Amongst a small collection of fossils lately forwarded to the writer for identification, by Dr. Rankin, of Carluke, from the Carboniferous beds of that neighbourhood, are some remains of Polyzoa, peculiar from the combination of characters presented by them, such as have hitherto been considered characteristic of separate genera. In Fenestella, Miller, as restricted by King, each interstice or stem of the frond is provided on one side only with two or more rows of cell-apertures, separated by a median keel. In Polypora, McCoy, on the contrary, the interstices or dissepiments are not carinated, and the former are always provided with numerous rows of cell-apertures, generally arranged more or less in quincunx, the dissepiments as in Fenestella, being non-celluliferous. In the specimens under consideration a combination of some of the above characters takes place, forming a connecting link between the two genera Fenestella and Polypora. An examination of the accompanying drawings will at once show that the fossils there represented cannot be referred to either of the above, but they, certainly appear to be the type of a new genus, which it is proposed to call Carinella. Only one species is at present known, which might with advantage be termed C. cellulifera.