RHOPALOCERA MALAVANA. H 



fall back upon the dictum of Mr. C. Darwiu, that " iu determining wliether a form should be 

 ranked as a species or variety, the opinion of naturalists having sound judgment and wide 

 experience seems the only guide to follow. We must, however, in many cases, decide by a 

 majority of naturalists, for few well-marked and well-known varieties can be named which have 

 not been ranked as species by at least some competent judges."* 



Genus DANAIS. 



Danais, LatreiUe, Euc. Mctb., is., p. 10 (1819) ; Boiscl., Lee. Lep. Am. Sept., p. 133 (1833) ; Doiibleday, Gen. 



Dium. Lop., p. 89 (1847) ; Trimeu, Ehop. Afr. Ausk., p. 84 (^1802) ; Goclm. & Salv., Biol. Ceutr. Am., 



Ehop., p. 1 (1879). 

 Danaidit, Latr., Hist. Nat. Crust. lus., xiv., p. 108 (1805). 

 Danaus, Latr., Geu. Crust. Lis., iv., p. 201 (1809). 



As some modern writers do not use this old and well-known name for the genus, it is 

 perhaps necessary, before giving a diagnosis of the same, to state the reasons why they have 

 discarded it, and why it is still used here. LatreiUe, finding his earlier name Danaida 

 preoccupied in Botany, supplanted it (1809) by the title Damnis. Mr. Scudderf argues that 

 as the first name is only used in Botany it ought to be restored. But Mr. Butler J has 

 remarked that "Daiiaida" is but the "plural form"' of D(/;;(//s, a term first used byGodart§ and 

 systematically more euphonious than Danaus, which last is, however, adopted in preference by 

 Mr. Kirby in his supplementary Catalogue (1877). Mr. Crotch || traces the name to Linnaeus, IT 

 who used it, however, only as a division of his genus Papilio ; and therefore Mr. Moore's 

 objection** that Danaus was adopted in a generic sense by Esper in 1777 and Panzer in 1801 

 for species of Pia-inw, and therefore cannot be retained in this group of butterflies, is an 

 argument that has not, at least hitherto, secured universal acceptance. 



'■i}'- 



Antenna gradually Init distinctly clavate. Wings more or less opaque and thickly covered with 

 scales. Anterior wings subtriaugular, somewhat elongate ; costal margin slightly arched from base ; apex 

 broad and rounded ; outer margin oblique and more or less sinuate ; inner margin more or less concave. 

 First siibcostal nervule emitted at some little distance before the end of cell ; second emitted sometimes 

 immediately before the end of cell, but generally not before termination of the same. Posterior wings 

 broad, subtriangular ; costal margin nearly straight or slightly curved; apex and anal angle rounded; 

 costal nervure and nervules variable. 



Male with one or more specialised scent-glands. 



It is difficult to definitely assess the exact number of known species and varieties of this 

 widely represented genus, but probably there are now about eighty distinct forms described. 

 Its distribution is almost universal, and it is found in both the warm-temperate and tropical 

 zones. One, an almost cosmopohtan species, is found in South-Eastern Europe, and others are 

 particularly abundant throughout the Malayan Archipelago, Papua, and the Pacific Kegion. 



* ' OriKiii of Species,' 6th eel., p. 37. f Proe. Am. Acad. Ai-ts & Seieuc, p. 153 (1875). 



I 3omn. Linu. Soc, ZooL, vol. xiv., p. 291. § Eno. Metii., ix., p. 172 (1819). 



II Cist. Ent., i., p. 60 (1872). If Syst. Nat., ed. x. (1758). 



** Lep. Ceyl., p. 1, note (1881). 



