OSTEOMETRY; THE MEASUREMENT OF THE BONES 51 



15. Interorbital breadth; the distance between the two lacrimalia (cf. 

 under Measurements slightly modified, below). SC. 



16. Orbital breadth; the inner terminus of this line is the dacryon, the 

 outer that point in the outer rim of the orbit which gives the maximum dis- 

 tance from the dacryon. This latter is called the ectoconchion, a movable 

 point. Let the line run as nearly as possible parallel with the upper and 

 lower orbital rims, which are inclined to be fairly straight and parallel 

 (cf. under Measurements slightly modified, below). SC. 



17. Orbital height; the maximum distance between the upper and lower 

 borders of the orbit at right angles to the previous measure (No. 16). In 

 taking this avoid the supra-orbital notch. SC. 



18. Maxillo-alveolar breadth; the distance between the two ectomalaria, 

 i.e., the most lateral points upon the outer surface of the alveolar ridge 

 opposite the second molar teeth. This measure gives the maximum 

 breadth of the alveolar ridge, and is to be taken at right angles to the 

 median axis of the palate (the prosthion-alveolon line of the next measure- 

 ment). Any exostosesor other projections, such as abnormal tooth roots, 

 are to be avoided. SC or Cr. 



18 (bis). Maxillo-alveolar length; the prosthion-alveolon line. The 

 alveolon is determined by the use of a fine knitting needle laid across the 

 posterior ends of the alveolar processes of the two sides. SC. The point 

 where this crosses the median line is the alveolon (cf. above, u 1 der 

 alveolon; also Fig. 25}. 



19. Measures of the bony palate (tentative).* 



(a) Palatal length* .the orale-staphylion line. This is sufficiently 

 described under the definitions of the two terms involved, 

 under Landmarks; also shown in Fig. 25. SC. 



(6) Palatal breadth; the greatest transverse breadth found within 

 the inner limits of the alveolar arch. The termini are found 

 along the inner (lingual) sides of the second molar teeth, at 

 the point v in Fig. 25 (ent omalare) . The line is to be 

 drawn at right angles to the prosthion-alveolon line. SC. 



20. Orbito-alveolar height; the least distance between the lower border 

 of the orbit and the alveolar border. This measure has been seldom 

 used, and is now practically given up. 



21. Occipital foramen. 



(a) Length; taken in the median line, f rom basion to opisthion. SC. 

 (6) Breadth; taken at right angles to the former; the maximum 

 breadth line. SC. 



22. Sagittal cranial arc; the length of the curve of the cranium, 

 measured along the median line with the tape measure, from nasion, 

 over the vertex, to opisthion. For this measure the skull is most con- 

 veniently held in the lap, or upon the knee, and the tape applied along 



* These two measurements, 19a and 6, have now come into general use and 

 are no longer to be considered tentative. 



