142 MR. W. p. PYCRAFT ON THE OSTEOLOGY [Feb. 20, 



continueil backwards by a pair of slender, abiiost filifoi-in limbs. 

 In the Dendrocolaptinte (text-fig. 50 d, i^. 140) and 8ynallaxinie 

 it is much reduced, the body being shOi't and broad, and the limbs 

 only moderately long. Anterioi'ly, as in the Conopophagida^, it 

 suppoits ossifications of the tux-binal cartilage. In some of the 

 8vnallaxinfe, e. g. Pseudocolaptes, these ossifications take the form 

 of a small pair of triangular plates set vertically. 



The pterygoid has a straight and more or less cylindrical shaft, 

 and extends far forward on to the para sphenoidal rostrum ; and 

 as a conseqvience of this forward position the basipterygoid 

 pi'ocesses have disappeared, and the facets for articulation there- 

 with have completely disappeared from this rod. 



As might be expected, there are some few exceptions to the 

 general rule among these groups as to the form of the shaft. 

 Thus in Pseudocolaptes the inner aspect of this rod has develojijed 

 a bi'oad phalange increasing in breadth from the proximal third 

 forwards to the palatine, while in Acanthidositta it is strongly 

 bowed forwai-ds. But the pneumatic apeiture which occurs near 

 the articulation for the rpiadratein the Eurylfemidje appears to be 

 wanting altogether in the types now under consideration except 

 in the Piprida?. The chief point of interest wdiich attaches to 

 this bone here concerns the form and i-elations of its distal 

 extremity. In the Piprida?, as in the smaller Cotingida?, this 

 shaft terminates in a long, hastate plate closely applied to the 

 parasphenoidal rostrum, and fused along its inferior border with 

 the palatine. The Ptei'optochidje at first sight appear also to 

 agree in this matter, but a more careful examination shows that 

 the expanded, hastate portion (hemipterygoid) is cut oflf by an 

 almost vertical section from the shaft, and appears as though it 

 were but an upgrowth of the dorsal edge of the palatine. 

 Hylactes differs from the rest of the Conopophagidfe in this only, 

 that the sutui'e between the main shaft and the heniiptei-ygoid 

 is more oblique. 



In the Pittida3 the shaft extends fin"ther forward, and terminates 

 some distance in front of and above the end of the palatine, in a 

 roughly quadrangular plate, deeply notched in front. With this 

 plate the hemiptei-ygoid forms what may almost be described 

 as a dove-tailed joint fitting into the notch just described, and 

 running backwards below the expanded end of the pterygoid 

 shaft as far as the end of the palatine with which it is fused. 



In the Philepittida? there is no hemipterygoid, the shaft being 

 continued forwards from the point where it meets the palatines 

 in the form of a long and delicate sword-shaped blade, curving 

 slightly upwards. The free end of this blade reaches the vomer, 

 which, however, is fused with the palatine. 



The Formicariinfe. Dendrocolaptina?, and Synallaxina? agree 

 exactly with the Pipridse and the smaller Cotingidte. The 

 Acanthosittinas, however, are quite peculiar in this matter, but 

 nearly resemble the true Passeres. The shaft, which is sigmoidally 

 curved, ends in a small pedate plate closely applied to the 



