820 General Notes. [ November, 
and are in harmony with Dana’s views of the great antiquity and 
permanence of the great ocean basins, which all recent deep-sea 
researches appear to support. Murray thus summarizes his 
views: 
1. That foundations have been prepared for barrier reefs and 
atolls by the disintegration of velcanic islands, and by the building 
up of submarine volcanoes by the deposition on their summits o 
organic and other sediments. 
hat the chief food of the corals consists of the abundant 
pelagic life of the tropical regions; and the extensive solvent 
action of sea water is shown by the removal of the carbonate of 
lime shells of these surface organisms from all the greater depths 
of the ocean. 
3. That when coral plantations build up from the submarine 
banks they assume an atoll form, owing to the more abundant 
supply of food to the outer margins, and the removal of dead 
coral rock from the interior portions by currents and by the action 
of the carbonic acid dissolved in sea water, 
4. That barrier reefs have built out from the shore ona founda- 
tion of volcanic débris or on a talus of coral blocks, coral sedi- 
ment, and pelagic shells, and the lagoon channel is formed in the 
same way as a lagoon, : 
. That it is not necessary to call in subsidence to explain any 
of the characteristic features of barrier reefs or atolls, and that all 
these features would exist alike in areas of slow elevation, of rest, 
or of slow subsidence. 
In conclusion it was pointed out that all the causes here ap- 
pealed to for an explanation of the structure of coral reefs are 
proximate, relatively well known and continuous in their action. 
Tre “Compres RENDUS STENOGRAPHIQUES” of the Congress 
of Geologists, held in the Trocadero Palace during the Expost- 
tion of Paris of 1878, has just appeared. It is an octavo volume 
-~ studies on fractures of the earth’s crust ; Favre on the effect of 
folds and lateral twists in geology ; Lapparent on the plications of 
the Cretaceous formation between France and England; Hall on 
the nomenclature of the Palzozoic rocks of the United States; 
De Moeller, the divisions of the Carboniferous; Cope, relations of 
-horizons of extinct Vertebrata of Europe and North America, 
Fannetaz on the propagation of heat through rocks; Hunt on 
the Precambrian rocks of North America; Ribeiro on .the geol- 
-ogy of Portugal. : 
» 
