GO 
THE VOYAGE OF H.M.S. CHALLENGER. 
was 71 ; of the five probable females 69. The maximum cephalic index in two of the 
crania (males) was 73 ; the minimum in one (female) 67*5. The skulls were therefore 
markedly dolichocephalic, for not a single specimen had a mesaticephalic, and still less a 
brachycephalic index. 
The mean vertical index of twelve crania was 72 ; that of the males was 73, of the 
females 70. The mean of the whole series and of the males was metriocephalic, that of 
the females tapeinocephalic. The maximum vertical index in one (male) was 77, the 
minimum in one (female) was 64. The mean height in relation to the length was some- 
what greater than the mean breadth ; a result which was due to the greater vertical 
diameter of the male crania. For the mean basi-bregmatic height of seven males was 
135 mm.; the maximum being 144, the minimum 131 mm. The mean corresponding- 
height of five females was only 125 mm. ; the maximum being 130, the minimum 125 mm. 
In the males the height exceeded the greatest breadth in five cases, but in two the breadth 
very slightly exceeded the height. In the females the height was slightly in excess of 
the breadth in four cases, whilst the breadth somewhat exceeded the height in one. 
Owing to the broken zygomatic processes in several of the crania, the bizygomatic 
diameter could only be taken in six specimens, and consequently in these only could the 
proportion of the breadth to the ophryo-alveolar length be measured, and a facial index be 
obtained. The mean facial index was 65 ; that of three males 62, and three females 68. 
The maximum facial index in one (female) was 73, the maximum in one (male) 59. 
The mean gnathic index of eleven crania was 103, and this general average was alike 
in the two sexes. The maximum gnathic index in one skull (female) was 114; the 
minimum in one (female) 96. If we take 103 as marking the lowest term of prognathism, 
then four of the crania reached this index, and only three exceeded it ; whilst three skulls 
ranged from 98 to 101, and one was below 98. Hence it may be said that one was 
orthognathous, three were mesognathous, four were at the lowest term of prognathism, 
and only three were decidedly prognathic. The mean average of the series was on the 
line between mesognathism and prognathism. The basi-nasal length was greater than 
the basi-alveolar in three crania, i.e., in those in which the gnathic index was below 100. 
The mean nasal index of eleven crania was 48 ; that of six males was 51, that of 
five females was 44. The maximum nasal index in one skull (male) was 55 ; the minimum 
in one skull (female) was 38. Four of the skulls, and these all males, were platyrhine, 
one, a female, was mesorhine, and the remaining six were leptorhine. The mean average 
was on the line between the leptorhine and mesorhine. 
The mean orbital index of twelve crania was 86 ; and this index was alike in the two 
sexes. The maximum orbital index was 97 in both a male and a female, the minimum 
was 78 (male). Both in the males and females the mean orbital index was mesoseme, 
although in two males and one female it rose to megaseme, and in four males and two 
females it sunk to microseme. 
