420 L. cle Niceville & Dr. L. Martin — Butterflies of Sumatra. [No. 3, 
yellow form could mimic, though, as Doherty has remarked, size is 
probably not an insuperable bar to mimicry, as the vertebrate enemies of 
insects probably think that insects in the perfect state grow as they do 
themselves, so that our large yellow female Atliyma probably does mimic 
the smaller yellow species of Neptis , such as N. hordonia, Stoll. 
201. Athyma assa, de Niceville. 
A. assa , de Niceville, Journ. Bomb. Nat. Hist. Soc., vol. viii, p. 42, n. 5, pi. K, 
fig. 8, male (1893). 
Occurs at the same localities and elevations as A. amhara, Druee, 
but is much rarer. It is a beautiful species, of which the first speci¬ 
mens were obtained in 1802. 
202. Euthalia (Dophla) derma, Kollar. 
Hagen. A very fine, large and rare species which is found from near 
the sea to the elevation of Bekantschan. It is, like the rare species of 
Charaxes , Prothoe , and also Athyma larymna , Doubleday and Hewitson, 
only met with singly or in pairs. Dr. Martin obtained his first pair 
in 1887 near Toentoengan at a place in a large forest where a Chinese 
carpenter w T as sawing w r ood, and the two butterflies were feeding on the 
wet sawdust. Dr. Martin possesses specimens from Stabat on the 
Wampoe River, and from Boekit Mas on the Besitan River. He is under 
the impression that like a pair of tigers or large birds of prey, which 
keep a large area of country solely for their own use and benefit and do 
not allow any other individuals of the same species to intrude into this 
area, that the above-named large and rare butterflies—but only in the 
subfamily Nymphalinse —behave similarly, as there are never found 
more than one or two specimens of each over a large area. The reason 
for this Dr. Martin is quite unable to explain. 
203. Euthalia (Dophla) dunya, Doubleday and Hewitson. 
Hagen. Even rarer than E. derma , Kollar. Dr. Martin only 
possesses two specimens, one from Bekantschan, and one from Kampong 
Singhapura, five miles south of Namoe Oekor, so is probably in Sumatra 
confined to the outer hills. It is very common in S.-E. Borneo. 
204. Euthalia ( Doplila ) eurus, de Niceville. 
E. (Dophla) eurus, de Niceville, Jonrn. A. S. B., vol. lxiii, pt. 2, p. 15, n. 13, 
pi. ii, figs. 3, male ; 4, female (1894). 
Of all the Dhithalias, this species approaches nearest to the sea, 
as Dr. Hagen has captured it near Laboean, and Dr. Martin both sexes 
in the forest between the Saentis Estate and the sea. Found not higher 
than Bindjei or Selesseh. Both sexes are rare, especially the female 
