The extraordinary richness of the littoral region and the deeper water surrounding Guernsey and Herm, as well as the marked southern character of many of the Annelidan types, formed, for instance, an excellent comparison with the ample series of specimens which the dredgings of Mr Jeffreys in the Shetland seas had lately brought before us; or, again, with the valuable collections procured during the expeditions of the “Porcupine,” in 1869 and 1870, the former chiefly from the Atlantic, the latter from the same region and the Mediterranean.