We trust our readers will be induced to get this valuable work and to study it for themselves; the text may be procured either in French or in Italian, so that it is readily accessible to all. At the same time we would take the opportunity of introducing to them another work by the same indefatigable author, which is also published both in French and in Italian. At least, such is the announcement of a prospectus now lying before us, which states that the French translation is published by Vives, in Paris. We have ourselves only seen the original Italian. It is a short monthly periodical, illustrations, _Bollettino di Archeologia Cristiana_, and is addressed not merely to _savans_, Fellows of Royal Societies, and the like, but rather to all educated men who care for the history of their religion and are capable of appreciating its evidences. De Rossi claims for the recent discoveries in the Roman catacombs the very highest place among the scientific events of the day which have an important religious bearing, and we think that the justice of his plea must be admitted. Unfortunately, however, the vastness of the subject, the multiplied engagements of the author, and (not least) the political vicissitudes of the times, have hitherto prevented the publication of these discoveries in a complete and extended form. We are happy to know that the work is satisfactorily progressing; but meanwhile he has been persuaded by the suggestions of many friends, and by the convenience of the thing itself, to publish this monthly periodical, which will keep us _au courant_ with the most important additions that are being made from time to time to our knowledge of those precious memorials of primitive Christianity, and also supply much interesting information on other archaeological matters. In these pages the reader is allowed to accompany, as it were, the author himself in his subterranean researches, to assist at his discoveries, to trace the happy but doubtful conjecture of a moment through all its gradual stages, until it reaches the moral certainty of a conclusion which can no longer be called in question; _e.g._, the author gives us a portion of a lecture which he delivered on July 3, 1852, to the Roman Pontifical Academy of Archaeology. In this lecture he maintained, in opposition to the usual nomenclature of the catacombs, and entirely on the strength of certain topographical observations, that a particular cemetery, into which a very partial opening had been made in 1848, was that anciently called by the name of Pretextatus, and in which were buried St. Januarius, the eldest of the seven sons of St. Felicitas, Felicissimus and Agapitus, deacons of St. Sixtus, Pope Urban, Quirinus, and other famous martyrs. Five years passed away, and this opinion had been neither confirmed nor refuted; but in 1857, excavations undertaken for another purpose introduced our author into a crypt of this cemetery,