208 



Ge7ietical Studies in Moths 



banded^ aberration of 0. dilutata I predicted the occurrence of similar 

 autumnata and filigrammaria forms and these I have since discovered. 

 A banded 0. christyi has not yet appeared but it will turn up. 



This ordered condition of the seemingly irregular, the appearance of 

 so many wonderful' aberrational forms and aberrations in parallel series 

 throughout the species and subspecies of the group is so striking as to 

 suggest that Elmer's theory of Orthogenesis^ has some foundation in 



TABLE I. 



Summary of characters differentiating O, autumnata and O. filigrammaria. 



Ova... 



Larvae 



Imagines 



Description 



Hatch ... 

 Description 



Food 

 Pupate . . . 



Emerge . . . 



Markings 

 and size 



Male genitalia Octavals ^ 



Female geni- 

 talia 



Chromosome 

 Number 



Cristae * 

 Labides^... 



Signa ® of 

 Bursa co- 

 pulatrix 



Haploid ... 

 Diploid . . . 



Oporahia aututnnala 



Salmon pink ; pitted, ridges 

 marked but pits shallow 



Date varies with season . . . 



Apple green varying slightly 

 in intensity in the local 

 races 



Betula, Alnus, Larix, Fi- 

 nns 



In typical form late, in 

 larch feeding forms earlier 



In typical form early Oc- 

 tober to November ; in 

 larchwood form Septem- 

 ber 16th to September 

 30th 



Ground often white, varies 

 to grey ; may be melanic ; 

 markings generally dis- 

 tinct but feeble and suf- 

 fused in larch form ; 

 female rather large 



Not large, widely apart ; de- 

 pression between shallow 



About 19 



Head wide ; vestiture thin 



Small and scobinate 



0. JiHgrammaria 



Much the same ; perhaps 

 slightly larger and colour 

 duller 



Always much earlier 



Blackish green, mottled ap- 

 pearance ; head smoky, 

 smaller 



Calluua, Erica, Vaccinium 



Always preceding any true 

 autumnata form 



August 

 20th 



20th— September 



38 

 76 



Colour similar; markings 

 and bars heavier and 

 clearer especially subter- 

 minal bar and on hind- 

 wings ; glossier ; smaller; 

 wings narrower ; female 

 smaller in proportion to 

 male 



Nearer ; depression deeper 



About 7 

 Head narrow 



Larger 



37 



74 



1 That is possessing a complete central band like Melanthia (Larentia) ocellata,Melanippe 

 (Larentia) rivata and M. (L.) sociata. 



2 Eimer, Orthogenesis d. Schmetterlinge, Leipzig (1897). 



3 Chitinous projections on 8th sternite. 

 ■* Patch of stiff hairs on juxta. 



5 Pair of rods rising from the chitinous bar extending from the costae of the valves; 

 fused and ending in a hairy head in these species. 

 " Chitinous armature of bursa copulatrix. 



