28 Canadian Record of Science. 



very great variation — there is every possible gradation. 

 Pyrameis Huntera, very closely allied to the cosmopolitan 

 Cardui, only differs perceptibly in the color of the trans- 

 verse bar near the apex of primaries which is white in 

 the male, bnt tawny in the female. In Danais Archippus 

 the sexual mark is a slight black swelling close to the 

 lowest median nervule of the hind wings, which is really a 

 pouch enclosing the androconia or scales peculiar to the 

 male sex. These androconia are thought by some to be 

 scent organs for the purpose of rendering the male 

 pleasing to the female, the male being thought to have 

 the power of opening at will the pouches or folds in which 

 they are contained. They are of very various forms and are 

 placed in different parts of the wing in different species. 



In the larger species of the genus Argynnis they occur 

 along the branches of the median and along the submedian 

 vein of the fore wings. They are covered up and pro- 

 tected by other scales, which gives the appearance of 

 a thickening of the veins, and these species also have 

 a row of hairs in the males above the subcostal vein of 

 the hind wings. 



In the Theclas or Hair Streaks, these scales are often 

 crowded together in a peculiar patch near the front of the 

 fore wing, and in some species of Satyrs, especially in the 

 genus Chionobas, they cluster together in a peculiar dash 

 on the front wings running towards the apex, and when 

 the species, as is frequently the case, are ornamented 

 with ocelli, these are generally larger and more con- 

 spicuous in the females. In other genera the sexes are 

 distinguished by a considerable difference in the shape of 

 the wings, a very striking example of this being found in 

 the genus Apatura, as in Apatura Clyton, where the 

 wings of the female are much fuller and more rounded 

 than in the male, and similarly in Thecla Titus the fore 

 wings of the male have a pointed tip and the hind wings 

 have the inner angle sharply defined, while in the female 



