As the geographical distribution of fossils is always an interesting subject, it has occurred to me that a few words on the Oolitic fossils of this part of England, not much visited by geologists, may be acceptable to, at least, some of the readers of the “Geologist.” It will not be my intention in this paper to treat so much of the geological features of the country, as to give complete lists of the organic remains which have been found by myself and a few others in the various strata of this district. The Oolites of North Bucks and Northampton, though of course presenting, for the most part, the usual character of the system as represented in other Oolitic districts of England (being, as they doubtless are, merely a continuation of those of Oxfordshire, &c.), yet possess several points of interest peculiar to themselves. The identity of the “Northampton Sands” (formerly classed with the Lias) with the Stonesfield Slate of Oxfordshire and Gloucestershire, and constituting the Lower Zone of the Great Oolite, the importance of these “sands” as an iron ore; the occurrence of land-plants similar to the Stonesfield specimens in the Forest-marble of the neighbourhood of Wolverton; the extensive development of the Kimmeridge Clay at Hartwell; and of the Great Oolite further north;—all these facts combine to invest these beds with much interest, both to the geologist and the palæontologist.