In describing the epicentral regions, the present distribution of the Archipelago into provinces has been used throughout the catalogue. This division is shown on the first of the two maps of the Philippines which accompany this catalogue (Plate I). As to the designation "Benguet" occasionally occurring in the text where provinces are enumerated, but not found on the map, we beg to offer the excuse that the region thus named is exceedingly well known in the Philippines as it contains Baguio, _the_ health resort of the Islands. For the readers outside of the Archipelago we remark that Benguet is at present a subprovince of the Mountain Province, of which it forms the southernmost part. The location of Baguio is shown on the map on Plate II. A similar remark applies to Lepanto and Bontoc, likewise divisions of the Mountain Province, whose capitals, Cervantes and Bontoc, are indicated on the same map. As we would hardly be justified in assuming that every reader is in possession of a detailed map of the Philippines, and a knowledge of the general distribution and the main directions of the principal mountain systems of an earthquake country is important, we add a second map on which these data are shown by means of dashes, together with the most important seismic regions, and the positions of the principal towns, bays, etc., mentioned in the text. (Plate II.) Near the left margin of this second map will be found an index of the seismic regions just mentioned, each of them being represented by its ordinal number (large Roman figures). Near each of these ordinals is placed the corresponding number of earthquakes since 1862 contained in the catalogue (Arabic figures), which is followed, in brackets, by an analysis of the said number, in which Roman figures designate the degrees of the earthquake, scale of De Rossi-Forel, while small Arabic figures, written like exponents, give the number of earthquakes of each degree of intensity. In drawing the map on Plate II it was not intended to represent the epicentric area of every individual earthquake center (which would have crowded the map beyond reasonable limits), but rather to show the principal seismic regions. Hence most of these curves contain more than one focus. The approximate position of each of the latter has, however, been indicated by a star, while the figure placed close to the star gives the number of earthquakes which proceeded from the said center. A word must be said in apology for the constant use in the following list of the Spanish word "_convento_." This word which means monastery, cloister, or convent, is universally used in the Philippines to designate also the habitation of the clergy attached to a parish church. Although these are, as a rule, spacious buildings and were formerly inhabited well-nigh exclusively by friars, they can not properly be called monasteries. Wherefore, in order to avoid lengthy circumlocutions, the Spanish word "_convento_" has been retained.