chap. rx. Elevation of Valparaiso. 241 



attention was called to this circumstance by a native 

 fisherman, whom I took to look at these shell-beds ; 

 and he ridiculed the notion of such small shells having 

 been brought up for food ; nor could some of the species 

 have adhered when alive to other larger shells. On 

 another hill, some miles distant, and 648 feet high, I 

 found shells of the Concholepas and Trochus, perfect, 

 though very old, with fragments of MyUlus Chiloensis, 

 all embedded in reddish-brown mould : I also found 

 these same species, with fragments of an Echinus and 

 of Balanus psittacus, on a hill 1 ,000 feet high. Above 

 this height, shells became very rare, though on a hill 

 1,300 feet high, 1 I collected the Concholepas, Trochus, 

 Fissurella, and a Patella. At these greater heights the 

 shells are almost invariably embedded in mould, and 

 sometimes are exposed only by tearing up bushes. 

 These shells obviously had a very much more ancient 

 appearance than those from the lesser heights; the 

 apices of the Trochi were often worn down ; the little 

 holes made by burrowing animals were greatly en- 

 larged ; and the Concholepas was often perforated quite 

 through, owing to the inner plates of shell having 

 scaled off. 



Many of these shells, as I have said, were packed in, 

 and were quite filled with, blackish or reddish-brown 

 earth, resting on the granitic detritus. I did not doubt 

 until lately that this mould was of purely terrestrial 

 origin, when with a microscope examining some of it 

 from the inside of a Concholepas from the height of 

 about 100 feet, I found that it was in considerable part 

 composed of minute fragments of the spines, mouth- 

 bones and shells of Echini, and of minute fragments, 



1 Measured by the barometer : the highest point in the range 

 behind Valparaiso I found to be 1,626 feet above the level of the 

 sea. 



