226 LLOYD'S NATURAL HISTORY. 



World, where they are extremely abundant. They are grega- 

 rious, sometimes assembling in large numbers on damp sand 

 (cf. vol. i. p. Ixiv.). They have a very rapid and powerful 

 flight, and frequently migrate in large flocks. The Butterflies 

 are of a white or yellow colour, and some of them very closely 

 resemble American species of allied genera. They are prob- 

 ably not all strictly speaking, congeneric; thus the Malayan 

 and Australian C. scylla (Linn.), a conspicuous Butterfly with 

 white fore-wings narrowly bordered with black, and orange 

 hind-wings, has a much stouter larva, and a stouter and more 

 regularly-formed pupa, with the thoracic hump rounded off. 



The type of the genus is C. crocale (Cramer), another very 

 abundant Indo-Malayan and Australian species, which measures 

 about 2^ or 3 inches across the wings. The male is greenish- 

 white, with the greater part of the costa and hind-margin 

 narrowly bordered with black ; the base of all the wings is 

 broadly sulphur-yellow, the outer limits of this colour being 

 very irregular, and narrowly produced for some distance below 

 the black edging of the costa of the fore-wings, and along the 

 inner-margin of the hind-wings. The female is of a more 

 creamy white, tinged with ochreous towards the base, and with 

 the costa of the fore-wings and the hind-margins of all the wings 

 more broadly edged with black. From the costa of the fore- 

 wings an irregular black mark descends over the disco-cellular 

 nervules, and towards the tip the black markings are broader, 

 forming the commencement of a spotted band. 



GENUS CALLIDRYAS. 



Callidryas, Boisduval & Leconte, Ldpid. Amer. Sept. p. 73 

 (1833); Boisduval, Spec. Gen. Lepid. i. p. 605 (1836); 

 Doubleday, Gen. Diurn. Lepid. p. 66 (1847); Butler, 

 Cist. Ent. i. pp. 36, 46 (1870); id. Lepid. Exot. pp. 22, 

 155 (1870-1873). 



