INTR O D UCTION. 1 5 



differences in modification. In all the orders of insects we can 

 recognise that certain families are probably late comers, for they 

 are made up of fragmentary groups, and the genera are rarely 

 endemic. For example, we have in the Lepidoptera, the Papilio- 

 nina, the Sphingidce and the Arctiada '; in the Diptera we have 

 the Mustidce ; in the Hymenoptera, the Apidce and Pompilida ; 

 in the Coleoptera t the Cicindelidce, Buprestidce, and the Lamelli- 

 fornia ; in the Hemiptera^ the Pentatomida and Cicadid<z : in the 

 Orthoptera we have the GryllidcB, Locustida, and Blattidce ; in 

 the Neuroptera, the Odonata. 



On the other hand, there are groups which are comparatively 

 well represented, and we recognise them as ancient inhabitants 

 because a large proportion of the genera are endemic. Thus in 

 the Lepidoptera we have the Scopariidce and the Tineina ; in the 

 Diptera, the Tipulidce. ; in the Hymenoptera, the Formicidce ; in 

 the Coleoptera, the Pselaphida, Colydiidce, Dascyllida, and the 

 Curculionidtz ; in the Hemiptera, the Fulgoridce ; in the Orthoptera, 

 the Stenopelmatida and Phasmidiv ; in the Neuroptera we have 

 the Trichoptera. 



The Mud-fish (Neochanna) must have been a long time in 

 New Zealand, because it has become so much modified ; and if it 

 is, as Dr. Gunther has suggested, a degraded form of Galaxias, 

 then Galaxias must have been here for a still longer time. But 

 Galaxias attenuates is found in Patagonia and Tasmania ; and it 

 is more closely related to G. maculatus of Tierra del Fuego and 

 Patagonia than to any of the New Zealand or Australian species. 

 From which it is evident that it must either have spread at a 

 comparatively late period from New Zealand to Patagonia, or that 

 Galaxias has been introduced twice into New Zealand. 



Again, in the Antarctic element, the earth-worms point to a 

 period of distribution long anterior to that of the marine fishes, 

 Crustacea and Mollusca, which form the greater part of the 

 group ; so that here, also, we seem to have two different periods 

 of migration. 



The connection between New Zealand and South America 

 shown by those species the geographical relations of which are 

 also Malayan, and which cannot be considered as Antarctic, 

 appears to have been at a very remote period No species are 

 identical, and only a few genera, chiefly in insects. In birds such 

 as Hymenolcemus and the Struthious birds, the relations are between 

 members of the same family only. It is the same with the 



