The object of this communication is to amplify and correct certain descriptions and sections of the Junction-Bed of the Middle and Upper Lias near Eypesmouth on the coast of Dorset, which I contributed as an appendix to Mr. S. S. Buckman's recent paper on Jurassic chronology. On the Dorset coast the long time-gap between the top of the Domerian, in the Middle Lias, and the base of the Yeovilian, or Bridport Sands, in the Upper Lias, is represented by only a few feet of strata, and these vary greatly from section to section and even within a few yards. These few feet constitute the Junction-Bed, and fossils collected inch by inch in the different exposures show that, although all the hemeræ recognized by Mr. Buckman as filling this gap have not been found, yet representatives of many hemerae occur, some in one exposure and some in another, and always in their appropriate order; so that it is fair to assume that the period was one of continual oscillation and penecontemporaneous erosion, and that the strata present a succession of non-sequences. At least in one exposure, at Watton Cliff, a considerable non-sequence can be directly demonstrated in a single block; here a bed belonging to a definite horizon thins out completely between two beds of respectively earlier and later dates. In order to make clear how much of the supposed complete sequence is represented and when the non-sequences occur, the following table is given, showing all the horizons of this date