LEPIDOPTERA 749 



States, and occurs occasionally north to Maine. It is one of the most 

 polymorphic of all butterflies ; the forms differ so much in appearance 

 that four or five of them have been described as distinct species. The 

 larva feeds on clover and allied plants, and is sometimes a pest in 

 alfalfa fields. 



l^hedog shead, Zerene ccBsonia.- — -The wings are lemon-yellow above 

 bordered on the outer margin with black. On the hind wings the 

 border is narrow, but on the fore wings it is broad. The outline of the 

 yellow of the fore wings suggests a head of a dog or of a duck, a 

 prominent black spot on the discal vein serving as the eye. This is 

 an abundant species in the Southeastern and Southwestern States, 

 extending from the Atlantic to the Pacific. The larva feeds on clover. 



The sleepy yellow, Eurema nicippe.- — -The wings above are bright 

 orange, marked with blackish brown as follows: on the fore wings a 

 narrow bar at the apex of the discal cell, the apical portion of the 

 wings, and the outer margin; on the hind wings, the outer margin. 

 In the female the outer marginal band is interrupted at the anal 

 angle of each wing, and on the hind wings it may be reduced to an 

 apical patch. The expanse of the wings is from 40 to 47 mm. 



The common name, sleepy yellow, was suggested by the fact that 

 the black spot near the middle of each fore wing is reduced to a 

 narrow transverse line, which looks like an eye almost closed. This 

 species occurs from southern New England to Florida and west to 

 Lower California. The larva feeds on several species of Cassia. 



The little sulphur, Eurema euterpe. — Although this species is 

 larger than the following one it is considerable below the average size 

 of our yellows, the larger individuals expanding less than 37 mm. 

 The wings are canary-yellow above, with the apex of the fore wings 

 and the outer margin of both fore and hind wings blackish brown. 

 The border of the hind wings is narrow and sometimes wanting. 

 There is a red-brown splash on the apex of the hind wings below. 



The distribution of this species is similar to that of the preceding 

 one. The larva feeds on Cassia. 



The dainty sulphur, Nathdlis iole.- — ^This little butterfi> can be 

 distinguished from all others described here by its small size, as it 

 expands only from less than 2 5 mm. to 30 mm. It is of a pale canary- 

 yellow color, with dark brown markings. There is a large apical 

 patch on the fore wings, and a broad band parallel with the inner 

 margin ; on the hind wings there is a stripe on the basal two-thirds of 

 the costa, and spots on the ends of the veins; these are more or less 

 connected on the margin of the wing, especially in the female. 



This species also is found from Southern New England to Florida 

 and west to Lower California. It, too, feeds on Cassia. 



The cloudless sulphur, CatopsUia euhUle. — This large butterfly 

 differs greatly in appearance from those described above. It expands 

 62 mm. The wings above are of uniform bright canary-yellow. In 

 the male they are without spots, except frequently an inconspicuous 

 brown dot at the tip of each vein, and a lilac-brown edging of the 

 costal border. In the female there is a discal dot on the fore wings 

 and a marginal row of brown spots at the ends of the veins. 



