Geology and Natural History. 177 



The upper Coal Measures (Monongahela) contains the important 

 Pittsburg, Redstone, Sewickly, Uniontown and Waynesburg 

 coals. Between the Sewickley and Uniontown the so-called 

 "great limestone" occurs to which the name Ben wood limestone 

 is applied. Many productive gas wells are scattered over the 

 Brownsville quadrangle, statistics of which are given, h. s. w. 



2. On the Geology of the Hawaiian Islands ; by Wm. H. 

 Dall. (Communicated.) — In the article by Dr. Branner on the 

 Geology of the Hawaiian Islands, in the October number of the 

 Journal, he comes (pp. 306-309) to a different conclusion with 

 regard to the calcareous layers interstratified with the tuffs of 

 Diamond Head, Oahu, from that to which I was led in 1899. 

 This difference is probably due to the fact that Dr. Branner did 

 not see all the area which I examined and reasoned from certain 

 beds which he did see and which are doubtless of a different 

 nature from those to which I referred. 



I found oysters, Chama, and numerous corals, fossilized as 

 they grew, and still adhering to the nearly horizontal surface of 

 the continuous thin sheet of lava which formed the basis of an 

 area of very considerable extent entirely outside of the slope 

 of the tuff cone but apparently continuous under it. The par- 

 ticular horizon which I examined formed the top of the ground 

 for a considerable distance inland, and the circumstances are 

 entirely incompatible with the idea of a subaerial formation. 

 That there may be subaerial formations around Diamond Head 

 in some places is highly probable, but that is another story. 



Smithsonian Institution, Washington, D. C, Dec. 15, 1903. 



3. Geological Commission, Cape of Good Hope ; G. S. Con- 

 storphine, Director. Annual Reports, 1900, 1901, 1902. — The geo- 

 logical work for 1900 was mainly in the district west of the Karroo 

 plateau. A new formation (the "Ibiquas Series") is reported 

 lying between the Malmesbury beds and the Table Mountain 

 sandstone. Glaciated pebbles were found in the Table Mountain 

 series (early Devonian). The underlying unconformity of the 

 Dwyka conglomerate (this Journal, xiii, 413) is changed to con- 

 formity at the south. Dolerite sheets and dikes cut the Paleo- 

 zoic sediments. Announcement is made of the discovery of a 

 new Mesozoic swimming reptile. 



Owing to the Transvaal war, the geologists of the Commission 

 spent the season of 1901 along the southeast coast line making 

 a general survey of Transkei and Pondoland with special studies 

 of the Cretaceous of Pondoland and of the igneous rocks (granite, 

 diorite, dolerite) of Kentani. The map shows a remarkable 

 adjustment of streams to the diorite. During 1902 Mr. E. H. L. 

 Schwartz made a survey of parts of the Matatiele Division in 

 Griqualand East. Perhaps the most interesting part of his work 

 is the description of a row of 19 volcanic necks trending north- 

 easterly, from which issued the lavas which form the crest of the 

 Drakensbergs. The cones and flows are deeply eroded or destroyed 

 on their east (wet) side but are well preserved on their west side. 



Am. Jour. Sci. — Fourth Series, Vol. XYII, No. 98. — February, 1904. 

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