64 ADAMS. 



Pico de Loro Mountains on the northwestern part of the region, as 

 has already been stated, are geologically a part of the western cordillera. 

 In the southwestern part of the region there is an area of high country 

 which occupies what is here called the Santiago Peninsula. To the 

 north it contains an eminence termed Mount Nasugbu and on its eastern 

 border there is a short serrate range presenting an escarpment to the 

 eastward. Mount San Pedrino on this range has an elevation of 362 

 meters. 



Calumpan Peninsula between Balayan and Batangas Bay is a moun- 

 tainous area with its highest peaks rising to elevations of from 320 to 

 562 meters. 



The relation of these peninsular areas to the neo-volcanic mountains 

 already described is not clear. It appears probable that Santiago 

 Peninsula has a core of igneous rocks. Calumpan Peninsula and the 

 Loboo Mountain region are separated from Maricaban and Verde Islands 

 by rather narrow channels and are not far distant from the high moun- 

 tainous island of Mindoro. Moreover, all three of the peninsular areas 

 appear to have been made parts of Luzon by the extension of the tuff 

 deposits which were not sufficient to fill the intervening bays. 



Taal Volcano, surrounded by a number of small extinct parasitic 

 cones, is near the center of an island in Lake Taal. The highest point 

 of the island is on the southwest rim of the crater which reaches an 

 elevation of 320 meters. The floor of the crater is at about the same 

 level as the water of the lake and but little above sea level. Mention 

 has already been made of the high ridge connecting Mount Gonzales and 

 Mount Batulao. Its slope to the north is gradual, but on the south it 

 presents an escarpment along its eastern part which faces Taal Lake, 

 and further to the west the country to the south of its crest is broken 

 and dissected by deep valleys in the part adjacent to Mount Batulao. 

 The country around the southern border of the lake lies at elevations 

 varying from 200 to 300 meters near the lake's shores, which in many 

 places are steep and even precipitous. Mount Macolod when seen from 

 a distance appears to have a precipitous face rising from the shore of 

 Taal Lake. On nearer examination this is not so striking a feature. 



The area lying between Maquiling and Malarayat Mountains on the 

 west and Cristobal and Banahao on the east, may be called the crater lake 

 country. Within it, distributed in an irregular way, there are twelve of 

 these lakes, varying from a half to more than one kilometer in diameter. 

 They lie in the tuff plains, their rims rising but a few meters above the 

 general level of the country. There is but little evidence of them until 

 one stands upon their borders. The coconut groves and other vegetation 

 disguise their presence so that passers by on a road within a minute's 

 walk of one of these lakes may not know of its existence. The lake to 

 the north of San Pablo may be reached by walking to the end of one of 



