242 Phytogeographical. 



mation) consisting alternately out of Breccia, Sandstone and Li- 

 mestone with a large proportion of Flint. 



In general the Pointe Blanche formation covers the northern 

 slope of the large range of hills and the south eastern slope of the 

 small range. These older sedimentary layers are probably of Creta- 

 ceous origin. Later sediments have but a short extension on 

 St. Martin. On the promontary near Simsonsbay a hard lime- 

 stone is found v^hich perhaps is iVIiocene. 



The Lowlands separated by Simsonsbaylagoon from the other 

 part of the Island is almost flat with some hills of which the 

 highest i-ises to about 90 m. and consist for the greater part 

 of a horizontal layer of soft marly limestone: it is of Miocene 

 age and quite resembles the Miocene formation of Anguilla. 

 The minerals I brought from this island were also determined 

 by Prof. Wichmann and proved to contain nothing particular for 

 this island ; I only mention gypsum, which I found on Green Key. 

 Plains of some importance are found between the eastern and 

 western ridges of hills, in the southern part (Prince quarter) 

 however bordered by a few isolated conical hills. By a gentle 

 slope the plain gradually passes into the western ridge of 

 hills. Cul de Sac as an important plain is bounded on the east- 

 northern- and western side by rather steep hills; especially Cen- 

 tryhill and surrounding is much more steep than the other part 

 of the hilly country of St. Martin. 



The principal rocks of the Island are composed of Quartz-diorite, 

 Mica-diorite or Phonalite ; the part that is exposed to view is 

 generally found unchanged only on the seacoasts. In the large 

 plain it is broken up 1 m. deep into a coarse-grained sand, 

 containing a large proportion of mica. It was not however 

 regularly crumbled down for there are a great many conical 

 parts that resisted the breaking up. These continued to stand 

 out when the wasted part was carried down by the water. So 

 the plain contains for the greater part an abundance of frag- 

 ments of rocks of considerable dimension. They form a real 

 „Felsenmeer" as is frequently met with on granitic soil. 

 Further there are some pieces of flat land between the ends of 

 the different ridges of the hilly country between Grande Case and 

 Marigot. 



In some places from Bethlehem to Mount Paradis deep valleys 

 are found whereas the valley in the District Colombier is one of 

 the few spots in St. Martin where a typical tropical vegetation is 

 met with. Especially here in the District Columbier and also near 



