Pier ine Butterflies of the Genus Dercas. 479 



In the l Genera ' Mr. Doubleday admits two species of the 

 genus Dercas — No. 7, Gonepteryse lycorias, Doubleday, male 

 only; and No. 8, Gonepteryx Verhuellii [recfce Verhuelli], with 

 Rhodocera lycorias, Doubleday, female only, as a synonym. 

 With regard to R. lycorias, Dr. A. R. Wallace in 1867 

 wrote : — " Mr. Doubleday puts his R. lycorias ? as a synonym 

 of D. Verhuellii, but retains lycorias $ as a distinct species 

 from Sylhet. As no specimen answering to his description 

 exists in the British Museum, or in any private collection 

 with which I am acquainted, I am inclined to think that the 

 specimen was probably compounded of the fore wings and. 

 body of D. Verhuellii, with the hind wings of a Callidryas u 

 [= Catopsilia~] . Mr. Hewitson in 1864 wrote : — u Gonepteryjs 

 licorias [sic] of Doubleday does not differ from G. Verhuellii." 

 Mr. W. F. Kirby, in his Syn. Cat., keeps D. lycorias dis- 

 tinct, but with the note " An spec, flct.?" Unfortunately 

 the work in which R. lycorias is described is not to be found 

 in the Calcutta libraries, so 1 propose to ignore the species 

 altogether *. 



The genus Dercas is found in the mountains of N.E. India 

 (Nepal, Sikkim, and Bhutan), in Assam, Western, Central, 

 and Southern China, Upper Burma (but not in Central and 

 Southern Burma), in the Malay Peninsula, Sumatra, Java, 

 and Borneo. Its headquarters would appear to be the Khasi 

 Hills, as in that wonderfully rich region three species are 

 found ; Sikkim (and also probably Nepal and Bhutan, which 

 are conterminous on either side of Sikkim) has two species ; 

 Southern China (Hongkong) has two species ; the other 

 regions one only. All the species appear to be extremely 

 constant, and no seasonal dimorphism is known to occur in 

 them. As far as is known they all inhabit large forests, 

 except the species found in Hongkong, where no forest, 

 strictly speaking, exists : when we took over that island from 

 the Chinese it was bare of trees, but during the fifty-seven 

 years of our occupation much has been done to reforest what 

 was in 1841 almost entirely bare granite rocks. The Chinese 

 have been well-named — though in joke — -Homo ligniperdus 

 by Mr. Sydney B.J. Skertchly, from their abominable wood- 

 destroying characteristics. 



* Since the above was put into type, Sir George F. Hampson, of the 

 J>ritish Museum, has sent me very kindly a transcript of the description 

 of Rhodocera lycorias, Doubleday ( ( Iraj s Zool. Misc. pp. 77, 7s, tin-, male, 

 L 842), and a tracing of the figure, from which it is clearly evidenl that 

 both sexes are synonymous with Dercas Verhuelli. The habitat given is 

 " Silhet. v lu the description 1). Verhuelli is not mentioned, so it may 

 be safely assumed that Doubleday had never heard of it, or he would not 

 have described his species. 



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