----------------+-----------+-----------+----------+------
| | Diameter | |
Group | Specimens | antero- | Diameter | Index
| | posterior | lateral |
----------------+-----------+-----------+----------+------
| | _cm._ | | _cm._
Northwest coast | (31) | 12.99 | 10.7 | 82.39
California | (16) | 13.2 | 10.56 | 80
Sioux | (12) | 13.03 | 10.98 | 84.26
Tennessee | (6) | 13.32 | 10.93 | 82.01
Kentucky | (8) | 13.09 | 10.66 | 81.42
New Mexico | (10) | 13.26 | 10.43 | 78.65
Arizona | (57) | 12.87 | 9.52 | 74.01
Mexico | (15) | 12.71 | 10.93 | 85.55
Peru | (13) | 12.71 | 10.12 | 79.58
----------------+-----------+-----------+----------+------
[88] Emmons’s series