6874 Birds. 



conglomerate. From these, ridges and spurs plunge so abruptly into 

 the Caribbean, in successive headlands and points, all down the coast, 

 perhaps as far as Portland, that the mountains almost seem to rise 

 from the sea. The little islet just below, crowned with its tuft of 

 green bush, and which renders the deep bay of Port Maria so pic- 

 turesque, is tertiary limestone, but the dark cliffs immediately behind 

 the town belong to the transition rocks of Sir H. de la Beche, as from 

 that point this, our oldest formation, commences. In the lower range 

 of the parish of Metcalfe this is represented by a shale, in thin layers, 

 often so contorted as to be schistose ; in this the mountain torrents 

 (called here rivers) have worn channels so deep that a great part of 

 their winding courses seems ever in gloomy shade. The rains also 

 have an extensive influence on it : when they are unusually heavy the 

 torrents carry off their banks, and thus, half water, half land-slip, rush 

 down to the rivers, tearing the mountain-sides with those tracks of ruin 

 and force familiar to travellers among mountain scenery. Over such 

 a country roads can only be carried with considerable difliculty, and 

 the river beds usually serve as such. Under the action of these 

 streams the shale seems to dissolve into mud and be entirely carried 

 away ; the river-beds are therefore composed of boulders and pebbles, 

 chiefly of amorphous rocks washed out of the conglomerates above. 

 This ' gravel,' as it is here called, which the Rio Minho must have 

 made you familiar with, fills these narrow gorges to the limit of the 

 flooding river, usually their whole extent, and composes its bed to the 

 sea. Sir Henry de la Beche has introduced between these mountains 

 of transition shale and the sea a band of tertiary limestone ; but I have 

 only been able in Metcalfe to find very occasionally masses of this 

 rock, the rest consisting of marls, — in some instances chalky and 

 white, but generally so mixed with sand and clays as to be scarcely 

 recognisable. 



" This forms a range of hills gently rounded as if by denudation, 

 and it is on these much of the sugar cultivation is carried on. The 

 narrow border between their base and the beach is occupied by an 

 alluvial, the site of a chain of lagoons and swamps. This alluvial 

 marks the line of junction of the limestone with the conglomerate, as, . 

 just below Dover estate, low reefs, close in-shore, of that formation 

 may easily be examined. From this the surf washes out a ' gravel ' 

 not distinguishable from that brought down by the rivers : its great 

 force and constant direction heap this into a ridge higher than the 

 land behind it, and thus the rivers on approaching make a sudden 

 angle, and after a course of some distance, almost parallel with the 



