26 University of Michigan 



top of this small mesa of the older limestone (25 meters) is 

 absolutely barren, but an impenetrable thicket of Opuntia and 

 a few, dwarfed thorn trees grow in the shelter of the leeward 

 end. A few living shells were collected under the rocks at the 

 western end of the top. 



A7c. Seroe Hudishihana (X; L70°, 3.45' 12° 36.70'). This 

 cap of extremely barren, ancient limestone (25 meters) 

 is near the northern tip of Aruba. A few dead shells of 

 Tudora fossor canasliitensis were obtained at the base of fhe 

 leeward escarpment near the lighthouse. 



Station A8. Near Boedoei (Z; L69° 59.35', 12° 32.89'). ^^ 

 Along the northern portion of the arid, northeast shore of 

 Aruba, the limestone is mainly limited to the immediate vicin- 

 ity of the shore cliffs. In a few places, narrow tongues of 

 dirty limestone lie in the valleys. Near the gold mines of 

 Boedoei, a small limestone remnant (26.2 meters) forms a 

 little knob on the northern side of the valley. Although this 

 locality is very barren, a few specimens were obtained. 



Bonaire 



Fundamentally, this island is very similar in structure to 

 Curasao and Aruba. However, apparently in quite recent 

 times, low, almost flat wings have been added on either side of 

 the main anticline, the long axis of which runs in the general 

 direction of the line between Seroe Brandaris (Plate II-W) 

 and the southern Seroe Grandi (I). The northeastern addi- 

 tion, which practically coincides with Campo Bolivia (0) is 

 the higher (mostly less than 30 meters) ; while the southwest- 

 em one forms the low area (less than 10 meters' altitude) 

 south of Kralendijk. Klein-Bonaire appears to be a continu- 

 ation of this latter emergence. Also, the southwestern side of 

 the main anticline still retains a large proportion of its cap 

 of older limestone, so the entire island has a proportionately 

 much greater exposure of the coral formations than either 



20 Boldingh, p. IfiO ; "The Hills near Andikurie, " describes the vege- 

 tation of the adjacent outcrops of quartz-diorite. 



