10 



sures is either broken up mechanically by the waves, or wasted away chemically frora being 

 more susceptible of rapid decomposition than the adjoining bands , and thus wider fis- 

 sures or chasms are produced. 



There is a small rocky islet or group of rocks near the SE. Point of P. Vhin called 

 S'kodo, from a fancied resemblance of one of the blocks to a frog. Those in the middle 

 are large and conneeted by sand in which some shrubs grow, and those scattered around 

 are smaller and much worn by the waves. Some large rocks also lie in the sea on the 

 south side of the central collection, and the longer sides of those run SW. by W., NE. 

 by E. Parellel reddish lines or bands about l / 1 an inch broad traverse the surfaces and 

 mark the planes of weaker cohesion. The sides of some of the blocks are peeling off in 



■ 



parallel layers. In some, another set of divisional planes, transverse to the former, are 

 well marked. Where the rock is breaking down, these two systems of planes divide it in- 

 to rhomboidal fragments. 



The rocks are of a large grained granite, and are in fact the best specimens of well mark- 

 ed and regular granitic crystallization that I have seen around Pulo Ubin. The hornblen- 

 de instead of being collected in nests of small granules intermixed with felspar, or disse- 

 minated in minute particles, as is generally the case even in the most highly crystallized 

 rocks of the Island, is here in well defined crystals of various sizes and mostly of a fibrous 

 structure. Mica is present of a fine lustrous black colour with a faint blush of red. Nests 

 occur from an inch to a few inches in diameter composed principally of finely granular 

 hornblende intermixed with a lesser proportion of felspar and containing occasionally a crys- 

 tal of mica. 



The eastern end of the Island, in place of contracting to a mere point like the western, 

 presents a coast of considerable extent. This arises from the eastern portion of the Island 

 consisting of two hill ranges, with a flat mangrove tract between them. The termination of 

 the northern range constitutes the NE. Point. The beach is composed of extended tabu- 

 lar masses of rock which slope curvately beneath the sea, and rise only a few feet 

 above it. They are crossed by fissures and small grooves , the direction of several of which 

 is S. by SW. All the principal lines have a general direction towards - SW. , although 

 they vary within a small range. In these a row of circular cavities lined with a ferrugi- 

 nous crust sometimes occurs ; and where this is the case, the surface of the rock has a semi- 

 calcined aspect. 



The rock varies, but is principally composed of an opaque bluish grey saccharoid fels- 

 pathic and quartzo felspathic base enclosing crystals and grains of hornblende, and translucent 

 crystals of felspar. It bears a close resemblance to a specimen of Vesuvian lava including 

 hornblende crystals which I possess. In some places it becomes compact, or the hornblende 

 granules are so minute as to appear like fine black dust sprinkled on snow. Where they 



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prevail over the felspar the rock has a bluish colour. The base has frequently. a reddish 

 brown and brownish grey colour, but this is probably the result of incipient decomposition. 

 Rounding the Point and proceeding westward along the northern coast, the rocks preserve 

 the same character. They are traversed here and there by rifts , and marked by fissures 

 or grooves of a greater or less depth , but mostly shallow. Where I noted the hearings of 



