MEMOIKS OF THE NATIONAL ACADEMY OF SCIENCES. 195 



NOTE OX THE MANNER OF TAKING Till-: (iKKMAN 1 KOFII.K ANGLE. 



I ll is measurement is taken by Spengel s craniometer, an instrument of great accuracy but of rather limited 

 usefulness. A close description of its mechanism is too long to be given here; for such e rrlVr to IlnrlrxK x l.i-hrbvch 

 ill i- / &amp;lt;;/i&amp;lt;(c/i( M- Aniitnm n, /write Aiillagi 1 , Stuttgart, 1876, pp. 506 el seq. 



It- is sufficient for our purpose to say that, as regards the facial angle, the eraniometer consists of a strong 

 metal table whereon the skull is placed vertex downwards with its right side lacing toward the operator and adjusted 

 in the plane of the Frankfurt agreement: and of a goniometer in a plane vertical to that of the table. 



It is not often that the skull is sufficiently symmetrical to allow the four points, two supra-auricular anil two 

 suborbital, of the required plane to be placed in the same level. It is practically impossible in cases where this 

 may be done to then find t\u;points de rep! re of the sagittal plane vertically one above another. As the goniometer 

 is vertical to the table which serves as a fixed point from which to determine the desired plane, it is evident that 

 in order to use it, the points in the sagittal plane must be vertically disposed. Therefore we place the skull so that 

 the alveolar point is exactly above the nasion while both are on the midline of the machine and face the goniometer. 

 Care is taken to see that some points in the posterior part of the sagittal plane are also iu the midline. The skull 

 is then so adjusted that the supra-auricular and suborbital points of the right side, which, as stated, faces the operator, 

 are in the same horizontal plane. The goniometer is put iu position and the angle is read. 



To sum up: The angle given in this report is, except in cases of skulls with the right side broken away, taken 

 with the skull in such a position that the sagittal plane is vertical and the right side of the Frankfurt plane is 

 horizontal. 



J 21. GNATHIC INDEX. 



In 39 cases we have been able to calculate the gnathio index of Busk and Flower, which is 

 found by multiplying the length of the basilo-alveolar radius by 100 and dividing the product by 

 the length of the busilo-misal radius. The results are shown in Tables xxxvi, xxxvn, and xxxviu, 

 in which we lind (according to Flower s classification) but two skulls (hat are prognathous (above 

 10, $). There are 10 mcsognathous V 9S to 103) and the remaining 27 are orthognathous (OS and 

 below). The minimum of the series is 88.78 and the maximum 110.11. The average, 05.92, is 

 orthognathous to a high degree and allows us, in respect to the character expressed by the gnathic 

 index, to class this people along with the highest European races.* 



( losse states that one of the effects of the occipital deformation, such as these skulls exhibit 

 (tele (Icprimee par tlcrritn), is to diminish the projection of the lower part of the face.t Possibly 

 we may thus explain the marked orthognathism of the Saladoans. Nevertheless we fail to dis 

 cover any direct relation between the facial angle and the occipital contour in this group. Exceed 

 ingly flattened occiputs may be found as often among skulls having high as among those having 

 low indices, and the average index of the apparently normal skulls (94.10) is less than that of the 

 obviously flattened, when, as an inference from Gosse s proposition, we might expect it to be 

 higher. 



$ 22. ALVEOLO-SUBNASAL I KOGNATHISM. 



The important character of alveolo-subnasal proguathism we have examined in 27 skulls, 

 according to the rules established by Topinard,f and we have tabulated the angle and the index 

 of this prognathism with the vertical and horizontal measurements which constitute the factors of 

 the latter. (Tables XXXIX-XLII.) 



Skull II. 43 has the lowest index, 14.28, and the greatest angle, 82. Skull EL 57 (Plate L) 

 has the highest index, 61.53, and the smallest angle, 59. 



The average index of the series is 37.27 and the average angle 70.03. In the tables given 

 by Topinard Americans arc not included. 11 is average index of the Malays, 37.42, is nearest to 

 that of the Saladoans, and the factors of the index are much the same, the horizontal being &amp;lt;&amp;gt;..&quot;&amp;gt; in 

 both races. The Malay angle, 69.7, though not the nearest to that of our collection, is but little 

 removed from it. The angle of the Polynesians. 70.8, and the angle of the Indo-Chinese, 70.1, 

 are nearest to that of our collection. Angles of other Mongoloid races, 72.(i to 7KO, are slightly 

 higher, and consequently may be supposed to indicate some evolutionary advancement. His 

 highest average Caucasian angle of 81.8 is not as high as the highest Saladoau, and his lowest 

 average Namaquois of 58.2 is lower than the Saladoan lowest. 



*TOPINAKI&amp;gt;; op. cit., p. 94. 



t Kssai snr Ics deformations artificielles &amp;lt;lu iT.-iue, Paris. |s.V&amp;gt;, p. 68. 



t&quot;l)u progmithiHiii alvenlo-sous-nasal.&quot; KYvne d aiiihropologie. Paris, Vol. i, 1S7L , p. 6-12 etseq. 



$ Op. cit., p. 668, and Elements d authropologie, p. 888. 



