240 Elevation of Valparaiso. paet ii. 



shells, about fourteen or fifteen feet above hisrh-water 

 mark, may be observed; and at this level the coast- 

 rocks, where precipitous, are corroded in a band. At 

 one spot, Mr. Alison, by removing some birds' dung, 

 found at this same level barnacles adhering to the rocks. 

 For several miles southward of the bay, almost every 

 flat little headland, between the heights of 60 and 230 

 feet (measured by the barometer), is smoothly coated 

 by a thick mass of comminuted shells, of the same 

 species, and apparently in the same proportional num- 

 bers with those existing in the adjoining sea. The 

 Concholepas is much the most abundant, and the best 

 preserved shell ; but I extracted perfectly preserved 

 specimens of the Fissurella biradiata, a Trochus and 

 Balanus (both well known, but according to Mr. Sowerby 

 yet unnamed) and parts of the Mytilus Chihensis. 

 Most of these shells, as well as an encrusting Nullipora, 

 partially retain their colour; but they are brittle, and 

 often stained red from the underlying brecciated mass 

 of primary rocks ; some are packed together, either in 

 black or reddish mould ; some lie loose on the bare 

 rocky surfaces. The total number of these shells is 

 immense ; they are less numerous, though still far from 

 rare, up a height of 1,000 feet above the sea. On the 

 summit of a hill, measured 557 feet, there was a small 

 horizontal band of comminuted shells, of which many 

 consisted (and likewise from lesser heights) of very 

 young and small specimens of the still living Con- 

 cholepas, Trochus, Patellse, Crepidula?, and of Mytilus 

 MageUanicus (?) : l several of these shells were under 

 a quarter of an inch in their greatest diameter. My 



1 Mr. Cuming informs me that he does not think this species 

 identical with, though closely resembling, the true M. Magellanicus 

 of the southern and eastern coast of South America ; it lives abun- 

 dantly on the coast of Chile. 



