234 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



As mentioned earlier the relationship of the New Zealand species is 

 with the Nearctic species, there being no observable association with 

 Australian species. There is a somewhat more pronounced general 

 comparison between types of species in Tasmania and New Zealand 

 than between the latter and Australia. The Australian species 

 (through 0. basalts) show a definite correlation to the Polynesian, 

 Oriental and Palaearctic regions. The Polynesian species, of which 

 there are only 3, exhibit an apparent transition between the Austra- 

 lian and Oriental regions. The Oriental region has 10 species, of 

 which 9 are endemic. 0. guttatus, the one nonendemic species, 

 reaches into the southern Palaearctic and southern Ethiopian regions. 

 For the most part, species of this region tend to merge into those of 

 the Polynesian and Australian regions. 



The Neotropical region contains 9 species, 2 of which are northern 

 and occur more commonly in the southern Nearctic subregion. The 

 other species exhibit rather definite and interesting relationships, 

 some being affiliated with those of Tasmania and New Zealand, some 

 with the Nearctic area, others with the Palaearctic area, while still 

 others are strictly endemic and unrelated. The Holarctic region 

 contains 37 species, nearly one-half of the total world species. 

 These are evenly separated in 18 Nearctic and 19 Palaearctic species. 

 The Holarctic correlation was mentioned above. Species of the 

 Nearctic subregion show affiliation with all regions except the Oriental 

 and Polynesian and show little endemicity. Those of the Palaearctic 

 subregion likewise connect with many other regions, the only notice- 

 able exception being the New Zealand subregion. There is also little 

 endemicity shown for species of this region. 



The other subgenera of Ogcodes are both monotypic. Neogcodes is 

 Nearctic and related to Nearctic species, while Protogcodes is Australian 

 and associated only with Australian species. 



General considerations: This study of Ogcodes species has shown 

 that the species groups have wide general distributions, most of them 

 covering two or more geographical regions. Endemicity occurs in 

 each area, but it is more common in the southern temperate faunas. 

 Islandic populations occur throughout the world; however, many 

 other insect-populated islands do not harbor Ogcodes species. The 

 great deserts of the world appear to have formed a permanent barrier 

 to these species, just as the colder limits of the Arctic and Antarctic 

 Circles have formed impediments. And yet, apparently only one 

 other acrocerid genus, Acrocera, appears to inhabit the Arctic climate 

 mth Ogcodes. There appear to be no pantropical or circumpolar 

 distributional patterns in Ogcodes. 



My studies would seem to indicate that both Holarctic and Aus- 

 tralian-Nearctic-Neotropical distributions have occurred through the 



