ItnoVALQCERA MALAYAN A, 



9 



Hab.— Malay Peninsula ; Fenang (colls, Brit. Hub. and Moore) ; Province "Wellestev {eolL Dist.) + — 

 Malacca (colls. Brit. Mus, and Moore); Singapore (colL Brifc, Mus,), — Sumatra (Gray). — Borneo (coll. 

 Brit. Mus.)* — China: Hong Kong (coll. Brit. Mus.)* 



Th ib species, even in the male sex, varies much in the shape of the anterior wings, and 

 affords thereby an illustration of the caution necessary before such a character can be used 

 as of differential value in separating species* 



The nearest allied species is /. gaum, Horsf., which inhabits Java, and which, with I. dw$ t 

 I take as typical of the genus* These two species in colour and markings approximate closely 

 to species of Hcstia ; the remaining species belonging to Idmpm are more or less tinged with 

 yellow, have the fuscous shadings broader, and approach the true Danaids* 



Note.— Although Gray described this insect in his ' Lepid. Ins, Nepaul,' he gives the 

 habitat Sumatra, which also applies to other insects in the same work. 



Genus RADENA, 



Radtna, Moore, L*?p. Ceylon, p. 3 (1881 1. 



Au tenure gradually but distinctly clavate. Wings more or less opaque, thickly covered with scales. 

 Anterior wings subtriangular, somewhat elongate; costal margin slightly arch oil from base; apex broad 

 and rounded ; outer margin obliqur- and moiv or ks* sinmilc : inner margin more or less concave. First 

 subcostal nervule emitted at some little distance before end of cell, and anastomosed with costal nervine ; 

 second subcostal nervule emitted slightly before end of cell. Posterior wings broad, subtriangular ; costal 

 margin nearly straight; apex and anal angle rounded; costal nervure convex at baBe, and extending 

 parallel lo margin ; subcostal nervules not widely separated, first arched and longest. 



Male with no specialised scent-gland. 



This genus is intermediate between Damu and Jdtopsis* Agreeing thoroughly with 

 the first in general appearance and coloration, it yet possesses no specialised scent- gland ; 

 while with Ideopsis it agrees in the position of the first subcostal nervule of anterior wing, but 

 differs strongly from that genus by the shape of the posterior wings. 



About ten described species or varieties are known, of unequal value, some showing strong 

 specific differentiation, whilst others appear to be simply constant geographical races of one 

 species; such as II vulgaris, But!,, the only species received from the Malay Peninsula, 

 which probably, as Mr. Wood- Mason * considers, is but a constant local race or form of 

 JR. similis, Linn., a Chinese species, of which other constant and allied forms are found in 

 Borneo, Nicobar Isles, and Ceylon. The last author, however, describes the male of his var. 

 nicobarica as " provided with a distinct, though little specialised, sexual mark or scent-gland." 

 I have not seen that form, but from an examination of other species of the genus, have been 

 unable to discover anything similar. 



The area of this genus is of wide extent. Specimens of R. vulgaris labelled " Bengal " and 

 "Nepaiil"' are contained in the British Museum; but Mr. Wood -Mason, writing from the 

 Calcutta Museum, f considers this a mistake, and states that he has seen uo specimen of it 

 from any region farther to the west than Upper Tenasserim* We ought therefore to accept 



* Journ. Asiai. Soe. BangL, vol. L. r p. 226 (1881). 1 Ibid. 



Mauch 31, 1882, d 



