142 MR. W. p. PYCRAPT OX THE OSTEOLOGY [Feb. 20, 



continued backwards by a pair of slender, ahnost filiform limbs. 

 In the Dendrocolaptinas (text-fig. 50 d, p. 140) and Synallaxinfe 

 it is much reduced, the body being short and broad, and the limbs 

 only moderately long. Anteriorly, as in the Conopophagidfe, it 

 supports ossifications of the turbinal cartilage. In some of the 

 Synallaxina^, 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, 

 j&xA extends far forward on to the parasphenoidal rostrum ; and 

 as a consequence of this forward position the basipterygoid 

 processes 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 

 o-eneral rule among these groups as to the form of the shaft. 

 Thus in Pseudocolcqjtes the inner aspect of this rod has developed 

 u broad phalange increasing in breadth from the proximal third 

 forwards to the palatine, while in Acanthidositta it is strongly 

 bowed forwai'ds. But the pneumatic aperture which occuis near 

 the articulation for the quadrate in the Eurylasmidaj appears to be 

 wanting altogether in the types now under consideration except 

 in the Pipridee. The chief point of interest which attaches to 

 this bone here concerns the form and relations of its distal 

 extremity. In the Pipridae, as in the smaller Cotingidse, 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'optochidse at first sight appear also to 

 ao-ree in this matter, but a more careful examination shows that 

 the expanded, hastate portion (hemipterygoid) is cut off 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 Conopophagida^ in this only, 

 that the suture between the main shaft and the hemipterygoid 

 is more oblique. 



In the Pittidaj the shaft extends further forward, and terminates 

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

 roughly quadrangulai- plate, deeply notched in front. With this 

 plate the hemipterygoid 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 Philepittidse 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 Formicai'iinaj, Dendrocolaptina?, and Synallaxinfe agree 

 exactly with the Piprid^e and the smaller Cotingidse. The 

 Acanthosittiupe, 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 



