93 
imagines emerged between June 17th and November 3rd, 1897. These 
consist of 65 ¢ and 56 @. 
iv. Hybrids between 8 T. crepuscularia (York) and 2 T. bistortata 
(Clevedon).—No. 4 of above list. Two batches of eggs obtained ; 
hatched April 21st to 23rd; larve fed up together; 40 imagines 
emerged between June 16th and November tst, 1897. ‘These consist 
of 40 males and no female. 
These crosses 111 and Iv are the reciprocal crosses of typical 
T. bistortata and T. crepuscularia. ‘The most noticeable point is that 
cross 111 produces 47 per cent. of females, and cross Iv no female. 
The earliest specimens to emerge (of both sexes) were pale, those 
longest in the pupal stage were the darkest. 
Ill. Hybrids obtained by Mr. Bacot. 
RECIPROCAL CROSSINGS OBTAINED.—Fertile reciprocal crossings 
obtained were— 
1. Z: bistortata 8 x T. ab. delamerensis 2 .—Paired March oth. 
2. Z. ab. delamerensis 6 xT: bistortata 3 .—Three pairings. «a. 
Paired February 26th; ova hatched April 6th. £8. Paired March 
5th. y. Paired March oth; ova hatched April 7th. 
3. LZ. bistortata 8 x T. crepuscularia 2 .—Two pairings. a. Paired 
March goth; hatched April 8th to 9th. (@. Paired March oth ; hatched 
April 8th to oth. 
4. T. crepuscularia 8 x T. bistortata 9 .—Paired February 27th. 
Crossings that failed were—(1) 7: crepuscularia 8 x T. bistortata@. 
Paired February 27th. (2) Z:ab. delamerensis 8 x T. bistortata 9. 
Paired March 4th. 
Hypsrips.—1. Hybrids between g T. bistortata x 3 T. ab. delame- 
rensts.—(Ova received from Dr, Riding. They are part of Dr. Riding’s 
cross marked 1.) Eggs laid March 15th; hatched April 26th to 27th. 
Twenty-one specimens emerged—r11 males, ro females. 
u. Hybrids between 8 T. ab. delamerensis x 9 T. bistortata.—No. 2a 
above. One batch of eggs, hatched April 6th; some larve full-fed 
by May oth; larvee mostly like that of the ? parent (dzs¢orta‘a), 
only a few having the apex of the A open like the larva of 7. 
crepuscularia. Most of the larvae pupated about the middle of May. 
Imagines commenced to emerge early in June, at first rapidly and 
afterwards more slowly, until end of June; there was then a break 
until July 16th, when they again commenced to emerge, and com- 
tinued to do so at intervals until the first week in September; one 
specimen emerged during the last week in October. Fifty-eight speci- 
mens emerged, all males—twenty-nine pale and twenty-nine dark 
specimens. 
ul. Hybrids between 8 T: bistortata x 9 T. crepuscularia.—Of 
this cross there were two different broods. Of the first, a (marked 
3a in Bacot’s pairings), the larve for the most part followed the ¢ 
parent (d7s/ortata), only a few have the apex of the A. mark open as 
in § parent ; full-fed from about 16th to zoth May. ‘Twenty-two speci- 
