68: WE, A. MTJltKA.T ON THE QEOGEAPniCAL DELATIONS OF 



dopterous insect in existence). It is an unusual thing at any 

 time to meet with a gay-coloured moth ; but one with metallic brilli- 

 ancy is still rarer : Urania exceeds any thing I know in this respect ; 

 and it stands per se, nothing else like it in any other genus. Of this 

 genus there are six species — one in Madagascar ( Urania JRipheus), 

 and the other five within the range of the Brazilian fauna, viz. 

 two in Brazil (on the Amazons), another in Venezuela, one in 

 Cuba, and one in Jamaica. Stelidota octomaculata is an example 

 of affinity with North America. The. mammal Solenodon of the 

 West Indies has been claimed as allied to the Madagascar 

 Gentetes (this, I think, on insufficient grounds) ; but Madagascar 

 is the only place where (with one exception) Iguanoid lizards oc- 

 cur out of America, and the only place in the Old AVorld which 

 furnishes examples of the American Colubrine forms Xiphosoma 

 and Heteroda. The Lemurs, too, as I have elsewhere argued, are 

 perhaps more nearly related to the Opossums or Squirrels tlian 

 to the Monkeys ; and if it be to the Opossums, that would bo a 

 link the more with Brazil. It is to be observed that all these affi- 

 nities are confined to Madagascar and do not touch South Africa. 

 According to my views, they are insoluble except by the supposi- 

 tion of a dry-land communication between Madagascar and South 

 America. My conjecture is that when the communication be- 

 tween Patagonia (the penultimate) and the Cape was interrupted 

 by the sinking of the land, all the laud did not sink. The ground 

 now occupied by Patagonia did sink ; the land next Africa also 

 sunk, but a mountain-range survived running; from Cape Prio 

 (Rio Janeiro) obliquely across the Atlantic to a point a little to 

 the south of the Cape of &ood Hope, there rounding the Cape 

 and running up to Madagascar exactly in the shortest line that 

 a ship could sail directly from Rio Janeiro to Madagascar. It 

 may seem too child-like and direct to the purpose to propose 

 such a route ; I felt it so until I studied the sea-bottom, when I 

 found that there a broad raised ridge does run along the bottom 

 of the sea exactly in the direction I have laid it down. I was 

 not aware of this until I saw it so mapped in a map of the bed 

 of the Atlantic in Mr. Keith's Johnston's New Physical Atlas. 

 No one will dispute the importance of the configuration of the 

 bottom of the sea as an indication of the line of ancient conti- 

 nents ; and on the strength of this and of the fauna of Madagascar, 

 I think I have very fair grounds on which to base my hypothesis. 

 Being a ridge, it would continue so when above water, and not 



