378 ON THE ANATOMY OF PASSERINE BIRDS. 
by Johannes Miiller. Both Hylactes and Grallaria are completely 
tracheophone, as he predicted they would be found to be, although 
they agree with one another, and differ from those previously 
described in having the syringeal end of the trachea less abruptly 
distinguishable as being composed of two parts. Neither Lipaugus, 
nor Heteropelma, nor Hadrostomus are far from the mesomyodian 
types already known, as far as their voice-organs are concerned, 
which structure clearly shows that our nomenclature is an inefficient 
one when it places Hadrostomus as far from Pachyrhamphus as either 
is from Tityra. 
Again, also, that the Pipridee and Cotingide should be considered 
to be different families is not borne out by the nature of the lower 
larynx; and it seems hardly possible to allow a difference in tarsal 
scutellation to constitute a family difference, when not borne out by 
more important points of internal structure. 
EXPLANATION OF PLATE 27. (LIIL.) 
Fig. 1. Syrinx of Grallaria guatemalensis, front view. 
2. The same, back view. 
3. The same, lateral view, from within, showing the fusiform processus 
vocalis. : 
4. Syrinx of Hylactes megapodius, front view. 
5. The same, back view. 
6. Syrinx of Lipaugus cineraceus, front view. 
7. The same, side view. 
8. Syrinx of Hadrostomus aglaia, front view. 
