nilOPALOCERA MALAYAN A. 17 



linear, and dentate separated by second median nervule, and two united at base between median and 

 submedian nervures ; two long linear streaks on abdominal margin divided by internal nervure, and a narrow 

 linear streak on inner side and about ceutre of submedian nervure ; a discal and mucli waved series of 

 fourteen ii-regularly sized spots (in some specimens the inner two are united to the two abdominal-marginal 

 streaks), and a much waved marginal series of smaller spots. Underside of wings much paler, markings 

 as above, and two spots at base of posterior wings divided by precostal nervm-e. Head and thorax above 

 dark fuscous, spotted and streaked with white; abdomen above brown, ochraceous beneath; sternum black, 

 spotted with white ; legs black ; under surfaces of palpi, trochanters and femora white. 



Male with a large and distinct scent-gland situated between third median nervule and median nervure. 



Exp. wings 82 to 108 millim. 



Has. — Continental India ; Cachar ; Nepaul (Brit. Mus.). — Ceylon (colls. Moore and Dist.). — Tenasserim 

 (Limborg.) — Malay Peninsula; Province Wellesley (coll. Dist.) ; Malacca (Brit. Mus.). — Java (coll. Moore). 



Males from the Malay Peninsula exhibit probably the maximum of size, and are in strong 

 contrast, in that respect, to some Ceylon specimens. Mr. Butler appends to his description the 

 very apphcable remark that " there can be no doubt that this is the Indian representative of the 

 Austrahan species D. hamata, M'Leay." All the differential characters rehed upon by Butler 

 are found in Malayan specimens, but certainly do not apply so strongly to all the Ceylon forms, 

 some of which in size and markings approximate much more closely to the Austrahan species. 



G. Semper, in a valuable paper, " Beitrag zur Rhopaloceren-Fauna von Australien,"* has 

 urged that I), septciitrionis and some other described forms are probably "local forms" of 

 D. hamata, which really agrees with Butler's views, already quoted, that the first-named may be 

 considered the "Indian representative" of the Austrahan species. It is necessary that these 

 qualitative views and potentiahties should be clearly understood, as they afford pregnant 

 illustration to the conclusions of Gabriel Koch.f This author, from an examination of the 

 species found in the South Asiatic and Australian Regions, concludes that in many cases the 

 differences between what are generally considered as distinct species are merely variations 

 consequent upon a change of habitat. (It is doul)tless imphed that the surrounding conditions 

 are also different.) This, however, with the manifold readings of the much-vexed term 

 "species," is unimportant. He, however, considered that these facts warranted a belief in an 

 Indian or South Asiatic fauna, which included the warmer parts of Asia, Malasia, Polynesia, 

 and Austraha, and Prittwitz, + in a notice of Koch's results, supplemented by his own 

 examination of VoUenhoven's Pierida: derived from the Dutch East Indian Possessions, agi-ees 

 with Koch in formulating the existence of an Indo-Australian Region. Koch, however, in 

 1870, § modified his views, dividing this proposed fauna into two parts, — a South Asiatic or 

 Indian and an Austrahan and Polynesian fauna, which last he considers, without doubt, has 

 been derived from the Indian by migration, the principal agents of which are the prevalent 

 monsoons. He then, however, seems to infer that the greatest modifying agent in the formation 

 of new species is the influence of climate. Oscar Schmidt, || after a study of Koch's labours, 



* Joui-n. Mus. Godeffr., vol. xiv., p. 138. 



t 'Die Indo-Australische LepiJoptereu-Fauna' (18GG). 



I Stett. Ent. Zeit., 1806, p. 259. 



§ 'Die geograpliisclie Verbreitung der Sckmetterliuge iiber die Erde,' Geogr. Mittb. (1870). 



II ' The Doctiine of Descent,' p. 227. 



March 31, 1882. f 



