A New Species of the Genus Nyctinomus. 235 



comes more frequent. Thus of all the genera of Simiae, Le- 

 mures, Cheiroptera and Insectivora now known, there is not 

 one, I may venture to affirm, whose existence in both continents 

 is unquestionable. The first instance that we find of this simul- 

 taneous existence in the two worlds, is in the Carnivora, where 

 we come to the Ursi, Feles, &c. 



Amongst all the families formed of genera, always exclusively 

 confined to one or other of the two continents, one of the most 

 remarkable is that of the Cheiroptera. Formerly, as is well known, 

 zoology included under one common denomination, all the known 

 species of Bat, and it might then be accurately asserted that the 

 genus Vespertilio inhabited every region and every part of the 

 globe. But, when naturalists, guided by more attentive and 

 scientific observations, discovered that the Bats, like the Monkeys, 

 ought to be considered, not as a genus, but as a large family ; 

 when in short, the numerous species of Bat had been divided into 

 natural genera, it is a curious fact, that all the new genera, pro- 

 perly natural, were found always to belong to only one of the two 

 continents, to the exclusion of the other. 



At present the genus Vespertilio, is the only one found in both 

 worlds ; but is it a natural genus ? must not some subdivision be 

 yet made in it ? I shall not attempt the solution of the question, 

 for it would lead me too far. I shall only observe that many cele- 

 brated zoologists have already proposed new subdivisions of 

 this genus. 



As to the genera Roussetie (Pleropus, Briss.) and RMnopome, 

 (Rhinopoma), and M. Raffinesque's genus Atalaphe, (Atalaphus) 

 which have been said to exist in both worlds, I shall observe 

 that the pretended Roussette of America is, as has been proved, 

 from India, and belongs to the species Pteropus Leschenaultii ; 

 and that the genus Rhinopoma * is not a natural genus, for, al- 

 though the two species that compose it, have some resemblances 

 to each other, they are not such as to unite them into one genus. 



* The genus RMnopome was established by my father, who tells me that he 

 intends to separate the species, hitherto called Rhinopome de la Caroline, from 

 RMnopome microphylle (Vespertilio Micro Phyllus. Schr.) the true type of the 

 genus, and to place it elsewhere. 



Q2 



