30 University of Michigan 



12° 17.13')-^^ Although extensive thickets of brush and 

 clumps of larger trees are present, the northern hills of 

 Bonaire are more arid and barren than those of Curagao. The 

 few shells collected come from the base of the leeward slopes 

 of Seroe Brandaris, the highest peak (240.4 meters) on 

 Bonaire. Here the thin soil overlies a substratum of mica- 

 porphyrite. 



Klein-Bonaire 



Station Kl. Klein-Bonaire (Y; L68° 18.02', 12" 9.51'). 

 This island is a low, almost flat mass of recent limestone (6.4 

 meters at the highest point), separated from Bonaire by a 

 narrow, but rather deep (34 fathoms) channel, which forms 

 the harbor of Kralendijk. The general aspect of the surface 

 is very similar to that of the region south of Kralendijk (figs. 

 vi-15, 16), but the vegetation is somewhat richer, especially 

 near the center of the island, where most of the collection was 

 made. The smaller shells are most numerous under slabs of 

 limestone around the bases of the larger trees. 



Freshwater Habitat 



The permanent bodies of freshwater on the Dutch Leeward 

 Islands, fall into three classes: (1) springs and pools in the 

 central portion, (2) sink-holes in the recent limestone, and (3) 

 the rivulets. As already discussed, the sparse precipitation 

 tends to fall in rather hea\y storms. During these, and for 

 some time aftei"ward, numerous streams pour down the roois, 

 and form shallow sheets of water on the flats. In the central 

 region of older rocks, extensive systems of artificial dikes hold 

 some of this water, and a few of these pools may even outlast 

 the dry periods (stations Cell, 13, 17). The porous rocks also 

 retain fresh to brackish water just above the level of the salt 

 water; this is reached by artificial wells in the older rocks 

 (Cc2), and by natural sink-holes in the recent limestone (Bel, 

 Kcl ) . All of the permanent streams emerge from caves in the 



31 See Boldingh, p. 163; "Brandaris.' 



