263 [White. 



large as a man's thigh. In this state it is very pure, enough 

 so to be used in the arts ; but is redissolved and recrystal- 

 lized to sell more readily in the markets. This region about 

 Clear Lake is a volcanic centre, and is the only locality of 

 borax as yet discovered on this continent; also there are 

 mines of sulphur worked, the mineral being simply dug from 

 the soil ; Geysers also occur there. 



He also spoke of the mines of Oxide of Tin near Los Ange- 

 los ; and exhibited specimens of the " Wood Tin " from Du- 

 rango County, Mexico, which is found by placer mining in the 

 alluvial clayey soil. It is called Wood tin from having lines 

 like those of the annual growth in wood ; it is very heavy, 

 and contains seventy-nine per cent, of metallic tin. He also 

 exhibited the gold bearing clay slate of Jurassic age, and 

 read some notes on the gold mines he had visited in Amidor 

 and Grass Valley. 



Dr. James C. White gave the following description of an 

 enormous human skull presented by Dr. C. T. Jackson in the 

 name of Dr. C. A. Eorkpatrick, U. S. A. 



This skull -was dug up in excavating for the foundations of Fort 

 Point, Golden Gate, at the entrance of the harbor of San Francisco. 

 As will be seen by the accompanying measurements, it is among the 

 largest skulls of the Red man ever described. The bones of the face, 

 including the lower jaw, are very massive. The nasals are flattened, 

 and the nasal cavity is nearly quadrangular. The supraciliary ridges 

 are very little developed, presenting in this, as in other respects, a 

 striking contrast to the California skulls, which are described on p. 

 6 9 of the present volume. The general shape of the skuU is brachy- 

 cephalic, the vertex being much elevated, and presenting a promi- 

 nent bulging at the junction of the coronal and sagittal sutures. The 

 zygomatic arches project but slightly when viewed from above. The 

 teeth are small and much worn. 



MEASUREMENTS. 



Internal capacity 100 cubic inches. 



Longitudinal diameter 7.50 inches. 



Parietal diameter 6.10 " 



Frontal diameter 4.20 " 



Vertical diameter 5.60 " 



Intermastoid arch 16.00 " 



Intermastoid line 4.50 " 



Occipito-frontal arch 15.00 " 



