408 Tertiary Formations : paet h. 



from Eastern Chiloe, which, whatever their age may be, 

 appear to me to belong to one group. I must, however, 

 again call attention to the fact that the Cardium auca 

 is found both at Concepcion and in the undoubtedly 

 tertiary strata of Coquimbo : nor should the possibility 

 be overlooked, that as Trigonia, though known in the 

 Northern Hemisphere only as a Secondary genus, has 

 living representatives in the Australian seas, so a Bacu- 

 lite, Ammonite, and Trigonia may have survived in this 

 remote part of the Southern Ocean to a somewhat later 

 period than to the north of the equator. 



Before passing in review the fossils from the other 

 localities, there are two points, with respect to the for- 

 mations between Concepcion and Chiloe, which deserve 

 some notice. First, that though the strata are generally 

 horizontal, they have been upheaved in Chiloe, in a set 

 of parallel anticlinal and uniclinal lines ranging north 

 and south, — in the district near P. Rumena by eight 

 or nine far-extended, most symmetrical, uniclinal lines 

 ranging nearly east and west, — and in the neighbourhood 

 of Concepcion by less regular single lines, directed both 

 NE. and SW., and NW. and SE. This fact is of some 

 interest, as showing that within a period which cannot 

 be considered as very ancient in relation to the history 

 of the continent, the strata between the Cordillera and 

 the Pacific have been broken up in the same variously- 

 directed manner as have the old plutonic and meta- 

 morphic rocks in this same district. The second point 

 is, that the sandstone between Concepcion and Southern 

 Chiloe is everywhere lignitiferous, and includes much 

 silicified wood ; whereas the formations in Northern 

 Chile do not include beds of lignite or coal, and in place 

 of the fragments of silicified wood there are silicified 

 bones. Now, at the present day, from Cape Horn to 

 near Concepcion, the land is entirely concealed by forests, 



