GEOLOGY. 247 



air. This egg -was truly metamorphic, since it contained scarcely 

 anything of its original constituents. It contained in 100 parts sul- 

 phate of potash, 70.59 ; sulphate of ammonia, 26.55 ; chloride of am- 

 monium, 1.25 ; chloride of sodium, 0.65 ; and organic matter, .06. It is 

 remarkable that it contained no lime or phosphoric acid, two substances 

 which never fail in the eggs of birds. The shell had undergone great 

 modification; yet there remained in 100 parts phosphate of lime, 

 77.82 ; silica, 0.45 ; potash, 2.33 ; and organic matter, 2.07. 



The Dinornis of New Zealand. Mr. Haast, President of the 

 Philosophical Society of New Zealand, in a recent inaugural address 

 at Canterbury, N. Z., states that two species of the Dinornis, new to 

 science, have recently been described. And to quote his own descrip- 

 tion, " another still larger Kiwi, provisionally named Apteryx maxima, 

 and called Roa by the natives, still exists in the western mountains of 

 the island. Living specimens of this bird, which is as large as a turkey, 

 have not yet been procured ; though," adds Mr. Haast, " I observed its 

 tracks in the fresh-fallen snow, and heard its call during the night." A 

 still larger Kiwi, Palapteryx ingens, is believed from " auricular evi- 

 dence " to be in existence in the great beech forests which cover for 

 many miles the slopes of the New Zealand Alps. 



Source of the Pennsylvania Petroleum. A recent number of the 

 Journal of the Franklin Institute contains a report on the oil district 

 of " Oil Creek," Penn., by Mr. T. S. Ridgeway, mining engineer and 

 geologist, who has carefully surveyed the whole oil region. 



He states that at one place there is a mass of oil-bearing strata 1,200 

 feet in thickness. The oil-bearing strata is broken up in huge cakes 

 of sandstones and shales, having fissures between the strata extending 

 to a great depth, and these are generally filled with gravel and peb- 

 bles. These openings are numerous in Oil Creek, and are the cause 

 of much perplexity to drillers in search of oil. In one case, a pipe 

 was sunk 160 feet below the surface before the permanent rock was 

 reached, while at a few yards distant the rock was struck at a depth 

 of thirty feet. At a distance of about 530 feet from the surface there 

 appears to be a great oil pool below, and for a distance of seven miles 

 down to the mouth of Oil Creek the flowing wells rise from it. Stones 

 taken out of the oil-bearing rocks are employed in several places for 

 buildings, and the petroleum may still be noticed sometimes trickling 

 from their surfaces. Mr. Ridgeway, from his examinations, is con- 

 vinced that the petroleum is not produced from the coal-fields, because 

 in that case it would have had to flow up hill into the oil basin. He 

 says : " Petroleum found in bituminous coal basins, no doubt, origi- 

 nates from beds of coal, but it is my opinion that the petroleum of the 

 Oil Creek valley is the result of the decomposition of marine plants. 

 The plants which produced the oil in the rock existed and flourished 

 at a long period of time before the vegetation which now forms coal- 

 beds ; they are unlike the vegetable impressions found in the accom- 

 panying shales and clays associated with beds of coal ; and they grew 

 where the flag-stones and shales of Oil Creek were laid down by salt- 

 water currents. The climate was so hot, during this age of marine 

 vegetation, and the growth of plants so rapid and rank, caused by the 

 supposed large amount of carbonic acid and hydrogen then composing 

 the atmosphere, that these conditions on the face of the earth produced 



