242 NORTHERN ZOOLOGY. 



The three subordinate divisions of the aberrant group contain,, as usual, genera 

 of much apparent dissimilarity ; they may, however, be defined as birds having 

 the bill much thicker and more powerful than those of the typical groups, while 

 their general structure is weaker and more imperfect. This inferiority is evinced, 

 among the Fringillidce, by their diminutive size ; in the Musophagidce, by the feet 

 being adapted only for frequenting trees, and in the restriction of their food to vege- 

 tables ; while in the bulky Hornbills (Buceridce) the tarsi are unusually short and 

 the toes nearly syndactyle. None of these imperfections are observed among the 

 Corvidce and the Sturnidce. We therefore agree with Mr. Vigors in considering 

 that these families represent the perfection of the ornithologic structure*. 



The precise manner in which the aberrant circle is closed, by the union of the 

 Fringillidce and the Buceridce, cannot at present be explained ; their absolute 

 affinity, however, has been already acknowledged, and their union insisted uponf. 

 As to the Musophagidce, comprising the genera Musophaga, Corythaix, Colius, 

 and Phytotoma, any ornithologist, who actually examines these birds, must be 

 convinced that they offer so many steps of gradation between the Buceridce and 

 the Fringillidce, yet too distinct to be comprehended under either of those families. 



We must pass over the analogical relations of the Conirostral group, and 

 merely confine ourselves to a few remarks upon the 



FRINGILLIDCE, 



as being that family which offers the greater number of species brought home by 

 the Expeditions. The primary divisions of this group, which is certainly the 

 most extensive in the whole circle of Ornithology, may be thus stated : — 



1. Typical group. 



Tribes of Insessob.es. Sub-families. 



f Bill thick, very conic, and entire, the margin of 1 



Conirostres. { ,.,,-,, } Coccothraustince. 



[ the upper mandible sinuated. J 



2. Sub-typical group. 



f Bill with the culmen bent, the upper mandible 1 

 Dentirostres. < , > Tanagrmce. 



clature of well-known species. In one of the modern systems, the T. viridis is placed between the Goatsuckers and the 

 Kingfishers, — and this situation is called natural ! — Sw. 



* A well-known zoologist, whose opinions in general carry much weight, considers that this perfection lies among 

 the Scansores, and that the Psittacidas are the typical group of the ornithological circle. We can only say that this 

 idea, which seems merely founded upon theory, receives no confirmation from analysis. Were it correct, it would not 

 only annul everything here written, but completely demolish that very system upon which the author has bestowed 

 such unqualified praise as to pronounce, that " Birds now form the only class in Zoology which has been arranged 

 according to the variation in structure." — Linn. Trans., xvi., p. 6. 



f Linn. Trans., xiv., p. 450. 



