*^* AND ^^-^^^ 



JOURNAL OF VARIATION. 



Vol. IX. No. 8. August 1st, 1897. 



Nemeophila plantaginis: its aberrations and varieties. 



(Illustrated by Plate.) 

 By J. W. TUTT, F.E.S. 



The British lepidopterist usually gets few good aberrations of N. 

 plaiifai/inis : yet, if each were to look carefully through his series, 

 assuming that the specimens have come from diiierent districts, he 

 would probably observe that they show a considerable range of minor 

 variation. The specimens from our northern and western mountains 

 exhibit the greatest amount of variation, whilst those from the Scotch 

 Highlands present many of the peculiar aberrational tendencies which 

 characterise the species in different parts of its wider range — for, if 

 the American petrosa be really only a specialised form of the ab. 

 lioapita, the species practically circles the north temperate region of 

 the world. 



There is, in the minor variation to be noticed everywhere, a dis- 

 tinct sexual difference to be observed. The male, with its pectinated 

 antenna?, slender body, and rapid flight in the late afternoon sun, has 

 rather more ample wings than the heavy-bodied female, with its slow 

 and lethargic movements, which is rarely seen on the wing, and never 

 at the time that the males are so active. 



The pale markings of the fore-wings may be described as consist- 

 ing of: — (1) A narrow longitudinal line at the base of the costa. 

 (2) A central transverse costal streak, situated a little less than mid- 

 way between the base and apex of the wing. (3) An oblique costal 

 streak, running from a point situated on the costa (at about one-third 

 from the apex towards the base) to the anal angle. (4) An apical 

 streak (near apex) parallel to the preceding. (5) A longitudinal 

 streak or band parallel to the inner margin. 



I find, in my long series of British specimens, that the costal 

 basal streak varies from complete obsolescence to a small rectangular 

 blotch, broadest at some little distance from the base ; occasionally it 

 forms two distinct costal spots, which are very rarely continued down- 

 wards to meet the longitudinal streak (No. 5 above), thus reducing 

 the basal portion of the black area almost to vanishing point. The 

 central costal streak varies very greatly ; sometimes it forms an irre- 

 gular spot of variable size, cut off from the costa by the black ground 

 colour ; more generally it is connected with the costa by a narrow 

 streak ; at other times it forms a large irregular blotch, extending 

 from the costa, and occasionally being connected with the central 



