476 SMITH. and quartz porpliyiies. ilelaphyre lie found again at Pujada Bay near Cape San Agustin. Quartz breccias also occur on the divide between Pujada and the Gulf of Davao. Serpentine accompanies the melaphyre to the south of Bislig' "Mr. Minard visited the gold-bearing region of Misamis, the northwestern province (A Mindanao. The sandstones and conglomerates of the Iponan Valley, dipping 12, are said to be broken through at many points by diorite and serpentine. The pebbles of the conglomerates include diorites, augite-porphyry, serpentine, jasper, and marble" Some years later Jlr. Abella made a reconnaissance of this region, examining the gold deposits along the courses of several rivers, all of which empty into Macajalar Bay. They are the Iponan, the Cagayan, the Bigaan, and the Human. In this region he found two considerable areas of old slates. One of these touches the Iponan River 10 or 12 miles from the sea. The other is intersected by the Human and approaches the sea within 2 miles, near the town of Agusan, which lies at the mouth of the Human River. Alluvial deposits fringe the shore of the bay and follow the streams. Otherwise the country, as depicted by Mr. Abella. is covered with strata provisionally referred to the Miocene. The slates are described as metamorphic and in part statistic. The pebbles of the Tertiary conglomerates consist of such slates, serpentinous rocks, and many varieties of 'trachytic rocks' I think that at the date of his memoir, 1879, Mr. Abella used this term for neo-volcanic rocks not basaltic in appearance. The description of the fossiliferous rocks overlying the slate leaves no doubt but that they are Tertiary or Recent, a fact which it is difficult to reconcile with Mr. Minard's statement that they are cut by serpentine and diorite. In the placer at the Bigot, tributary to the Cagayan, Mr. Abella found slightly rounded, large pebbles of orthoclase' "A few miles north's-est of Zamljoanga (in southwestern mindanao), at Caldera. Dana observed hornblende and talcose schist in pebbles' and on ilalanipa, about 13 miles E. by S. from Zamboanga, the Challenger expedition collected serpentinized peridotite, studied by Mr. Renard" " III. GENERAL GEOGRAPHIC DESCRIPTION AND ITINERARY. The main body of the Philippine Archipelago is connected with Borneo b' two parallel chains of islands, one consists of Busuanga, Linapacan, Palawan and Balabac, while the other extends southwest from the Zamboanga Peninsula, comprising Basilan, Sidu, Siasi, and Tawi-tawi. The inference is that there has been entire land connection at some time in the past. This question will be referred to in a future chapter, at this place it is sufficient to state that there are some objections of a very reasonable nature to such a conclusion. The Sulu Group and Mindanao together possess a rough likeness to a long-handled dip23er, the Sulu Islands and Zamboanga Peninsula constituting the handle, the eastern part of Mindanao the bowl. Mindanao is marked by its great number of lines and gulfs, its two great rivers, 'Mission aux lies Phil. (1879-1881), 272-277. 'Bull. Soo. geol France (1874), V, 2, 403-406. 'Mem. acerca de los criaderos auriferos Misamis (1879). 4, 18, 32. 45. V. S. Expl. Exp. (1849). 10, 539. Ibid.