Here is the defining classification:
German system:
C.I. 55.0 - 59.9 = ultradolichocephalic (extremely long-/narrow-headed)
C.I. 60.0 - 64.9 = hyperdolichocephalic (very long-/narrow-headed)
C.I. - 74.9 = dolichocephalic (long-/narrow-headed)
C.I. 75.0 - 79.9 = mesocephalic (intermediate in head form)
C.I. 80.0 - = brachycephalic (round-/short-/broad-headed)
C.I. 85.0 - 89.9 = hyperbrachycephalic (very round-/short-/broad-headed)
C.I. 90.0 - 94.9 = ultrabrachycephalic (extremely round-/short-/broad-headed)
French system:
C.I. - 75.00 = dolichocephalic
C.I. 75.01 - 77.77 = subdolichocephalic
C.I. 77.78 - 80.00 = mesocephalic
C.I. 80.01 - 83.33 = subbrachycephalic
C.I. 83.34 - = brachycephalic
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C.I. of 81.5 - 83.0 places Jews in the "brachycephalic" (German) or "subbrachycephalic" (French) categories.