Geology and Natural History. 397 



gold 76*81, silver 23*04, copper and iron 0*15. The purest speci- 

 men was a sample of sponge gold from Boulder, East Coolgardie ; 

 this yielded gold 99*91, silver 0-09. 



Some further information is given in regard to the problemat- 

 ical tantalo-niobate from the tin-bearing gravels at Greenbushes, 

 called by Goyder stibiotantalite. (Dana Min., App. I, p. 64.) 

 This allows of a somewhat fuller description of the mineral than 

 has been given before, and the hope is held out that material 

 pure enough for complete analysis may be separated. Associated 

 with this mineral, grains of metallic tin were identified. Cobalt- 

 iferous asbolite has been found at Norseman and Kanowna; it is 

 associated with gold, at the latter place being often studded with 

 minute crystals. 



5. Geology of Texas. — The Transactions of the Texas Academy 

 of Science for 1899, volume iii, contains a summary, prepared by 

 Prof. F, W. Simonds, of publications on the Geology of Texas up 

 to the end of 1896; a brief summary of the contents of each 

 paper is given. 



6. Concretions from the Charnplain Clays of the Connecticut 

 Valley ; by J. M. Arms Sheldon. With one hundred and sixty 



illustrations by Katharine Peirson Ramsay, L.R.Martin, and 

 F. S. and M. E. Allen. Pp. 45, pi. i-xiv, 4to. Boston, 1900. — The 

 author has given in this volume an interesting and exhaustive 

 account of the concretions found in the Connecticut Valley clays. 

 They were collected at different points between Dummerston, 

 Vermont, and Deerfield, Massachusetts. The method of occur- 

 rence is fully described and the origin, chemical composition, and 

 other points are discussed with all necessary detail. A consider- 

 able series of analyses shows a substantially uniform composition, 

 differing somewhat for samples from different layers. The 

 memoir closes with a full bibliography; it is illustrated by a 

 series of fourteen admirable heliotype plates, which leave noth- 

 ing to be desired in the way of presenting the varieties of form 

 and structure. 



7. Study of the Gabbroid Rocks of Minnesota. — The elaborate 

 memoir by Alexander N. Winchell, containing a mineralog- 

 ical and petrographic study of the gabbroid rocks of Minnesota, 

 and more particularly of the plagioclastyes, noticed on page 89 of 

 this volume of the Journal and republished in the American 

 Geologist (volume xxvi), has been recently issued in pamphlet 

 form. 



8. On the Flow of Marble under Pressure. — The full memoir 

 by Adams and Nicolson on this subject, of which an abstract 

 was given in the number of this Journal for November last 

 (p. 401), has recently been issued (pp. 363-401 of vol. cxcv, Pt. A 

 of the Philosophical Transactions of Royal Society of London). 

 The plates and other illustrations accompanying it add much to 

 the clearness of the description and increase the general interest 

 of the subject. 



Am. Jour. Sci.— Fourth Series, Vol. XI, No. 65 —May, 1901. 

 26 



