No. 405.] STUDIES IN CRANIAL VARIATION. 741 
obtained by Dr. Matthews from an examination of Cibolan 
(New Mexican) crania. Professor Boas informs me that some 
northwest coast tribes exhibit a high percentage of occipital 
anomalies. Compare Anutchin's! tables with the above. 
NUMBER. CoMPLETE. Guiness 
Amerinds “except Peruvians” . . 390 1.30 .26 
six voa Dp e a 664 5.46 1.05 
As Anutchin’s observations were made upon crania that 
were less uniformly deformed, they were probably in part of 
another tribe. This illustrates the desirability of abandoning 
the loose and unscientific term “ Peruvians.” 
Platybasic Crania. — Occasionally a skull is found that has 
the occipital condyles and adjoining portions of the base thrust 
upward, as it were, into the cranial cavity. Presumably due to 
a greater or less degree of yielding of the floor of the calvaria 
to weight and muscular tension, it naturally occurs in all stages 
of development, according to the conditions. It is, therefore, 
difficult at times to distinguish between normal and platybasic 
crania; Topinard describes three varieties. Only well-marked 
. examples are here noted. The results so far as they go seem 
to show that no relation exists between this condition and 
either cephalic index or artificial deformation. The highest 
percentage of occurrence is found among the Eskimos, who 
have the largest cranial capacity, but the number of skulls is 
too small to attach much significance to this. 
Jugular Process. — The above table includes statistics con- 
cerning this somewhat rare anomaly, in which the process is 
enlarged until it extends beyond the plane of the condyles 
(Fig. 6). It is homologous with the paramastoid of the dog, 
etc. It occurs about once in one hundred crania from Peru 
and somewhat less frequently in North America. 
Aymará Fossa. — Particular interest attaches to this charac- 
Lis (Figs. 7, 8), owing to its supposed frequency of occurrence 
in the crania of criminals. As the fossa is very variable in 
1 Rev. d’ Anth., T. vi, Sér, 2, p. 143. s 
