THE CANADIAN ENTOMOLOGIST. 227 



the open were found on the smaller bashes. The egg is almost always 

 placed on the under surface of the leaflet. O-it of sixty three eggs only 

 two were placed on the calyx, and of the other sixty-one, fifty-five, or over 

 ninety per cent., were between the centre of the leaflet and the tip, the 

 remainder being between the base and the centre of the leaflet. In 

 confinement the butterfly lays her eggs on the leaves, sepals and petals, 

 upper or lower surfaces, indiscriminately, but even here the larger number 

 of the eggs will be located on the under surfaces of the leaflets. 



An enemy of dorcas was discovered in a lemon-yellow spider. 

 Several times I caught a spider with one of the butterflies in its grasp. In 

 this connection I observed a peculiar thing : sitting on one of the yellow 

 flowers was a small pale-coloured spider, probably the same as the lemon- 

 coloured one. A butterfly was approaching the flower, when suddenly 

 within about a foot and a half he gave a quick jerk, turning in another 

 direction as if he had seen the menace to his safety in the waiting spider. 

 His leisurely approach, abrupt turn and startled flight were at least 

 suggestive. Once I found an egg with a circular puncture, but outside of 

 the spider no enemy has yet been detected. 



There are two or three further observations of interest. It was found 

 that the butterflies when seated on the flowers usually held their wings 

 upright or nearly so in the case of the males, and horizontally in the 

 females. After a few visits with the butterflies I became able to 

 distinguish the females when on the wing, even at some distance, not from 

 the character of the flight, but from the shade of colour of the under side 

 of the wings. This side is more in evidence when the insect is flying, and 

 the feature presenting the difference of the sexes was the uniformity of the 

 bright colour of the under side in the female. In the males there is a 

 faint purplish tint on this surface on the hind wings and on the tips of the 

 fore wings, lacking or feebly expressed in the females. 



A peculiar disparity in the lengths of the antennae occurred in four 

 butterflies taken at the same place on the same day. The normal length 

 of the antenna in the male is between 6.5 and 7 mm., in the female about 

 0.5 mm. shorter. In the male specimen taken the left antenna was of 

 normal length, while the right measured 5.5 mm. In two females the left 

 antenna was normal in each, the right 4 mm. long in one, 4.5 mm. in the 

 other. In the fourth specimen, a female, both antennse were short, the 

 left 4 mm., the right 5 mm. long. 



When Michigan becomes better known entomologically, dorcas will 

 undoubtedly be found over a large portion of it, both north and south, for 



