chap. xii. Navidad. 401 



here only state that the Cardium auca is found also at 

 Coquirnbo, the beds at which place, there can be no 

 doubt, are tertiary. 



Navidad} — The Ooncepcion formation extends some 

 distance northward, but how far I know not ; for the 

 next point at which I landed was at Navidad, 160 miles 

 north of Concepcion, and 60 miles south of Valparaiso. 

 The cliffs here are about 800 feet in height; they 

 consist, wherever I could examine them, of fine-grained, 

 yellowish, earthy sandstones, with ferruginous veins, and 

 with concretions of hard calcareous sandstone. In one 

 part, there were many pebbles of the common meta- 

 morphic porphyries of the Cordillera : and near the 

 base of the cliff, I observed a single rounded boulder of 

 greenstone, nearly a yard in diameter. I traced this 

 sandstone formation beneath the superficial covering of 

 gravel, for some distance inland : the strata are slightly 

 inclined from the sea towards the Cordillera, which 

 apparently has been caused by their having been accu- 

 mulated against or round, outlying masses of granite, 

 of which some points project near the coast. The sand- 

 stone contains fragments of wood, either in the state of 

 lignite or partially silicified, sharks' teeth, and shells in 

 great abundance, both high up and low down the sea- 

 cliffs. Pectunculus and Oliva were most numerous in 

 individuals, and next to them Turritella and Fusus. I 

 collected in a short time, though suffering from illness, 

 the following thirty-one species, all of which are extinct, 

 and several of the genera do not now range (as we shall 

 hereafter show) nearly so far south : — 



1. Gastridium cepa, G. B. Sowerby, PL IV. f . 68, 69. 



2. Monoceros, fragments of, considered by M. d'Orbigny as a new 



species, 



1 I was guided to this locality by the Report on M. Gay's « Geolo- 

 gical Researches,' in the ' Annales des Scienc. Nat.' (1st series) torn. 28. 



