1863.] MR. H. W. BATKS ON INSECTS FROM MADAGASCAR. 475 



be, as in the South American, Australian, and Indian provinces, 

 many such groups with clusters of peculiar genera and species. It 

 might be said that, with the exception of the absence of so many 

 groups of continental Mammals, Birds, and other classes, the pecu- 

 liarities of Madagascar are not very much greater than those of some 

 areas of similar dimensions forming parts of a continuous continent. 

 There are areas of this size in Tropical America which contain num- 

 bers of genera and species in various classes, some of them highly 

 peculiar, found nowhere else on the same continent. Regarding the 

 existence of anti-African types, it must not be forgotten that many 

 countries contain one or more isolated forms which are more nearly 

 related to others of distant regions than to those of their own. Africa 

 itself contains, in the midst of a fauna completely distinct, a few 

 scattered Tropical American genera — that is, genera found in these 

 two lands, and nowhere else on the globe. Lepidosiren is one of 

 these, and Hiletus, an equally anomalous genus of Coleopterous in- 

 sects, another. 



The view taken by Dr. Hartlaub, were it pushed to an explanation, 

 would naturally lead to the hypothesis that Madagascar with its 

 islands was once more isolated from Africa than from lands since 

 submerged in the Indian Ocean, containing a fauna of an Indian 

 character ; for on such a supposition only could the predominance of 

 Indian over African features be explained, if it were true. But if the 

 independence and peculiarity of its fauna be more insisted on, we 

 should have to suppose that the island is the site of an ancient tract 

 of land in the Indian Ocean, which had throughout long ages main- 

 tained an independent fauna. It seems to me, however, that the 

 peculiar organic features of Madagascar would be better explained 

 by supposing that the island (whether previouly stocked with anti- 

 African forms, or not) was at one time much more closely connected 

 with Africa than it now is, and that the time of connexion was 

 anterior to the date when the continent became peopled by SimiideB 

 and the bulk of its present Mammalia, but posterior to the intro- 

 duction of Lemurs. Subsequently to this epoch we may suppose 

 it to have become isolated as we now find it ; the lapse of time since 

 the severance having been sufficient to cause the present divergence 

 of the faunas — a divergence caused, however, as much by the extinc- 

 tion of old forms on the continent, once common to both lands, through 

 the immigration or introduction of so many new ones, as by the ori- 

 gination of new species and genera in Madagascar allied to proto- 

 types once common to island and continent. The changes in the 

 Madagascar fauna have not been carried on in all the groups, a family 

 here and there only having shown this multiplication of genera and 

 species. As proof of this, I may mention that out of the 26 genera 

 of insects peculiar to Madagascar, no less than 1 7 belong to one (the 

 Cetoniadce) out of our 1 1 groups ; the Lemurs may possibly be a 

 similar case. 



It must be confessed, however, that our knowledge of the faunas 

 of these lands is not yet sufficient to enable us to come to sound 

 conclusions on these interesting subjects. These remarks must be 



