GEOGEAPHICAL DISTEIBUTION. xix 



Their raua-e is summarized as follows : 



a 



1. Chelidon PalsearcfiCj Ethiopian, and Indian. 



2. Cotile Pakearctic, Ethiopian, Indian, and Nearctic. 



3. Biblis Pala3arctic, Ethiopian, and Indian. 



4. Tachycineta Nearctic and Neotropical. 



5. Pliedina Ethiopian. 



6. Hirundo Pakearctic, Ethiopian, Indian, Australian, 



Nearctic, and Neotropical. 



7. Cherammca Australian. 



8. Progne Nearctic and Neotropical. 



9. Atticora Neotropical. 



10. Petrochelidon ' Ethiopian, Indian, Australian, Nearctic, and 



Neotropical. 



11. Pscdidoprocne Ethiopian. 



12. Stelgidopteryx Nearctic and Neotropical. 



Erom the foregoing Tables it becomes evident that, as regards the Hirundinidse, 

 the Ethiopian Region is the richest in species, Avith 45 peculiar species and 2 peculiar 

 genera. The Neotropical Region follows, with 25 peculiar species and 1 genus. Next 

 in order is the Indian Region, with 10 species, but no genus peculiar to its area. Then 

 the Australian Region with 6 species and 1 genus, followed by the Palsearctic and 

 Nearctic Regions, with 7 and 6 species respectively, but neither possessing a peculiar 

 genus. 



Some slight modification in these results will be obtained, if Cecropis be considered 

 distinct from Hirundo, if Wirundo dimidiata be separated off generically, and Ilglo- 

 chelidon be reckoned generically distinct from Fetivchelidon, all of which changes are 

 distinctly feasible [vide antea, pp. xiii, xiv). 



In 1893 we published a paper " On the Zoo-Geographical Areas of the "\V(irld, 



illustrating the Distribution of Birds"' (Natural Science, iii. pp. 100-108), in whicli wo 



endeavoured to summarize the sub-divisions into which the six Zoological Kegions of tlic 



Globe have froni time to time been partitioned l)y zoologists. "We therefore now 



proceed to discuss the validity of these divisions from t]ie standpoint of the irn-iindinidir, 



but it is unlikelv that anv strikintr results caii l)u ohlaiiicd in a faniilv so susecid iblr In 



modification of habits as the Swallows are. Not only are (hey migr.itory w ilhin limited. 



as well as large, areas, but, as in the ease o'i I'i'dcjuc tliey e;in he indueed to change their 



6-2 



