522 L. de Niceville & Dr. L. Martin— Butterflies of Sumatra. [No. 3, 
Originally described from the Malay Peninsula and is a local race of P. can - 
nus, Westwood, of Java. It is one of a group which are amongst the most 
perfect mimics known, their models being the different local races of 
Euplcea diocletianus, Fabricius. It is very rare, Dr. Martin in thirteen 
years has obtained two specimens only, both males, in forest near Selesseh, 
the first on 23rd April, 1893, the second on 15th July, 1894. The first 
was captured by a very clever Chinese collector, who watched and 
followed the butterfly for nearly half the day before he was able to 
catch it. He correctly took it for a Papilio, but thought it might be a 
female of P. butleri, Janson. Rothschild records this species from 
Sumatra as P. caunus segialus , Distant, and notes that “ The type- 
specimen of P. segialus , Distant, now in my collection, does not differ 
from that of P. velutinus , Butler, in the British Museum, except in the 
submarginal markings of the hindwing, which are a little smaller in 
P. velutinus ; one of my three P. pegialus from the Malay Peninsula has 
these spots, however, not larger than the type of P. velutinus 
594. Papilio ( Achillides ) arjuna, Horsfield. 
P. arjuna, Horsfield, var. gedeensis, Fruhstorfer, Ent. Nach., vol. xix, p. 287 
(1893) ; idem, id., Stet. Ent. Zeit., vol. lv, p. 118 (1894). 
Wallace. Hagen. Staudinger. Herr H. Fruhstorfer has recently 
described not only P. gedeensis from W. Java and Sumatra, but also 
P. prillwitzi from W. Java, and P. tenggerensis from E. Java, while 
admitting the occurrence of P. arjuna also in Java. I have not suffi¬ 
cient material to form an opinion as to whether or not all these four 
species (five including P. Jcarna, Felder), all closely allied, and from 
one island, are distinct and valid. Herr Fruhstorfer has sent me 
specimens of P. gedeensis from Java which agree with my Sumatran 
examples of P. arjuna. They differ from Horsfield’s figure of the 
latter in lacking a pale green band across the disc of the fore¬ 
wing on the upperside. In Sumatra specimens are found with and 
without the green band; the latter are the commoner. Further obser¬ 
vations appear to be necessary before Herr Fruhstorfor’s species 
can be accepted. P. arjuna in Sumatra is restricted to the Central 
Plateau, where it is common and flies throughout the year, as the 
collectors brought in specimens in every month. Is not nearly so 
shy or quick on the wing as P. palinurus , Fabricius. Rothschild 
places P. tenggerensis as a pure synonym of P. arjuna ; he gives 
P. gedeensis as P. arjuna, Horsfield, (a 2 ), ab. gedeensis, Fruhstorfer; 
and allows P. prillwitzi full specific rank. 
