350 SMITH. 



and one more frequently traveled, is by way of the Hijo to Compostela. 

 Practically the only published data regarding the Tagum River are taken 

 from Mr. Goodman's narrative. He describes it as a tortuous stream, 

 about 90 meters wide at its mouth, but only about 30 at the confluence 

 of the Sahug and the Tagum; at this point its banks are 5 meters 

 above the water level and the formation is a brown and blue clay overly- 

 ing sandstone. At Matinlud the river shoaled so much that a loaded 

 banco, could not be floated. The coiintry it traverses is all heavily wooded 

 and occupied by Mandayas. Dr. J. Montano, a French traveler, also 

 made this trip, but gives us very meager notes on the physiography of 

 the region. A map is given in his book showing a long ridge at right 

 angles to the Apo Eange and curving to the northwest. Goodman, also, 

 mentions this ridge. Montano likewise gives some geologic notes, to which 

 I shall refer in' the next section of the paper. He published a sketch 

 map which is taken probably entirely from d' Almonte. 



(2) The Agus River. — This river drains Lake Lanao and flows north 

 to empty into Iligan Bay. It is approximately 32 kilometers long and 

 drops from 671 meters to sea-level. It has an average fall of 20 meters 

 per kilometer (110 feet per mile). However, this is not uniform, for 

 at Maria Christina Falls there is a sheer drop of 58 meters. The river 

 is very narrow and swift, flowing over a basalt formation throughout its 

 length. The army engineers have ascertained the depth and width at 

 Mumungan to be 26.5 and 15.5 meters respectively. The flow of water 

 has recently been measured by Mr. Bradshaw of the Bureau of Public 

 Works, at Pantar bridge. Here the flow amounted to 9 second-meters, 

 giving approximately 40,000 electric horsepower. 



(3) The Mataling is another short river with a considerable fall. It 

 rises in the ridge south of Lake Lanao, and flows southwest into Illana 

 Bay. It likewise flows over a basalt formation, and at Mataling Palls 

 drops over a hard layer of this rock into a pool 16 meters below. From 

 here on the rock is much softer, and the river a mile or two beyond flows 

 through a low plain of loose, bluish-black volcanic ash. The Mataling is 

 very narrow, 10 meters on an average, and very swift. Its source in part 

 is undoubtedly Lake Lanao, although there is no connection apparent on. 

 the surface ; it also receives the run-off from Davao Lake, a small body of 

 water near the southwest corner of Lake Lanao. 



A very important series of rivers in the northern part of Mindanao 

 rises in the mountainous interior of the subprovince of Bukidnon and 

 flows north through the Province of Misamis into Makahalar Bay. The 

 most important of these are the Iponan, the Cagayan, and the Tagoloan. 

 They for many decades, perhaps for centuries, have been favorite localities 

 for gold-panning. Ickis traversed and mapped one of them, the Tago- 

 loan, throughout its whole length. This river shows some interesting 

 features. It rises near Tibua Mountain and is separated by a very 



