ADDENDA. 369 



DoDswoETH, C. Lead Mining in Limestone [N. of England.]. Min. 

 Journ. April 18. 



DoNAYRE, F. M. Datos geologico-mineros recojidos en la Provincia 



de Guadalajara y en el termino de Yaldesotos, Bol. Com. map. 



geol. Espaii. vol. i. 



In these notes on the geology and mineralogy of the Province of 



Guadalajara the author describes a coalfield near Yaldesotos, which he 



considers cannot be profitably worked. J. M'P. 



. Bosquejo de una descripcion fisico-geologica de la Provincia 



de Zaragoza. Mem. Com. map. geol. Espaii. 



The first part describes the geography, meteorology, and agriculture 

 of the province of Zaragoza, and gives a list of the heights and geological 

 horizons of about 250 localities. The second part is a geological de- 

 scription of that district, where, besides eruptive rocks, the Silurian, 

 Devonian, Triassic, Jurassic, Cretaceous, Tertiary, and Recent forma- 

 tions appear. The diff'erent fossils of each formation are mentioned ; 

 and a descriptive list of about 350 rocks is annexed, together with a 

 note on the mineral wealth of the country. A coloured geological map 

 to the scale of joi/oTTTr» ^ sections, 3 landscapes, and a plate representing 

 several species of Cruziana from the Silurian deposits accompany the 

 work. J. M'P. 



DoRNES, — . [The St. Louis Canal and the Mouths of the Rhone.] 

 Mem. Soc. Ing. Civ. no. 4, pp. 740-746. 



Gives an account of alluvial changes near the mouth of the Rhone, 

 observed during and since the construction of the canal. (Abstract in 

 Proc. Inst. Civ. Eng. vol. xli. pp. 251-253.) W. T. 



Dunn, E. J. On the Mode of Occurrence of Diamonds in South 

 Africa. Quart. Journ. Geol. Soc. vol. xxx. pp. 54-60, 2 woodcuts. 



Diamonds occur in circular " pipes " or " pans," which are regarded 

 as old volcanic vents. They have been worked to a depth of 130 feet ; 

 the upper part contains surface-products ; then comes soft decomposed 

 euphotide or gabbro (?), which gets harder and less altered below. 

 The altered rock contains garnet, calc-spar, mica, bronzite, augite, 

 diopside, diallage, iron-pyrites, &c. ; and in this the diamonds occur, 

 often in fragments. The gems differ in character in the various 

 diggings. The shale at the sides of the pipes is always turned upwards. 

 The other intrusive rocks of the district are noticed. Diamonds also 

 occur in Drift deposits of two ages : the older Drifts are at a higher 

 level along the Vaal than the newer, and they also occur as out- 

 liers. W. T 



Ehrenbero, — . De la Toba fitolitaria de Valle do Toluca (Trans- 

 lation). Naturaleza, t. iii. pp. 118-132.' 



Endlich, Dr. F. M. Mineralogical Collection, and List of Minerals 

 in the National Museum, 1873. Ann. Rep. Smithson. Inst, for 

 1873, pp. 61-63, 70, 71. 



1874. 2 B 



