736 ON THE VOLCANO OF TAAL, 



6. Gypsum in tablets. Volcano, bottom of the crater between 

 the two lagoons. 



7. Concretionary gypsum impregnated with alum. Volcano, 

 bottom of the crater east of the yellow lake. 



8. Doniite, impregnated with alum.* Interior of the crater. 



9. Laterite.f 



10. Basalt, somewhat scoriaceous. Ditto. 



11. Wacke, (earthy basalt? in which traces of retinite or 

 pitchstone are observable). Ditto. 



12. Spongy basaltic scoriae. North edge of great crater. 



13. Basalt. Ditto. 



14. Volcanic breccia. Ditto. 



15. Basaltic lava. Ditto. 



16. Volcanic tufa. Ditto. 



17. Ditto. Central volcano, escai-pments on north and north- 

 west. 



18. Ditto. Localities — north margin of the crater and Binin- 

 tiang Malaki. 



19. Basalt covered with a crust proceeding from the decomposi- 

 tion of the rock, Pinag Ulbuan. 



20. Superficial crust covering volcanic detritus. Central volcano, 

 the highest portion of the island. 



21. Ditto. Interior of the crater of Balantoc. 



22. Dolerite with magnetic iron affecting the compass. Volcano, 

 and Binintiang Malaki. 



23. Scoriae. Volcano and Binintiang Malaki. 



24. Mimosite (i). Volcano and Binintiang Malaki. Declivity 

 of the crater. 



25. Grey-stone (Graustein) of Werner. Volcano and Binintiang 

 Malaki at the foot of the declivity. 



*Domite. By this term I presume is understood a kind of trachyte with 

 a large proportion of silica not in the form of quartz but tridymite. 



+Red earthy matter with much per-oxide of iron resultmg from the 

 decomposition of lava. 



