this group of butterflies in 1816 by Hubner, and adopted by Mr. Rothschild Tin his very valuable and masterly 

 "Review of the Papilionidaj of the Eastern Hemisphere, exclusive of Africa, (Novitates Zoologies;, Vol. III., 1895) "] 

 as the generic name of the whole of the Ornithoptera without distinction, therewith introducing a trinomial and 

 possibly quadrinomial nomenclature, which it is difficult to believe he will not, with his great knowledge, ultimately 

 modify, as being cumbersome and inconvenient to the ordinary student. 



That the whole of the so-called species included in the author's restricted genus Ornithoptera, or the old Priamus 

 Group, may well be regarded as geographical forms of the type species Priamus, it will be wise to admit ; and this most 

 entomologists are agreed upon. The superficial differences, i.e., those of pattern, are not too great, especially in the $ 

 sex, and the external structural characters so far as they have been studied, do not appear to diverge in any important 

 degree throughout the multitude of named forms, from the type species. 



It would appear that the whole of the Ornithoptera are in a very unstable condition, none of the forms appear to 

 be as approximately permanent in pattern and colour as Vanessa atalanta, V. Urtica, Danais Archippus, or even the 

 American Argynnidae. In both sexes it is almost impossible to find a specimen in which the markings are symmetrical 

 on both wings, on either surface ; and still more difficult to find two examples which in size and markings are absolutely 

 alike ; while the intensity and quality of colour differ to a wonderful extent throughout the group. Of course all this 

 instability is intended to enable different members of the group to adapt themselves to the varied conditions of their 

 numerous island homes and continental environments, and to the changes which in the former at least are incessantly 

 taking place— changes which, while they may not be apparent to us, yet are capable of slowly but profoundly modifying 

 the morphological character of all animal and vegetable life. 



The nominal species which appear to afford the most stable specific characters are — 1st, the type form Priamus, 

 which is always large, very melanistic or fairly light in the ground colour of the 2 , and with the anterior wing-cell 

 immaculate ; but an occasional example will be met with where the cell has a small light patch in it ; whilst occasionally 

 the cell of other forms will possess only a rudimentary mark, or it may be altogether absent, notwithstandingthat the 

 rule is for the cell in all those other forms to exhibit a more or less light patch. 2nd, Richmondia, from the Richmond 

 River, Australia, which only differs from Cassandra in being the smallest of the genus Ornithoptera — its variations on 

 the under surface of the $ being as numerous as are those of Cassandra, and identical in patterns : in other words that 

 given a special variation of pattern in the larger species, the same pattern may be found in the smaller, a phenomenon 

 that is very suggestive. So that Richmondia is simply a geographical name for Cassandra, only justified by the small size 

 of all the specimens which inhabit the district of the Richmond River. It may be remarked, however, that some very 

 small S example of other species have been met with that are not larger than the average Richmondia, while on the 

 other hand some abnormally large specimens of the 2 of Cassandra may be found in collections. 3rd, Crcesus. The 

 colour of the $ $ of this species is very permanent in its character — generally, however, betraying a tendency to become 

 less red and more yellow and green in specimens that are bred. As everyone is aware the ? $ of the two forms Crcesus 

 and Lydius are very distinct — the latter being quite abnormal and acrseoid, and permanently so, so far as our knowledge 

 of it goes. 4th, Urvilliana is distinguished by the $ $ being apparently always blue, green blue, violet or lilac— though 

 the size and markings— but more especially the scaling of the posterior wings present many diversities extending from 

 the type form to the interesting geographical variety (Ccelestis, Rothschild) from the Louisiade Archipelago. In this 

 latter the light mark in the anterior wing-cell of the 5 is very fairly uniform in shape and size in all the examples that 

 have been collected. The individuals of both sexes are also smaller than those from other localities, and the colour of 

 the <? is very blue. Now the $ ? of Urvilliana vary to a considerable extent, in depth of colour, from a very light 

 sienna brown to the darkest brown — the light markings present every degree of size, shape, and division that is found 

 in other so-called species of the Priamus group (notably in Poseidon) and they are nearly always large-sized insects ; so 

 that the differentiation from other species is always less in this sex than in the S — notably so in the case of the New 

 Britain example of Aruana and Urvilliana. 



But while all these facts tend to unite the different forms of the genus Ornithoptera (as the author restricts the 

 genus) into one good species, there are other peculiarities of the $ $ which render the evidence of that unity over- 

 whelming, (a) The general pattern of all the $ $ throughout the group is really very uniform, especially on the 

 anterior wing, and so is the colour. We have in Priamus, Cassandra, and Richmondia black and green wings (more or 

 less golden green), with a varying extent of black or colour scaling common to all the species of the genus. The shape 

 and size of the green subcostal band, and of the inner and outer marginal green band are always similar — so much so 

 that a tyro, seeing only plain figures of the species is apt to suppose that they all belong to one species. In the three 

 species quoted, the median vein of the anterior wing is not indicated by green atoms or scales ; but from, and including 

 Pegasus all the forms are more or less green scaled along this vein and its branches ; in a few examples this green 

 scaling becomes so extensive as to encroach largely over the dark area of the wing, and to suggest the possibility 

 that some day examples with the upper wings entirely green may be discovered. In Crcesus, this scaling is not present ; 

 but it re-appears in Urvilliana, in some examples. On the posterior wings there is generally a discal row of suborbicular 

 black spots, ranging in number from 5 to 1. In the three species named these are larger ; and never probably entirely 

 absent ; but in all the other species from Pegasus to Crcesus they are generally not so large, or only rudimentary ; and 

 in many examples are entirely absent. In Urvilliana they are sometimes small, varied in number, but generally large, 

 and often fused into the dark scaling of the lower wing. In all the forms this scaling, which is densest at the base of 

 the wings, is generally present, varying in the extent of its area, till it seems to attain its greatest development in some 

 of the examples of Urvilliana. On the underside of the hind wings of all the species this row of black spots is always 

 present : the spots are longer than above, more irregular in shape, and always either six or seven in number. Again, 



(7) 



