134 Zoological Proceedings of Societies, 



natural station of the birds in which they are found. In the course 

 of these observations he adverted to the importance of the modern 

 generic characters in leading to a just discrimination even of 

 species ; and he brought forward some instances, where different 

 species, bearing a general resemblance to each other in colour 

 and external appearance, have been confounded together in con- 

 sequence of a want of attention to minute but essential generic 

 characters. 



In the discussion which ensued, Mr. W. S. MacLeay mentioned 

 in illustration of the importance which is to be attached to minute 

 generic characters as affecting the distinction of species, the fact, 

 that Linnaeus, having the two insects before him, confounded 

 together under the name of Scarab ceus pilularius an American and 

 an European insect. These, although analogically so like as to be 

 scarcely distinguishable as species in a rudely constructed genus, 

 are evidently, on the examination of the characters which, modern 

 naturalists have considered sufficient to distinguish genera, refer- 

 able to distinct groups ; one of them being Ateuchus volvens^ 

 MacL., and the other Gymnopleurus pilularius^ 111. 



Mr. Gray being referred to by the Secretary, adduced another 

 instance in illustration of the same fact, in the circumstance of the 

 Ursus Arciosy Linn., and the Ut^sus ferox, Lew. and Clarke, 

 having been confounded together ; an error which has been re- 

 tained even in the publication of M. Desmarest. These animals, 

 however, although apparently agreeing in general points of resem- 

 blance, differ in the structure of their claws, which evinces an im- 

 portant difference in their economy j the claws of one being 

 adapted to climbing trees, whilst those of the other are designed 

 for burrowing. 



Dr. Such, in like manner, added his testimony in corroboration 

 of the importance of generic characters as serving to distinguish 

 species. He observed, that in endeavouring to ascertain the names 

 of several species of the Columbidce, which he had lately brought 

 from Brazil, he found considerable difficulty in distinguishing 

 them, in consequence of the similarity that prevails among the 

 specific descriptions hitherto given by naturalists : and that he was 

 ultimately led to the knowledge of these species by attending to 

 some minute generic characters which were subsequently pointed 



