SHUFELDT : OSTEOLOGY OF THE STEGANOPODES 153 



inferior view, many of the points already described can be distinctly seen. This is 

 due to the peculiar flattened conformation of the cranium. Indeed, the form of the 

 brain-case indicates that Anhinga has an elongated, vertically compressed brain, but 



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relatively not as much so as it is in a Cormorant, where it is also wider. The basi- 

 temporal area is small and triangular, with moderately prominent paroccipital 

 processes, each one descending from one of its postero-external angles. The anterior 

 apex of the basitemporals is run out as a scale-like point, which underlaps the 

 meeting of the thoroughly open Eustachian grooves. The usual foramina for the 

 facial, glossopharyngeal, vagus and hypoglossal nerves, and the internal carotid 

 arteries are plainly seen in this region. They are quite distinct from each other, and, 

 as a rule, nearly circular in outline. The rostrum of the sphenoid is a very delicate, 

 rod-like bone that is extended backwards in the median line under the cranium as 

 far as the eustachian entrance, as a sharpened osseous ridge. In front it fuses 

 with the mesethmoid. For their posterior moieties, the 'palatines are thoroughly 

 coossified in the middle line, where they send down a faint crest from the sutural 

 juncture. As thus constituted the common bone lies in the horizontal plane, with 

 postero-external angles but faintly indicated, but with a short process extending 

 directly backwards from either side of the united facets for the pterygoids. Anteri- 

 orly, the palatines are much narrower, where they are also in the horizontal plane, 

 and mesially separated by an elongated opening that leads above into the rhinal 

 chamber. Their distal ends run forward to fuse with the nasals, maxillaries, and pre- 

 maxillaries. 



The maxillo-palatines are very wide apart, and each one is simply a subvertical, 

 thin, plate-like scale of bone for the most part free behind, but fusing with the usual 

 bones in front. A shallow, medio-longitudinal groove marks the united palatines 

 behind, and this is occupied by the slender, presphenoidal rod. A quadrate has a 

 small, spine-like orbital process; a compressed mastoidal head of no great size, which 

 is barely divided into two facets ; a large, antero-posteriorly disposed facet for the 

 mandible which is separated by a pronounced cleft from a much smaller one, the 

 entire outer side of which is occupied by the pit for the end of the zygoma. The 

 bone I believe to be pneumatic. 



The pterygoids are flake-like, flattened bones with very sharp edges, and with 

 very distinct ends bearing the articular facettes for the bones with which they artic- 

 ulate. Each pterygoid has a length of a little more than a centimeter. A circlet 

 of small "sclerotal plates" are found in either eye, and the hyoidean apparatus is but 

 feebly developed. I have not examined the ossicles of the ear. (conforming to the 

 shape of the cranium and superior mandible, we find the lower jaw assumes the form 



