146 DENDROCOLAPTIDA. 
II. Synallaxine ; 
III. Philydorine ; 
IV. Sclerurine ; 
V. Dendrocolaptine : 
the subordinate characters being taken from the size of the bill and the length of the 
tarsus. 
When the definitions of these subfamilies are submitted to test, we find that they do 
not give satisfactory results, so that we are obliged to modify them considerably by 
introducing the shape and structure of the nostrils as a character of importance; the 
relative length of the hallux is also useful as a diagnostic feature. 
We cannot here go into all the modifications involved in Mr. Sclater’s classification 
when the shape of the nostrils is taken into consideration, but in illustration we note 
that when the nostrils of Pseudocolaptes are examined it will be seen that they are 
linear and overhung, and not open and oval. This character places Pseudocolaptes in 
the Synallaxinz and not with the Philydorine. The Philydorine are also affected by 
this character, and great changes must be made in the grouping of a large number of 
South-American genera, and even the species of some genera must be re-examined—as, 
for example, Thripophaga, which, as exemplified by its type 7. striolata, has an open 
oval nostril and is allied to Philydor; but all the other birds associated with it have 
linear overhung nostrils, and must be placed in the Synallaxinez, perhaps in the genus 
Placelodomus. 
The Dendrocolaptide of Mexico and Central America may be divided as follows :— 
A. Rectrices laxze, rhachidibus ad apicem haud rigidis. 
a. Nares lineares et membrano obtecte ad marginem inferiorem 
fosse nasalis posite . . . . . . . . . . .) .) .) 6SYNALLAXINAE. 
b. Nares apertz, ovales, ad finem fossz nasalis site . . . . . PuHityporina. 
B. Rectrices rigide, rhachidibus prolongatis, acutis. 
c. Hallux longus fere digitum medium zquans. 
a’, Naresaperte,ovales . . . . . . . . . . . . SOLERURINA. 
6'. Nares lineares, membrano obtecte . . . . . . . . MARGARORNITHINA. 
d. Hallux brevis, quam digitum medium multo brevior. 
c’. Nares lineares, arcuate, membrano obtecte . . . . . GLyPHORHYNCHINE. 
d’, Nares aperte, ovals . . . . . . . . . . . . Denprocozarrina. 
The Central-American Synallaxine as thus defined contain three genera including in 
all six species ; the Philydorine four genera and fifteen species ; the Sclerurins the genus 
Sclerurus, with three species; the Margarornithine the genus Margarornis, with two 
species; the Glyphorhynchine, Glyphorhynchus, with one species; and the Dendro- 
colaptinee seven genera and nineteen or, perhaps, twenty species: the total number 
of genera being seventeen, with forty-six or forty-seven species. Of the genera not 
one is peculiar to Central America; but of the species twenty-nine are not found 
