310 



DB. E. W. SHUFELDt's MORPHOLOGICAL 



far as this character goes, theu, Ampelis agrees, as it does in so 

 many other particulars already defined above, with the Oscines 

 rather than with the Clamatores. 



AVe also notice that upon the underside of the superior osseous 

 mandible in the Tyrant Tlycatchers the greater portion of that 

 space which occurs between the anterior limbs of the palatines is 

 filled in by a continuous plate of bone, which joins them, while 

 in Ampelis (PL XVII. fig. 6) this space is open, as we likewise find 

 it in most (or perhaps all) Oscines. In the Tyrants the osseous 

 nasal septum unites with this bony inter-palatine plate above and 

 along its median longitudinal line. 



There is but little to detain us upon the superior aspect of the 

 skull ; all the three specimens shown in PL XVII. figs. 3-5 are 

 rather broad in this region, between the orbital margins, while a 

 moderately well-marked median furrow is to be seen, which is 

 best exemplified in the Thrush, and least so in the Tyrant Ply- 

 catcher. All the higher Thrushes have the facio-cranial line 

 fairly v>^ell defined on this aspect. I have already remarked that 

 it is barely traceable in Ampelis. 



Upon the lateral view of the skull of this Chatterer (PL XVII. 

 fig. 4) there are two or three points presented of more 

 or less interest. The " pars plana," or antorbital plate, is found 

 to be ample, and completely divides the orbit from the rhinal 

 chamber. In front of this, on either side, is to be found 

 ?i freely articulated little ossicle which I take to represent the 

 lacrymal. It shows a constriction at its middle, giving rise to 

 enlarged superior and inferior extremities. The superior end 

 is wedged in between tlie antorbital plate and the postero- 

 superior edge of the corresponding nasal. Below, its inferior 

 dilatation rests upon the maxillary bar. Behind, it is applied 

 against the antt'rior surface of the pars plana, while in front it 

 is only in contact with the nasal superiorly, as already described. 

 I find this bone present in all of the Nortli- American Tijrannidce, 

 in the true Corvidce, in the genus Sturnella, but absent in the 

 Icteridce, in the true Thrushes {Merula, HesperocicJila, PL XVII. 

 fig. 5), in Otocoris, and others. I am not prepared, as yet, to 

 say of what value it will eventually prove to be as a taxonomic 

 character; but in the present instance it is just as well to note 

 that this free lacrymal bone is found in Ampelis and the 

 Clamatores {Tyrannidce), and not in the true Thrushes. 



