Reviews — Geology of Guatemala and Salvador. 455 



J. L. LoUey.— On fhe distribution of tlie British Fossil Lamelli- 



branchiata. 

 Bev. J. D. La ToucJie — On Spheroidal structure in Silurian Eocks. 

 N. Whitley — On the distribution of shattered chalk-flints and flakes 



in Devon and Cornwall. 

 Professor Tennant — Diamonds received from the Cape of Good Hope 



during the last year. 

 J. Jeffreys — On the action upon earthy minerals and compounds, of 



water in the form of heated steam, urged by wood fuel, &c. 

 J. W. Beid — On the Physical causes which have produced the 



unequal distribution of land and water between the Hemispheres. 

 C JecTcs — On the Crag Formation. 

 J. E. Lee — Notice of remarkable Glacial Strise, lately exposed at 



Portmadoc. 



I. — Voyage Geologiqtje dans les Eepubliques de Guatemala et 

 DE Salvador, par M.M. A. Dollfus et E. de Montserrat. 

 Paris, 1868. 



MM. Dollfus and Montserrat were attached as Geologists to the 

 , Scientific Mission which accompanied the Mexican Expedi- 

 tion from France in 1864. The volume before us, printed at the 

 Imperial Press in a magnificent quarto, contains their Eeport on 

 the Geology, not of Mexico, but of the Central American Provinces 

 of Guatemala and San Salvador, to which they directed their 

 researches, finding the political state of Mexico at the time 

 unfavouralDle to their object. The volume is illustrated with maps, 

 sections, and engraved views. A large portion of it contains the 

 narrative of several journeys through this part of Central America, 

 undertaken by the authors, with chapters on the physical geography, 

 climatology, and meteorology of the country. We shall, however, 

 pass at once to those which describe its geological features, es- 

 pecially the volcanic formations and phenomena of which this 

 portion of America presents some of the most interesting examples 

 to be met with on the globe. This part of the work comprises not 

 only the personal observations of the authors, but also extracts from 

 the accounts of earlier observers. 



The axis of this section of the American continent appears to 

 consist of granite shouldering off a series of metamorphic and 

 sedimentary rocks, Mica and Talcose schists, with patches of 

 Jura limestone, chiefly occurring on the eastern slopes, i.e., to- 

 wards the Atlantic, which are much broader and less steep than 

 those towards the Pacific. The watershed line dividing the two 

 is formed, for the most part, of a rock, to which these Geologists 

 give the name of trachytic porphyry, which appears to have been 

 developed on a most extensive scale throughout a zone stretclung 

 in the direction N.W., S.E. ; that is, coincident ^vith the general 

 trend of the continent. No Tertiary, or other marine strata of later 



