SHrFELDT: OSTF.OI.OCY OK IIIK 1 I IRODIONES. 217 



The palatinrs are very short and broad bones ; and they develop 

 very conspicuous internal and external descending plates of bone. In 

 front they completely fuse with other elements forming the roof of the 

 mouth, while for the short distance between their internal descending 

 plates they are separated from each other by a narrow, spindle-shaped 

 space with its long axis on the middle line. Posterior to this again, 

 and up to the point where they articulate with the pterygoid, they 

 completely unite with each other in osseous union. Superior to this 

 coossified portion they make a common longitudinal cavity for the 

 rostrum, which later, by close contact, rests in the same. 



The vomrr is a long, narrow, thin and transversely compressed spine 

 of bone. Behind, it coossifies thoroughly with the united palatines 

 in the middle line ; it then arches over to the fused mass of the spongy 

 part of the maxillo-palatines — the concavity of the arch being below. 



After it reaches the maxillo-palatine mass it becomes of needle-like 

 dimensions, and in this form, as a free spine, it is still extended for- 

 wards between them in the middle line, lying in a crease which de- 

 notes their place of fusion. This is an unusual form of the vomerine 

 element among birds, and very different from anything we find in the 

 Herons. Either pterygoid is short, stout and straight, and of a tri- 

 hedral form, with sharpened edges, especially the superior one. They 

 are in contact anteriorly when articulated /;/ situ. A quadrate is com- 

 paratively large and bulky in its proportions, with powerful orbital 

 and mastoidal processes. The latter is compressed transversely with 

 truncated end, while the latter, somewhat twisted upon itself, has a 

 distinct double head at its articulation. The mandibular part is mas- 

 sive with an arrangement of facets entirely different from what we 

 found in the Herons. There are but two of these, upon either quad- 

 rate they are separated from each other by a transverse valley. The 

 anterior facet — rather the smaller of the two — is three times as long as 

 it is broad, and its long axis is perpendicular to the vertical median 

 plane of the skull. With it the posterior one makes a slight angle, its 

 outer end being the most anterior, and, at the same time, the one 

 found below the cup for the proximal end of the zygoma. At this 

 point the space intervening between it and the anterior mandibular facet 

 of the quadrate is very narrow. Most of these bones at the base of 

 the cranium are more or less pneumatic. 



The Eustachian passages are open anteriorly, and the foramina for 

 the internal carotid arteries are likewise exposed, being unshielded by 



