CRANIA FROM THE MOUNDS OF FLORIDA. 425 



It will be observed that the word " mastoid " is eliminated. In a morphological 

 sense this is consistent. But in the anatomy needed in practical medicine the 

 separation of the mastoid process, as above proposed, does not present advantages 

 which are sufficient for the desertion of old land marks. According to B. A. Ran- 

 dall : it is true that the mastoid cells may be confined to what is here called the 

 post-squamosal portion, while the ecto-petrosal remains diploetic, a condition which 

 harmonizes morphological with clinical considerations. But in many instances the 

 cells of the mastoid which communicate with the tympanic chamber are not con- 

 fined to the post-squamosal part, but range freely into the ecto-petrosal and. 

 according to Hyrtl, may reach even to the pneumatic cells of the occipital bone. 



The clinician, however, acknowledges that the word "mastoid" and its sub- 

 divisions are not in all respects satisfactory. The "mastoid region" and the "mas- 

 toid process " are vaguely defined : the mastoid region being an anatomical residuum 

 accounted for after the conventional description of the squamosal and petrous por- 

 tions of the bone is completed. The word " petro-mastoid " is sometimes reserved 

 for that which in this text is called ecto-petrosal. — In Quain's Anatomy 2 it is stated 

 that the ridge limiting the temporal fossa interiorly back and above the external 

 auditory meatus becomes the supra-mastoid ridge (linea temporalis, temporal ridge). 

 This attempt to define the upward limit of the mastoid process is inadequate, 

 since it leaves the region called in this memoir the serpiginous portion still 

 undescribed. Macalister 3 calls the entire mastoid region "the base of the petrous 

 portion," which again does not account for the serpiginous portion, for this is in the 

 cranial parieties above the pars petrosa. . 



(9). The malar bone. The malar bone, serving as it does to separate the orbit 

 from the temporal fossa, is one of the most important elements of the primate skull. 

 Assuming that the main object in creating an orbito-temporal septum is to give 

 increased resistance to the upper molars in the attrition of food, the bone should be 

 considered as part of a group of appearances which embrace the upper and lower 

 maxilla?. The origin of the masseter muscle on the bone is the next most 

 important factor leading to variation along its lower border. The marginal process 

 varies exceedingly in form and size, and these peculiarities should be noted ; it 

 presents one of the best characters for sex, being large in males and small or 

 absent in females. — The bi-partite malar is so infrequently present that each 

 instance when noted should be care full}' recorded. From the collection of the 

 Academy it would appear that the examples of bi-partite malar can be grouped as 

 follows: (a) An ossicle lying in the zygomatic arch at the malo-zygomatic suture. 

 Fig. 15, a. b, c, d. In the four examples (Nos. 1,556, 5, 1,305 and 1,442), three were 

 placed at the upper border of the arch and one at the lower, (b) An ossicle occu- 

 pying the lower part of the malar bone its entire length. Of this peculiarity two 

 examples are herewith given: Nos. 83 and 1.225, figs. 10 and 17; also fig. 10, 

 Huron, p. 411. 



1 Wood's Ref. Handbook, Supplement, 1893. 



^ 10th Ed., 1890. 



3 Human Anatomy. 1889, 222. 



