18 University of Michigan 



Cl2h. Top of Ronde Klip (L68° 52.02', 12° 8.98'). The 

 plane summit (129 meters) of the mesa slopes slightly towards 

 the north. The brush is dwarfed and much less luxuriant 

 than in C12a. 



Station Ch6a. Shore, Campo Marchena (6-X; L68° 57.73', 

 12° 7.72'). An old fruit plantation on the east shore of the 

 Sehottegat (5-R) was searched, but Succinea gyrata was the 

 only species obtained. 



Station Ch6h. Hill with ruins, Campo Blenheim (6-Y; 

 L68° 57.1', 12° 7.94'). This small knob (20 meters) is formed 

 by an outcrop of diabase, but the reddish color of the residual 

 soil gives evidence of the former limestone cap (compare 

 fig. vii-18). The type locality of Cerion uva desculptum is 

 probably some similar hill in this vicinity, as it forms here a 

 small proportion of the Cerion population. The shells occur 

 only on the rather barren hill, although it is near fertile and 

 wooded valleys. 



Station Ch7. Near Landhuis Klein Piscadera (7-C; L68° 

 59.03', 12° 8.64'). A few dead shells were collected among 

 leaves at the edge of an irrigated fruit plantation near the 

 highway. Diabase is the underlying rock. 



Station ChlO. Near Seroe Mainsjie (10-K; L68" 49.21', 

 12° 6.75'). This hill (30.7 meters) formed by an outcrop of 

 diabase, is partially protected by the ridges nearer the shore. 

 Cerion uva desculptum occurs here, along with the sculptured 

 form. 



Station C13. Seroe Largoe (13-R; L69° 4.18', 12° 12.17'). 

 The sloping top (73.2 meters) of this headland is covered with 

 a rather thick growth of brush. At the base of the high north- 

 ern and western escarpments of the older limestone, Bursera 

 and other large trees are quite numerous. The molluscan 

 population of this station is a mixture of the northern and 

 central elements of the Curasao fauna. Tudora fossor djeri- 

 mensis occurs especially along the base of the escarpment, 

 while T. megacheilos spreitensis and T. muskusi hullenensis 

 share the mesa top itself. The ccrions are representative of 

 the southern subspecies, C. uva uva. 



