92 THE CANADIAN ENTOMOLOGIST. 



spot may be very small or very large, and may be isolated, joined to the 

 oblique bar, or connected with the longitudinal stripe. The longitudinal 

 stripe of f. w. is peculiarly vacillating. Sometimes it shows large develop- 

 ment in an otherwise very dark wing, as seen in figs. 3 and 9 ; on the 

 contrary, in some patterns it is but a mere basal spur, although the other 

 light elements are highly conspicuous, as in fig. 5. 



In the summer of 1888 three families were bred from eggs. 



Progeny in family A. : 



Males. — 5 formal Petrosa ; fig. 16 of the plate is one of them. One 

 intergrade, somewhat nearer to Petrosa than to Scudderi in the method 

 of its pattern, but at least as near to Scudderi as to Petrosa in degree of 

 development of pattern ; this is fig. 1 1 of the plate. 



Females. — 3 nearly formal Petrosa; fig. 12 is one. Ten intergrades, 

 all nearer to Scudderi than to Petrosa^ of which the one nearest to 

 Scudderi is fig. 1 7 of plate. 



Progeny in family B. : 



Males. — -One, formal Petrosa. Two, near Petrosa. Six, a little 

 nearer to Petrosa than to Scudderi, and all much alike. 



Females. — One, nearly formal Petrosa. Seven, a little nearer to 

 Scudderi than to Petrosa, and all much alike. Three, nearly Scudderi. 



Family C. — Eggs from a female of extreme Petrosa characters. 

 Resulting progeny, 3 composite males, Scudderi as to hind wing, but 

 with f w. approximating Petrosa nearly in equal degree to the f. w. of fig. 

 II. Two of them are precisely the form '• Geo metrica," Si's, figured in 

 Plate 2, Proc. Ent. Soc, Phil., Vol. 4, 1865. The third specimen differs 

 by having a single small white dot on each hind wing. 



A question has been raised whether Nemeophila plantaginis occurs 

 in North America. At Laggan, Plantaginis is not found. The local 

 Petrosa, throughout its immense range of variation, is at no point of its 

 pattern-sequence coincident with Plantaginis. Of the latter I have com- 

 pared a small but broadly geographical series. The typical Plantaginis 

 from Saxony is a larger form than our moth of the Bow Valley, and is 

 besides a far more gorgeous affair, with hind wing black and red in the ? , 

 black and saffron in the ^ . The type form from polar Norway is 

 smaller, but retains nearly the same pattern, and in my examples the 

 colours are but little toned down. From northern Finland I have a pair, 



