THE CHIEF COLEOPTEROUS FAUNiE. 65 



distant lands south of the equator," I have endeavoured to make 

 sure that none which I cite can come under that category ; so 

 that my argument cannot be touched by it. At the same time, I 

 may say that I do not know to what species Mr. Bentham refers 

 as falling under that category. I know of none. Lastly, as 

 regards the opinion with which he closes, that " from a very early 

 period in the history of organic life the broad Atlantic from the 

 southern tropic to far into the north temperate region has been 

 an impassable gulf for terrestrial organisms," I have only to say, 

 " So be it, I do not dispute it." Carryback the date to as early period 

 as you will ; all I say is that at some period, and that a period 

 subsequent to the appearance of the present forms of Coleoptera, 

 the broad Atlantic was traversed, in at least two directions, and 

 probably at three different times, by a stretch of dry land which 

 united "West Africa with Brazil, which united Patagonia with the 

 Cape, and which, last of all and probably not without relation 

 to the preceding, united Brazil with Madagascar. 



At the outset I endeavoured to show the long-continued persist- 

 ence of the present forms of Coleoptera ; I pointed out that in 

 the Miocene times they almost all come within our existing ge- 

 nera, that the same facies already existed in the Coal-epoch ; and 

 I do not suppose that Mr. Bentham or any one else will exact a 

 higher antiquity for the Atlantic than that time ; or if they do, 

 there seems no reason why, since the forms of our Coleoptera 

 have endured for so long a period, they should not stretch as 

 much further back as any friend of the Atlantic may choose to 

 carry its age. 



On the strength, then, of the presence of the Brazilian types 

 which I have shown to exist in "West Africa, I think I am entitled 

 to infer the former union of Brazil and that country. Now "West 

 Africa is almost entirely destitute of microtypal forms : there are 

 a few; but their proportion is so trifling that it sufficiently indi- 

 cates that they form no part of the original stirps, and are to be 

 regarded as intruders who have made their way in from abroad. 

 But if "West Africa has little microtypal intrusion, no distinct 

 fauna has more than Brazil ; and it might reasonably be antici- 

 pated that, if the two countries had been united, a portion of the 

 microtypal stirps would have filtered into "West Africa through 

 Brazil ; but we do not find it to be so. Not only are there few 

 microtypal genera in "West Africa, but those which exist are not 

 species whose origin we should think of referring to Brazil : 



LINN. JOURN. ZOOLOOT, VOL. XI. 5 



