284 On a fossil Ox from the Mississippi. 



furrows, separated by intervening ridges, are observed on its 

 surface. The most anterior of these ridges is presumed to 

 have been the posterior limits of the base of the horns. 



If we now turn our attention to the anterior part of this 

 cranium, where it has been separated from the bones of the 

 face, we observe numerous irregular cells communicating 

 with each other, and with the cells on the hollow surface be- 

 tween the horns previously described. These are, doubtless, 

 the frontal sinuses. Below these again we notice the nasal 

 opening, formerly covered by the cribriform plate, of which 

 nothing now remains, but the crest which separates these 

 openings from each other. Situated more posteriorly, are 

 the round and oval foramina at the base of the skull, for the 

 transmission of the superior and inferior nerves, Sic. 



Pursuing the order proposed in the investigation of this 

 relic, we arrive at the base of the skull, and it is deemed 

 necessary to state, that the very rounded and worn condition 

 of the specimen, injuring its principal features, must serve as 

 an apology for any errors that may arise either in the dimen- 

 sions or the description. 



The occipital bone which, as is known, is double in 

 many quadrupeds, exhibits a small vestige at the occipital 

 foramen, of its former division into two parts. The condyloid 

 processes are large and elongated. Their articulating sur- 

 face broad, and not separated by a prominent ridge. In the 

 substance of the processes, the foramina for the transmission 

 of the ninth pair are still visible. 



The cuneiform process is broad, and its junction with the 

 sphenoidal indistinct. The antero-posterior, and transverse 

 diameters of the occipital foramen, are equal. 



A little in advance of the external auditory hole, we may 

 trace the vestiges of a broken process, which is supposed to 

 have been the commencement of that process which is sent off 

 in many quadrupeds, to unite anteriorly with a similar process 



