New Form in the Fringillidce. 535 



Art. V. Characters of a new Form in the Fringillidce ; with a 

 Description of the only Species yet referrible to it. By Andrew 

 Smith, M.D., Surgeon to the Forces, Superintendent of the 

 late Expedition for exploring the Interior of South Africa. 



In the many instances in which we have already de- 

 tected, amongst birds, well-defined natural groups, we have 

 found a certain harmony of characters pervading the entire 

 of their species: indeed, it has been that evident harmony 

 which led to their being regarded as natural groups. It is 

 true, in each group some species are found which do not 

 exhibit all the characters of the more typical ones ; yet they 

 nevertheless present us with sufficient indications of their re- 

 lationship to enable us at once to perceive their proper con- 

 nexions. 



If, then, the existence of these marked corresponding cha- 

 racters are to be regarded as the essence of such groups, it 

 will be necessary, whenever a species presents itself which 

 does not possess the qualifications requisite for admitting it 

 amongst forms already established, to view it as a legitimate 

 object for the type of a new subdivision. Under such circum- 

 stances, the Sociable Finch of Southern Africa presents itself 

 to our notice. Whilst no one will deny this bird a place in 

 the Fringillidae, most observers will admit it deficient in the 

 series of subordinate characters which would admit of its 

 being properly included in any of the yet characterised sub- 

 divisions of the family ; and, in proof of what we have affirmed, 

 no two original observers have hitherto placed it in the same 

 genus. By the most accurate enquirers, it has either been 

 placed in the Ploceus of Cuvier or the Euplectes of Swainson. 



Unless we are to allow the characters of a group to stand 

 so loosely defined as to admit of the introduction of forms so 

 remote from the typical ones, that no two observers would, in 

 all probability, refer them to the same genus, we cannot pos- 

 sibly regard the bird now under consideration as appertaining 

 either to Ploceus or Euplectes. It has not that series of ex- 

 ternal characters which would establish its place either in the 

 one or the other ; and its resorts and habits are directly op- 

 posed to both ; unless it be believed that we have already 

 sufficient evidence to warrant the conclusion, that every na- 

 tural genus must of necessity have certain modified forms as 

 representatives of other genera. 



If it is to be discarded from any connexion with either of 

 the above genera, its legitimate position is far from evident; 

 and, therefore, to speculate upon probabilities might only 

 increase that obscurity. What is quite incomprehensible 

 with our present materials, will doubtless become evident, 



