178 CALIFORNIA ACADEMY OF SCIENCES. 



abruptly ending tables 400 to 600 feet high, form a rocky 

 coast line, which continues down to Cape St. Miguel. (See 

 Plate II.) Beyond the coast higher, fiat-topped mountains, 

 probably also of volcanic origin, rise. At the cape just 

 mentioned, the great bay of Todos Santos, or All Saints, 

 opens, forming a wide sweep and terminating southward 

 at the rough promontory of Punta Banda. (See Plate II.) 

 Mountains 2,000 to 3,000 feet high form a sort of am- 

 phitheater around the bay, and the foothills come 

 down close to the shore. One may distinguish several sep- 

 arate chains or masses, one running E. S. E.-W. N. W., 

 forms Punta Banda, ending westward in a sharp j)eak 1,200 

 feet high, and culminating in the 3,500 feet high mountain 

 between the Maneadero and Santo Tomas. Another mass, 

 extending N.-S., but cut in two by a lower pass east of 

 Ensenada, has its culminating point in a peak about ten miles 

 N. N.E. of Ensenada. The rivers carrying but little water 

 and mostly sinking in the sand before reaching the sea, run 

 in deep canons to a few miles distance from the coast, 

 when they debouch in large, level, alluvial valleys, contain- 

 ing some arable land; such are Ensenada Valley and El 

 Maneadero. At other places, the foothills, distant a mile or 

 two from the sea, are skirted by a band of mesa land rising 

 gently or in terraces from the sea to an elevation of 50 feet ; 

 so, for instance, at San Carlos, between Ensenada and El 

 Maneadero. The region adjoining Todos Santos Bay has 

 been examined in a somewhat more detailed way, and a 

 geological sketch map of it prepared. (See Plate IV.) 



The maps of the International Colonization Company of 

 Ensenada and surroundings, extended by my own observa- 

 tions, have been used as a topographic basis. 



The different terranes on this special map will now be 

 discussed separately. 



