TUE CHIEF COLEOPTEROUS EAUN^. 59 



forms in the face of thousands of allied forms would bo a poor 

 foundation on which to rest a distinct fauna. As a subfauna 

 distinguished by the numbers of Anthribidse, new forms of 

 BrenthidsB, beautiful Tesosterni, &c., it may pass ; but even then 

 the line cannot be drawn, as in mammals and birds, with any 

 sharpness. Australia, as it has been affected slightly by the 

 vicinity of this Indian fauna, also has contributed a little of its 

 own specialities to the nearest islands. 



Mr. Frederick Smith's Table of the geographical distribution 

 of the species of Hymenoptera collected in this archipelago by 

 Mr. Wallace shows the same thing (Linn. Soc. Proc. vii. p. 109, 

 1864) ; and a still more striking result to the same effect would 

 be exhibited if the genera were contrasted in the same way as he 

 has dealt with the species. 



The Philippine islands belong to the same group, although, like 

 Formosa (which is on the boundary), they are probably not with- 

 out a microtypal tinge. The Pachyrhyncld may fairly be consi- 

 dered to be representatives of the strictly microtypal genus Otio- 

 rliynclius. 



Africa (south of the Sahara, of course) is better entitled to claim 

 rank as a separate province than India. The general facies is dif- 

 ferent, the character and tone of the scenery is more decided — no 

 doubt, owing to the difference in the conditions of each country, 

 which has given greater predominence to one part of the same 

 fauna in the one, and to another part in another. In Africa the 

 great sandy deserts have encouraged the development of Adesmia 

 and such desert-loving Heteromera, while in India there has 

 been not only apparently a greater admixture of foreign elements, 

 but in much of it, especially in the moist forest- overgrown island- 

 mountains, there is no scope or suitable conditions for such spe- 

 cies, but the other members of the fauna which flourish in wooded 

 lands take their place. 



One strong argument in favour of the original unity of the 

 stock of India and Africa is that most of the genera which occur 

 in the one country are to be found in the other when suitable con- 

 ditions present themselves. It must always be kept in mind that 

 while the presence of uncongenial conditions is a perfectly good ex- 

 planation of the absence of any forms we might expect to meet, we 

 have no right to expect something else to be there unless that 

 something is a member, an ally, or a modification of something 

 already in the fauna. Thus the absence of sandy deserts will account 



