282 OBSERVATIONS ON CRANIA 



Up to this point in the effort to assign the typical skull from these 

 islands to its proper class the averages of the two collections of Washing- 

 ton and Cambridge have been taken. In what follows, however, owing to 

 a difference in the methods of measurement employed, my observations 

 must be limited to the collection in the Museum at Cambridge. For- 

 tunately this is quite large, and as the crania from the islands, as well 

 as from the mainland, now in the Army Medical Museum, agree very 

 closely, both in shape and size, with those now held in Cambridge from 

 the same group of islands, it is safe to assert that the conclusions drawn 

 from a study of the one collection will appty with equal force to the other. 

 Supplementing, then, the results heretofore obtained from a consideration 

 of the two series by the additional measiirements taken of the specimens 

 in Cambridge alone, and continuing the process of classification, it will 

 be seen that the mean breadth of frontal,* at the narrowest point on the 

 temporal ridge, is 91™". This is a little less than that of the Peruvian from 

 the coast,f though the average capacity of the skulls now under considera- 

 tion is greater. Its deficiency in this quarter, as well as in breadth, seems 

 to be more than compensated by the increased development of the occipital 

 portion of the head. In one hundred and twenty-two out of one hundred 

 and fifty-one specimens examined, or 81 per cent., the distance between the 

 temporal and frontal bones, measured along the line of the spheno-parietal 

 suture, was found to be more than half a centimetre, thus forming what Dr. 

 Broca calls the Ptereon in H, which, according to the same high authority, 

 is the normal condition in European skulls. In thirteen it was less than 

 half a centimetre; in one the two bones were in contact, and in fifteen there 

 were small, extra ("epipteric") bones in the upper part of the great wing 

 of the sphenoid. Turning now to those peculiar conditions that strike the 

 eye, but of which do measurement can give us a correct idea, we find that 

 in fourteen of these crania wormian bones were developed in the lambdoidal 



* In the Eleventh Annual Report of the Peabody Museum, p. 368, the mean frontal diameter of one 

 hundred and three "crania from Santa Barbara" is put down at 98 mm . This was a- clerical error, as 

 the diameter is much less. Information received since the publication of that report assigns .most of 

 these crania to Santa Cruz Island, and in Table No. I they will be found correctly placed and the meas- 

 urements accurately given. 



t Average of Tables II, III, IV, V, VI, and VII, in Fourth Annual Report of the Peabody Museum, 

 p. 14 et seq. 



