MKMOIKS OF THE NATIOIS'AL ACADEMY OF SCIENCES. 195 



rillll-II.K ANlil.R. 



Tills moiisiircuiciit i.s takiMi liy S]ioiigurs criiiiioiiii'tvr, iiii iii.stiiiiiuMit ol' great iieciiracy but of rather limited 

 iiHefuliie»s. A close (leM!ri|itiou ofil« iiiecliniiitiiii is too long to Uo given lii-re; for hiuIi we refer to J/artemi'K Lehrbuch 

 iler I'laalhcheu Amitomk, zweito Aiillugo, Stuttgart, l«7ti, pp. 500 el sni. 



It is suflicient for our purpose to say that, as regards tUe faeial angle, llie cranionictcr eoiisistM of a strong 

 metal table wliorvou tlio skull is plaued vertex downwards with its right side facing toward the operator and adjusted 

 in the jilano of the Frankfurt agn'cment; and of a goniometer in a phiiie vertical lo that of the table. 



It is not often that the skull is sufllciently Byiiinietrieal to allow the four points, two supra-auricular and two 

 suborbital, of the reijuirud piano to be placed in the siiiue level. It is practically iuipossible in cases where this 

 may bo done to then find the^uinffi lie rcpire of the sagittal plane vertically one above another. As the goniometer 

 is vertical lo 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 ninst be vertically disposed. Therefore wo place the skull so that 

 the alveolar point is exactly above the nasiou while both are on the midline of the uiacliine and face the goiiionieter. 

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

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

 are in the same horizontal plane. The goniometer is put in 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 suili a position that the sagittal plane is vertical and the right side of the Frankfurt piano is 

 horizontal. 



{ 21. GNATHIC INDEX. 



lu 3!) t-asos we have been able to calculate the gnathic index of Busk and Flower, which is 

 found by multiplying the length of the basilo alveolar radius by 100 and ilividing the iiroduct by 

 the length of the basilonasal radius. The results are shown in Tables xxxvi, xxxvii, and xxxviii, 

 in which we find (according to Flower's classification) but two skulls that are prognathous (above 

 10.1). There arc 10 nicsognatlious ^1)8 to 103) and the remaining 27 are orthognath<ms (OS and 

 below). The minimum of the series is 88.78 and the maximum 110.11. The average, 9.j.9i', is 

 orthognathous to a high degree and allows us, in respect to the character exi)ressed by the gnathic 

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



Gosse states that one of the efi'ects of the occipital deformation, such as these skulls cxliibit 

 {ti'te diprimce jntr derricre), is to diminish thti projection of the lower part of the lace.t I'ossibly 

 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 riattened 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 (Ol.lO) is less than that of the 

 obviou.sly flattened, when, as an inference from Gosse's proposition, we might expect it to be 

 higher. 



i 22. ALVEOLO-SUBNASAL PROGNATHISM. 



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

 according to tlie rules establisiied by Topinard,| and we have tabulated the angle and the index 

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

 the latter. (Tables xxxix-XLii.) 



Skull U. 43 has the lowest index, 14.28, and the greatest angle, 82°. Skull H. 57 (Plate L) 

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



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

 by Topinard§ Americans are not included. His 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 6.5 in 

 both races. The Malay angle, 09.7°, though not the nearest to that of our collection, is but little 

 removed fiom 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, 72.0 to 71.0, are slightly 

 higher, and consequently nmy be supjjosed to indicate some evolutioiuiry advancement. His 

 highest average Caucasian angle of 81.8 is not as high as the highest Saladoan, and ids lowest 

 average Namaquois of 58.2 is lower than the Saladoan lowest. 



*ToPiXAi[i>; op. ci(., p. 94. 



t Essa! siir les d^'formations artificielles du crAne, Paris, 1855, p. 68. 



i " Du prognathism alveolo-sous-nasal." Revue d'anthropologie. Paris, Vol. i, 1872, p. <!-I2 et seq. 



^ Op. cit., p. 668, and filcmeiils d'anthropologie, p. 888. 



