198 D. DAVIDSON BLACK 



There is thus every indication of bilateral symmetry in the 

 cornea, the conjunctival sac, the palpebrae, and, as will be subse- 

 quently seen, in the contents of the orbital fossa. 



The uvula and soft palate are present but the posterior nares 

 are represented only by a slight recess above these structures. 



Cranial cavity, dura in situ 



As it was desired to preserve the external form of the specimen 

 for museum purposes, many of the following descriptions are 

 necessarily incomplete. 



The cranial cavity presents a somewhat elongated appearance, 

 as is indicated in figure 4, and is divided into anterior, middle 

 and posterior fossae. 



Posterior fossa. Ttie posterior fossa and its boundaries are 

 approximately normal in appearance. The dural foramina for 

 the exit of the nerves normally leaving the cranial cavity in 

 this region may be made out with the exception of the foramen 

 for the trochlear nerve. The vertebral arteries and the acces- 

 sory nerves may be made out in the foramen magnum. The 

 internal occipital protuberance is well marked. The attach- 

 ment and extent of the tentorium are normal. 



Middle fossa. The middle fossa is subdivided into two lateral 

 portions by a much elongated, sharp, median ridge. Slightly 

 more than 1 cm. from the anterior end of this ridge, a single 

 large artery opens on its dorsal surface. At its anterior extremity 

 the median ridge becomes continuous with the median process 

 of the posterior boundary of the anterior fossa. 



Anterior fossa. The anterior fossa, which is quite extensive, 

 is bounded on either side posteriorly by curved ridges whose 

 concavity is directed backward. 



Cranial cavity, dura removed 



Anterior fossa. No ethmoid element can be made out. A 

 wide metopic suture is present (fig. 5). In the mid-line, slightly 

 in front of the junction of the posterior boundary of the anterior 

 fossa with the median ridge of the middle fossa, there is seen a 

 slight prolongation of the dura into a small pit in the bone. 



