420 L. de 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 Athyma probably does mimic 

 the smaller yellow species of Nejptis, such as N. hordonia, Stoll. 



201. Athyma assa, de Niceville. 



A. assa, de Niceville, Joam. Bomb. Nat. Hist. Soc, vol. viii, p. 42, n. 5, pi. K, 

 fig. 8, waZe (1893). 



Occurs at the same localities and elevations as A. amhara, Druce, 

 but is much rarer. It is a beautiful species, of which the first speci- 

 mens were obtained in 1892. 



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 

 Char axes, Prothoii, 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 was sawing wood, 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 

 keen a largo 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 (Bophla) 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 (Bophla) eurus, de Niceville. 



E. (Dophta) eurus, de Niceville, Jonrn. A. S. B., vol. lxiii, pt. 2, p. 15, n. 13, 

 pi. ii, figs. 3, male ; 4, female (IS94). * 



Of all the EuthaJias, 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 



