis and viburni among 

 themselves. They all seem to be fertile with one another, and though 

 no imagines resulted in many cases, this is not to be put down to any 

 lack of fertility due to cross-breeding, but to accidental causes insepar- 

 able from rearing large numbers of larvfe ab ovo. 



It must be supposed that, in nature, owing to the two epochs of 

 emergence being separated by an interval of two months, cross-pairing 

 of Jj. weridionalis and L. viburni is rare. Should it occur no doubt the 

 strain would gradually approximate to and get merged with one or 

 other type. 



The derivations of L. ineridionalis x L. viburni otherwise than 

 inter se or with the parent races will be noticed in their places. 



Various Crosses. — (1) L. weridionalis 3' X L. callunae 2 ( = ^3 X 

 8 2 )• — Paired end of June, 1897, by my brother, Oscar E. Warburg. 

 Mr. Bacot reared one cripple from the larvjB he had. The following 

 are particulars of mine. Three larva? were described when 2^ inches 

 long. They were of tAvo types : 



a*. Back dull unicolorous black. Only the subdorsal tufts of the '^quercils 

 pattern " with slightly longer greyish-white hairs. Face as in English L. qtterciis. 



*a and (3 with conspicuous white spiracles and dashes, a is perhaps like 

 typical L. callunae. I do not know the larva. Mr. Bacot has since confirmed 

 this opinion. 



