229 [Mann. 



Fortunately the long duration of tlic Uluui'natcd train gave ample 

 time for retlection and for observations. 



Dr. Jackson next gave a brief outline of the geology of California 

 and Nevada, describing the cretaceous and tertiary rocks of the coast 

 range of California, so remarkably metamorphosed, containing serpen- 

 tine and other rocks heretofl}re supposed to belong to much older 

 formations. He noticed the mercury mines of Almaden and the coal 

 formation of the Mt. Diablo range which are in tlie cretaceous rocks, 

 the petroleum springs of Santa Barbara and of Humboldt, which are 

 in the tertiary strata, or between the cretaceous and tertiary, the 

 asphaltum beds and veins, etc. He then described a geological sec- 

 tion of the strata from the coast at San Francisco to the Cortez 

 district, seventy miles west of Austin, Nevada, mentioning the re- 

 markable elevations which he had measured barometrically along 

 his line of section. He described the gold bearing rocks of Amidor 

 county and Grass Valley, California, the copper mines of Calaveras 

 county, Cal., and the silver mines of Virginia City, Nevada, and of 

 Austin, Nevada, of which he said he should give detailed descrip- 

 tions at some future meetings of the Society, when he hoped to pre- 

 sent a series of specimens, now on their way to Boston via Cape Horn, 

 which would fidly illustrate the subject of the mines. 



Mr. H. Mann said, in referiing to some Hawaiian human 

 crania and skeletons which were upon the table, that they 

 were obtained near the beach beyond Diamond Hill on 

 Oahu, about eight miles from Honolulu, in what is supposed 

 to have been an old battle ground, the fight having been 

 to oppose the landing of natives from another island. 

 There were several places on or near beaches on different 

 islands where there are great numbers of skeletons lying ex- 

 posed in the sand. It is difficult, at this late day, to ascertain 

 whether these are all battle-grounds, or if some of them may 

 not have been burial places. The presence of the skulls and 

 skeletons of females, and also of infants, would seem to flivor 

 the latter supposition, while the customs of the natives in not 

 usually burying their dead in such places, and in such a 

 manner, would be an objection. One place on Kauai near 

 Koloa he mentioned especially as having a very large num- 

 ber of skeletons, including those of infants. 



Mr. Mann then said a few words in regard to the volcano 

 of Kilauea at the time of his visit in August, 1864, when it 

 was in sluggish action, the lava lake being about three hun- 



