Systematic Position of Zeledonia coronata. 23 



Nevertheless, it seems to me that there can be no doubt 

 about the Turdine affinities of Zeledonia. Whether further 

 research would justify the formation of a separate subfamily 

 for this bird, as has been proposed, remains to be seen. Its 

 nearest allies seem to be among the Sialiinae. 



That it is an isolated form, primitive in some respects, 

 highly specialized in others, seems beyond dispute. Its 

 powers of flight must be of a very limited description ; the 

 small size of the keel of the breast-bone and the peculiar 

 form of the wing bear out this contention. In this matter 

 of the reduction of the wing it is significant to remark that 

 it takes place, not by a decrease in the length of all the 

 remiges, but by the shortening of the outer primaries only, 

 leaving the inner primaries and secondaries still unreduced. 

 This is exactly what takes place during the early stages of 

 the degeneration of the wing throughout the class Aves. 



To keep this paper within the smallest possible limits I 

 have been obliged to omit the results of comparisons with 

 the more distant allies of the Turdidae and of those reputed 

 to hold such a position; but I would say here that there 

 seems good ground for believing that further research will 

 demand the formation of one large group of Turdiform birds. 



This would include the Timeliidae of Dr. Sharpe's ' Hand- 

 list' (in part.), the Pycnonotidre, Mimida?, Turdidae, Sylviidae, 

 Mniotiltidae, Regulidse, Cinclidae, Troglodytidse, Alaudidae, 

 and Motacillidse. The relationship of these groups one to 

 another is a matter upon which I am now engaged, and 

 is one of extreme difficulty. 



I am ecrually unable, at the present juncture, to say any- 

 thing definite as to the probable nearest allies of this great 

 Turdiform group. Suffice it to say, I do not think that this 

 group stands so low in the scale as some have imagined, if 

 we may give any weight to the form of the maxillo-palatine 

 processes and the relations of the squamosal in the nestling ; 

 and to my mind these are characters of some importance. 

 Neither do I believe that they stand so high as others have 

 contended ; but, as I have just remarked, this is a matter 

 which I am now trying to sift. 



