picid^e. 299 



The manner in which the aberrant group may be closed, by the union of the 

 Certhiadce and the Ramphastidce, can only be conjectured ; since there is 

 every reason to suppose that, in the latter family, some of the primary forms 

 are either extinct or undiscovered. As most of the scansorial birds brought 

 home by the Expeditions belong to the family of 



PICID.E, 



we must content ourselves with offering a general view of the groups which 

 belong to it ; beautifully perfect in some of its details, and remarkably deficient 

 in others. 



1. Typical group. 



Analogies. Sub-families. 



{Bill more or less wedge-shaped, entire ; tail and ) 

 c ■ , } PlCIANvE. 



feet scansorial. J 



2. Sub-typical group. 

 ( Bill strong, with the culmen arched, typically } 



DENTIROSTRES. { i j r ■ i i c xi c ) BuCCONIN^. 



\ toothed ; feet scansorial ; tail feathers soft. 



3. Aberrant group. 

 Scansores. Unknown. * * * * 



Tenuirostres. f Bill acute, entire ; Claws scansorial, or broad, 1 Yunxin^e. 

 Fissirostres. \ compressed, and hooked. J OxyrhynchiNjE. 



It may appear, at first, somewhat absurd to suppose that the scansorial type 

 of the Picidce is unknown, seeing that the whole family is pre-eminently scansorial. 

 But it must be remembered that in every perfect group there is one form which 

 is terrestrial, thereby representing either the Grallatores or the Rasores, and con- 

 sequently the Tenuirostres or the Scansores. After six years' reflection upon this 

 subject, we can no longer doubt on the natural station of the genus Buphaga*: 

 if we therefore said that the rasorial type was deficient, the truth would appear 

 more obvious, since we are as yet unacquainted with any walking bird which 

 shows the least affinity with the tooth-billed Barbuts and the Parrots ; and it 

 is precisely at this point that the scansorial type must occur. We cannot, how- 

 ever, dwell upon this abstruse point, but must pass to the sub-family of the 



* This is the only bird which, in our opinion, can be suspected of representing one of these tribes; indeed, no 

 analogy can be more beautiful than that which Buphaga bears to the Tenuirostres, or suctorial tribe : the latter 

 suck by means of the tongue, the former by the bill. We view it, however, as entering the rasorial division of the 

 Certhiadce, wherein it probably represents the Tenuirostres. — Sw. 



2Q2 



